From d8fa72a6e47e66de7156943d8db9196e38855c84 Mon Sep 17 00:00:00 2001
From: Usman Saleem <usman@usmans.info>
Date: Tue, 20 Aug 2024 10:01:30 +1000
Subject: [PATCH 01/26] feat: Report discarded transactions to external
 endpoint

---
 .../LineaTransactionSelectorPlugin.java       |  4 ++--
 .../selectors/LineaTransactionSelector.java   | 20 +++++++++++++++++++
 2 files changed, 22 insertions(+), 2 deletions(-)

diff --git a/sequencer/src/main/java/net/consensys/linea/sequencer/txselection/LineaTransactionSelectorPlugin.java b/sequencer/src/main/java/net/consensys/linea/sequencer/txselection/LineaTransactionSelectorPlugin.java
index 3e938a5a..000b0671 100644
--- a/sequencer/src/main/java/net/consensys/linea/sequencer/txselection/LineaTransactionSelectorPlugin.java
+++ b/sequencer/src/main/java/net/consensys/linea/sequencer/txselection/LineaTransactionSelectorPlugin.java
@@ -64,8 +64,8 @@ public void doRegister(final BesuContext context) {
   }
 
   @Override
-  public void beforeExternalServices() {
-    super.beforeExternalServices();
+  public void start() {
+    super.start();
     transactionSelectionService.registerPluginTransactionSelectorFactory(
         new LineaTransactionSelectorFactory(
             blockchainService,
diff --git a/sequencer/src/main/java/net/consensys/linea/sequencer/txselection/selectors/LineaTransactionSelector.java b/sequencer/src/main/java/net/consensys/linea/sequencer/txselection/selectors/LineaTransactionSelector.java
index ea9e15f3..9714d234 100644
--- a/sequencer/src/main/java/net/consensys/linea/sequencer/txselection/selectors/LineaTransactionSelector.java
+++ b/sequencer/src/main/java/net/consensys/linea/sequencer/txselection/selectors/LineaTransactionSelector.java
@@ -149,6 +149,26 @@ public void onTransactionNotSelected(
     selectors.forEach(
         selector ->
             selector.onTransactionNotSelected(evaluationContext, transactionSelectionResult));
+
+    notifyDiscardedTransaction(evaluationContext, transactionSelectionResult);
+  }
+
+  private void notifyDiscardedTransaction(
+      TransactionEvaluationContext<? extends PendingTransaction> evaluationContext,
+      TransactionSelectionResult transactionSelectionResult) {
+    if (transactionSelectionResult.discard()) {
+      log.debug(
+          "Discarding transaction {} because of {}",
+          evaluationContext.getPendingTransaction().getTransaction().getHash(),
+          transactionSelectionResult);
+      // Once Besu
+      // https://github.com/hyperledger/besu/commit/19e1a9aaf6f00eb79b70eff13e2d33963f377cf0 is
+      // released,
+      // we can use the following line
+      // evaluationContext.getPendingBlockHeader();
+
+      // TODO: Submit the details to provided endpoint API
+    }
   }
 
   /**

From 68fb015276abeee18a7c3ca0fd275c14793c1f83 Mon Sep 17 00:00:00 2001
From: Usman Saleem <usman@usmans.info>
Date: Thu, 22 Aug 2024 09:54:36 +1000
Subject: [PATCH 02/26] Use PendingBlockHeader

---
 .../selectors/LineaTransactionSelector.java   | 32 ++++++++++++++-----
 1 file changed, 24 insertions(+), 8 deletions(-)

diff --git a/sequencer/src/main/java/net/consensys/linea/sequencer/txselection/selectors/LineaTransactionSelector.java b/sequencer/src/main/java/net/consensys/linea/sequencer/txselection/selectors/LineaTransactionSelector.java
index 9714d234..b3ed0c37 100644
--- a/sequencer/src/main/java/net/consensys/linea/sequencer/txselection/selectors/LineaTransactionSelector.java
+++ b/sequencer/src/main/java/net/consensys/linea/sequencer/txselection/selectors/LineaTransactionSelector.java
@@ -23,6 +23,7 @@
 import net.consensys.linea.config.LineaTransactionSelectorConfiguration;
 import net.consensys.linea.plugins.config.LineaL1L2BridgeSharedConfiguration;
 import org.hyperledger.besu.datatypes.PendingTransaction;
+import org.hyperledger.besu.plugin.data.ProcessableBlockHeader;
 import org.hyperledger.besu.plugin.data.TransactionProcessingResult;
 import org.hyperledger.besu.plugin.data.TransactionSelectionResult;
 import org.hyperledger.besu.plugin.services.BlockchainService;
@@ -157,17 +158,32 @@ private void notifyDiscardedTransaction(
       TransactionEvaluationContext<? extends PendingTransaction> evaluationContext,
       TransactionSelectionResult transactionSelectionResult) {
     if (transactionSelectionResult.discard()) {
+      final PendingTransaction pendingTransaction = evaluationContext.getPendingTransaction();
+      final ProcessableBlockHeader pendingBlockHeader = evaluationContext.getPendingBlockHeader();
+
       log.debug(
-          "Discarding transaction {} because of {}",
-          evaluationContext.getPendingTransaction().getTransaction().getHash(),
-          transactionSelectionResult);
-      // Once Besu
-      // https://github.com/hyperledger/besu/commit/19e1a9aaf6f00eb79b70eff13e2d33963f377cf0 is
-      // released,
-      // we can use the following line
-      // evaluationContext.getPendingBlockHeader();
+          "Discarding transaction {} because of {}. Block number: {}",
+          pendingTransaction.getTransaction().getHash(),
+          transactionSelectionResult, pendingBlockHeader.getNumber());
+
 
       // TODO: Submit the details to provided endpoint API
+      /*
+      linea_saveRejectedTransaction({
+          "blockNumber": "base 10 number",
+          "transactionRLP": "transaction as the user sent in eth_sendRawTransaction",
+          "reasonMessage": "Transaction line count for module ADD=402 is above the limit 70"
+          "overflows": [{
+            "module": "ADD",
+            "count": 402,
+            "limit": 70
+          }, {
+            "module": "MUL",
+            "count": 587,
+            "limit": 400
+          }]
+      })
+       */
     }
   }
 

From da8a2cfb8f7b37fdb4f040164fc8ad2864148ef9 Mon Sep 17 00:00:00 2001
From: Usman Saleem <usman@usmans.info>
Date: Thu, 22 Aug 2024 09:55:36 +1000
Subject: [PATCH 03/26] simplify discard condition

---
 .../selectors/LineaTransactionSelector.java   | 57 ++++++++++---------
 1 file changed, 30 insertions(+), 27 deletions(-)

diff --git a/sequencer/src/main/java/net/consensys/linea/sequencer/txselection/selectors/LineaTransactionSelector.java b/sequencer/src/main/java/net/consensys/linea/sequencer/txselection/selectors/LineaTransactionSelector.java
index b3ed0c37..508e2df7 100644
--- a/sequencer/src/main/java/net/consensys/linea/sequencer/txselection/selectors/LineaTransactionSelector.java
+++ b/sequencer/src/main/java/net/consensys/linea/sequencer/txselection/selectors/LineaTransactionSelector.java
@@ -157,34 +157,37 @@ public void onTransactionNotSelected(
   private void notifyDiscardedTransaction(
       TransactionEvaluationContext<? extends PendingTransaction> evaluationContext,
       TransactionSelectionResult transactionSelectionResult) {
-    if (transactionSelectionResult.discard()) {
-      final PendingTransaction pendingTransaction = evaluationContext.getPendingTransaction();
-      final ProcessableBlockHeader pendingBlockHeader = evaluationContext.getPendingBlockHeader();
-
-      log.debug(
-          "Discarding transaction {} because of {}. Block number: {}",
-          pendingTransaction.getTransaction().getHash(),
-          transactionSelectionResult, pendingBlockHeader.getNumber());
-
-
-      // TODO: Submit the details to provided endpoint API
-      /*
-      linea_saveRejectedTransaction({
-          "blockNumber": "base 10 number",
-          "transactionRLP": "transaction as the user sent in eth_sendRawTransaction",
-          "reasonMessage": "Transaction line count for module ADD=402 is above the limit 70"
-          "overflows": [{
-            "module": "ADD",
-            "count": 402,
-            "limit": 70
-          }, {
-            "module": "MUL",
-            "count": 587,
-            "limit": 400
-          }]
-      })
-       */
+    if (!transactionSelectionResult.discard()) {
+      return;
     }
+
+    final PendingTransaction pendingTransaction = evaluationContext.getPendingTransaction();
+    final ProcessableBlockHeader pendingBlockHeader = evaluationContext.getPendingBlockHeader();
+
+    log.debug(
+        "Discarding transaction {} because of {}. Block number: {}",
+        pendingTransaction.getTransaction().getHash(),
+        transactionSelectionResult,
+        pendingBlockHeader.getNumber());
+
+    // TODO: Submit the details to provided endpoint API
+    /*
+    linea_saveRejectedTransaction({
+        "blockNumber": "base 10 number",
+        "transactionRLP": "transaction as the user sent in eth_sendRawTransaction",
+        "reasonMessage": "Transaction line count for module ADD=402 is above the limit 70"
+        "overflows": [{
+          "module": "ADD",
+          "count": 402,
+          "limit": 70
+        }, {
+          "module": "MUL",
+          "count": 587,
+          "limit": 400
+        }]
+    })
+     */
+
   }
 
   /**

From 69710a02e4ecde3b05a5b4163c143c43e1865f79 Mon Sep 17 00:00:00 2001
From: Usman Saleem <usman@usmans.info>
Date: Tue, 27 Aug 2024 20:43:36 +1000
Subject: [PATCH 04/26] feat: Make json-rpc call for discarded tx

---
 .../linea/jsonrpc/JsonRpcClient.java          | 65 +++++++++++++++++++
 .../linea/jsonrpc/JsonRpcRequestBuilder.java  | 14 ++++
 .../selectors/LineaTransactionSelector.java   | 17 ++++-
 3 files changed, 94 insertions(+), 2 deletions(-)
 create mode 100644 sequencer/src/main/java/net/consensys/linea/jsonrpc/JsonRpcClient.java
 create mode 100644 sequencer/src/main/java/net/consensys/linea/jsonrpc/JsonRpcRequestBuilder.java

diff --git a/sequencer/src/main/java/net/consensys/linea/jsonrpc/JsonRpcClient.java b/sequencer/src/main/java/net/consensys/linea/jsonrpc/JsonRpcClient.java
new file mode 100644
index 00000000..f4c89701
--- /dev/null
+++ b/sequencer/src/main/java/net/consensys/linea/jsonrpc/JsonRpcClient.java
@@ -0,0 +1,65 @@
+package net.consensys.linea.jsonrpc;
+
+import java.io.IOException;
+import java.io.OutputStream;
+import java.net.HttpURLConnection;
+import java.net.URL;
+import java.nio.charset.StandardCharsets;
+import java.util.Scanner;
+import java.util.concurrent.Callable;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.concurrent.Future;
+
+public class JsonRpcClient {
+  private static final int MAX_RETRIES = 3;
+  private static final ExecutorService executorService = Executors.newCachedThreadPool();
+
+  public static String sendRequest(String urlString, String jsonInputString) throws Exception {
+    HttpURLConnection conn = getHttpURLConnection(urlString, jsonInputString);
+
+    int responseCode = conn.getResponseCode();
+    if (responseCode == HttpURLConnection.HTTP_OK) {
+      try (Scanner scanner = new Scanner(conn.getInputStream(), StandardCharsets.UTF_8)) {
+        return scanner.useDelimiter("\\A").next();
+      }
+    } else {
+      throw new RuntimeException("Failed : HTTP error code : " + responseCode);
+    }
+  }
+
+  private static HttpURLConnection getHttpURLConnection(String urlString, String jsonInputString)
+      throws IOException {
+    URL url = new URL(urlString);
+    HttpURLConnection conn = (HttpURLConnection) url.openConnection();
+    conn.setRequestMethod("POST");
+    conn.setRequestProperty("Content-Type", "application/json; utf-8");
+    conn.setRequestProperty("Accept", "application/json");
+    conn.setDoOutput(true);
+
+    try (OutputStream os = conn.getOutputStream()) {
+      byte[] input = jsonInputString.getBytes(StandardCharsets.UTF_8);
+      os.write(input, 0, input.length);
+    }
+    return conn;
+  }
+
+  public static Future<String> sendRequestWithRetries(String urlString, String jsonInputString) {
+    Callable<String> task =
+        () -> {
+          int attempt = 0;
+          while (attempt < MAX_RETRIES) {
+            try {
+              return sendRequest(urlString, jsonInputString);
+            } catch (Exception e) {
+              attempt++;
+              if (attempt >= MAX_RETRIES) {
+                throw e;
+              }
+            }
+          }
+          return null;
+        };
+    return executorService.submit(task);
+  }
+}
diff --git a/sequencer/src/main/java/net/consensys/linea/jsonrpc/JsonRpcRequestBuilder.java b/sequencer/src/main/java/net/consensys/linea/jsonrpc/JsonRpcRequestBuilder.java
new file mode 100644
index 00000000..5b345241
--- /dev/null
+++ b/sequencer/src/main/java/net/consensys/linea/jsonrpc/JsonRpcRequestBuilder.java
@@ -0,0 +1,14 @@
+package net.consensys.linea.jsonrpc;
+
+import com.google.gson.JsonObject;
+
+public class JsonRpcRequestBuilder {
+  public static String buildRequest(final String method, final JsonObject params, int id) {
+    JsonObject request = new JsonObject();
+    request.addProperty("jsonrpc", "2.0");
+    request.addProperty("method", method);
+    request.add("params", params);
+    request.addProperty("id", id);
+    return request.toString();
+  }
+}
diff --git a/sequencer/src/main/java/net/consensys/linea/sequencer/txselection/selectors/LineaTransactionSelector.java b/sequencer/src/main/java/net/consensys/linea/sequencer/txselection/selectors/LineaTransactionSelector.java
index 508e2df7..5ba3208d 100644
--- a/sequencer/src/main/java/net/consensys/linea/sequencer/txselection/selectors/LineaTransactionSelector.java
+++ b/sequencer/src/main/java/net/consensys/linea/sequencer/txselection/selectors/LineaTransactionSelector.java
@@ -17,10 +17,13 @@
 import java.util.List;
 import java.util.Map;
 
+import com.google.gson.JsonObject;
 import lombok.extern.slf4j.Slf4j;
 import net.consensys.linea.config.LineaProfitabilityConfiguration;
 import net.consensys.linea.config.LineaTracerConfiguration;
 import net.consensys.linea.config.LineaTransactionSelectorConfiguration;
+import net.consensys.linea.jsonrpc.JsonRpcClient;
+import net.consensys.linea.jsonrpc.JsonRpcRequestBuilder;
 import net.consensys.linea.plugins.config.LineaL1L2BridgeSharedConfiguration;
 import org.hyperledger.besu.datatypes.PendingTransaction;
 import org.hyperledger.besu.plugin.data.ProcessableBlockHeader;
@@ -170,7 +173,6 @@ private void notifyDiscardedTransaction(
         transactionSelectionResult,
         pendingBlockHeader.getNumber());
 
-    // TODO: Submit the details to provided endpoint API
     /*
     linea_saveRejectedTransaction({
         "blockNumber": "base 10 number",
@@ -187,7 +189,18 @@ private void notifyDiscardedTransaction(
         }]
     })
      */
-
+    // Build JSON-RPC request
+    JsonObject params = new JsonObject();
+    params.addProperty("blockNumber", pendingBlockHeader.getNumber());
+    params.addProperty(
+        "transactionRLP", pendingTransaction.getTransaction().encoded().toHexString());
+    params.addProperty("reasonMessage", transactionSelectionResult.maybeInvalidReason().orElse(""));
+
+    String jsonRequest =
+        JsonRpcRequestBuilder.buildRequest("linea_saveRejectedTransaction", params, 1);
+
+    // Send JSON-RPC request with retries in a new thread
+    JsonRpcClient.sendRequestWithRetries("http://your-json-rpc-endpoint", jsonRequest);
   }
 
   /**

From 957b3dab8bf87d298c6895ef9e347270b9ee32ea Mon Sep 17 00:00:00 2001
From: Usman Saleem <usman@usmans.info>
Date: Tue, 27 Aug 2024 21:04:45 +1000
Subject: [PATCH 05/26] cli option for reporting rejected tx endpoint

---
 .../LineaTransactionSelectorCliOptions.java   | 14 +++++++++++
 ...LineaTransactionSelectorConfiguration.java |  5 +++-
 .../linea/jsonrpc/JsonRpcClient.java          | 23 +++++++++++--------
 .../selectors/LineaTransactionSelector.java   | 22 +++++++++++-------
 4 files changed, 45 insertions(+), 19 deletions(-)

diff --git a/sequencer/src/main/java/net/consensys/linea/config/LineaTransactionSelectorCliOptions.java b/sequencer/src/main/java/net/consensys/linea/config/LineaTransactionSelectorCliOptions.java
index e5b20e30..3eadcaa3 100644
--- a/sequencer/src/main/java/net/consensys/linea/config/LineaTransactionSelectorCliOptions.java
+++ b/sequencer/src/main/java/net/consensys/linea/config/LineaTransactionSelectorCliOptions.java
@@ -15,6 +15,8 @@
 
 package net.consensys.linea.config;
 
+import java.net.URI;
+
 import com.google.common.base.MoreObjects;
 import jakarta.validation.constraints.Positive;
 import net.consensys.linea.plugins.LineaCliOptions;
@@ -39,6 +41,8 @@ public class LineaTransactionSelectorCliOptions implements LineaCliOptions {
   public static final String UNPROFITABLE_RETRY_LIMIT = "--plugin-linea-unprofitable-retry-limit";
   public static final int DEFAULT_UNPROFITABLE_RETRY_LIMIT = 10;
 
+  public static final String REJECTED_TX_ENDPOINT = "--plugin-linea-rejected-tx-endpoint";
+
   @Positive
   @CommandLine.Option(
       names = {MAX_BLOCK_CALLDATA_SIZE},
@@ -82,6 +86,13 @@ public class LineaTransactionSelectorCliOptions implements LineaCliOptions {
           "Max number of unprofitable transactions we retry on each block creation (default: ${DEFAULT-VALUE})")
   private int unprofitableRetryLimit = DEFAULT_UNPROFITABLE_RETRY_LIMIT;
 
+  @CommandLine.Option(
+      names = {REJECTED_TX_ENDPOINT},
+      hidden = true,
+      paramLabel = "<URI>",
+      description = "Endpoint URI for reporting rejected transactions  (default: ${DEFAULT-VALUE})")
+  private URI rejectedTxEndpoint = null;
+
   private LineaTransactionSelectorCliOptions() {}
 
   /**
@@ -107,6 +118,7 @@ public static LineaTransactionSelectorCliOptions fromConfig(
     options.maxGasPerBlock = config.maxGasPerBlock();
     options.unprofitableCacheSize = config.unprofitableCacheSize();
     options.unprofitableRetryLimit = config.unprofitableRetryLimit();
+    options.rejectedTxEndpoint = config.rejectedTxEndpoint();
     return options;
   }
 
@@ -123,6 +135,7 @@ public LineaTransactionSelectorConfiguration toDomainObject() {
         .maxGasPerBlock(maxGasPerBlock)
         .unprofitableCacheSize(unprofitableCacheSize)
         .unprofitableRetryLimit(unprofitableRetryLimit)
+        .rejectedTxEndpoint(rejectedTxEndpoint)
         .build();
   }
 
@@ -134,6 +147,7 @@ public String toString() {
         .add(MAX_GAS_PER_BLOCK, maxGasPerBlock)
         .add(UNPROFITABLE_CACHE_SIZE, unprofitableCacheSize)
         .add(UNPROFITABLE_RETRY_LIMIT, unprofitableRetryLimit)
+        .add(REJECTED_TX_ENDPOINT, rejectedTxEndpoint)
         .toString();
   }
 }
diff --git a/sequencer/src/main/java/net/consensys/linea/config/LineaTransactionSelectorConfiguration.java b/sequencer/src/main/java/net/consensys/linea/config/LineaTransactionSelectorConfiguration.java
index 6c178797..726c8932 100644
--- a/sequencer/src/main/java/net/consensys/linea/config/LineaTransactionSelectorConfiguration.java
+++ b/sequencer/src/main/java/net/consensys/linea/config/LineaTransactionSelectorConfiguration.java
@@ -15,6 +15,8 @@
 
 package net.consensys.linea.config;
 
+import java.net.URI;
+
 import lombok.Builder;
 import net.consensys.linea.plugins.LineaOptionsConfiguration;
 
@@ -25,5 +27,6 @@ public record LineaTransactionSelectorConfiguration(
     int overLinesLimitCacheSize,
     long maxGasPerBlock,
     int unprofitableCacheSize,
-    int unprofitableRetryLimit)
+    int unprofitableRetryLimit,
+    URI rejectedTxEndpoint)
     implements LineaOptionsConfiguration {}
diff --git a/sequencer/src/main/java/net/consensys/linea/jsonrpc/JsonRpcClient.java b/sequencer/src/main/java/net/consensys/linea/jsonrpc/JsonRpcClient.java
index f4c89701..64c6cbb1 100644
--- a/sequencer/src/main/java/net/consensys/linea/jsonrpc/JsonRpcClient.java
+++ b/sequencer/src/main/java/net/consensys/linea/jsonrpc/JsonRpcClient.java
@@ -3,6 +3,7 @@
 import java.io.IOException;
 import java.io.OutputStream;
 import java.net.HttpURLConnection;
+import java.net.URI;
 import java.net.URL;
 import java.nio.charset.StandardCharsets;
 import java.util.Scanner;
@@ -15,8 +16,9 @@ public class JsonRpcClient {
   private static final int MAX_RETRIES = 3;
   private static final ExecutorService executorService = Executors.newCachedThreadPool();
 
-  public static String sendRequest(String urlString, String jsonInputString) throws Exception {
-    HttpURLConnection conn = getHttpURLConnection(urlString, jsonInputString);
+  public static String sendRequest(final URI endpoint, final String jsonInputString)
+      throws Exception {
+    HttpURLConnection conn = getHttpURLConnection(endpoint, jsonInputString);
 
     int responseCode = conn.getResponseCode();
     if (responseCode == HttpURLConnection.HTTP_OK) {
@@ -28,29 +30,30 @@ public static String sendRequest(String urlString, String jsonInputString) throw
     }
   }
 
-  private static HttpURLConnection getHttpURLConnection(String urlString, String jsonInputString)
-      throws IOException {
-    URL url = new URL(urlString);
-    HttpURLConnection conn = (HttpURLConnection) url.openConnection();
+  private static HttpURLConnection getHttpURLConnection(
+      final URI endpoint, final String jsonInputString) throws IOException {
+    final URL url = endpoint.toURL();
+    final HttpURLConnection conn = (HttpURLConnection) url.openConnection();
     conn.setRequestMethod("POST");
     conn.setRequestProperty("Content-Type", "application/json; utf-8");
     conn.setRequestProperty("Accept", "application/json");
     conn.setDoOutput(true);
 
