HDDS-10425. Increase OM transaction index for non-Ratis based on exis…

…ting Ratis transactionInfoTable (#6281)

hadoop-ozone/integration-test/src/test/java/org/apache/hadoop/ozone/om/TestOMEpochForNonRatis.java

@@ -24,6 +24,8 @@
 import org.apache.hadoop.hdds.client.ReplicationFactor