-    try (OutputStream os = conn.getOutputStream()) {
-      byte[] input = jsonInputString.getBytes(StandardCharsets.UTF_8);
+    try (final OutputStream os = conn.getOutputStream()) {
+      final byte[] input = jsonInputString.getBytes(StandardCharsets.UTF_8);
       os.write(input, 0, input.length);
     }
     return conn;
   }
 
-  public static Future<String> sendRequestWithRetries(String urlString, String jsonInputString) {
+  public static Future<String> sendRequestWithRetries(
+      final URI endpoint, final String jsonInputString) {
     Callable<String> task =
         () -> {
           int attempt = 0;
           while (attempt < MAX_RETRIES) {
             try {
-              return sendRequest(urlString, jsonInputString);
+              return sendRequest(endpoint, jsonInputString);
             } catch (Exception e) {
               attempt++;
               if (attempt >= MAX_RETRIES) {
diff --git a/sequencer/src/main/java/net/consensys/linea/sequencer/txselection/selectors/LineaTransactionSelector.java b/sequencer/src/main/java/net/consensys/linea/sequencer/txselection/selectors/LineaTransactionSelector.java
index 5ba3208d..a6d8c17f 100644
--- a/sequencer/src/main/java/net/consensys/linea/sequencer/txselection/selectors/LineaTransactionSelector.java
+++ b/sequencer/src/main/java/net/consensys/linea/sequencer/txselection/selectors/LineaTransactionSelector.java
@@ -14,8 +14,10 @@
  */
 package net.consensys.linea.sequencer.txselection.selectors;
 
+import java.net.URI;
 import java.util.List;
 import java.util.Map;
+import java.util.Optional;
 
 import com.google.gson.JsonObject;
 import lombok.extern.slf4j.Slf4j;
@@ -40,6 +42,7 @@ public class LineaTransactionSelector implements PluginTransactionSelector {
 
   private TraceLineLimitTransactionSelector traceLineLimitTransactionSelector;
   private final List<PluginTransactionSelector> selectors;
+  private final Optional<URI> rejectedTxEndpoint;
 
   public LineaTransactionSelector(
       final BlockchainService blockchainService,
@@ -48,7 +51,8 @@ public LineaTransactionSelector(
       final LineaProfitabilityConfiguration profitabilityConfiguration,
       final LineaTracerConfiguration tracerConfiguration,
       final Map<String, Integer> limitsMap) {
-    this.selectors =
+    rejectedTxEndpoint = Optional.ofNullable(txSelectorConfiguration.rejectedTxEndpoint());
+    selectors =
         createTransactionSelectors(
             blockchainService,
             txSelectorConfiguration,
@@ -154,12 +158,14 @@ public void onTransactionNotSelected(
         selector ->
             selector.onTransactionNotSelected(evaluationContext, transactionSelectionResult));
 
-    notifyDiscardedTransaction(evaluationContext, transactionSelectionResult);
+    rejectedTxEndpoint.ifPresent(
+        uri -> notifyDiscardedTransaction(evaluationContext, transactionSelectionResult, uri));
   }
 
-  private void notifyDiscardedTransaction(
-      TransactionEvaluationContext<? extends PendingTransaction> evaluationContext,
-      TransactionSelectionResult transactionSelectionResult) {
+  private static void notifyDiscardedTransaction(
+      final TransactionEvaluationContext<? extends PendingTransaction> evaluationContext,
+      final TransactionSelectionResult transactionSelectionResult,
+      final URI rejectedTxEndpoint) {
     if (!transactionSelectionResult.discard()) {
       return;
     }
@@ -190,17 +196,17 @@ private void notifyDiscardedTransaction(
     })
      */
     // Build JSON-RPC request
-    JsonObject params = new JsonObject();
+    final JsonObject params = new JsonObject();
     params.addProperty("blockNumber", pendingBlockHeader.getNumber());
     params.addProperty(
         "transactionRLP", pendingTransaction.getTransaction().encoded().toHexString());
     params.addProperty("reasonMessage", transactionSelectionResult.maybeInvalidReason().orElse(""));
 
-    String jsonRequest =
+    final String jsonRequest =
         JsonRpcRequestBuilder.buildRequest("linea_saveRejectedTransaction", params, 1);
 
     // Send JSON-RPC request with retries in a new thread
-    JsonRpcClient.sendRequestWithRetries("http://your-json-rpc-endpoint", jsonRequest);
+    JsonRpcClient.sendRequestWithRetries(rejectedTxEndpoint, jsonRequest);
   }
 
   /**

From d38b539cfb133d18061a54b024f20f503cee075f Mon Sep 17 00:00:00 2001
From: Usman Saleem <usman@usmans.info>
Date: Wed, 28 Aug 2024 08:52:13 +1000
Subject: [PATCH 06/26] add spdx header

---
 .../consensys/linea/jsonrpc/JsonRpcClient.java    | 15 +++++++++++++++
 .../linea/jsonrpc/JsonRpcRequestBuilder.java      | 15 +++++++++++++++
 2 files changed, 30 insertions(+)

diff --git a/sequencer/src/main/java/net/consensys/linea/jsonrpc/JsonRpcClient.java b/sequencer/src/main/java/net/consensys/linea/jsonrpc/JsonRpcClient.java
index 64c6cbb1..ef8f2c05 100644
--- a/sequencer/src/main/java/net/consensys/linea/jsonrpc/JsonRpcClient.java
+++ b/sequencer/src/main/java/net/consensys/linea/jsonrpc/JsonRpcClient.java
@@ -1,3 +1,18 @@
+/*
+ * Copyright Consensys Software Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on
+ * an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
 package net.consensys.linea.jsonrpc;
 
 import java.io.IOException;
diff --git a/sequencer/src/main/java/net/consensys/linea/jsonrpc/JsonRpcRequestBuilder.java b/sequencer/src/main/java/net/consensys/linea/jsonrpc/JsonRpcRequestBuilder.java
index 5b345241..f047c701 100644
--- a/sequencer/src/main/java/net/consensys/linea/jsonrpc/JsonRpcRequestBuilder.java
+++ b/sequencer/src/main/java/net/consensys/linea/jsonrpc/JsonRpcRequestBuilder.java
@@ -1,3 +1,18 @@
+/*
+ * Copyright Consensys Software Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on
+ * an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
 package net.consensys.linea.jsonrpc;
 
 import com.google.gson.JsonObject;

From 7a8d380df50ebf82ca5d471761be87bf4f480ae3 Mon Sep 17 00:00:00 2001
From: Usman Saleem <usman@usmans.info>
Date: Mon, 2 Sep 2024 10:40:56 +1000
Subject: [PATCH 07/26] build: Add wiremock dependency

---
 gradle/common-dependencies.gradle   | 2 ++
 gradle/dependency-management.gradle | 2 ++
 2 files changed, 4 insertions(+)

diff --git a/gradle/common-dependencies.gradle b/gradle/common-dependencies.gradle
index 3289c148..03663674 100644
--- a/gradle/common-dependencies.gradle
+++ b/gradle/common-dependencies.gradle
@@ -34,4 +34,6 @@ dependencies {
 
   testImplementation 'org.mockito:mockito-core'
   testImplementation 'org.mockito:mockito-junit-jupiter'
+
+  testImplementation "org.wiremock:wiremock"
 }
diff --git a/gradle/dependency-management.gradle b/gradle/dependency-management.gradle
index b8104a56..f4401380 100644
--- a/gradle/dependency-management.gradle
+++ b/gradle/dependency-management.gradle
@@ -157,5 +157,7 @@ dependencyManagement {
       entry 'core'
       entry 'crypto'
     }
+
+    dependency "org.wiremock:wiremock:3.9.1"
   }
 }

From 425f05cb9271488bc46b05efdc15a7956eb20d30 Mon Sep 17 00:00:00 2001
From: Usman Saleem <usman@usmans.info>
Date: Wed, 4 Sep 2024 17:46:47 +1000
Subject: [PATCH 08/26] Add unit test

---
 sequencer/build.gradle                        |  1 +
 .../selectors/LineaTransactionSelector.java   | 53 +-----------
 .../selectors/ReportRejectedTransaction.java  | 73 ++++++++++++++++
 .../selectors/ReportDroppedTxTest.java        | 83 +++++++++++++++++++
 .../TestTransactionEvaluationContext.java     | 13 +++
 5 files changed, 172 insertions(+), 51 deletions(-)
 create mode 100644 sequencer/src/main/java/net/consensys/linea/sequencer/txselection/selectors/ReportRejectedTransaction.java
 create mode 100644 sequencer/src/test/java/net/consensys/linea/sequencer/txselection/selectors/ReportDroppedTxTest.java

diff --git a/sequencer/build.gradle b/sequencer/build.gradle
index 5a536fa9..b503fe05 100644
--- a/sequencer/build.gradle
+++ b/sequencer/build.gradle
@@ -68,6 +68,7 @@ dependencies {
   testImplementation "${besuArtifactGroup}.internal:core"
   testImplementation "${besuArtifactGroup}.internal:rlp"
   testImplementation "${besuArtifactGroup}.internal:core"
+  testImplementation "${besuArtifactGroup}:plugin-api"
 
   // workaround for bug https://github.com/dnsjava/dnsjava/issues/329, remove when upgraded upstream
   testImplementation 'dnsjava:dnsjava:3.6.1'
diff --git a/sequencer/src/main/java/net/consensys/linea/sequencer/txselection/selectors/LineaTransactionSelector.java b/sequencer/src/main/java/net/consensys/linea/sequencer/txselection/selectors/LineaTransactionSelector.java
index a6d8c17f..8318054e 100644
--- a/sequencer/src/main/java/net/consensys/linea/sequencer/txselection/selectors/LineaTransactionSelector.java
+++ b/sequencer/src/main/java/net/consensys/linea/sequencer/txselection/selectors/LineaTransactionSelector.java
@@ -14,21 +14,19 @@
  */
 package net.consensys.linea.sequencer.txselection.selectors;
 
+import static net.consensys.linea.sequencer.txselection.selectors.ReportRejectedTransaction.notifyDiscardedTransaction;
+
 import java.net.URI;
 import java.util.List;
 import java.util.Map;
 import java.util.Optional;
 
-import com.google.gson.JsonObject;
 import lombok.extern.slf4j.Slf4j;
 import net.consensys.linea.config.LineaProfitabilityConfiguration;
 import net.consensys.linea.config.LineaTracerConfiguration;
 import net.consensys.linea.config.LineaTransactionSelectorConfiguration;
-import net.consensys.linea.jsonrpc.JsonRpcClient;
-import net.consensys.linea.jsonrpc.JsonRpcRequestBuilder;
 import net.consensys.linea.plugins.config.LineaL1L2BridgeSharedConfiguration;
 import org.hyperledger.besu.datatypes.PendingTransaction;
-import org.hyperledger.besu.plugin.data.ProcessableBlockHeader;
 import org.hyperledger.besu.plugin.data.TransactionProcessingResult;
 import org.hyperledger.besu.plugin.data.TransactionSelectionResult;
 import org.hyperledger.besu.plugin.services.BlockchainService;
@@ -162,53 +160,6 @@ public void onTransactionNotSelected(
         uri -> notifyDiscardedTransaction(evaluationContext, transactionSelectionResult, uri));
   }
 
-  private static void notifyDiscardedTransaction(
-      final TransactionEvaluationContext<? extends PendingTransaction> evaluationContext,
-      final TransactionSelectionResult transactionSelectionResult,
-      final URI rejectedTxEndpoint) {
-    if (!transactionSelectionResult.discard()) {
-      return;
-    }
-
-    final PendingTransaction pendingTransaction = evaluationContext.getPendingTransaction();
-    final ProcessableBlockHeader pendingBlockHeader = evaluationContext.getPendingBlockHeader();
-
-    log.debug(
-        "Discarding transaction {} because of {}. Block number: {}",
-        pendingTransaction.getTransaction().getHash(),
-        transactionSelectionResult,
-        pendingBlockHeader.getNumber());
-
-    /*
-    linea_saveRejectedTransaction({
-        "blockNumber": "base 10 number",
-        "transactionRLP": "transaction as the user sent in eth_sendRawTransaction",
-        "reasonMessage": "Transaction line count for module ADD=402 is above the limit 70"
-        "overflows": [{
-          "module": "ADD",
-          "count": 402,
-          "limit": 70
-        }, {
-          "module": "MUL",
-          "count": 587,
-          "limit": 400
-        }]
-    })
-     */
-    // Build JSON-RPC request
-    final JsonObject params = new JsonObject();
-    params.addProperty("blockNumber", pendingBlockHeader.getNumber());
-    params.addProperty(
-        "transactionRLP", pendingTransaction.getTransaction().encoded().toHexString());
-    params.addProperty("reasonMessage", transactionSelectionResult.maybeInvalidReason().orElse(""));
-
-    final String jsonRequest =
-        JsonRpcRequestBuilder.buildRequest("linea_saveRejectedTransaction", params, 1);
-
-    // Send JSON-RPC request with retries in a new thread
-    JsonRpcClient.sendRequestWithRetries(rejectedTxEndpoint, jsonRequest);
-  }
-
   /**
    * Returns the operation tracer to be used while processing the transactions for the block.
    *
diff --git a/sequencer/src/main/java/net/consensys/linea/sequencer/txselection/selectors/ReportRejectedTransaction.java b/sequencer/src/main/java/net/consensys/linea/sequencer/txselection/selectors/ReportRejectedTransaction.java
new file mode 100644
index 00000000..84c8af23
--- /dev/null
+++ b/sequencer/src/main/java/net/consensys/linea/sequencer/txselection/selectors/ReportRejectedTransaction.java
@@ -0,0 +1,73 @@
+/*
+ * Copyright Consensys Software Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on
+ * an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+package net.consensys.linea.sequencer.txselection.selectors;
+
+import java.net.URI;
+
+import com.google.gson.JsonObject;
+import net.consensys.linea.jsonrpc.JsonRpcClient;
+import net.consensys.linea.jsonrpc.JsonRpcRequestBuilder;
+import org.hyperledger.besu.datatypes.PendingTransaction;
+import org.hyperledger.besu.plugin.data.ProcessableBlockHeader;
+import org.hyperledger.besu.plugin.data.TransactionSelectionResult;
+import org.hyperledger.besu.plugin.services.txselection.TransactionEvaluationContext;
+
+/**
+ *
+ *
+ * <pre>
+ * {@code linea_saveRejectedTransaction({
+ *         "blockNumber": "base 10 number",
+ *         "transactionRLP": "transaction as the user sent in eth_sendRawTransaction",
+ *         "reasonMessage": "Transaction line count for module ADD=402 is above the limit 70"
+ *         "overflows": [{
+ *           "module": "ADD",
+ *           "count": 402,
+ *           "limit": 70
+ *         }, {
+ *           "module": "MUL",
+ *           "count": 587,
+ *           "limit": 400
+ *         }]
+ *     })
+ * }
+ * </pre>
+ */
+public class ReportRejectedTransaction {
+  static void notifyDiscardedTransaction(
+      final TransactionEvaluationContext<? extends PendingTransaction> evaluationContext,
+      final TransactionSelectionResult transactionSelectionResult,
+      final URI rejectedTxEndpoint) {
+    if (!transactionSelectionResult.discard()) {
+      return;
+    }
+
+    final PendingTransaction pendingTransaction = evaluationContext.getPendingTransaction();
+    final ProcessableBlockHeader pendingBlockHeader = evaluationContext.getPendingBlockHeader();
+
+    // Build JSON-RPC request
+    final JsonObject params = new JsonObject();
+    params.addProperty("blockNumber", pendingBlockHeader.getNumber());
+    params.addProperty(
+        "transactionRLP", pendingTransaction.getTransaction().encoded().toHexString());
+    params.addProperty("reasonMessage", transactionSelectionResult.maybeInvalidReason().orElse(""));
+
+    final String jsonRequest =
+        JsonRpcRequestBuilder.buildRequest("linea_saveRejectedTransaction", params, 1);
+
+    // Send JSON-RPC request with retries in a new thread
+    JsonRpcClient.sendRequestWithRetries(rejectedTxEndpoint, jsonRequest);
+  }
+}
diff --git a/sequencer/src/test/java/net/consensys/linea/sequencer/txselection/selectors/ReportDroppedTxTest.java b/sequencer/src/test/java/net/consensys/linea/sequencer/txselection/selectors/ReportDroppedTxTest.java
new file mode 100644
index 00000000..08906a81
--- /dev/null
+++ b/sequencer/src/test/java/net/consensys/linea/sequencer/txselection/selectors/ReportDroppedTxTest.java
@@ -0,0 +1,83 @@
+/*
+ * Copyright Consensys Software Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on
+ * an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package net.consensys.linea.sequencer.txselection.selectors;
+
+import static com.github.tomakehurst.wiremock.client.WireMock.aResponse;
+import static com.github.tomakehurst.wiremock.client.WireMock.equalToJson;
+import static com.github.tomakehurst.wiremock.client.WireMock.post;
+import static com.github.tomakehurst.wiremock.client.WireMock.postRequestedFor;
+import static com.github.tomakehurst.wiremock.client.WireMock.stubFor;
+import static com.github.tomakehurst.wiremock.client.WireMock.urlEqualTo;
+import static com.github.tomakehurst.wiremock.client.WireMock.verify;
+import static org.mockito.Mockito.when;
+
+import java.net.URI;
+
+import com.github.tomakehurst.wiremock.junit5.WireMockRuntimeInfo;
+import com.github.tomakehurst.wiremock.junit5.WireMockTest;
+import org.apache.tuweni.bytes.Bytes;
+import org.hyperledger.besu.datatypes.PendingTransaction;
+import org.hyperledger.besu.datatypes.Transaction;
+import org.hyperledger.besu.plugin.data.ProcessableBlockHeader;
+import org.hyperledger.besu.plugin.data.TransactionSelectionResult;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.mockito.Mock;
+import org.mockito.junit.jupiter.MockitoExtension;
+
+@WireMockTest
+@ExtendWith(MockitoExtension.class)
+class ReportDroppedTxTest {
+  @Mock PendingTransaction pendingTransaction;
+  @Mock ProcessableBlockHeader pendingBlockHeader;
+  @Mock Transaction transaction;
+
+  @Test
+  void droppedTxIsReported(final WireMockRuntimeInfo wmInfo) throws Exception {
+    when(pendingBlockHeader.getNumber()).thenReturn(1L);
+    when(pendingTransaction.getTransaction()).thenReturn(transaction);
+    Bytes randomEncodedBytes = Bytes.random(32);
+    when(transaction.encoded()).thenReturn(randomEncodedBytes);
+
+    // json-rpc stubbing
+    stubFor(
+        post(urlEqualTo("/"))
+            .willReturn(
+                aResponse()
+                    .withStatus(200)
+                    .withHeader("Content-Type", "application/json")
+                    .withBody("{\"jsonrpc\":\"2.0\",\"result\":true,\"id\":1}")));
+
+    TestTransactionEvaluationContext context =
+        new TestTransactionEvaluationContext(pendingTransaction)
+            .setPendingBlockHeader(pendingBlockHeader);
+    TransactionSelectionResult result = TransactionSelectionResult.invalid("test");
+
+    ReportRejectedTransaction.notifyDiscardedTransaction(
+        context, result, URI.create(wmInfo.getHttpBaseUrl()));
+
+    // assert wiremock was called
+    Thread.sleep(1000);
+
+    verify(
+        postRequestedFor(urlEqualTo("/"))
+            .withRequestBody(
+                equalToJson(
+                    "{\"jsonrpc\":\"2.0\",\"method\":\"linea_saveRejectedTransaction\",\"params\":{\"blockNumber\":1,\"transactionRLP\":\""
+                        + randomEncodedBytes.toHexString()
+                        + "\",\"reasonMessage\":\"test\"},\"id\":1}")));
+  }
+}
diff --git a/sequencer/src/test/java/net/consensys/linea/sequencer/txselection/selectors/TestTransactionEvaluationContext.java b/sequencer/src/test/java/net/consensys/linea/sequencer/txselection/selectors/TestTransactionEvaluationContext.java
index 5ee9700f..4edce437 100644
--- a/sequencer/src/test/java/net/consensys/linea/sequencer/txselection/selectors/TestTransactionEvaluationContext.java
+++ b/sequencer/src/test/java/net/consensys/linea/sequencer/txselection/selectors/TestTransactionEvaluationContext.java
@@ -17,12 +17,14 @@
 import com.google.common.base.Stopwatch;
 import org.hyperledger.besu.datatypes.PendingTransaction;
 import org.hyperledger.besu.datatypes.Wei;
+import org.hyperledger.besu.plugin.data.ProcessableBlockHeader;
 import org.hyperledger.besu.plugin.services.txselection.TransactionEvaluationContext;
 
 class TestTransactionEvaluationContext implements TransactionEvaluationContext<PendingTransaction> {
   private PendingTransaction pendingTransaction;
   private Wei transactionGasPrice;
   private Wei minGasPrice;
+  private ProcessableBlockHeader pendingBlockHeader;
 
   public TestTransactionEvaluationContext(
       final PendingTransaction pendingTransaction,
@@ -37,6 +39,11 @@ public TestTransactionEvaluationContext(final PendingTransaction pendingTransact
     this(pendingTransaction, Wei.ONE, Wei.ONE);
   }
 
+  @Override
+  public ProcessableBlockHeader getPendingBlockHeader() {
+    return pendingBlockHeader;
+  }
+
   @Override
   public PendingTransaction getPendingTransaction() {
     return pendingTransaction;
@@ -72,4 +79,10 @@ public TestTransactionEvaluationContext setTransactionGasPrice(final Wei transac
     this.transactionGasPrice = transactionGasPrice;
     return this;
   }
+
+  public TestTransactionEvaluationContext setPendingBlockHeader(
+      final ProcessableBlockHeader pendingBlockHeader) {
+    this.pendingBlockHeader = pendingBlockHeader;
+    return this;
+  }
 }

From 0ce850dcbdcfee5f99fc0f97fec42c73e05a7dd8 Mon Sep 17 00:00:00 2001
From: Usman Saleem <usman@usmans.info>
Date: Thu, 5 Sep 2024 09:05:26 +1000
Subject: [PATCH 09/26] Update json-rpc method and unit tests

---
 .../selectors/LineaTransactionSelector.java   |  7 ++-
 ....java => RejectedTransactionNotifier.java} | 17 +++++---
 ...a => RejectedTransactionNotifierTest.java} | 43 ++++++++++++-------
 3 files changed, 45 insertions(+), 22 deletions(-)
 rename sequencer/src/main/java/net/consensys/linea/sequencer/txselection/selectors/{ReportRejectedTransaction.java => RejectedTransactionNotifier.java} (81%)
 rename sequencer/src/test/java/net/consensys/linea/sequencer/txselection/selectors/{ReportDroppedTxTest.java => RejectedTransactionNotifierTest.java} (65%)

diff --git a/sequencer/src/main/java/net/consensys/linea/sequencer/txselection/selectors/LineaTransactionSelector.java b/sequencer/src/main/java/net/consensys/linea/sequencer/txselection/selectors/LineaTransactionSelector.java
index 8318054e..d7bb598c 100644
--- a/sequencer/src/main/java/net/consensys/linea/sequencer/txselection/selectors/LineaTransactionSelector.java
+++ b/sequencer/src/main/java/net/consensys/linea/sequencer/txselection/selectors/LineaTransactionSelector.java
@@ -14,9 +14,10 @@
  */
 package net.consensys.linea.sequencer.txselection.selectors;
 
-import static net.consensys.linea.sequencer.txselection.selectors.ReportRejectedTransaction.notifyDiscardedTransaction;
+import static net.consensys.linea.sequencer.txselection.selectors.RejectedTransactionNotifier.notifyDiscardedTransactionAsync;
 
 import java.net.URI;
+import java.time.Instant;
 import java.util.List;
 import java.util.Map;
 import java.util.Optional;
@@ -157,7 +158,9 @@ public void onTransactionNotSelected(
             selector.onTransactionNotSelected(evaluationContext, transactionSelectionResult));
 
     rejectedTxEndpoint.ifPresent(
-        uri -> notifyDiscardedTransaction(evaluationContext, transactionSelectionResult, uri));
+        uri ->
+            notifyDiscardedTransactionAsync(
+                evaluationContext, transactionSelectionResult, Instant.now(), uri));
   }
 
   /**
diff --git a/sequencer/src/main/java/net/consensys/linea/sequencer/txselection/selectors/ReportRejectedTransaction.java b/sequencer/src/main/java/net/consensys/linea/sequencer/txselection/selectors/RejectedTransactionNotifier.java
similarity index 81%
rename from sequencer/src/main/java/net/consensys/linea/sequencer/txselection/selectors/ReportRejectedTransaction.java
rename to sequencer/src/main/java/net/consensys/linea/sequencer/txselection/selectors/RejectedTransactionNotifier.java
index 84c8af23..c5403c14 100644
--- a/sequencer/src/main/java/net/consensys/linea/sequencer/txselection/selectors/ReportRejectedTransaction.java
+++ b/sequencer/src/main/java/net/consensys/linea/sequencer/txselection/selectors/RejectedTransactionNotifier.java
@@ -15,6 +15,7 @@
 package net.consensys.linea.sequencer.txselection.selectors;
 
 import java.net.URI;
+import java.time.Instant;
 
 import com.google.gson.JsonObject;
 import net.consensys.linea.jsonrpc.JsonRpcClient;
@@ -28,10 +29,12 @@
  *
  *
  * <pre>
- * {@code linea_saveRejectedTransaction({
+ * {@code linea_saveRejectedTransactionV1({
+ *         "txRejectionStage": "SEQUENCER/RPC/P2P",
+ *         "timestamp": "2024-08-22T09:18:51Z", # ISO8601 UTC+0 when tx was rejected by node, usefull if P2P edge node.
  *         "blockNumber": "base 10 number",
  *         "transactionRLP": "transaction as the user sent in eth_sendRawTransaction",
- *         "reasonMessage": "Transaction line count for module ADD=402 is above the limit 70"
+ *         "reason": "Transaction line count for module ADD=402 is above the limit 70"
  *         "overflows": [{
  *           "module": "ADD",
  *           "count": 402,
@@ -45,10 +48,12 @@
  * }
  * </pre>
  */
-public class ReportRejectedTransaction {
-  static void notifyDiscardedTransaction(
+public class RejectedTransactionNotifier {
+
+  static void notifyDiscardedTransactionAsync(
       final TransactionEvaluationContext<? extends PendingTransaction> evaluationContext,
       final TransactionSelectionResult transactionSelectionResult,
+      final Instant timestamp,
       final URI rejectedTxEndpoint) {
     if (!transactionSelectionResult.discard()) {
       return;
@@ -59,13 +64,15 @@ static void notifyDiscardedTransaction(
 
     // Build JSON-RPC request
     final JsonObject params = new JsonObject();
+    params.addProperty("txRejectionStage", "SEQUENCER");
+    params.addProperty("timestamp", timestamp.toString());
     params.addProperty("blockNumber", pendingBlockHeader.getNumber());
     params.addProperty(
         "transactionRLP", pendingTransaction.getTransaction().encoded().toHexString());
     params.addProperty("reasonMessage", transactionSelectionResult.maybeInvalidReason().orElse(""));
 
     final String jsonRequest =
-        JsonRpcRequestBuilder.buildRequest("linea_saveRejectedTransaction", params, 1);
+        JsonRpcRequestBuilder.buildRequest("linea_saveRejectedTransactionV1", params, 1);
 
     // Send JSON-RPC request with retries in a new thread
     JsonRpcClient.sendRequestWithRetries(rejectedTxEndpoint, jsonRequest);
diff --git a/sequencer/src/test/java/net/consensys/linea/sequencer/txselection/selectors/ReportDroppedTxTest.java b/sequencer/src/test/java/net/consensys/linea/sequencer/txselection/selectors/RejectedTransactionNotifierTest.java
similarity index 65%
rename from sequencer/src/test/java/net/consensys/linea/sequencer/txselection/selectors/ReportDroppedTxTest.java
rename to sequencer/src/test/java/net/consensys/linea/sequencer/txselection/selectors/RejectedTransactionNotifierTest.java
index 08906a81..cae53913 100644
--- a/sequencer/src/test/java/net/consensys/linea/sequencer/txselection/selectors/ReportDroppedTxTest.java
+++ b/sequencer/src/test/java/net/consensys/linea/sequencer/txselection/selectors/RejectedTransactionNotifierTest.java
@@ -25,9 +25,12 @@
 import static org.mockito.Mockito.when;
 
 import java.net.URI;
+import java.time.Instant;
 
 import com.github.tomakehurst.wiremock.junit5.WireMockRuntimeInfo;
 import com.github.tomakehurst.wiremock.junit5.WireMockTest;
+import com.google.gson.JsonObject;
+import net.consensys.linea.jsonrpc.JsonRpcRequestBuilder;
 import org.apache.tuweni.bytes.Bytes;
 import org.hyperledger.besu.datatypes.PendingTransaction;
 import org.hyperledger.besu.datatypes.Transaction;
@@ -40,16 +43,17 @@
 
 @WireMockTest
 @ExtendWith(MockitoExtension.class)
-class ReportDroppedTxTest {
+class RejectedTransactionNotifierTest {
   @Mock PendingTransaction pendingTransaction;
   @Mock ProcessableBlockHeader pendingBlockHeader;
   @Mock Transaction transaction;
 
   @Test
   void droppedTxIsReported(final WireMockRuntimeInfo wmInfo) throws Exception {
+    // mock stubbing
     when(pendingBlockHeader.getNumber()).thenReturn(1L);
     when(pendingTransaction.getTransaction()).thenReturn(transaction);
-    Bytes randomEncodedBytes = Bytes.random(32);
+    final Bytes randomEncodedBytes = Bytes.random(32);
     when(transaction.encoded()).thenReturn(randomEncodedBytes);
 
     // json-rpc stubbing
@@ -59,25 +63,34 @@ void droppedTxIsReported(final WireMockRuntimeInfo wmInfo) throws Exception {
                 aResponse()
                     .withStatus(200)
                     .withHeader("Content-Type", "application/json")
-                    .withBody("{\"jsonrpc\":\"2.0\",\"result\":true,\"id\":1}")));
+                    .withBody(
+                        "{\"jsonrpc\":\"2.0\",\"result\":{ \"status\": \"SAVED\"},\"id\":1}")));
 
-    TestTransactionEvaluationContext context =
+    final TestTransactionEvaluationContext context =
         new TestTransactionEvaluationContext(pendingTransaction)
             .setPendingBlockHeader(pendingBlockHeader);
-    TransactionSelectionResult result = TransactionSelectionResult.invalid("test");
+    final TransactionSelectionResult result = TransactionSelectionResult.invalid("test");
+    final Instant timestamp = Instant.now();
 
-    ReportRejectedTransaction.notifyDiscardedTransaction(
-        context, result, URI.create(wmInfo.getHttpBaseUrl()));
+    // call the method under test
+    RejectedTransactionNotifier.notifyDiscardedTransactionAsync(
+        context, result, timestamp, URI.create(wmInfo.getHttpBaseUrl()));
 
-    // assert wiremock was called
+    // sleep a bit to allow async processing
     Thread.sleep(1000);
 
-    verify(
-        postRequestedFor(urlEqualTo("/"))
-            .withRequestBody(
-                equalToJson(
-                    "{\"jsonrpc\":\"2.0\",\"method\":\"linea_saveRejectedTransaction\",\"params\":{\"blockNumber\":1,\"transactionRLP\":\""
-                        + randomEncodedBytes.toHexString()
-                        + "\",\"reasonMessage\":\"test\"},\"id\":1}")));
+    // build expected json-rpc request
+    final JsonObject params = new JsonObject();
+    params.addProperty("txRejectionStage", "SEQUENCER");
+    params.addProperty("timestamp", timestamp.toString());
+    params.addProperty("blockNumber", 1);
+    params.addProperty("transactionRLP", randomEncodedBytes.toHexString());
+    params.addProperty("reasonMessage", "test");
+
+    final String jsonRequest =
+        JsonRpcRequestBuilder.buildRequest("linea_saveRejectedTransactionV1", params, 1);
+
+    // assert that the expected json-rpc request was sent to WireMock
+    verify(postRequestedFor(urlEqualTo("/")).withRequestBody(equalToJson(jsonRequest)));
   }
 }

From 5e01ae9ba0854e04e40121ca99b023ced7bb076b Mon Sep 17 00:00:00 2001
From: Usman Saleem <usman@usmans.info>
Date: Tue, 10 Sep 2024 15:46:44 +1000
Subject: [PATCH 10/26] Adding JsonRpcManager

---
 .../linea/jsonrpc/JsonRpcManager.java         | 138 ++++++++++++++++++
 .../LineaTransactionSelectorFactory.java      |   5 +
 .../LineaTransactionSelectorPlugin.java       |  11 ++
 .../selectors/LineaTransactionSelector.java   |  10 +-
 .../RejectedTransactionNotifier.java          |   4 +-
 5 files changed, 166 insertions(+), 2 deletions(-)
 create mode 100644 sequencer/src/main/java/net/consensys/linea/jsonrpc/JsonRpcManager.java

diff --git a/sequencer/src/main/java/net/consensys/linea/jsonrpc/JsonRpcManager.java b/sequencer/src/main/java/net/consensys/linea/jsonrpc/JsonRpcManager.java
new file mode 100644
index 00000000..f69da6a6
--- /dev/null
+++ b/sequencer/src/main/java/net/consensys/linea/jsonrpc/JsonRpcManager.java
@@ -0,0 +1,138 @@
+/*
+ * Copyright Consensys Software Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on
+ * an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package net.consensys.linea.jsonrpc;
+
+import lombok.extern.slf4j.Slf4j;
+
+import java.io.IOException;
+import java.net.URI;
+import java.nio.file.DirectoryStream;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.concurrent.ScheduledExecutorService;
+import java.util.concurrent.TimeUnit;
+
+/**
+ * This class is responsible for managing JSON-RPC requests for reporting rejected transactions
+ */
+@Slf4j
+public class JsonRpcManager {
+    private static final int MAX_THREADS = Math.min(32, Runtime.getRuntime().availableProcessors() * 2);
+    private static final long MAX_RETRY_DURATION = TimeUnit.HOURS.toMillis(2);
+
+    private final Path jsonDirectory;
+    private final URI rejectedTxEndpoint;
+    private final ExecutorService executorService;
+    private final ScheduledExecutorService schedulerService;
+
+    /**
+     * Creates a new JSON-RPC manager.
+     * @param jsonDirectory The directory to store and load JSON files containing json-rpc calls
+     * @param rejectedTxEndpoint The endpoint to send rejected transactions to
+     */
+    public JsonRpcManager(final Path jsonDirectory, final URI rejectedTxEndpoint) {
+        this.jsonDirectory = jsonDirectory;
+        this.rejectedTxEndpoint = rejectedTxEndpoint;
+        this.executorService = Executors.newFixedThreadPool(MAX_THREADS);
+        this.schedulerService = Executors.newScheduledThreadPool(1);
+    }
+
+    /**
+     * Load existing JSON-RPC and submit them.
+     */
+    public void start() {
+        loadExistingJsonFiles();
+    }
+
+    /**
+     * Shuts down the executor service and scheduler service.
+     */
+    public void shutdown() {
+        executorService.shutdown();
+        schedulerService.shutdown();
+    }
+
+    /**
+     * Submits a new JSON-RPC call.
+     * @param jsonContent The JSON content to submit
+     */
+    public void submitNewJsonRpcCall(final String jsonContent) {
+        try {
+            final Path jsonFile = saveJsonToFile(jsonContent);
+            submitJsonRpcCall(jsonFile);
+        } catch (final IOException e) {
+            log.error("Failed to save JSON content", e);
+        }
+    }
+
+    private void loadExistingJsonFiles() {
+        try (final DirectoryStream<Path> stream = Files.newDirectoryStream(jsonDirectory, "rpc_*.json")) {
+            for (Path path : stream) {
+                submitJsonRpcCall(path);
+            }
+        } catch (IOException e) {
+            log.error("Failed to load existing JSON files", e);
+        }
+    }
+
+    private void submitJsonRpcCall(final Path jsonFile) {
+        executorService.submit(() -> {
+            if (!Files.exists(jsonFile)) {
+                log.debug("json-rpc file no longer exists, skipping processing: {}", jsonFile);
+                return;
+            }
+            try {
+                final String jsonContent = new String(Files.readAllBytes(jsonFile));
+                final boolean success = sendJsonRpcCall(jsonContent);
+                if (success) {
+                    Files.deleteIfExists(jsonFile);
+                } else {
+                    log.warn("Failed to send JSON-RPC call to {}, retrying: {}", rejectedTxEndpoint, jsonFile);
+                    scheduleRetry(jsonFile, System.currentTimeMillis(), 1000);
+                }
+            } catch (final IOException e) {
+                log.error("Failed to process json-rpc file: {}", jsonFile, e);
+            }
+        });
+    }
+
+    private void scheduleRetry(final Path jsonFile, final long startTime, final long delay) {
+        // check if we're still within the maximum retry duration
+        if (System.currentTimeMillis() - startTime < MAX_RETRY_DURATION) {
+            // schedule a retry
+            schedulerService.schedule(() -> submitJsonRpcCall(jsonFile), delay, TimeUnit.MILLISECONDS);
+
+            // exponential backoff with a maximum delay of 1 minute
+            long nextDelay = Math.min(delay * 2, TimeUnit.MINUTES.toMillis(1));
+            scheduleRetry(jsonFile, startTime, nextDelay);
+        }
+    }
+
+    private boolean sendJsonRpcCall(final String jsonContent) {
+        // Implement your JSON-RPC call logic here
+        // Return true if successful, false otherwise
+        return false; // Placeholder
+    }
+
+    private Path saveJsonToFile(final String jsonContent) throws IOException {
+        final String fileName = "rpc_" + System.currentTimeMillis() + ".json";
+        final Path filePath = jsonDirectory.resolve(fileName);
+        Files.write(filePath, jsonContent.getBytes());
+        return filePath;
+    }
+}
diff --git a/sequencer/src/main/java/net/consensys/linea/sequencer/txselection/LineaTransactionSelectorFactory.java b/sequencer/src/main/java/net/consensys/linea/sequencer/txselection/LineaTransactionSelectorFactory.java
index d71ddd89..d325f31c 100644
--- a/sequencer/src/main/java/net/consensys/linea/sequencer/txselection/LineaTransactionSelectorFactory.java
+++ b/sequencer/src/main/java/net/consensys/linea/sequencer/txselection/LineaTransactionSelectorFactory.java
@@ -22,6 +22,7 @@
 import net.consensys.linea.config.LineaTransactionSelectorConfiguration;
 import net.consensys.linea.plugins.config.LineaL1L2BridgeSharedConfiguration;
 import net.consensys.linea.sequencer.txselection.selectors.LineaTransactionSelector;
+import org.hyperledger.besu.plugin.services.BesuConfiguration;
 import org.hyperledger.besu.plugin.services.BlockchainService;
 import org.hyperledger.besu.plugin.services.txselection.PluginTransactionSelector;
 import org.hyperledger.besu.plugin.services.txselection.PluginTransactionSelectorFactory;
@@ -32,6 +33,7 @@
  */
 public class LineaTransactionSelectorFactory implements PluginTransactionSelectorFactory {
   private final BlockchainService blockchainService;
+  private final BesuConfiguration besuConfiguration;
   private final LineaTransactionSelectorConfiguration txSelectorConfiguration;
   private final LineaL1L2BridgeSharedConfiguration l1L2BridgeConfiguration;
   private final LineaProfitabilityConfiguration profitabilityConfiguration;
@@ -41,12 +43,14 @@ public class LineaTransactionSelectorFactory implements PluginTransactionSelecto
 
   public LineaTransactionSelectorFactory(
       final BlockchainService blockchainService,
+      final BesuConfiguration besuConfiguration,
       final LineaTransactionSelectorConfiguration txSelectorConfiguration,
       final LineaL1L2BridgeSharedConfiguration l1L2BridgeConfiguration,
       final LineaProfitabilityConfiguration profitabilityConfiguration,
       final LineaTracerConfiguration tracerConfiguration,
       final Map<String, Integer> limitsMap) {
     this.blockchainService = blockchainService;
+    this.besuConfiguration = besuConfiguration;
     this.txSelectorConfiguration = txSelectorConfiguration;
     this.l1L2BridgeConfiguration = l1L2BridgeConfiguration;
     this.profitabilityConfiguration = profitabilityConfiguration;
@@ -58,6 +62,7 @@ public LineaTransactionSelectorFactory(
   public PluginTransactionSelector create() {
     return new LineaTransactionSelector(
         blockchainService,
+        besuConfiguration,
         txSelectorConfiguration,
         l1L2BridgeConfiguration,
         profitabilityConfiguration,
diff --git a/sequencer/src/main/java/net/consensys/linea/sequencer/txselection/LineaTransactionSelectorPlugin.java b/sequencer/src/main/java/net/consensys/linea/sequencer/txselection/LineaTransactionSelectorPlugin.java
index 000b0671..d142995c 100644
--- a/sequencer/src/main/java/net/consensys/linea/sequencer/txselection/LineaTransactionSelectorPlugin.java
+++ b/sequencer/src/main/java/net/consensys/linea/sequencer/txselection/LineaTransactionSelectorPlugin.java
@@ -24,6 +24,7 @@
 import net.consensys.linea.AbstractLineaRequiredPlugin;
 import org.hyperledger.besu.plugin.BesuContext;
 import org.hyperledger.besu.plugin.BesuPlugin;
+import org.hyperledger.besu.plugin.services.BesuConfiguration;
 import org.hyperledger.besu.plugin.services.BlockchainService;
 import org.hyperledger.besu.plugin.services.TransactionSelectionService;
 
@@ -38,6 +39,7 @@ public class LineaTransactionSelectorPlugin extends AbstractLineaRequiredPlugin
   public static final String NAME = "linea";
   private TransactionSelectionService transactionSelectionService;
   private BlockchainService blockchainService;
+  private BesuConfiguration besuConfiguration;
 
   @Override
   public Optional<String> getName() {
@@ -61,6 +63,14 @@ public void doRegister(final BesuContext context) {
                 () ->
                     new RuntimeException(
                         "Failed to obtain BlockchainService from the BesuContext."));
+
+    besuConfiguration =
+        context
+            .getService(BesuConfiguration.class)
+            .orElseThrow(
+                () ->
+                    new RuntimeException(
+                        "Failed to obtain BesuConfiguration from the BesuContext."));
   }
 
   @Override
@@ -69,6 +79,7 @@ public void start() {
     transactionSelectionService.registerPluginTransactionSelectorFactory(
         new LineaTransactionSelectorFactory(
             blockchainService,
+            besuConfiguration,
             transactionSelectorConfiguration(),
             l1L2BridgeSharedConfiguration(),
             profitabilityConfiguration(),
diff --git a/sequencer/src/main/java/net/consensys/linea/sequencer/txselection/selectors/LineaTransactionSelector.java b/sequencer/src/main/java/net/consensys/linea/sequencer/txselection/selectors/LineaTransactionSelector.java
index d7bb598c..fbf23a2d 100644
--- a/sequencer/src/main/java/net/consensys/linea/sequencer/txselection/selectors/LineaTransactionSelector.java
+++ b/sequencer/src/main/java/net/consensys/linea/sequencer/txselection/selectors/LineaTransactionSelector.java
@@ -30,6 +30,7 @@
 import org.hyperledger.besu.datatypes.PendingTransaction;
 import org.hyperledger.besu.plugin.data.TransactionProcessingResult;
 import org.hyperledger.besu.plugin.data.TransactionSelectionResult;
+import org.hyperledger.besu.plugin.services.BesuConfiguration;
 import org.hyperledger.besu.plugin.services.BlockchainService;
 import org.hyperledger.besu.plugin.services.tracer.BlockAwareOperationTracer;
 import org.hyperledger.besu.plugin.services.txselection.PluginTransactionSelector;
@@ -41,15 +42,18 @@ public class LineaTransactionSelector implements PluginTransactionSelector {
 
   private TraceLineLimitTransactionSelector traceLineLimitTransactionSelector;
   private final List<PluginTransactionSelector> selectors;
+  private final BesuConfiguration besuConfiguration;
   private final Optional<URI> rejectedTxEndpoint;
 
   public LineaTransactionSelector(
       final BlockchainService blockchainService,
+      final BesuConfiguration besuConfiguration,
       final LineaTransactionSelectorConfiguration txSelectorConfiguration,
       final LineaL1L2BridgeSharedConfiguration l1L2BridgeConfiguration,
       final LineaProfitabilityConfiguration profitabilityConfiguration,
       final LineaTracerConfiguration tracerConfiguration,
       final Map<String, Integer> limitsMap) {
+    this.besuConfiguration = besuConfiguration;
     rejectedTxEndpoint = Optional.ofNullable(txSelectorConfiguration.rejectedTxEndpoint());
     selectors =
         createTransactionSelectors(
@@ -160,7 +164,11 @@ public void onTransactionNotSelected(
     rejectedTxEndpoint.ifPresent(
         uri ->
             notifyDiscardedTransactionAsync(
-                evaluationContext, transactionSelectionResult, Instant.now(), uri));
+                evaluationContext,
+                transactionSelectionResult,
+                Instant.now(),
+                uri,
+                this.besuConfiguration.getDataPath()));
   }
 
   /**
diff --git a/sequencer/src/main/java/net/consensys/linea/sequencer/txselection/selectors/RejectedTransactionNotifier.java b/sequencer/src/main/java/net/consensys/linea/sequencer/txselection/selectors/RejectedTransactionNotifier.java
index c5403c14..587781cb 100644
--- a/sequencer/src/main/java/net/consensys/linea/sequencer/txselection/selectors/RejectedTransactionNotifier.java
+++ b/sequencer/src/main/java/net/consensys/linea/sequencer/txselection/selectors/RejectedTransactionNotifier.java
@@ -15,6 +15,7 @@
 package net.consensys.linea.sequencer.txselection.selectors;
 
 import java.net.URI;
+import java.nio.file.Path;
 import java.time.Instant;
 
 import com.google.gson.JsonObject;
@@ -54,7 +55,8 @@ static void notifyDiscardedTransactionAsync(
       final TransactionEvaluationContext<? extends PendingTransaction> evaluationContext,
       final TransactionSelectionResult transactionSelectionResult,
       final Instant timestamp,
-      final URI rejectedTxEndpoint) {
+      final URI rejectedTxEndpoint,
+      final Path besuDataPath) {
     if (!transactionSelectionResult.discard()) {
       return;
     }

From 6fb16d651e8a333bd1a70a0e53f45874fd8daeda Mon Sep 17 00:00:00 2001
From: Usman Saleem <usman@usmans.info>
Date: Tue, 10 Sep 2024 16:23:55 +1000
Subject: [PATCH 11/26] Adding compileOnly okhttp dependency

---
 gradle/dependency-management.gradle           |   2 +
 sequencer/build.gradle                        |   2 +
 .../linea/jsonrpc/JsonRpcManager.java         | 185 +++++++++---------
 .../linea/jsonrpc/JsonRpcRequestBuilder.java  |  57 +++++-
 .../LineaTransactionSelectorFactory.java      |  15 +-
 .../LineaTransactionSelectorPlugin.java       |  23 ++-
 .../selectors/LineaTransactionSelector.java   |  36 ++--
 7 files changed, 194 insertions(+), 126 deletions(-)

diff --git a/gradle/dependency-management.gradle b/gradle/dependency-management.gradle
index f4401380..2891965b 100644
--- a/gradle/dependency-management.gradle
+++ b/gradle/dependency-management.gradle
@@ -104,6 +104,8 @@ dependencyManagement {
       entry 'picocli-codegen'
     }
 
+    dependency 'com.squareup.okhttp3:okhttp:4.12.0'
+
     dependencySet(group: 'io.tmio', version: '2.4.2') {
       entry 'tuweni-bytes'
       entry 'tuweni-net'
diff --git a/sequencer/build.gradle b/sequencer/build.gradle
index b503fe05..782b9938 100644
--- a/sequencer/build.gradle
+++ b/sequencer/build.gradle
@@ -47,6 +47,8 @@ dependencies {
 
   compileOnly 'io.vertx:vertx-core'
 
+  compileOnly 'com.squareup.okhttp3:okhttp'
+
   implementation project(":native:compress")
 
   implementation 'com.fasterxml.jackson.core:jackson-databind'
diff --git a/sequencer/src/main/java/net/consensys/linea/jsonrpc/JsonRpcManager.java b/sequencer/src/main/java/net/consensys/linea/jsonrpc/JsonRpcManager.java
index f69da6a6..bbd541ec 100644
--- a/sequencer/src/main/java/net/consensys/linea/jsonrpc/JsonRpcManager.java
+++ b/sequencer/src/main/java/net/consensys/linea/jsonrpc/JsonRpcManager.java
@@ -15,8 +15,6 @@
 
 package net.consensys.linea.jsonrpc;
 
-import lombok.extern.slf4j.Slf4j;
-
 import java.io.IOException;
 import java.net.URI;
 import java.nio.file.DirectoryStream;
@@ -27,112 +25,115 @@
 import java.util.concurrent.ScheduledExecutorService;
 import java.util.concurrent.TimeUnit;
 
-/**
- * This class is responsible for managing JSON-RPC requests for reporting rejected transactions
- */
+import lombok.extern.slf4j.Slf4j;
+
+/** This class is responsible for managing JSON-RPC requests for reporting rejected transactions */
 @Slf4j
 public class JsonRpcManager {
-    private static final int MAX_THREADS = Math.min(32, Runtime.getRuntime().availableProcessors() * 2);
-    private static final long MAX_RETRY_DURATION = TimeUnit.HOURS.toMillis(2);
+  private static final int MAX_THREADS =
+      Math.min(32, Runtime.getRuntime().availableProcessors() * 2);
+  private static final long MAX_RETRY_DURATION = TimeUnit.HOURS.toMillis(2);
 
-    private final Path jsonDirectory;
-    private final URI rejectedTxEndpoint;
-    private final ExecutorService executorService;
-    private final ScheduledExecutorService schedulerService;
+  private final Path jsonDirectory;
+  private final URI rejectedTxEndpoint;
+  private final ExecutorService executorService;
+  private final ScheduledExecutorService schedulerService;
 
-    /**
-     * Creates a new JSON-RPC manager.
-     * @param jsonDirectory The directory to store and load JSON files containing json-rpc calls
-     * @param rejectedTxEndpoint The endpoint to send rejected transactions to
-     */
-    public JsonRpcManager(final Path jsonDirectory, final URI rejectedTxEndpoint) {
-        this.jsonDirectory = jsonDirectory;
-        this.rejectedTxEndpoint = rejectedTxEndpoint;
-        this.executorService = Executors.newFixedThreadPool(MAX_THREADS);
-        this.schedulerService = Executors.newScheduledThreadPool(1);
-    }
+  /**
+   * Creates a new JSON-RPC manager.
+   *
+   * @param jsonDirectory The directory to store and load JSON files containing json-rpc calls
+   * @param rejectedTxEndpoint The endpoint to send rejected transactions to
+   */
+  public JsonRpcManager(final Path jsonDirectory, final URI rejectedTxEndpoint) {
+    this.jsonDirectory = jsonDirectory;
+    this.rejectedTxEndpoint = rejectedTxEndpoint;
+    this.executorService = Executors.newFixedThreadPool(MAX_THREADS);
+    this.schedulerService = Executors.newScheduledThreadPool(1);
+  }
 
-    /**
-     * Load existing JSON-RPC and submit them.
-     */
-    public void start() {
-        loadExistingJsonFiles();
-    }
+  /** Load existing JSON-RPC and submit them. */
+  public JsonRpcManager start() {
+    loadExistingJsonFiles();
+    return this;
+  }
 
-    /**
-     * Shuts down the executor service and scheduler service.
-     */
-    public void shutdown() {
-        executorService.shutdown();
-        schedulerService.shutdown();
-    }
+  /** Shuts down the executor service and scheduler service. */
+  public void shutdown() {
+    executorService.shutdown();
+    schedulerService.shutdown();
+  }
 
-    /**
-     * Submits a new JSON-RPC call.
-     * @param jsonContent The JSON content to submit
-     */
-    public void submitNewJsonRpcCall(final String jsonContent) {
-        try {
-            final Path jsonFile = saveJsonToFile(jsonContent);
-            submitJsonRpcCall(jsonFile);
-        } catch (final IOException e) {
-            log.error("Failed to save JSON content", e);
-        }
+  /**
+   * Submits a new JSON-RPC call.
+   *
+   * @param jsonContent The JSON content to submit
+   */
+  public void submitNewJsonRpcCall(final String jsonContent) {
+    try {
+      final Path jsonFile = saveJsonToFile(jsonContent);
+      submitJsonRpcCall(jsonFile);
+    } catch (final IOException e) {
+      log.error("Failed to save JSON content", e);
     }
+  }
 
-    private void loadExistingJsonFiles() {
-        try (final DirectoryStream<Path> stream = Files.newDirectoryStream(jsonDirectory, "rpc_*.json")) {
-            for (Path path : stream) {
-                submitJsonRpcCall(path);
-            }
-        } catch (IOException e) {
-            log.error("Failed to load existing JSON files", e);
-        }
+  private void loadExistingJsonFiles() {
+    try (final DirectoryStream<Path> stream =
+        Files.newDirectoryStream(jsonDirectory, "rpc_*.json")) {
+      for (Path path : stream) {
+        submitJsonRpcCall(path);
+      }
+    } catch (IOException e) {
+      log.error("Failed to load existing JSON files", e);
     }
+  }
 
-    private void submitJsonRpcCall(final Path jsonFile) {
-        executorService.submit(() -> {
-            if (!Files.exists(jsonFile)) {
-                log.debug("json-rpc file no longer exists, skipping processing: {}", jsonFile);
-                return;
-            }
-            try {
-                final String jsonContent = new String(Files.readAllBytes(jsonFile));
-                final boolean success = sendJsonRpcCall(jsonContent);
-                if (success) {
-                    Files.deleteIfExists(jsonFile);
-                } else {
-                    log.warn("Failed to send JSON-RPC call to {}, retrying: {}", rejectedTxEndpoint, jsonFile);
-                    scheduleRetry(jsonFile, System.currentTimeMillis(), 1000);
-                }
-            } catch (final IOException e) {
-                log.error("Failed to process json-rpc file: {}", jsonFile, e);
+  private void submitJsonRpcCall(final Path jsonFile) {
+    executorService.submit(
+        () -> {
+          if (!Files.exists(jsonFile)) {
+            log.debug("json-rpc file no longer exists, skipping processing: {}", jsonFile);
+            return;
+          }
+          try {
+            final String jsonContent = new String(Files.readAllBytes(jsonFile));
+            final boolean success = sendJsonRpcCall(jsonContent);
+            if (success) {
+              Files.deleteIfExists(jsonFile);
+            } else {
+              log.warn(
+                  "Failed to send JSON-RPC call to {}, retrying: {}", rejectedTxEndpoint, jsonFile);
+              scheduleRetry(jsonFile, System.currentTimeMillis(), 1000);
             }
+          } catch (final IOException e) {
+            log.error("Failed to process json-rpc file: {}", jsonFile, e);
+          }
         });
-    }
+  }
 
-    private void scheduleRetry(final Path jsonFile, final long startTime, final long delay) {
-        // check if we're still within the maximum retry duration
-        if (System.currentTimeMillis() - startTime < MAX_RETRY_DURATION) {
-            // schedule a retry
-            schedulerService.schedule(() -> submitJsonRpcCall(jsonFile), delay, TimeUnit.MILLISECONDS);
+  private void scheduleRetry(final Path jsonFile, final long startTime, final long delay) {
+    // check if we're still within the maximum retry duration
+    if (System.currentTimeMillis() - startTime < MAX_RETRY_DURATION) {
+      // schedule a retry
+      schedulerService.schedule(() -> submitJsonRpcCall(jsonFile), delay, TimeUnit.MILLISECONDS);
 
-            // exponential backoff with a maximum delay of 1 minute
-            long nextDelay = Math.min(delay * 2, TimeUnit.MINUTES.toMillis(1));
-            scheduleRetry(jsonFile, startTime, nextDelay);
-        }
+      // exponential backoff with a maximum delay of 1 minute
+      long nextDelay = Math.min(delay * 2, TimeUnit.MINUTES.toMillis(1));
+      scheduleRetry(jsonFile, startTime, nextDelay);
     }
+  }
 
-    private boolean sendJsonRpcCall(final String jsonContent) {
-        // Implement your JSON-RPC call logic here
-        // Return true if successful, false otherwise
-        return false; // Placeholder
-    }
+  private boolean sendJsonRpcCall(final String jsonContent) {
+    // Implement your JSON-RPC call logic here
+    // Return true if successful, false otherwise
+    return false; // Placeholder
+  }
 
-    private Path saveJsonToFile(final String jsonContent) throws IOException {
-        final String fileName = "rpc_" + System.currentTimeMillis() + ".json";
-        final Path filePath = jsonDirectory.resolve(fileName);
-        Files.write(filePath, jsonContent.getBytes());
-        return filePath;
-    }
+  private Path saveJsonToFile(final String jsonContent) throws IOException {
+    final String fileName = "rpc_" + System.currentTimeMillis() + ".json";
+    final Path filePath = jsonDirectory.resolve(fileName);
+    Files.write(filePath, jsonContent.getBytes());
+    return filePath;
+  }
 }
diff --git a/sequencer/src/main/java/net/consensys/linea/jsonrpc/JsonRpcRequestBuilder.java b/sequencer/src/main/java/net/consensys/linea/jsonrpc/JsonRpcRequestBuilder.java
index f047c701..d6cd0abd 100644
--- a/sequencer/src/main/java/net/consensys/linea/jsonrpc/JsonRpcRequestBuilder.java
+++ b/sequencer/src/main/java/net/consensys/linea/jsonrpc/JsonRpcRequestBuilder.java
@@ -15,15 +15,64 @@
 
 package net.consensys.linea.jsonrpc;
 
+import java.time.Instant;
+
 import com.google.gson.JsonObject;
+import org.hyperledger.besu.datatypes.PendingTransaction;
+import org.hyperledger.besu.plugin.data.ProcessableBlockHeader;
+import org.hyperledger.besu.plugin.data.TransactionSelectionResult;
+import org.hyperledger.besu.plugin.services.txselection.TransactionEvaluationContext;
 
+/** Helper class to build JSON-RPC requests for rejected transactions. */
 public class JsonRpcRequestBuilder {
-  public static String buildRequest(final String method, final JsonObject params, int id) {
-    JsonObject request = new JsonObject();
+  /**
+   *
+   *
+   * <pre>
+   * {@code linea_saveRejectedTransactionV1({
+   *         "txRejectionStage": "SEQUENCER/RPC/P2P",
+   *         "timestamp": "2024-08-22T09:18:51Z", # ISO8601 UTC+0 when tx was rejected by node, usefull if P2P edge node.
+   *         "blockNumber": "base 10 number",
+   *         "transactionRLP": "transaction as the user sent in eth_sendRawTransaction",
+   *         "reason": "Transaction line count for module ADD=402 is above the limit 70"
+   *         "overflows": [{
+   *           "module": "ADD",
+   *           "count": 402,
+   *           "limit": 70
+   *         }, {
+   *           "module": "MUL",
+   *           "count": 587,
+   *           "limit": 400
+   *         }]
+   *     })
+   * }
+   * </pre>
+   */
+  public static String buildRejectedTxRequest(
+      final TransactionEvaluationContext<? extends PendingTransaction> evaluationContext,
+      final TransactionSelectionResult transactionSelectionResult,
+      final Instant timestamp) {
+    //    if (!transactionSelectionResult.discard()) {
+    //      return;
+    //    }
+
+    final PendingTransaction pendingTransaction = evaluationContext.getPendingTransaction();
+    final ProcessableBlockHeader pendingBlockHeader = evaluationContext.getPendingBlockHeader();
+
+    // Build JSON-RPC request
+    final JsonObject params = new JsonObject();
+    params.addProperty("txRejectionStage", "SEQUENCER");
+    params.addProperty("timestamp", timestamp.toString());
+    params.addProperty("blockNumber", pendingBlockHeader.getNumber());
+    params.addProperty(
+        "transactionRLP", pendingTransaction.getTransaction().encoded().toHexString());
+    params.addProperty("reasonMessage", transactionSelectionResult.maybeInvalidReason().orElse(""));
+
+    final JsonObject request = new JsonObject();
     request.addProperty("jsonrpc", "2.0");
-    request.addProperty("method", method);
+    request.addProperty("method", "linea_saveRejectedTransactionV1");
     request.add("params", params);
-    request.addProperty("id", id);
+    request.addProperty("id", 1);
     return request.toString();
   }
 }
diff --git a/sequencer/src/main/java/net/consensys/linea/sequencer/txselection/LineaTransactionSelectorFactory.java b/sequencer/src/main/java/net/consensys/linea/sequencer/txselection/LineaTransactionSelectorFactory.java
index d325f31c..0d5fc6ff 100644
--- a/sequencer/src/main/java/net/consensys/linea/sequencer/txselection/LineaTransactionSelectorFactory.java
+++ b/sequencer/src/main/java/net/consensys/linea/sequencer/txselection/LineaTransactionSelectorFactory.java
@@ -16,13 +16,14 @@
 package net.consensys.linea.sequencer.txselection;
 
 import java.util.Map;
+import java.util.Optional;
 
 import net.consensys.linea.config.LineaProfitabilityConfiguration;
 import net.consensys.linea.config.LineaTracerConfiguration;
 import net.consensys.linea.config.LineaTransactionSelectorConfiguration;
+import net.consensys.linea.jsonrpc.JsonRpcManager;
 import net.consensys.linea.plugins.config.LineaL1L2BridgeSharedConfiguration;
 import net.consensys.linea.sequencer.txselection.selectors.LineaTransactionSelector;
-import org.hyperledger.besu.plugin.services.BesuConfiguration;
 import org.hyperledger.besu.plugin.services.BlockchainService;
 import org.hyperledger.besu.plugin.services.txselection.PluginTransactionSelector;
 import org.hyperledger.besu.plugin.services.txselection.PluginTransactionSelectorFactory;
@@ -33,7 +34,7 @@
  */
 public class LineaTransactionSelectorFactory implements PluginTransactionSelectorFactory {
   private final BlockchainService blockchainService;
-  private final BesuConfiguration besuConfiguration;
+  private final Optional<JsonRpcManager> rejectedTxJsonRpcManager;
   private final LineaTransactionSelectorConfiguration txSelectorConfiguration;
   private final LineaL1L2BridgeSharedConfiguration l1L2BridgeConfiguration;
   private final LineaProfitabilityConfiguration profitabilityConfiguration;
@@ -43,30 +44,30 @@ public class LineaTransactionSelectorFactory implements PluginTransactionSelecto
 
   public LineaTransactionSelectorFactory(
       final BlockchainService blockchainService,
-      final BesuConfiguration besuConfiguration,
       final LineaTransactionSelectorConfiguration txSelectorConfiguration,
       final LineaL1L2BridgeSharedConfiguration l1L2BridgeConfiguration,
       final LineaProfitabilityConfiguration profitabilityConfiguration,
       final LineaTracerConfiguration tracerConfiguration,
-      final Map<String, Integer> limitsMap) {
+      final Map<String, Integer> limitsMap,
+      final Optional<JsonRpcManager> rejectedTxJsonRpcManager) {
     this.blockchainService = blockchainService;
-    this.besuConfiguration = besuConfiguration;
     this.txSelectorConfiguration = txSelectorConfiguration;
     this.l1L2BridgeConfiguration = l1L2BridgeConfiguration;
     this.profitabilityConfiguration = profitabilityConfiguration;
     this.tracerConfiguration = tracerConfiguration;
     this.limitsMap = limitsMap;
+    this.rejectedTxJsonRpcManager = rejectedTxJsonRpcManager;
   }
 
   @Override
   public PluginTransactionSelector create() {
     return new LineaTransactionSelector(
         blockchainService,
-        besuConfiguration,
         txSelectorConfiguration,
         l1L2BridgeConfiguration,
         profitabilityConfiguration,
         tracerConfiguration,
-        limitsMap);
+        limitsMap,
+        rejectedTxJsonRpcManager);
   }
 }
diff --git a/sequencer/src/main/java/net/consensys/linea/sequencer/txselection/LineaTransactionSelectorPlugin.java b/sequencer/src/main/java/net/consensys/linea/sequencer/txselection/LineaTransactionSelectorPlugin.java
index d142995c..1bf48bc5 100644
--- a/sequencer/src/main/java/net/consensys/linea/sequencer/txselection/LineaTransactionSelectorPlugin.java
+++ b/sequencer/src/main/java/net/consensys/linea/sequencer/txselection/LineaTransactionSelectorPlugin.java
@@ -22,6 +22,8 @@
 import com.google.auto.service.AutoService;
 import lombok.extern.slf4j.Slf4j;
 import net.consensys.linea.AbstractLineaRequiredPlugin;
+import net.consensys.linea.config.LineaTransactionSelectorConfiguration;
+import net.consensys.linea.jsonrpc.JsonRpcManager;
 import org.hyperledger.besu.plugin.BesuContext;
 import org.hyperledger.besu.plugin.BesuPlugin;
 import org.hyperledger.besu.plugin.services.BesuConfiguration;
@@ -39,6 +41,7 @@ public class LineaTransactionSelectorPlugin extends AbstractLineaRequiredPlugin
   public static final String NAME = "linea";
   private TransactionSelectionService transactionSelectionService;
   private BlockchainService blockchainService;
+  private Optional<JsonRpcManager> rejectedTxJsonRpcManager = Optional.empty();
   private BesuConfiguration besuConfiguration;
 
   @Override
@@ -76,14 +79,28 @@ public void doRegister(final BesuContext context) {
   @Override
   public void start() {
     super.start();
+    final LineaTransactionSelectorConfiguration txSelectorConfiguration =
+        transactionSelectorConfiguration();
+    rejectedTxJsonRpcManager =
+        Optional.ofNullable(txSelectorConfiguration.rejectedTxEndpoint())
+            .map(
+                endpoint ->
+                    new JsonRpcManager(
+                        besuConfiguration.getDataPath().resolve("rej_tx_rpc"), endpoint));
     transactionSelectionService.registerPluginTransactionSelectorFactory(
         new LineaTransactionSelectorFactory(
             blockchainService,
-            besuConfiguration,
-            transactionSelectorConfiguration(),
+            txSelectorConfiguration,
             l1L2BridgeSharedConfiguration(),
             profitabilityConfiguration(),
             tracerConfiguration(),
-            createLimitModules(tracerConfiguration())));
+            createLimitModules(tracerConfiguration()),
+            rejectedTxJsonRpcManager));
+  }
+
+  @Override
+  public void stop() {
+    super.stop();
+    rejectedTxJsonRpcManager.ifPresent(JsonRpcManager::shutdown);
   }
 }
diff --git a/sequencer/src/main/java/net/consensys/linea/sequencer/txselection/selectors/LineaTransactionSelector.java b/sequencer/src/main/java/net/consensys/linea/sequencer/txselection/selectors/LineaTransactionSelector.java
index fbf23a2d..d532501e 100644
--- a/sequencer/src/main/java/net/consensys/linea/sequencer/txselection/selectors/LineaTransactionSelector.java
+++ b/sequencer/src/main/java/net/consensys/linea/sequencer/txselection/selectors/LineaTransactionSelector.java
@@ -14,9 +14,6 @@
  */
 package net.consensys.linea.sequencer.txselection.selectors;
 
-import static net.consensys.linea.sequencer.txselection.selectors.RejectedTransactionNotifier.notifyDiscardedTransactionAsync;
-
-import java.net.URI;
 import java.time.Instant;
 import java.util.List;
 import java.util.Map;
@@ -26,11 +23,12 @@
 import net.consensys.linea.config.LineaProfitabilityConfiguration;
 import net.consensys.linea.config.LineaTracerConfiguration;
 import net.consensys.linea.config.LineaTransactionSelectorConfiguration;
+import net.consensys.linea.jsonrpc.JsonRpcManager;
+import net.consensys.linea.jsonrpc.JsonRpcRequestBuilder;
 import net.consensys.linea.plugins.config.LineaL1L2BridgeSharedConfiguration;
 import org.hyperledger.besu.datatypes.PendingTransaction;
 import org.hyperledger.besu.plugin.data.TransactionProcessingResult;
 import org.hyperledger.besu.plugin.data.TransactionSelectionResult;
-import org.hyperledger.besu.plugin.services.BesuConfiguration;
 import org.hyperledger.besu.plugin.services.BlockchainService;
 import org.hyperledger.besu.plugin.services.tracer.BlockAwareOperationTracer;
 import org.hyperledger.besu.plugin.services.txselection.PluginTransactionSelector;
@@ -42,19 +40,17 @@ public class LineaTransactionSelector implements PluginTransactionSelector {
 
   private TraceLineLimitTransactionSelector traceLineLimitTransactionSelector;
   private final List<PluginTransactionSelector> selectors;
-  private final BesuConfiguration besuConfiguration;
-  private final Optional<URI> rejectedTxEndpoint;
+  private final Optional<JsonRpcManager> rejectedTxJsonRpcManager;
 
   public LineaTransactionSelector(
       final BlockchainService blockchainService,
-      final BesuConfiguration besuConfiguration,
       final LineaTransactionSelectorConfiguration txSelectorConfiguration,
       final LineaL1L2BridgeSharedConfiguration l1L2BridgeConfiguration,
       final LineaProfitabilityConfiguration profitabilityConfiguration,
       final LineaTracerConfiguration tracerConfiguration,
-      final Map<String, Integer> limitsMap) {
-    this.besuConfiguration = besuConfiguration;
-    rejectedTxEndpoint = Optional.ofNullable(txSelectorConfiguration.rejectedTxEndpoint());
+      final Map<String, Integer> limitsMap,
+      final Optional<JsonRpcManager> rejectedTxJsonRpcManager) {
+    this.rejectedTxJsonRpcManager = rejectedTxJsonRpcManager;
     selectors =
         createTransactionSelectors(
             blockchainService,
@@ -68,9 +64,9 @@ public LineaTransactionSelector(
   /**
    * Creates a list of selectors based on Linea configuration.
    *
-   * @param blockchainService
+   * @param blockchainService Blockchain service.
    * @param txSelectorConfiguration The configuration to use.
-   * @param profitabilityConfiguration
+   * @param profitabilityConfiguration The profitability configuration.
    * @param limitsMap The limits map.
    * @return A list of selectors.
    */
@@ -161,14 +157,14 @@ public void onTransactionNotSelected(
         selector ->
             selector.onTransactionNotSelected(evaluationContext, transactionSelectionResult));
 
-    rejectedTxEndpoint.ifPresent(
-        uri ->
-            notifyDiscardedTransactionAsync(
-                evaluationContext,
-                transactionSelectionResult,
-                Instant.now(),
-                uri,
-                this.besuConfiguration.getDataPath()));
+    rejectedTxJsonRpcManager.ifPresent(
+        jsonRpcManager -> {
+          if (transactionSelectionResult.discard()) {
+            jsonRpcManager.submitNewJsonRpcCall(
+                JsonRpcRequestBuilder.buildRejectedTxRequest(
+                    evaluationContext, transactionSelectionResult, Instant.now()));
+          }
+        });
   }
 
   /**

From 4af7d4a0694ae3aaca5ed0c918c8110e19d7edb7 Mon Sep 17 00:00:00 2001
From: Usman Saleem <usman@usmans.info>
Date: Tue, 10 Sep 2024 17:04:14 +1000
Subject: [PATCH 12/26] Updated JsonRPCManagerTests

---
 .../linea/jsonrpc/JsonRpcManager.java         | 84 ++++++++++++++++---
 .../LineaTransactionSelectorPlugin.java       |  5 +-
 .../RejectedTransactionNotifier.java          | 82 ------------------
 .../JsonRpcManagerTest.java}                  | 68 +++++++--------
 .../TestTransactionEvaluationContext.java     |  3 +-
 5 files changed, 104 insertions(+), 138 deletions(-)
 delete mode 100644 sequencer/src/main/java/net/consensys/linea/sequencer/txselection/selectors/RejectedTransactionNotifier.java
 rename sequencer/src/test/java/net/consensys/linea/{sequencer/txselection/selectors/RejectedTransactionNotifierTest.java => jsonrpc/JsonRpcManagerTest.java} (57%)

diff --git a/sequencer/src/main/java/net/consensys/linea/jsonrpc/JsonRpcManager.java b/sequencer/src/main/java/net/consensys/linea/jsonrpc/JsonRpcManager.java
index bbd541ec..b01db026 100644
--- a/sequencer/src/main/java/net/consensys/linea/jsonrpc/JsonRpcManager.java
+++ b/sequencer/src/main/java/net/consensys/linea/jsonrpc/JsonRpcManager.java
@@ -16,6 +16,7 @@
 package net.consensys.linea.jsonrpc;
 
 import java.io.IOException;
+import java.io.UncheckedIOException;
 import java.net.URI;
 import java.nio.file.DirectoryStream;
 import java.nio.file.Files;
@@ -25,7 +26,14 @@
 import java.util.concurrent.ScheduledExecutorService;
 import java.util.concurrent.TimeUnit;
 
+import com.fasterxml.jackson.databind.JsonNode;
+import com.fasterxml.jackson.databind.ObjectMapper;
 import lombok.extern.slf4j.Slf4j;
+import okhttp3.MediaType;
+import okhttp3.OkHttpClient;
+import okhttp3.Request;
+import okhttp3.RequestBody;
+import okhttp3.Response;
 
 /** This class is responsible for managing JSON-RPC requests for reporting rejected transactions */
 @Slf4j
@@ -33,8 +41,12 @@ public class JsonRpcManager {
   private static final int MAX_THREADS =
       Math.min(32, Runtime.getRuntime().availableProcessors() * 2);
   private static final long MAX_RETRY_DURATION = TimeUnit.HOURS.toMillis(2);
+  private static final MediaType JSON = MediaType.get("application/json; charset=utf-8");
 
-  private final Path jsonDirectory;
+  private final OkHttpClient client = new OkHttpClient();
+  private final ObjectMapper objectMapper = new ObjectMapper();
+
+  private final Path rejTxRpcDirectory;
   private final URI rejectedTxEndpoint;
   private final ExecutorService executorService;
   private final ScheduledExecutorService schedulerService;
@@ -42,11 +54,12 @@ public class JsonRpcManager {
   /**
    * Creates a new JSON-RPC manager.
    *
-   * @param jsonDirectory The directory to store and load JSON files containing json-rpc calls
+   * @param besuDataDir Path to Besu data directory. The json-rpc files will be stored here under
+   *     rej-tx-rpc subdirectory.
    * @param rejectedTxEndpoint The endpoint to send rejected transactions to
    */
-  public JsonRpcManager(final Path jsonDirectory, final URI rejectedTxEndpoint) {
-    this.jsonDirectory = jsonDirectory;
+  public JsonRpcManager(final Path besuDataDir, final URI rejectedTxEndpoint) {
+    this.rejTxRpcDirectory = besuDataDir.resolve("rej_tx_rpc");
     this.rejectedTxEndpoint = rejectedTxEndpoint;
     this.executorService = Executors.newFixedThreadPool(MAX_THREADS);
     this.schedulerService = Executors.newScheduledThreadPool(1);
@@ -54,8 +67,17 @@ public JsonRpcManager(final Path jsonDirectory, final URI rejectedTxEndpoint) {
 
   /** Load existing JSON-RPC and submit them. */
   public JsonRpcManager start() {
-    loadExistingJsonFiles();
-    return this;
+    try {
+      // Create the rej-tx-rpc directory if it doesn't exist
+      Files.createDirectories(rejTxRpcDirectory);
+
+      // Load existing JSON files
+      loadExistingJsonFiles();
+      return this;
+    } catch (IOException e) {
+      log.error("Failed to create or access rej-tx-rpc directory", e);
+      throw new UncheckedIOException(e);
+    }
   }
 
   /** Shuts down the executor service and scheduler service. */
@@ -80,11 +102,11 @@ public void submitNewJsonRpcCall(final String jsonContent) {
 
   private void loadExistingJsonFiles() {
     try (final DirectoryStream<Path> stream =
-        Files.newDirectoryStream(jsonDirectory, "rpc_*.json")) {
-      for (Path path : stream) {
+        Files.newDirectoryStream(rejTxRpcDirectory, "rpc_*.json")) {
+      for (final Path path : stream) {
         submitJsonRpcCall(path);
       }
-    } catch (IOException e) {
+    } catch (final IOException e) {
       log.error("Failed to load existing JSON files", e);
     }
   }
@@ -125,14 +147,50 @@ private void scheduleRetry(final Path jsonFile, final long startTime, final long
   }
 
   private boolean sendJsonRpcCall(final String jsonContent) {
-    // Implement your JSON-RPC call logic here
-    // Return true if successful, false otherwise
-    return false; // Placeholder
+    final RequestBody body = RequestBody.create(jsonContent, JSON);
+    final Request request =
+        new Request.Builder().url(rejectedTxEndpoint.toString()).post(body).build();
+
+    try (final Response response = client.newCall(request).execute()) {
+      if (!response.isSuccessful()) {
+        log.error("Unexpected response code from rejected-tx endpoint: {}", response.code());
+        return false;
+      }
+
+      // process the response body here ...
+      final String responseBody = response.body() != null ? response.body().string() : null;
+      if (responseBody == null) {
+        log.error("Unexpected empty response body from rejected-tx endpoint");
+        return false;
+      }
+
+      final JsonNode jsonNode = objectMapper.readTree(responseBody);
+      if (jsonNode == null) {
+        log.error("Failed to parse JSON response from rejected-tx endpoint: {}", responseBody);
+        return false;
+      }
+      if (jsonNode.has("error")) {
+        log.error("Error response from rejected-tx endpoint: {}", jsonNode.get("error"));
+        return false;
+      }
+      // Check for result
+      if (jsonNode.has("result")) {
+        String status = jsonNode.get("result").get("status").asText();
+        log.debug("Rejected-tx JSON-RPC call successful. Status: {}", status);
+        return true;
+      }
+
+      log.warn("Unexpected rejected-tx JSON-RPC response format: {}", responseBody);
+      return false;
+    } catch (final IOException e) {
+      log.error("Failed to send JSON-RPC call to rejected-tx endpoint {}", rejectedTxEndpoint, e);
+      return false;
+    }
   }
 
   private Path saveJsonToFile(final String jsonContent) throws IOException {
     final String fileName = "rpc_" + System.currentTimeMillis() + ".json";
-    final Path filePath = jsonDirectory.resolve(fileName);
+    final Path filePath = rejTxRpcDirectory.resolve(fileName);
     Files.write(filePath, jsonContent.getBytes());
     return filePath;
   }
diff --git a/sequencer/src/main/java/net/consensys/linea/sequencer/txselection/LineaTransactionSelectorPlugin.java b/sequencer/src/main/java/net/consensys/linea/sequencer/txselection/LineaTransactionSelectorPlugin.java
index 1bf48bc5..1ca96d48 100644
--- a/sequencer/src/main/java/net/consensys/linea/sequencer/txselection/LineaTransactionSelectorPlugin.java
+++ b/sequencer/src/main/java/net/consensys/linea/sequencer/txselection/LineaTransactionSelectorPlugin.java
@@ -83,10 +83,7 @@ public void start() {
         transactionSelectorConfiguration();
     rejectedTxJsonRpcManager =
         Optional.ofNullable(txSelectorConfiguration.rejectedTxEndpoint())
-            .map(
-                endpoint ->
-                    new JsonRpcManager(
-                        besuConfiguration.getDataPath().resolve("rej_tx_rpc"), endpoint));
+            .map(endpoint -> new JsonRpcManager(besuConfiguration.getDataPath(), endpoint).start());
     transactionSelectionService.registerPluginTransactionSelectorFactory(
         new LineaTransactionSelectorFactory(
             blockchainService,
diff --git a/sequencer/src/main/java/net/consensys/linea/sequencer/txselection/selectors/RejectedTransactionNotifier.java b/sequencer/src/main/java/net/consensys/linea/sequencer/txselection/selectors/RejectedTransactionNotifier.java
deleted file mode 100644
index 587781cb..00000000
--- a/sequencer/src/main/java/net/consensys/linea/sequencer/txselection/selectors/RejectedTransactionNotifier.java
+++ /dev/null
@@ -1,82 +0,0 @@
-/*
- * Copyright Consensys Software Inc.
- *
- * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with
- * the License. You may obtain a copy of the License at
- *
- * http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on
- * an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the
- * specific language governing permissions and limitations under the License.
- *
- * SPDX-License-Identifier: Apache-2.0
- */
-package net.consensys.linea.sequencer.txselection.selectors;
-
-import java.net.URI;
-import java.nio.file.Path;
-import java.time.Instant;
-
-import com.google.gson.JsonObject;
-import net.consensys.linea.jsonrpc.JsonRpcClient;
-import net.consensys.linea.jsonrpc.JsonRpcRequestBuilder;
-import org.hyperledger.besu.datatypes.PendingTransaction;
-import org.hyperledger.besu.plugin.data.ProcessableBlockHeader;
-import org.hyperledger.besu.plugin.data.TransactionSelectionResult;
-import org.hyperledger.besu.plugin.services.txselection.TransactionEvaluationContext;
-
-/**
- *
- *
- * <pre>
- * {@code linea_saveRejectedTransactionV1({
- *         "txRejectionStage": "SEQUENCER/RPC/P2P",
- *         "timestamp": "2024-08-22T09:18:51Z", # ISO8601 UTC+0 when tx was rejected by node, usefull if P2P edge node.
- *         "blockNumber": "base 10 number",
- *         "transactionRLP": "transaction as the user sent in eth_sendRawTransaction",
- *         "reason": "Transaction line count for module ADD=402 is above the limit 70"
- *         "overflows": [{
- *           "module": "ADD",
- *           "count": 402,
- *           "limit": 70
- *         }, {
- *           "module": "MUL",
- *           "count": 587,
- *           "limit": 400
- *         }]
- *     })
- * }
- * </pre>
- */
-public class RejectedTransactionNotifier {
-
-  static void notifyDiscardedTransactionAsync(
-      final TransactionEvaluationContext<? extends PendingTransaction> evaluationContext,
-      final TransactionSelectionResult transactionSelectionResult,
-      final Instant timestamp,
-      final URI rejectedTxEndpoint,
-      final Path besuDataPath) {
-    if (!transactionSelectionResult.discard()) {
-      return;
-    }
-
-    final PendingTransaction pendingTransaction = evaluationContext.getPendingTransaction();
-    final ProcessableBlockHeader pendingBlockHeader = evaluationContext.getPendingBlockHeader();
-
-    // Build JSON-RPC request
-    final JsonObject params = new JsonObject();
-    params.addProperty("txRejectionStage", "SEQUENCER");
-    params.addProperty("timestamp", timestamp.toString());
-    params.addProperty("blockNumber", pendingBlockHeader.getNumber());
-    params.addProperty(
-        "transactionRLP", pendingTransaction.getTransaction().encoded().toHexString());
-    params.addProperty("reasonMessage", transactionSelectionResult.maybeInvalidReason().orElse(""));
-
-    final String jsonRequest =
-        JsonRpcRequestBuilder.buildRequest("linea_saveRejectedTransactionV1", params, 1);
-
-    // Send JSON-RPC request with retries in a new thread
-    JsonRpcClient.sendRequestWithRetries(rejectedTxEndpoint, jsonRequest);
-  }
-}
diff --git a/sequencer/src/test/java/net/consensys/linea/sequencer/txselection/selectors/RejectedTransactionNotifierTest.java b/sequencer/src/test/java/net/consensys/linea/jsonrpc/JsonRpcManagerTest.java
similarity index 57%
rename from sequencer/src/test/java/net/consensys/linea/sequencer/txselection/selectors/RejectedTransactionNotifierTest.java
rename to sequencer/src/test/java/net/consensys/linea/jsonrpc/JsonRpcManagerTest.java
index cae53913..43bae5b8 100644
--- a/sequencer/src/test/java/net/consensys/linea/sequencer/txselection/selectors/RejectedTransactionNotifierTest.java
+++ b/sequencer/src/test/java/net/consensys/linea/jsonrpc/JsonRpcManagerTest.java
@@ -1,19 +1,4 @@
-/*
- * Copyright Consensys Software Inc.
- *
- * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with
- * the License. You may obtain a copy of the License at
- *
- * http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on
- * an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the
- * specific language governing permissions and limitations under the License.
- *
- * SPDX-License-Identifier: Apache-2.0
- */
-
-package net.consensys.linea.sequencer.txselection.selectors;
+package net.consensys.linea.jsonrpc;
 
 import static com.github.tomakehurst.wiremock.client.WireMock.aResponse;
 import static com.github.tomakehurst.wiremock.client.WireMock.equalToJson;
@@ -25,31 +10,48 @@
 import static org.mockito.Mockito.when;
 
 import java.net.URI;
+import java.nio.file.Path;
 import java.time.Instant;
 
 import com.github.tomakehurst.wiremock.junit5.WireMockRuntimeInfo;
 import com.github.tomakehurst.wiremock.junit5.WireMockTest;
-import com.google.gson.JsonObject;
-import net.consensys.linea.jsonrpc.JsonRpcRequestBuilder;
+import net.consensys.linea.sequencer.txselection.selectors.TestTransactionEvaluationContext;
 import org.apache.tuweni.bytes.Bytes;
 import org.hyperledger.besu.datatypes.PendingTransaction;
 import org.hyperledger.besu.datatypes.Transaction;
 import org.hyperledger.besu.plugin.data.ProcessableBlockHeader;
 import org.hyperledger.besu.plugin.data.TransactionSelectionResult;
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.extension.ExtendWith;
+import org.junit.jupiter.api.io.TempDir;
 import org.mockito.Mock;
 import org.mockito.junit.jupiter.MockitoExtension;
 
 @WireMockTest
 @ExtendWith(MockitoExtension.class)
-class RejectedTransactionNotifierTest {
-  @Mock PendingTransaction pendingTransaction;
-  @Mock ProcessableBlockHeader pendingBlockHeader;
-  @Mock Transaction transaction;
+class JsonRpcManagerTest {
+  @TempDir private Path tempDataDir;
+  private JsonRpcManager jsonRpcManager;
+
+  @Mock private PendingTransaction pendingTransaction;
+  @Mock private ProcessableBlockHeader pendingBlockHeader;
+  @Mock private Transaction transaction;
+
+  @BeforeEach
+  void init(final WireMockRuntimeInfo wmInfo) {
+    jsonRpcManager = new JsonRpcManager(tempDataDir, URI.create(wmInfo.getHttpBaseUrl()));
+    jsonRpcManager.start();
+  }
+
+  @AfterEach
+  void cleanup() {
+    jsonRpcManager.shutdown();
+  }
 
   @Test
-  void droppedTxIsReported(final WireMockRuntimeInfo wmInfo) throws Exception {
+  void rejectedTxIsReported() throws InterruptedException {
     // mock stubbing
     when(pendingBlockHeader.getNumber()).thenReturn(1L);
     when(pendingTransaction.getTransaction()).thenReturn(transaction);
@@ -72,25 +74,15 @@ void droppedTxIsReported(final WireMockRuntimeInfo wmInfo) throws Exception {
     final TransactionSelectionResult result = TransactionSelectionResult.invalid("test");
     final Instant timestamp = Instant.now();
 
-    // call the method under test
-    RejectedTransactionNotifier.notifyDiscardedTransactionAsync(
-        context, result, timestamp, URI.create(wmInfo.getHttpBaseUrl()));
+    // method under test
+    final String jsonRpcCall =
+        JsonRpcRequestBuilder.buildRejectedTxRequest(context, result, timestamp);
+    jsonRpcManager.submitNewJsonRpcCall(jsonRpcCall);
 
     // sleep a bit to allow async processing
     Thread.sleep(1000);
 
-    // build expected json-rpc request
-    final JsonObject params = new JsonObject();
-    params.addProperty("txRejectionStage", "SEQUENCER");
-    params.addProperty("timestamp", timestamp.toString());
-    params.addProperty("blockNumber", 1);
-    params.addProperty("transactionRLP", randomEncodedBytes.toHexString());
-    params.addProperty("reasonMessage", "test");
-
-    final String jsonRequest =
-        JsonRpcRequestBuilder.buildRequest("linea_saveRejectedTransactionV1", params, 1);
-
     // assert that the expected json-rpc request was sent to WireMock
-    verify(postRequestedFor(urlEqualTo("/")).withRequestBody(equalToJson(jsonRequest)));
+    verify(postRequestedFor(urlEqualTo("/")).withRequestBody(equalToJson(jsonRpcCall)));
   }
 }
diff --git a/sequencer/src/test/java/net/consensys/linea/sequencer/txselection/selectors/TestTransactionEvaluationContext.java b/sequencer/src/test/java/net/consensys/linea/sequencer/txselection/selectors/TestTransactionEvaluationContext.java
index 4edce437..bc9a48ba 100644
--- a/sequencer/src/test/java/net/consensys/linea/sequencer/txselection/selectors/TestTransactionEvaluationContext.java
+++ b/sequencer/src/test/java/net/consensys/linea/sequencer/txselection/selectors/TestTransactionEvaluationContext.java
@@ -20,7 +20,8 @@
 import org.hyperledger.besu.plugin.data.ProcessableBlockHeader;
 import org.hyperledger.besu.plugin.services.txselection.TransactionEvaluationContext;
 
-class TestTransactionEvaluationContext implements TransactionEvaluationContext<PendingTransaction> {
+public class TestTransactionEvaluationContext
+    implements TransactionEvaluationContext<PendingTransaction> {
   private PendingTransaction pendingTransaction;
   private Wei transactionGasPrice;
   private Wei minGasPrice;

From 5dcf745b3991edbb7567ecc89b164d6b935c424d Mon Sep 17 00:00:00 2001
From: Usman Saleem <usman@usmans.info>
Date: Tue, 10 Sep 2024 17:31:36 +1000
Subject: [PATCH 13/26] Adding license header

---
 .../linea/jsonrpc/JsonRpcManagerTest.java         | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/sequencer/src/test/java/net/consensys/linea/jsonrpc/JsonRpcManagerTest.java b/sequencer/src/test/java/net/consensys/linea/jsonrpc/JsonRpcManagerTest.java
index 43bae5b8..ea4e7a2e 100644
--- a/sequencer/src/test/java/net/consensys/linea/jsonrpc/JsonRpcManagerTest.java
+++ b/sequencer/src/test/java/net/consensys/linea/jsonrpc/JsonRpcManagerTest.java
@@ -1,3 +1,18 @@
+/*
+ * Copyright Consensys Software Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on
+ * an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
 package net.consensys.linea.jsonrpc;
 
 import static com.github.tomakehurst.wiremock.client.WireMock.aResponse;

From 3eb843d0668c7bc9409747e30b5eb58ce7dc7252 Mon Sep 17 00:00:00 2001
From: Usman Saleem <usman@usmans.info>
Date: Tue, 10 Sep 2024 17:32:59 +1000
Subject: [PATCH 14/26] Removing initial implementation of json rpc client

---
 .../linea/jsonrpc/JsonRpcClient.java          | 83 -------------------
 1 file changed, 83 deletions(-)
 delete mode 100644 sequencer/src/main/java/net/consensys/linea/jsonrpc/JsonRpcClient.java

diff --git a/sequencer/src/main/java/net/consensys/linea/jsonrpc/JsonRpcClient.java b/sequencer/src/main/java/net/consensys/linea/jsonrpc/JsonRpcClient.java
deleted file mode 100644
index ef8f2c05..00000000
--- a/sequencer/src/main/java/net/consensys/linea/jsonrpc/JsonRpcClient.java
+++ /dev/null
@@ -1,83 +0,0 @@
-/*
- * Copyright Consensys Software Inc.
- *
- * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with
- * the License. You may obtain a copy of the License at
- *
- * http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on
- * an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the
- * specific language governing permissions and limitations under the License.
- *
- * SPDX-License-Identifier: Apache-2.0
- */
-
-package net.consensys.linea.jsonrpc;
-
-import java.io.IOException;
-import java.io.OutputStream;
-import java.net.HttpURLConnection;
-import java.net.URI;
-import java.net.URL;
-import java.nio.charset.StandardCharsets;
-import java.util.Scanner;
-import java.util.concurrent.Callable;
-import java.util.concurrent.ExecutorService;
-import java.util.concurrent.Executors;
-import java.util.concurrent.Future;
-
-public class JsonRpcClient {
-  private static final int MAX_RETRIES = 3;
-  private static final ExecutorService executorService = Executors.newCachedThreadPool();
-
-  public static String sendRequest(final URI endpoint, final String jsonInputString)
-      throws Exception {
-    HttpURLConnection conn = getHttpURLConnection(endpoint, jsonInputString);
-
-    int responseCode = conn.getResponseCode();
-    if (responseCode == HttpURLConnection.HTTP_OK) {
-      try (Scanner scanner = new Scanner(conn.getInputStream(), StandardCharsets.UTF_8)) {
-        return scanner.useDelimiter("\\A").next();
-      }
-    } else {
-      throw new RuntimeException("Failed : HTTP error code : " + responseCode);
-    }
-  }
-
-  private static HttpURLConnection getHttpURLConnection(
-      final URI endpoint, final String jsonInputString) throws IOException {
-    final URL url = endpoint.toURL();
-    final HttpURLConnection conn = (HttpURLConnection) url.openConnection();
-    conn.setRequestMethod("POST");
-    conn.setRequestProperty("Content-Type", "application/json; utf-8");
-    conn.setRequestProperty("Accept", "application/json");
-    conn.setDoOutput(true);
-
-    try (final OutputStream os = conn.getOutputStream()) {
-      final byte[] input = jsonInputString.getBytes(StandardCharsets.UTF_8);
-      os.write(input, 0, input.length);
-    }
-    return conn;
-  }
-
-  public static Future<String> sendRequestWithRetries(
-      final URI endpoint, final String jsonInputString) {
-    Callable<String> task =
-        () -> {
-          int attempt = 0;
-          while (attempt < MAX_RETRIES) {
-            try {
-              return sendRequest(endpoint, jsonInputString);
-            } catch (Exception e) {
-              attempt++;
-              if (attempt >= MAX_RETRIES) {
-                throw e;
-              }
-            }
-          }
-          return null;
-        };
-    return executorService.submit(task);
-  }
-}

From 7a6a78a4b802dcc0916d2428f90b7ee39f41e83e Mon Sep 17 00:00:00 2001
From: Usman Saleem <usman@usmans.info>
Date: Tue, 10 Sep 2024 21:45:48 +1000
Subject: [PATCH 15/26] Updating retry schedule logic

---
 .../linea/jsonrpc/JsonRpcManager.java         |  84 ++++++---
 .../linea/jsonrpc/JsonRpcManagerTest.java     | 177 +++++++++++++++++-
 2 files changed, 229 insertions(+), 32 deletions(-)

diff --git a/sequencer/src/main/java/net/consensys/linea/jsonrpc/JsonRpcManager.java b/sequencer/src/main/java/net/consensys/linea/jsonrpc/JsonRpcManager.java
index b01db026..0db2203f 100644
--- a/sequencer/src/main/java/net/consensys/linea/jsonrpc/JsonRpcManager.java
+++ b/sequencer/src/main/java/net/consensys/linea/jsonrpc/JsonRpcManager.java
@@ -19,8 +19,14 @@
 import java.io.UncheckedIOException;
 import java.net.URI;
 import java.nio.file.DirectoryStream;
+import java.nio.file.FileAlreadyExistsException;
 import java.nio.file.Files;
 import java.nio.file.Path;
+import java.nio.file.StandardOpenOption;
+import java.util.Comparator;
+import java.util.Map;
+import java.util.TreeSet;
+import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.ExecutorService;
 import java.util.concurrent.Executors;
 import java.util.concurrent.ScheduledExecutorService;
@@ -38,6 +44,7 @@
 /** This class is responsible for managing JSON-RPC requests for reporting rejected transactions */
 @Slf4j
 public class JsonRpcManager {
+  private static final long INITIAL_RETRY_DELAY = 1000L;
   private static final int MAX_THREADS =
       Math.min(32, Runtime.getRuntime().availableProcessors() * 2);
   private static final long MAX_RETRY_DURATION = TimeUnit.HOURS.toMillis(2);
@@ -45,11 +52,12 @@ public class JsonRpcManager {
 
   private final OkHttpClient client = new OkHttpClient();
   private final ObjectMapper objectMapper = new ObjectMapper();
+  private final Map<Path, Long> fileStartTimes = new ConcurrentHashMap<>();
 
   private final Path rejTxRpcDirectory;
   private final URI rejectedTxEndpoint;
   private final ExecutorService executorService;
-  private final ScheduledExecutorService schedulerService;
+  private final ScheduledExecutorService retrySchedulerService;
 
   /**
    * Creates a new JSON-RPC manager.
@@ -62,7 +70,7 @@ public JsonRpcManager(final Path besuDataDir, final URI rejectedTxEndpoint) {
     this.rejTxRpcDirectory = besuDataDir.resolve("rej_tx_rpc");
     this.rejectedTxEndpoint = rejectedTxEndpoint;
     this.executorService = Executors.newFixedThreadPool(MAX_THREADS);
-    this.schedulerService = Executors.newScheduledThreadPool(1);
+    this.retrySchedulerService = Executors.newScheduledThreadPool(1);
   }
 
   /** Load existing JSON-RPC and submit them. */
@@ -83,7 +91,7 @@ public JsonRpcManager start() {
   /** Shuts down the executor service and scheduler service. */
   public void shutdown() {
     executorService.shutdown();
-    schedulerService.shutdown();
+    retrySchedulerService.shutdown();
   }
 
   /**
@@ -94,28 +102,41 @@ public void shutdown() {
   public void submitNewJsonRpcCall(final String jsonContent) {
     try {
       final Path jsonFile = saveJsonToFile(jsonContent);
-      submitJsonRpcCall(jsonFile);
+      fileStartTimes.put(jsonFile, System.currentTimeMillis());
+      submitJsonRpcCall(jsonFile, INITIAL_RETRY_DELAY);
     } catch (final IOException e) {
       log.error("Failed to save JSON content", e);
     }
   }
 
   private void loadExistingJsonFiles() {
-    try (final DirectoryStream<Path> stream =
-        Files.newDirectoryStream(rejTxRpcDirectory, "rpc_*.json")) {
-      for (final Path path : stream) {
-        submitJsonRpcCall(path);
+    try {
+      final TreeSet<Path> sortedFiles = new TreeSet<>(Comparator.comparing(Path::getFileName));
+
+      try (DirectoryStream<Path> stream =
+          Files.newDirectoryStream(rejTxRpcDirectory, "rpc_*.json")) {
+        for (Path path : stream) {
+          sortedFiles.add(path);
+        }
+      }
+
+      for (Path path : sortedFiles) {
+        fileStartTimes.put(path, System.currentTimeMillis());
+        submitJsonRpcCall(path, INITIAL_RETRY_DELAY);
       }
+
+      log.info("Loaded {} existing JSON files for rej-tx reporting", sortedFiles.size());
     } catch (final IOException e) {
       log.error("Failed to load existing JSON files", e);
     }
   }
 
-  private void submitJsonRpcCall(final Path jsonFile) {
+  private void submitJsonRpcCall(final Path jsonFile, final long nextDelay) {
     executorService.submit(
         () -> {
           if (!Files.exists(jsonFile)) {
             log.debug("json-rpc file no longer exists, skipping processing: {}", jsonFile);
+            fileStartTimes.remove(jsonFile);
             return;
           }
           try {
@@ -123,26 +144,35 @@ private void submitJsonRpcCall(final Path jsonFile) {
             final boolean success = sendJsonRpcCall(jsonContent);
             if (success) {
               Files.deleteIfExists(jsonFile);
+              fileStartTimes.remove(jsonFile);
             } else {
-              log.warn(
+              log.error(
                   "Failed to send JSON-RPC call to {}, retrying: {}", rejectedTxEndpoint, jsonFile);
-              scheduleRetry(jsonFile, System.currentTimeMillis(), 1000);
+              scheduleRetry(jsonFile, nextDelay);
             }
-          } catch (final IOException e) {
+          } catch (final Exception e) {
             log.error("Failed to process json-rpc file: {}", jsonFile, e);
+            scheduleRetry(jsonFile, nextDelay);
           }
         });
   }
 
-  private void scheduleRetry(final Path jsonFile, final long startTime, final long delay) {
+  private void scheduleRetry(final Path jsonFile, final long currentDelay) {
+    final Long startTime = fileStartTimes.get(jsonFile);
+    if (startTime == null) {
+      log.debug("No start time found for file: {}. Skipping retry.", jsonFile);
+      return;
+    }
+
     // check if we're still within the maximum retry duration
     if (System.currentTimeMillis() - startTime < MAX_RETRY_DURATION) {
-      // schedule a retry
-      schedulerService.schedule(() -> submitJsonRpcCall(jsonFile), delay, TimeUnit.MILLISECONDS);
-
-      // exponential backoff with a maximum delay of 1 minute
-      long nextDelay = Math.min(delay * 2, TimeUnit.MINUTES.toMillis(1));
-      scheduleRetry(jsonFile, startTime, nextDelay);
+      // schedule a retry with exponential backoff
+      long nextDelay = Math.min(currentDelay * 2, TimeUnit.MINUTES.toMillis(1)); // Cap at 1 minute
+      retrySchedulerService.schedule(
+          () -> submitJsonRpcCall(jsonFile, nextDelay), currentDelay, TimeUnit.MILLISECONDS);
+    } else {
+      log.error("Exceeded maximum retry duration for rej-tx json-rpc file: {}", jsonFile);
+      fileStartTimes.remove(jsonFile);
     }
   }
 
@@ -150,7 +180,6 @@ private boolean sendJsonRpcCall(final String jsonContent) {
     final RequestBody body = RequestBody.create(jsonContent, JSON);
     final Request request =
         new Request.Builder().url(rejectedTxEndpoint.toString()).post(body).build();
-
     try (final Response response = client.newCall(request).execute()) {
       if (!response.isSuccessful()) {
         log.error("Unexpected response code from rejected-tx endpoint: {}", response.code());
@@ -189,9 +218,16 @@ private boolean sendJsonRpcCall(final String jsonContent) {
   }
 
   private Path saveJsonToFile(final String jsonContent) throws IOException {
-    final String fileName = "rpc_" + System.currentTimeMillis() + ".json";
-    final Path filePath = rejTxRpcDirectory.resolve(fileName);
-    Files.write(filePath, jsonContent.getBytes());
-    return filePath;
+    long timestamp = System.currentTimeMillis();
+    for (int attempt = 0; attempt < 100; attempt++) {
+      final String fileName = String.format("rpc_%d_%d.json", timestamp, attempt);
+      final Path filePath = rejTxRpcDirectory.resolve(fileName);
+      try {
+        return Files.writeString(filePath, jsonContent, StandardOpenOption.CREATE_NEW);
+      } catch (final FileAlreadyExistsException e) {
+        log.trace("File already exists {}, retrying.", filePath);
+      }
+    }
+    throw new IOException("Failed to save JSON content after 100 attempts");
   }
 }
diff --git a/sequencer/src/test/java/net/consensys/linea/jsonrpc/JsonRpcManagerTest.java b/sequencer/src/test/java/net/consensys/linea/jsonrpc/JsonRpcManagerTest.java
index ea4e7a2e..efd57c6e 100644
--- a/sequencer/src/test/java/net/consensys/linea/jsonrpc/JsonRpcManagerTest.java
+++ b/sequencer/src/test/java/net/consensys/linea/jsonrpc/JsonRpcManagerTest.java
@@ -17,19 +17,26 @@
 
 import static com.github.tomakehurst.wiremock.client.WireMock.aResponse;
 import static com.github.tomakehurst.wiremock.client.WireMock.equalToJson;
+import static com.github.tomakehurst.wiremock.client.WireMock.exactly;
 import static com.github.tomakehurst.wiremock.client.WireMock.post;
 import static com.github.tomakehurst.wiremock.client.WireMock.postRequestedFor;
 import static com.github.tomakehurst.wiremock.client.WireMock.stubFor;
 import static com.github.tomakehurst.wiremock.client.WireMock.urlEqualTo;
 import static com.github.tomakehurst.wiremock.client.WireMock.verify;
+import static org.assertj.core.api.Assertions.assertThat;
 import static org.mockito.Mockito.when;
 
+import java.io.IOException;
 import java.net.URI;
+import java.nio.file.Files;
 import java.nio.file.Path;
 import java.time.Instant;
+import java.util.stream.Stream;
 
+import com.github.tomakehurst.wiremock.http.Fault;
 import com.github.tomakehurst.wiremock.junit5.WireMockRuntimeInfo;
 import com.github.tomakehurst.wiremock.junit5.WireMockTest;
+import com.github.tomakehurst.wiremock.stubbing.Scenario;
 import net.consensys.linea.sequencer.txselection.selectors.TestTransactionEvaluationContext;
 import org.apache.tuweni.bytes.Bytes;
 import org.hyperledger.besu.datatypes.PendingTransaction;
@@ -49,13 +56,18 @@
 class JsonRpcManagerTest {
   @TempDir private Path tempDataDir;
   private JsonRpcManager jsonRpcManager;
-
+  private final Bytes randomEncodedBytes = Bytes.random(32);
   @Mock private PendingTransaction pendingTransaction;
   @Mock private ProcessableBlockHeader pendingBlockHeader;
   @Mock private Transaction transaction;
 
   @BeforeEach
   void init(final WireMockRuntimeInfo wmInfo) {
+    // mock stubbing
+    when(pendingBlockHeader.getNumber()).thenReturn(1L);
+    when(pendingTransaction.getTransaction()).thenReturn(transaction);
+    when(transaction.encoded()).thenReturn(randomEncodedBytes);
+
     jsonRpcManager = new JsonRpcManager(tempDataDir, URI.create(wmInfo.getHttpBaseUrl()));
     jsonRpcManager.start();
   }
@@ -67,12 +79,6 @@ void cleanup() {
 
   @Test
   void rejectedTxIsReported() throws InterruptedException {
-    // mock stubbing
-    when(pendingBlockHeader.getNumber()).thenReturn(1L);
-    when(pendingTransaction.getTransaction()).thenReturn(transaction);
-    final Bytes randomEncodedBytes = Bytes.random(32);
-    when(transaction.encoded()).thenReturn(randomEncodedBytes);
-
     // json-rpc stubbing
     stubFor(
         post(urlEqualTo("/"))
@@ -98,6 +104,161 @@ void rejectedTxIsReported() throws InterruptedException {
     Thread.sleep(1000);
 
     // assert that the expected json-rpc request was sent to WireMock
-    verify(postRequestedFor(urlEqualTo("/")).withRequestBody(equalToJson(jsonRpcCall)));
+    verify(exactly(1), postRequestedFor(urlEqualTo("/")).withRequestBody(equalToJson(jsonRpcCall)));
+  }
+
+  @Test
+  void firstCallErrorSecondCallSuccessScenario() throws InterruptedException, IOException {
+    stubFor(
+        post(urlEqualTo("/"))
+            .inScenario("RPC Calls")
+            .whenScenarioStateIs(Scenario.STARTED)
+            .willReturn(
+                aResponse()
+                    .withStatus(500)
+                    .withHeader("Content-Type", "application/json")
+                    .withBody(
+                        "{\"jsonrpc\":\"2.0\",\"error\":{\"code\":-32000,\"message\":\"Internal error\"},\"id\":1}"))
+            .willSetStateTo("Second Call"));
+
+    stubFor(
+        post(urlEqualTo("/"))
+            .inScenario("RPC Calls")
+            .whenScenarioStateIs("Second Call")
+            .willReturn(
+                aResponse()
+                    .withStatus(200)
+                    .withHeader("Content-Type", "application/json")
+                    .withBody(
+                        "{\"jsonrpc\":\"2.0\",\"result\":{ \"status\": \"SAVED\"},\"id\":1}")));
+
+    // Prepare test data
+    final TestTransactionEvaluationContext context =
+        new TestTransactionEvaluationContext(pendingTransaction)
+            .setPendingBlockHeader(pendingBlockHeader);
+    final TransactionSelectionResult result = TransactionSelectionResult.invalid("test");
+    final Instant timestamp = Instant.now();
+
+    // Generate JSON-RPC call
+    final String jsonRpcCall =
+        JsonRpcRequestBuilder.buildRejectedTxRequest(context, result, timestamp);
+
+    // Submit the call, the scheduler will retry the failed call
+    jsonRpcManager.submitNewJsonRpcCall(jsonRpcCall);
+
+    // Sleep to allow async processing
+    Thread.sleep(2000); // Increased sleep time to allow for two calls
+
+    // Verify that two requests were made
+    verify(exactly(2), postRequestedFor(urlEqualTo("/")).withRequestBody(equalToJson(jsonRpcCall)));
+
+    // Verify that the JSON file no longer exists in the directory (as the second call was
+    // successful)
+    Path rejTxRpcDir = tempDataDir.resolve("rej_tx_rpc");
+    try (Stream<Path> files = Files.list(rejTxRpcDir)) {
+      long fileCount = files.filter(path -> path.toString().endsWith(".json")).count();
+      assertThat(fileCount).isEqualTo(0);
+    }
+  }
+
+  @Test
+  void serverRespondingWithErrorScenario() throws InterruptedException, IOException {
+    // Stub for error response
+    stubFor(
+        post(urlEqualTo("/"))
+            .willReturn(
+                aResponse()
+                    .withStatus(500)
+                    .withHeader("Content-Type", "application/json")
+                    .withBody(
+                        "{\"jsonrpc\":\"2.0\",\"error\":{\"code\":-32000,\"message\":\"Internal error\"},\"id\":1}")));
+
+    // Prepare test data
+    final TestTransactionEvaluationContext context =
+        new TestTransactionEvaluationContext(pendingTransaction)
+            .setPendingBlockHeader(pendingBlockHeader);
+    final TransactionSelectionResult result = TransactionSelectionResult.invalid("test");
+    final Instant timestamp = Instant.now();
+
+    // Generate JSON-RPC call
+    final String jsonRpcCall =
+        JsonRpcRequestBuilder.buildRejectedTxRequest(context, result, timestamp);
+
+    // Submit the call
+    jsonRpcManager.submitNewJsonRpcCall(jsonRpcCall);
+
+    // Sleep to allow async processing
+    Thread.sleep(1000);
+
+    // Verify that the request was made
+    verify(exactly(1), postRequestedFor(urlEqualTo("/")).withRequestBody(equalToJson(jsonRpcCall)));
+
+    // Verify that the JSON file still exists in the directory (as the call was unsuccessful)
+    final Path rejTxRpcDir = tempDataDir.resolve("rej_tx_rpc");
+    try (Stream<Path> files = Files.list(rejTxRpcDir)) {
+      long fileCount = files.filter(path -> path.toString().endsWith(".json")).count();
+      assertThat(fileCount).as("JSON file should exist as server responded with error").isOne();
+    }
+  }
+
+  @Test
+  void firstTwoCallsErrorThenLastCallSuccessScenario() throws InterruptedException, IOException {
+    stubFor(
+        post(urlEqualTo("/"))
+            .inScenario("RPC Calls")
+            .whenScenarioStateIs(Scenario.STARTED)
+            .willReturn(aResponse().withFault(Fault.MALFORMED_RESPONSE_CHUNK))
+            .willSetStateTo("Second Call"));
+
+    stubFor(
+        post(urlEqualTo("/"))
+            .inScenario("RPC Calls")
+            .whenScenarioStateIs("Second Call")
+            .willReturn(
+                aResponse()
+                    .withStatus(500)
+                    .withHeader("Content-Type", "application/json")
+                    .withBody(
+                        "{\"jsonrpc\":\"2.0\",\"error\":{\"code\":-32000,\"message\":\"Internal error\"},\"id\":1}"))
+            .willSetStateTo("Third Call"));
+
+    stubFor(
+        post(urlEqualTo("/"))
+            .inScenario("RPC Calls")
+            .whenScenarioStateIs("Third Call")
+            .willReturn(
+                aResponse()
+                    .withStatus(200)
+                    .withHeader("Content-Type", "application/json")
+                    .withBody(
+                        "{\"jsonrpc\":\"2.0\",\"result\":{ \"status\": \"SAVED\"},\"id\":1}")));
+
+    // Prepare test data
+    final TestTransactionEvaluationContext context =
+        new TestTransactionEvaluationContext(pendingTransaction)
+            .setPendingBlockHeader(pendingBlockHeader);
+    final TransactionSelectionResult result = TransactionSelectionResult.invalid("test");
+    final Instant timestamp = Instant.now();
+
+    // Generate JSON-RPC call
+    final String jsonRpcCall =
+        JsonRpcRequestBuilder.buildRejectedTxRequest(context, result, timestamp);
+
+    // Submit the call, the scheduler will retry the failed calls
+    jsonRpcManager.submitNewJsonRpcCall(jsonRpcCall);
+
+    // Sleep to allow async processing
+    Thread.sleep(6000); // Increased sleep time to allow for three calls
+
+    // Verify that two requests were made
+    verify(exactly(3), postRequestedFor(urlEqualTo("/")).withRequestBody(equalToJson(jsonRpcCall)));
+
+    // Verify that the JSON file no longer exists in the directory (as the second call was
+    // successful)
+    Path rejTxRpcDir = tempDataDir.resolve("rej_tx_rpc");
+    try (Stream<Path> files = Files.list(rejTxRpcDir)) {
+      long fileCount = files.filter(path -> path.toString().endsWith(".json")).count();
+      assertThat(fileCount).isEqualTo(0);
+    }
   }
 }

From 386008a7ef0dd770c91f2d420abc1f75e042693c Mon Sep 17 00:00:00 2001
From: Usman Saleem <usman@usmans.info>
Date: Wed, 11 Sep 2024 09:25:38 +1000
Subject: [PATCH 16/26] review suggestions

---
 .../java/net/consensys/linea/jsonrpc/JsonRpcManager.java | 4 ++--
 .../consensys/linea/jsonrpc/JsonRpcRequestBuilder.java   | 9 ++++-----
 2 files changed, 6 insertions(+), 7 deletions(-)

diff --git a/sequencer/src/main/java/net/consensys/linea/jsonrpc/JsonRpcManager.java b/sequencer/src/main/java/net/consensys/linea/jsonrpc/JsonRpcManager.java
index 0db2203f..c9b38605 100644
--- a/sequencer/src/main/java/net/consensys/linea/jsonrpc/JsonRpcManager.java
+++ b/sequencer/src/main/java/net/consensys/linea/jsonrpc/JsonRpcManager.java
@@ -80,7 +80,7 @@ public JsonRpcManager start() {
       Files.createDirectories(rejTxRpcDirectory);
 
       // Load existing JSON files
-      loadExistingJsonFiles();
+      processExistingJsonFiles();
       return this;
     } catch (IOException e) {
       log.error("Failed to create or access rej-tx-rpc directory", e);
@@ -109,7 +109,7 @@ public void submitNewJsonRpcCall(final String jsonContent) {
     }
   }
 
-  private void loadExistingJsonFiles() {
+  private void processExistingJsonFiles() {
     try {
       final TreeSet<Path> sortedFiles = new TreeSet<>(Comparator.comparing(Path::getFileName));
 
diff --git a/sequencer/src/main/java/net/consensys/linea/jsonrpc/JsonRpcRequestBuilder.java b/sequencer/src/main/java/net/consensys/linea/jsonrpc/JsonRpcRequestBuilder.java
index d6cd0abd..26906eea 100644
--- a/sequencer/src/main/java/net/consensys/linea/jsonrpc/JsonRpcRequestBuilder.java
+++ b/sequencer/src/main/java/net/consensys/linea/jsonrpc/JsonRpcRequestBuilder.java
@@ -16,6 +16,7 @@
 package net.consensys.linea.jsonrpc;
 
 import java.time.Instant;
+import java.util.concurrent.atomic.AtomicLong;
 
 import com.google.gson.JsonObject;
 import org.hyperledger.besu.datatypes.PendingTransaction;
@@ -25,6 +26,8 @@
 
 /** Helper class to build JSON-RPC requests for rejected transactions. */
 public class JsonRpcRequestBuilder {
+  private static final AtomicLong idCounter = new AtomicLong(1);
+
   /**
    *
    *
@@ -52,10 +55,6 @@ public static String buildRejectedTxRequest(
       final TransactionEvaluationContext<? extends PendingTransaction> evaluationContext,
       final TransactionSelectionResult transactionSelectionResult,
       final Instant timestamp) {
-    //    if (!transactionSelectionResult.discard()) {
-    //      return;
-    //    }
-
     final PendingTransaction pendingTransaction = evaluationContext.getPendingTransaction();
     final ProcessableBlockHeader pendingBlockHeader = evaluationContext.getPendingBlockHeader();
 
@@ -72,7 +71,7 @@ public static String buildRejectedTxRequest(
     request.addProperty("jsonrpc", "2.0");
     request.addProperty("method", "linea_saveRejectedTransactionV1");
     request.add("params", params);
-    request.addProperty("id", 1);
+    request.addProperty("id", idCounter.getAndIncrement());
     return request.toString();
   }
 }

From f32b3797d0a33860ddf1b64119e50fc1ee5803ea Mon Sep 17 00:00:00 2001
From: Usman Saleem <usman@usmans.info>
Date: Wed, 11 Sep 2024 09:42:57 +1000
Subject: [PATCH 17/26] Changing json-rpc ExecutorService to use virtual
 threads

---
 .../java/net/consensys/linea/jsonrpc/JsonRpcManager.java    | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/sequencer/src/main/java/net/consensys/linea/jsonrpc/JsonRpcManager.java b/sequencer/src/main/java/net/consensys/linea/jsonrpc/JsonRpcManager.java
index c9b38605..036d8ae9 100644
--- a/sequencer/src/main/java/net/consensys/linea/jsonrpc/JsonRpcManager.java
+++ b/sequencer/src/main/java/net/consensys/linea/jsonrpc/JsonRpcManager.java
@@ -45,8 +45,6 @@
 @Slf4j
 public class JsonRpcManager {
   private static final long INITIAL_RETRY_DELAY = 1000L;
-  private static final int MAX_THREADS =
-      Math.min(32, Runtime.getRuntime().availableProcessors() * 2);
   private static final long MAX_RETRY_DURATION = TimeUnit.HOURS.toMillis(2);
   private static final MediaType JSON = MediaType.get("application/json; charset=utf-8");
 
@@ -69,8 +67,8 @@ public class JsonRpcManager {
   public JsonRpcManager(final Path besuDataDir, final URI rejectedTxEndpoint) {
     this.rejTxRpcDirectory = besuDataDir.resolve("rej_tx_rpc");
     this.rejectedTxEndpoint = rejectedTxEndpoint;
-    this.executorService = Executors.newFixedThreadPool(MAX_THREADS);
-    this.retrySchedulerService = Executors.newScheduledThreadPool(1);
+    this.executorService = Executors.newVirtualThreadPerTaskExecutor();
+    this.retrySchedulerService = Executors.newSingleThreadScheduledExecutor();
   }
 
   /** Load existing JSON-RPC and submit them. */

From 140cb48027545ce3554f6fa396272d90434357ce Mon Sep 17 00:00:00 2001
From: Usman Saleem <usman@usmans.info>
Date: Wed, 11 Sep 2024 10:01:31 +1000
Subject: [PATCH 18/26] Adding comments to saveJsonToFile method

---
 .../linea/jsonrpc/JsonRpcManager.java         | 23 +++++++++++++++++--
 1 file changed, 21 insertions(+), 2 deletions(-)

diff --git a/sequencer/src/main/java/net/consensys/linea/jsonrpc/JsonRpcManager.java b/sequencer/src/main/java/net/consensys/linea/jsonrpc/JsonRpcManager.java
index 036d8ae9..52697829 100644
--- a/sequencer/src/main/java/net/consensys/linea/jsonrpc/JsonRpcManager.java
+++ b/sequencer/src/main/java/net/consensys/linea/jsonrpc/JsonRpcManager.java
@@ -215,10 +215,21 @@ private boolean sendJsonRpcCall(final String jsonContent) {
     }
   }
 
+  /**
+   * Saves the JSON content to a file in the rej-tx-rpc directory. The file name is generated based
+   * on a timestamp and an attempt number to allow sorted loading in case of restart.
+   *
+   * @param jsonContent The JSON content to save
+   * @return The path to the saved file
+   * @throws IOException If an I/O error occurs or failed to save JSON content after 100 attempts
+   *     due to collision
+   */
   private Path saveJsonToFile(final String jsonContent) throws IOException {
-    long timestamp = System.currentTimeMillis();
+    final String timestamp = generateTimestampWithNanos();
+    // there is a very low chance of collision that multiple rejected tx being notified within same
+    // current timestamp, but we'll retry up to 100 times
     for (int attempt = 0; attempt < 100; attempt++) {
-      final String fileName = String.format("rpc_%d_%d.json", timestamp, attempt);
+      final String fileName = String.format("rpc_%s_%d.json", timestamp, attempt);
       final Path filePath = rejTxRpcDirectory.resolve(fileName);
       try {
         return Files.writeString(filePath, jsonContent, StandardOpenOption.CREATE_NEW);
@@ -228,4 +239,12 @@ private Path saveJsonToFile(final String jsonContent) throws IOException {
     }
     throw new IOException("Failed to save JSON content after 100 attempts");
   }
+
+  private static String generateTimestampWithNanos() {
+    long millis = System.currentTimeMillis();
+    long nanos = System.nanoTime();
+    long millisPart = millis % 1000;
+    long nanosPart = nanos % 1_000_000;
+    return String.format("%d%03d%06d", millis / 1000, millisPart, nanosPart);
+  }
 }

From 80de637a8db8f39001af796c7f207c2e69889983 Mon Sep 17 00:00:00 2001
From: Usman Saleem <usman@usmans.info>
Date: Wed, 11 Sep 2024 10:17:58 +1000
Subject: [PATCH 19/26] Use high-precision timestamp and a UUID to ensure
 uniqueness

---
 .../linea/jsonrpc/JsonRpcManager.java         | 36 ++++++++++---------
 1 file changed, 19 insertions(+), 17 deletions(-)

diff --git a/sequencer/src/main/java/net/consensys/linea/jsonrpc/JsonRpcManager.java b/sequencer/src/main/java/net/consensys/linea/jsonrpc/JsonRpcManager.java
index 52697829..181f7180 100644
--- a/sequencer/src/main/java/net/consensys/linea/jsonrpc/JsonRpcManager.java
+++ b/sequencer/src/main/java/net/consensys/linea/jsonrpc/JsonRpcManager.java
@@ -26,6 +26,7 @@
 import java.util.Comparator;
 import java.util.Map;
 import java.util.TreeSet;
+import java.util.UUID;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.ExecutorService;
 import java.util.concurrent.Executors;
@@ -216,28 +217,29 @@ private boolean sendJsonRpcCall(final String jsonContent) {
   }
 
   /**
-   * Saves the JSON content to a file in the rej-tx-rpc directory. The file name is generated based
-   * on a timestamp and an attempt number to allow sorted loading in case of restart.
+   * Saves the given JSON content to a file in the rejected transactions RPC directory. The filename
+   * is generated using a high-precision timestamp and a UUID to ensure uniqueness.
    *
-   * @param jsonContent The JSON content to save
-   * @return The path to the saved file
-   * @throws IOException If an I/O error occurs or failed to save JSON content after 100 attempts
-   *     due to collision
+   * <p>The file naming format is: rpc_[timestamp]_[uuid].json</p>
+   *
+   * @param jsonContent The JSON string to be written to the file.
+   * @return The Path object representing the newly created file.
+   * @throws IOException If an I/O error occurs while writing the file, including unexpected file
+   *     collisions.
    */
   private Path saveJsonToFile(final String jsonContent) throws IOException {
     final String timestamp = generateTimestampWithNanos();
-    // there is a very low chance of collision that multiple rejected tx being notified within same
-    // current timestamp, but we'll retry up to 100 times
-    for (int attempt = 0; attempt < 100; attempt++) {
-      final String fileName = String.format("rpc_%s_%d.json", timestamp, attempt);
-      final Path filePath = rejTxRpcDirectory.resolve(fileName);
-      try {
-        return Files.writeString(filePath, jsonContent, StandardOpenOption.CREATE_NEW);
-      } catch (final FileAlreadyExistsException e) {
-        log.trace("File already exists {}, retrying.", filePath);
-      }
+    final String uuid = UUID.randomUUID().toString();
+    final String fileName = String.format("rpc_%s_%s.json", timestamp, uuid);
+    final Path filePath = rejTxRpcDirectory.resolve(fileName);
+
+    try {
+      return Files.writeString(filePath, jsonContent, StandardOpenOption.CREATE_NEW);
+    } catch (final FileAlreadyExistsException e) {
+      // This should never happen with UUID, but just in case
+      log.warn("Unexpected file collision occurred: {}", filePath);
+      throw new IOException("Unexpected file name collision", e);
     }
-    throw new IOException("Failed to save JSON content after 100 attempts");
   }
 
   private static String generateTimestampWithNanos() {

From 3122a927f836a03bf21cb6679ef6efcc7f5531fb Mon Sep 17 00:00:00 2001
From: Usman Saleem <usman@usmans.info>
Date: Wed, 11 Sep 2024 10:36:22 +1000
Subject: [PATCH 20/26] Use Duration and Instant instead of long

---
 .../linea/jsonrpc/JsonRpcManager.java         | 41 +++++++++++--------
 1 file changed, 25 insertions(+), 16 deletions(-)

diff --git a/sequencer/src/main/java/net/consensys/linea/jsonrpc/JsonRpcManager.java b/sequencer/src/main/java/net/consensys/linea/jsonrpc/JsonRpcManager.java
index 181f7180..a597bd02 100644
--- a/sequencer/src/main/java/net/consensys/linea/jsonrpc/JsonRpcManager.java
+++ b/sequencer/src/main/java/net/consensys/linea/jsonrpc/JsonRpcManager.java
@@ -23,6 +23,8 @@
 import java.nio.file.Files;
 import java.nio.file.Path;
 import java.nio.file.StandardOpenOption;
+import java.time.Duration;
+import java.time.Instant;
 import java.util.Comparator;
 import java.util.Map;
 import java.util.TreeSet;
@@ -45,13 +47,13 @@
 /** This class is responsible for managing JSON-RPC requests for reporting rejected transactions */
 @Slf4j
 public class JsonRpcManager {
-  private static final long INITIAL_RETRY_DELAY = 1000L;
-  private static final long MAX_RETRY_DURATION = TimeUnit.HOURS.toMillis(2);
+  private static final Duration INITIAL_RETRY_DELAY_DURATION = Duration.ofSeconds(1);
+  private static final Duration MAX_RETRY_DURATION = Duration.ofHours(2);
   private static final MediaType JSON = MediaType.get("application/json; charset=utf-8");
 
   private final OkHttpClient client = new OkHttpClient();
   private final ObjectMapper objectMapper = new ObjectMapper();
-  private final Map<Path, Long> fileStartTimes = new ConcurrentHashMap<>();
+  private final Map<Path, Instant> fileStartTimes = new ConcurrentHashMap<>();
 
   private final Path rejTxRpcDirectory;
   private final URI rejectedTxEndpoint;
@@ -101,8 +103,8 @@ public void shutdown() {
   public void submitNewJsonRpcCall(final String jsonContent) {
     try {
       final Path jsonFile = saveJsonToFile(jsonContent);
-      fileStartTimes.put(jsonFile, System.currentTimeMillis());
-      submitJsonRpcCall(jsonFile, INITIAL_RETRY_DELAY);
+      fileStartTimes.put(jsonFile, Instant.now());
+      submitJsonRpcCall(jsonFile, INITIAL_RETRY_DELAY_DURATION);
     } catch (final IOException e) {
       log.error("Failed to save JSON content", e);
     }
@@ -120,8 +122,8 @@ private void processExistingJsonFiles() {
       }
 
       for (Path path : sortedFiles) {
-        fileStartTimes.put(path, System.currentTimeMillis());
-        submitJsonRpcCall(path, INITIAL_RETRY_DELAY);
+        fileStartTimes.put(path, Instant.now());
+        submitJsonRpcCall(path, INITIAL_RETRY_DELAY_DURATION);
       }
 
       log.info("Loaded {} existing JSON files for rej-tx reporting", sortedFiles.size());
@@ -130,7 +132,7 @@ private void processExistingJsonFiles() {
     }
   }
 
-  private void submitJsonRpcCall(final Path jsonFile, final long nextDelay) {
+  private void submitJsonRpcCall(final Path jsonFile, final Duration nextDelay) {
     executorService.submit(
         () -> {
           if (!Files.exists(jsonFile)) {
@@ -156,22 +158,29 @@ private void submitJsonRpcCall(final Path jsonFile, final long nextDelay) {
         });
   }
 
-  private void scheduleRetry(final Path jsonFile, final long currentDelay) {
-    final Long startTime = fileStartTimes.get(jsonFile);
+  private void scheduleRetry(final Path jsonFile, final Duration currentDelay) {
+    final Instant startTime = fileStartTimes.get(jsonFile);
     if (startTime == null) {
       log.debug("No start time found for file: {}. Skipping retry.", jsonFile);
       return;
     }
 
-    // check if we're still within the maximum retry duration
-    if (System.currentTimeMillis() - startTime < MAX_RETRY_DURATION) {
-      // schedule a retry with exponential backoff
-      long nextDelay = Math.min(currentDelay * 2, TimeUnit.MINUTES.toMillis(1)); // Cap at 1 minute
+    // Check if we're still within the maximum retry duration
+    if (Duration.between(startTime, Instant.now()).compareTo(MAX_RETRY_DURATION) < 0) {
+      // Calculate next delay with exponential backoff, capped at 1 minute
+      final Duration nextDelay =
+          Duration.ofMillis(
+              Math.min(currentDelay.multipliedBy(2).toMillis(), Duration.ofMinutes(1).toMillis()));
+
+      // Schedule a retry
       retrySchedulerService.schedule(
-          () -> submitJsonRpcCall(jsonFile, nextDelay), currentDelay, TimeUnit.MILLISECONDS);
+          () -> submitJsonRpcCall(jsonFile, nextDelay),
+          currentDelay.toMillis(),
+          TimeUnit.MILLISECONDS);
     } else {
       log.error("Exceeded maximum retry duration for rej-tx json-rpc file: {}", jsonFile);
       fileStartTimes.remove(jsonFile);
+      // TODO (review suggestion) : Log that notification is discarded and not sent to endpoint
     }
   }
 
@@ -220,7 +229,7 @@ private boolean sendJsonRpcCall(final String jsonContent) {
    * Saves the given JSON content to a file in the rejected transactions RPC directory. The filename
    * is generated using a high-precision timestamp and a UUID to ensure uniqueness.
    *
-   * <p>The file naming format is: rpc_[timestamp]_[uuid].json</p>
+   * <p>The file naming format is: rpc_[timestamp]_[uuid].json
    *
    * @param jsonContent The JSON string to be written to the file.
    * @return The Path object representing the newly created file.

From 9199fddf5cd1b00e10a27477fab21f16452a0e7b Mon Sep 17 00:00:00 2001
From: Usman Saleem <usman@usmans.info>
Date: Wed, 11 Sep 2024 17:20:00 +1000
Subject: [PATCH 21/26] Updating logs entry in submitJsonRpcCall

---
 .../consensys/linea/jsonrpc/JsonRpcManager.java    | 14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)

diff --git a/sequencer/src/main/java/net/consensys/linea/jsonrpc/JsonRpcManager.java b/sequencer/src/main/java/net/consensys/linea/jsonrpc/JsonRpcManager.java
index a597bd02..24aeb60e 100644
--- a/sequencer/src/main/java/net/consensys/linea/jsonrpc/JsonRpcManager.java
+++ b/sequencer/src/main/java/net/consensys/linea/jsonrpc/JsonRpcManager.java
@@ -136,7 +136,7 @@ private void submitJsonRpcCall(final Path jsonFile, final Duration nextDelay) {
     executorService.submit(
         () -> {
           if (!Files.exists(jsonFile)) {
-            log.debug("json-rpc file no longer exists, skipping processing: {}", jsonFile);
+            log.debug("JSON-RPC file {} no longer exists, skipping processing.", jsonFile);
             fileStartTimes.remove(jsonFile);
             return;
           }
@@ -148,11 +148,16 @@ private void submitJsonRpcCall(final Path jsonFile, final Duration nextDelay) {
               fileStartTimes.remove(jsonFile);
             } else {
               log.error(
-                  "Failed to send JSON-RPC call to {}, retrying: {}", rejectedTxEndpoint, jsonFile);
+                  "Failed to send JSON-RPC file {} to {}, Scheduling retry ...",
+                  jsonFile,
+                  rejectedTxEndpoint);
               scheduleRetry(jsonFile, nextDelay);
             }
           } catch (final Exception e) {
-            log.error("Failed to process json-rpc file: {}", jsonFile, e);
+            log.error(
+                "Failed to process JSON-RPC file {} due to unexpected error: {}. Scheduling retry ...",
+                jsonFile,
+                e.getMessage());
             scheduleRetry(jsonFile, nextDelay);
           }
         });
@@ -161,7 +166,7 @@ private void submitJsonRpcCall(final Path jsonFile, final Duration nextDelay) {
   private void scheduleRetry(final Path jsonFile, final Duration currentDelay) {
     final Instant startTime = fileStartTimes.get(jsonFile);
     if (startTime == null) {
-      log.debug("No start time found for file: {}. Skipping retry.", jsonFile);
+      log.debug("No start time found for JSON-RPC file: {}. Skipping retry.", jsonFile);
       return;
     }
 
@@ -181,6 +186,7 @@ private void scheduleRetry(final Path jsonFile, final Duration currentDelay) {
       log.error("Exceeded maximum retry duration for rej-tx json-rpc file: {}", jsonFile);
       fileStartTimes.remove(jsonFile);
       // TODO (review suggestion) : Log that notification is discarded and not sent to endpoint
+      // TODO : Consider moving the file to `failed` directory for manual inspection
     }
   }
 

From 45363ccbc10c174c0e095b915c370b312cc11bfb Mon Sep 17 00:00:00 2001
From: Usman Saleem <usman@usmans.info>
Date: Wed, 11 Sep 2024 17:45:12 +1000
Subject: [PATCH 22/26] Update logs message. Move discarded json-rpc calls to
 separate directory for manual inspection

---
 .../linea/jsonrpc/JsonRpcManager.java         | 49 ++++++++++++-------
 1 file changed, 32 insertions(+), 17 deletions(-)

diff --git a/sequencer/src/main/java/net/consensys/linea/jsonrpc/JsonRpcManager.java b/sequencer/src/main/java/net/consensys/linea/jsonrpc/JsonRpcManager.java
index 24aeb60e..52187d03 100644
--- a/sequencer/src/main/java/net/consensys/linea/jsonrpc/JsonRpcManager.java
+++ b/sequencer/src/main/java/net/consensys/linea/jsonrpc/JsonRpcManager.java
@@ -22,6 +22,7 @@
 import java.nio.file.FileAlreadyExistsException;
 import java.nio.file.Files;
 import java.nio.file.Path;
+import java.nio.file.StandardCopyOption;
 import java.nio.file.StandardOpenOption;
 import java.time.Duration;
 import java.time.Instant;
@@ -77,14 +78,14 @@ public JsonRpcManager(final Path besuDataDir, final URI rejectedTxEndpoint) {
   /** Load existing JSON-RPC and submit them. */
   public JsonRpcManager start() {
     try {
-      // Create the rej-tx-rpc directory if it doesn't exist
-      Files.createDirectories(rejTxRpcDirectory);
+      // Create the rej_tx_rpc/discarded directories if it doesn't exist
+      Files.createDirectories(rejTxRpcDirectory.resolve("discarded"));
 
       // Load existing JSON files
       processExistingJsonFiles();
       return this;
-    } catch (IOException e) {
-      log.error("Failed to create or access rej-tx-rpc directory", e);
+    } catch (final IOException e) {
+      log.error("Failed to create or access directory: {}", rejTxRpcDirectory, e);
       throw new UncheckedIOException(e);
     }
   }
@@ -101,13 +102,16 @@ public void shutdown() {
    * @param jsonContent The JSON content to submit
    */
   public void submitNewJsonRpcCall(final String jsonContent) {
+    final Path jsonFile;
     try {
-      final Path jsonFile = saveJsonToFile(jsonContent);
-      fileStartTimes.put(jsonFile, Instant.now());
-      submitJsonRpcCall(jsonFile, INITIAL_RETRY_DELAY_DURATION);
+      jsonFile = saveJsonToFile(jsonContent);
     } catch (final IOException e) {
-      log.error("Failed to save JSON content", e);
+      log.error("Failed to save JSON-RPC content", e);
+      return;
     }
+
+    fileStartTimes.put(jsonFile, Instant.now());
+    submitJsonRpcCall(jsonFile, INITIAL_RETRY_DELAY_DURATION);
   }
 
   private void processExistingJsonFiles() {
@@ -121,14 +125,14 @@ private void processExistingJsonFiles() {
         }
       }
 
+      log.info("Loaded {} existing JSON-RPC files for reporting", sortedFiles.size());
+
       for (Path path : sortedFiles) {
         fileStartTimes.put(path, Instant.now());
         submitJsonRpcCall(path, INITIAL_RETRY_DELAY_DURATION);
       }
-
-      log.info("Loaded {} existing JSON files for rej-tx reporting", sortedFiles.size());
     } catch (final IOException e) {
-      log.error("Failed to load existing JSON files", e);
+      log.error("Failed to load existing JSON-RPC files", e);
     }
   }
 
@@ -183,10 +187,21 @@ private void scheduleRetry(final Path jsonFile, final Duration currentDelay) {
           currentDelay.toMillis(),
           TimeUnit.MILLISECONDS);
     } else {
-      log.error("Exceeded maximum retry duration for rej-tx json-rpc file: {}", jsonFile);
-      fileStartTimes.remove(jsonFile);
-      // TODO (review suggestion) : Log that notification is discarded and not sent to endpoint
-      // TODO : Consider moving the file to `failed` directory for manual inspection
+      log.error("Exceeded maximum retry duration for JSON-RPC file: {}.", jsonFile);
+      final Path destination =
+          rejTxRpcDirectory.resolve("discarded").resolve(jsonFile.getFileName());
+
+      try {
+        Files.move(jsonFile, destination, StandardCopyOption.REPLACE_EXISTING);
+        log.error(
+            "The JSON-RPC file {} has been moved to: {}. The tx notification has been discarded.",
+            jsonFile,
+            destination);
+      } catch (final IOException e) {
+        log.error("Failed to move JSON-RPC file to discarded directory: {}", jsonFile, e);
+      } finally {
+        fileStartTimes.remove(jsonFile);
+      }
     }
   }
 
@@ -218,7 +233,7 @@ private boolean sendJsonRpcCall(final String jsonContent) {
       }
       // Check for result
       if (jsonNode.has("result")) {
-        String status = jsonNode.get("result").get("status").asText();
+        final String status = jsonNode.get("result").get("status").asText();
         log.debug("Rejected-tx JSON-RPC call successful. Status: {}", status);
         return true;
       }
@@ -252,7 +267,7 @@ private Path saveJsonToFile(final String jsonContent) throws IOException {
       return Files.writeString(filePath, jsonContent, StandardOpenOption.CREATE_NEW);
     } catch (final FileAlreadyExistsException e) {
       // This should never happen with UUID, but just in case
-      log.warn("Unexpected file collision occurred: {}", filePath);
+      log.warn("Unexpected JSON-RPC filename collision occurred: {}", filePath);
       throw new IOException("Unexpected file name collision", e);
     }
   }

From a784018fa8083b79e10d681a7524a825a7ff4df0 Mon Sep 17 00:00:00 2001
From: Usman Saleem <usman@usmans.info>
Date: Wed, 11 Sep 2024 18:33:53 +1000
Subject: [PATCH 23/26] Added unit test for processing json-rpc during start.
 Also introduced Awaitaility instead of Thread.sleep

---
 sequencer/build.gradle                        |   1 +
 .../linea/jsonrpc/JsonRpcManager.java         |   8 +-
 .../jsonrpc/JsonRpcManagerStartTest.java      | 111 ++++++++++++++++++
 .../linea/jsonrpc/JsonRpcManagerTest.java     |  54 +++++----
 4 files changed, 152 insertions(+), 22 deletions(-)
 create mode 100644 sequencer/src/test/java/net/consensys/linea/jsonrpc/JsonRpcManagerStartTest.java

diff --git a/sequencer/build.gradle b/sequencer/build.gradle
index 782b9938..a68b8970 100644
--- a/sequencer/build.gradle
+++ b/sequencer/build.gradle
@@ -71,6 +71,7 @@ dependencies {
   testImplementation "${besuArtifactGroup}.internal:rlp"
   testImplementation "${besuArtifactGroup}.internal:core"
   testImplementation "${besuArtifactGroup}:plugin-api"
+  testImplementation "org.awaitility:awaitility"
 
   // workaround for bug https://github.com/dnsjava/dnsjava/issues/329, remove when upgraded upstream
   testImplementation 'dnsjava:dnsjava:3.6.1'
diff --git a/sequencer/src/main/java/net/consensys/linea/jsonrpc/JsonRpcManager.java b/sequencer/src/main/java/net/consensys/linea/jsonrpc/JsonRpcManager.java
index 52187d03..a0331579 100644
--- a/sequencer/src/main/java/net/consensys/linea/jsonrpc/JsonRpcManager.java
+++ b/sequencer/src/main/java/net/consensys/linea/jsonrpc/JsonRpcManager.java
@@ -38,6 +38,7 @@
 
 import com.fasterxml.jackson.databind.JsonNode;
 import com.fasterxml.jackson.databind.ObjectMapper;
+import com.google.common.annotations.VisibleForTesting;
 import lombok.extern.slf4j.Slf4j;
 import okhttp3.MediaType;
 import okhttp3.OkHttpClient;
@@ -104,7 +105,7 @@ public void shutdown() {
   public void submitNewJsonRpcCall(final String jsonContent) {
     final Path jsonFile;
     try {
-      jsonFile = saveJsonToFile(jsonContent);
+      jsonFile = saveJsonToDir(jsonContent, rejTxRpcDirectory);
     } catch (final IOException e) {
       log.error("Failed to save JSON-RPC content", e);
       return;
@@ -253,11 +254,14 @@ private boolean sendJsonRpcCall(final String jsonContent) {
    * <p>The file naming format is: rpc_[timestamp]_[uuid].json
    *
    * @param jsonContent The JSON string to be written to the file.
+   * @param rejTxRpcDirectory The directory where the file should be saved.
    * @return The Path object representing the newly created file.
    * @throws IOException If an I/O error occurs while writing the file, including unexpected file
    *     collisions.
    */
-  private Path saveJsonToFile(final String jsonContent) throws IOException {
+  @VisibleForTesting
+  static Path saveJsonToDir(final String jsonContent, final Path rejTxRpcDirectory)
+      throws IOException {
     final String timestamp = generateTimestampWithNanos();
     final String uuid = UUID.randomUUID().toString();
     final String fileName = String.format("rpc_%s_%s.json", timestamp, uuid);
diff --git a/sequencer/src/test/java/net/consensys/linea/jsonrpc/JsonRpcManagerStartTest.java b/sequencer/src/test/java/net/consensys/linea/jsonrpc/JsonRpcManagerStartTest.java
new file mode 100644
index 00000000..6119f4b0
--- /dev/null
+++ b/sequencer/src/test/java/net/consensys/linea/jsonrpc/JsonRpcManagerStartTest.java
@@ -0,0 +1,111 @@
+/*
+ * Copyright Consensys Software Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on
+ * an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+package net.consensys.linea.jsonrpc;
+
+import static com.github.tomakehurst.wiremock.client.WireMock.aResponse;
+import static com.github.tomakehurst.wiremock.client.WireMock.exactly;
+import static com.github.tomakehurst.wiremock.client.WireMock.post;
+import static com.github.tomakehurst.wiremock.client.WireMock.postRequestedFor;
+import static com.github.tomakehurst.wiremock.client.WireMock.stubFor;
+import static com.github.tomakehurst.wiremock.client.WireMock.urlEqualTo;
+import static com.github.tomakehurst.wiremock.client.WireMock.verify;
+import static java.util.concurrent.TimeUnit.SECONDS;
+import static org.awaitility.Awaitility.await;
+import static org.mockito.Mockito.when;
+
+import java.io.IOException;
+import java.net.URI;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.time.Instant;
+
+import com.github.tomakehurst.wiremock.junit5.WireMockRuntimeInfo;
+import com.github.tomakehurst.wiremock.junit5.WireMockTest;
+import net.consensys.linea.sequencer.txselection.selectors.TestTransactionEvaluationContext;
+import org.apache.tuweni.bytes.Bytes;
+import org.hyperledger.besu.datatypes.PendingTransaction;
+import org.hyperledger.besu.datatypes.Transaction;
+import org.hyperledger.besu.plugin.data.ProcessableBlockHeader;
+import org.hyperledger.besu.plugin.data.TransactionSelectionResult;
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.junit.jupiter.api.io.TempDir;
+import org.mockito.Mock;
+import org.mockito.junit.jupiter.MockitoExtension;
+
+@WireMockTest
+@ExtendWith(MockitoExtension.class)
+public class JsonRpcManagerStartTest {
+  @TempDir private Path tempDataDir;
+  private JsonRpcManager jsonRpcManager;
+  private final Bytes randomEncodedBytes = Bytes.random(32);
+  @Mock private PendingTransaction pendingTransaction;
+  @Mock private ProcessableBlockHeader pendingBlockHeader;
+  @Mock private Transaction transaction;
+
+  @BeforeEach
+  void init(final WireMockRuntimeInfo wmInfo) throws IOException {
+    // create temp directories
+    final Path rejectedTxDir = tempDataDir.resolve("rej_tx_rpc");
+    Files.createDirectories(rejectedTxDir);
+
+    // mock stubbing
+    when(pendingBlockHeader.getNumber()).thenReturn(1L);
+    when(pendingTransaction.getTransaction()).thenReturn(transaction);
+    when(transaction.encoded()).thenReturn(randomEncodedBytes);
+
+    // save rejected transaction in tempDataDir so that they are processed by the
+    // JsonRpcManager.start
+    for (int i = 0; i < 3; i++) {
+      final TestTransactionEvaluationContext context =
+          new TestTransactionEvaluationContext(pendingTransaction)
+              .setPendingBlockHeader(pendingBlockHeader);
+      final TransactionSelectionResult result = TransactionSelectionResult.invalid("test" + i);
+      final Instant timestamp = Instant.now();
+      final String jsonRpcCall =
+          JsonRpcRequestBuilder.buildRejectedTxRequest(context, result, timestamp);
+
+      JsonRpcManager.saveJsonToDir(jsonRpcCall, rejectedTxDir);
+    }
+
+    jsonRpcManager = new JsonRpcManager(tempDataDir, URI.create(wmInfo.getHttpBaseUrl()));
+  }
+
+  @AfterEach
+  void cleanup() {
+    jsonRpcManager.shutdown();
+  }
+
+  @Test
+  void existingJsonRpcFilesAreProcessedOnStart() throws InterruptedException {
+    stubFor(
+        post(urlEqualTo("/"))
+            .willReturn(
+                aResponse()
+                    .withStatus(200)
+                    .withHeader("Content-Type", "application/json")
+                    .withBody(
+                        "{\"jsonrpc\":\"2.0\",\"result\":{ \"status\": \"SAVED\"},\"id\":1}")));
+    // method under test
+    jsonRpcManager.start();
+
+    // Use Awaitility to wait for the condition to be met
+    await()
+        .atMost(2, SECONDS)
+        .untilAsserted(() -> verify(exactly(3), postRequestedFor(urlEqualTo("/"))));
+  }
+}
diff --git a/sequencer/src/test/java/net/consensys/linea/jsonrpc/JsonRpcManagerTest.java b/sequencer/src/test/java/net/consensys/linea/jsonrpc/JsonRpcManagerTest.java
index efd57c6e..d736505b 100644
--- a/sequencer/src/test/java/net/consensys/linea/jsonrpc/JsonRpcManagerTest.java
+++ b/sequencer/src/test/java/net/consensys/linea/jsonrpc/JsonRpcManagerTest.java
@@ -23,7 +23,9 @@
 import static com.github.tomakehurst.wiremock.client.WireMock.stubFor;
 import static com.github.tomakehurst.wiremock.client.WireMock.urlEqualTo;
 import static com.github.tomakehurst.wiremock.client.WireMock.verify;
+import static java.util.concurrent.TimeUnit.SECONDS;
 import static org.assertj.core.api.Assertions.assertThat;
+import static org.awaitility.Awaitility.await;
 import static org.mockito.Mockito.when;
 
 import java.io.IOException;
@@ -100,11 +102,14 @@ void rejectedTxIsReported() throws InterruptedException {
         JsonRpcRequestBuilder.buildRejectedTxRequest(context, result, timestamp);
     jsonRpcManager.submitNewJsonRpcCall(jsonRpcCall);
 
-    // sleep a bit to allow async processing
-    Thread.sleep(1000);
-
-    // assert that the expected json-rpc request was sent to WireMock
-    verify(exactly(1), postRequestedFor(urlEqualTo("/")).withRequestBody(equalToJson(jsonRpcCall)));
+    // Use Awaitility to wait for the condition to be met
+    await()
+        .atMost(2, SECONDS)
+        .untilAsserted(
+            () ->
+                verify(
+                    exactly(1),
+                    postRequestedFor(urlEqualTo("/")).withRequestBody(equalToJson(jsonRpcCall))));
   }
 
   @Test
@@ -146,11 +151,14 @@ void firstCallErrorSecondCallSuccessScenario() throws InterruptedException, IOEx
     // Submit the call, the scheduler will retry the failed call
     jsonRpcManager.submitNewJsonRpcCall(jsonRpcCall);
 
-    // Sleep to allow async processing
-    Thread.sleep(2000); // Increased sleep time to allow for two calls
-
-    // Verify that two requests were made
-    verify(exactly(2), postRequestedFor(urlEqualTo("/")).withRequestBody(equalToJson(jsonRpcCall)));
+    // Use Awaitility to wait for the condition to be met
+    await()
+        .atMost(2, SECONDS)
+        .untilAsserted(
+            () ->
+                verify(
+                    exactly(2),
+                    postRequestedFor(urlEqualTo("/")).withRequestBody(equalToJson(jsonRpcCall))));
 
     // Verify that the JSON file no longer exists in the directory (as the second call was
     // successful)
@@ -187,11 +195,14 @@ void serverRespondingWithErrorScenario() throws InterruptedException, IOExceptio
     // Submit the call
     jsonRpcManager.submitNewJsonRpcCall(jsonRpcCall);
 
-    // Sleep to allow async processing
-    Thread.sleep(1000);
-
-    // Verify that the request was made
-    verify(exactly(1), postRequestedFor(urlEqualTo("/")).withRequestBody(equalToJson(jsonRpcCall)));
+    // Use Awaitility to wait for the condition to be met
+    await()
+        .atMost(2, SECONDS)
+        .untilAsserted(
+            () ->
+                verify(
+                    exactly(1),
+                    postRequestedFor(urlEqualTo("/")).withRequestBody(equalToJson(jsonRpcCall))));
 
     // Verify that the JSON file still exists in the directory (as the call was unsuccessful)
     final Path rejTxRpcDir = tempDataDir.resolve("rej_tx_rpc");
@@ -247,11 +258,14 @@ void firstTwoCallsErrorThenLastCallSuccessScenario() throws InterruptedException
     // Submit the call, the scheduler will retry the failed calls
     jsonRpcManager.submitNewJsonRpcCall(jsonRpcCall);
 
-    // Sleep to allow async processing
-    Thread.sleep(6000); // Increased sleep time to allow for three calls
-
-    // Verify that two requests were made
-    verify(exactly(3), postRequestedFor(urlEqualTo("/")).withRequestBody(equalToJson(jsonRpcCall)));
+    // Use Awaitility to wait for the condition to be met
+    await()
+        .atMost(6, SECONDS)
+        .untilAsserted(
+            () ->
+                verify(
+                    exactly(3),
+                    postRequestedFor(urlEqualTo("/")).withRequestBody(equalToJson(jsonRpcCall))));
 
     // Verify that the JSON file no longer exists in the directory (as the second call was
     // successful)

From 4cde3219163255c200fc497f1feaee6fe1622f13 Mon Sep 17 00:00:00 2001
From: Usman Saleem <usman@usmans.info>
Date: Thu, 12 Sep 2024 10:10:44 +1000
Subject: [PATCH 24/26] Use Instant.now to generate timestamp

---
 .../net/consensys/linea/jsonrpc/JsonRpcManager.java   | 11 +++++------
 1 file changed, 5 insertions(+), 6 deletions(-)

diff --git a/sequencer/src/main/java/net/consensys/linea/jsonrpc/JsonRpcManager.java b/sequencer/src/main/java/net/consensys/linea/jsonrpc/JsonRpcManager.java
index a0331579..c2a5b530 100644
--- a/sequencer/src/main/java/net/consensys/linea/jsonrpc/JsonRpcManager.java
+++ b/sequencer/src/main/java/net/consensys/linea/jsonrpc/JsonRpcManager.java
@@ -276,11 +276,10 @@ static Path saveJsonToDir(final String jsonContent, final Path rejTxRpcDirectory
     }
   }
 
-  private static String generateTimestampWithNanos() {
-    long millis = System.currentTimeMillis();
-    long nanos = System.nanoTime();
-    long millisPart = millis % 1000;
-    long nanosPart = nanos % 1_000_000;
-    return String.format("%d%03d%06d", millis / 1000, millisPart, nanosPart);
+  static String generateTimestampWithNanos() {
+    final Instant now = Instant.now();
+    final long seconds = now.getEpochSecond();
+    final int nanos = now.getNano();
+    return String.format("%d%09d", seconds, nanos);
   }
 }

From aabf838abe3d2cf914b22990f297351c9a18a7c7 Mon Sep 17 00:00:00 2001
From: Usman Saleem <usman@usmans.info>
Date: Thu, 12 Sep 2024 14:27:51 +1000
Subject: [PATCH 25/26] Update changelog

---
 CHANGELOG.md | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index d5bcc41d..13b3f36f 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,8 @@
 # Changelog
 
+# Next release
+* feat: Report rejected transactions to an external service [#69](https://github.com/Consensys/linea-sequencer/pull/69)
+
 ## 0.3.0-rc2.1
 * bump linea-arithmetization version to 0.3.0-rc2 [#62](https://github.com/Consensys/linea-sequencer/pull/62)
 * bump Linea-Besu version to 24.7-develop-c0029e6 (delivery-28) [#62](https://github.com/Consensys/linea-sequencer/pull/62)

From 900ba408117fa0b7aa6610f745432ba09bcf3987 Mon Sep 17 00:00:00 2001
From: Usman Saleem <usman@usmans.info>
Date: Thu, 12 Sep 2024 21:34:01 +1000
Subject: [PATCH 26/26] post merge

---
 .../linea/jsonrpc/JsonRpcManagerStartTest.java       |  3 +--
 .../consensys/linea/jsonrpc/JsonRpcManagerTest.java  | 12 ++++--------
 .../selectors/TestTransactionEvaluationContext.java  |  4 ++--
 3 files changed, 7 insertions(+), 12 deletions(-)

diff --git a/sequencer/src/test/java/net/consensys/linea/jsonrpc/JsonRpcManagerStartTest.java b/sequencer/src/test/java/net/consensys/linea/jsonrpc/JsonRpcManagerStartTest.java
index 6119f4b0..98c6be2a 100644
--- a/sequencer/src/test/java/net/consensys/linea/jsonrpc/JsonRpcManagerStartTest.java
+++ b/sequencer/src/test/java/net/consensys/linea/jsonrpc/JsonRpcManagerStartTest.java
@@ -72,8 +72,7 @@ void init(final WireMockRuntimeInfo wmInfo) throws IOException {
     // JsonRpcManager.start
     for (int i = 0; i < 3; i++) {
       final TestTransactionEvaluationContext context =
-          new TestTransactionEvaluationContext(pendingTransaction)
-              .setPendingBlockHeader(pendingBlockHeader);
+          new TestTransactionEvaluationContext(pendingBlockHeader, pendingTransaction);
       final TransactionSelectionResult result = TransactionSelectionResult.invalid("test" + i);
       final Instant timestamp = Instant.now();
       final String jsonRpcCall =
diff --git a/sequencer/src/test/java/net/consensys/linea/jsonrpc/JsonRpcManagerTest.java b/sequencer/src/test/java/net/consensys/linea/jsonrpc/JsonRpcManagerTest.java
index d736505b..d0f567c9 100644
--- a/sequencer/src/test/java/net/consensys/linea/jsonrpc/JsonRpcManagerTest.java
+++ b/sequencer/src/test/java/net/consensys/linea/jsonrpc/JsonRpcManagerTest.java
@@ -92,8 +92,7 @@ void rejectedTxIsReported() throws InterruptedException {
                         "{\"jsonrpc\":\"2.0\",\"result\":{ \"status\": \"SAVED\"},\"id\":1}")));
 
     final TestTransactionEvaluationContext context =
-        new TestTransactionEvaluationContext(pendingTransaction)
-            .setPendingBlockHeader(pendingBlockHeader);
+        new TestTransactionEvaluationContext(pendingBlockHeader, pendingTransaction);
     final TransactionSelectionResult result = TransactionSelectionResult.invalid("test");
     final Instant timestamp = Instant.now();
 
@@ -139,8 +138,7 @@ void firstCallErrorSecondCallSuccessScenario() throws InterruptedException, IOEx
 
     // Prepare test data
     final TestTransactionEvaluationContext context =
-        new TestTransactionEvaluationContext(pendingTransaction)
-            .setPendingBlockHeader(pendingBlockHeader);
+        new TestTransactionEvaluationContext(pendingBlockHeader, pendingTransaction);
     final TransactionSelectionResult result = TransactionSelectionResult.invalid("test");
     final Instant timestamp = Instant.now();
 
@@ -183,8 +181,7 @@ void serverRespondingWithErrorScenario() throws InterruptedException, IOExceptio
 
     // Prepare test data
     final TestTransactionEvaluationContext context =
-        new TestTransactionEvaluationContext(pendingTransaction)
-            .setPendingBlockHeader(pendingBlockHeader);
+        new TestTransactionEvaluationContext(pendingBlockHeader, pendingTransaction);
     final TransactionSelectionResult result = TransactionSelectionResult.invalid("test");
     final Instant timestamp = Instant.now();
 
@@ -246,8 +243,7 @@ void firstTwoCallsErrorThenLastCallSuccessScenario() throws InterruptedException
 
     // Prepare test data
     final TestTransactionEvaluationContext context =
-        new TestTransactionEvaluationContext(pendingTransaction)
-            .setPendingBlockHeader(pendingBlockHeader);
+        new TestTransactionEvaluationContext(pendingBlockHeader, pendingTransaction);
     final TransactionSelectionResult result = TransactionSelectionResult.invalid("test");
     final Instant timestamp = Instant.now();
 
diff --git a/sequencer/src/test/java/net/consensys/linea/sequencer/txselection/selectors/TestTransactionEvaluationContext.java b/sequencer/src/test/java/net/consensys/linea/sequencer/txselection/selectors/TestTransactionEvaluationContext.java
index a08533ce..45782244 100644
--- a/sequencer/src/test/java/net/consensys/linea/sequencer/txselection/selectors/TestTransactionEvaluationContext.java
+++ b/sequencer/src/test/java/net/consensys/linea/sequencer/txselection/selectors/TestTransactionEvaluationContext.java
@@ -20,7 +20,8 @@
 import org.hyperledger.besu.plugin.data.ProcessableBlockHeader;
 import org.hyperledger.besu.plugin.services.txselection.TransactionEvaluationContext;
 
-class TestTransactionEvaluationContext implements TransactionEvaluationContext<PendingTransaction> {
+public class TestTransactionEvaluationContext
+    implements TransactionEvaluationContext<PendingTransaction> {
   private ProcessableBlockHeader processableBlockHeader;
   private PendingTransaction pendingTransaction;
   private Wei transactionGasPrice;
@@ -48,7 +49,6 @@ public ProcessableBlockHeader getPendingBlockHeader() {
     return processableBlockHeader;
   }
 
-
   @Override
   public PendingTransaction getPendingTransaction() {
     return pendingTransaction;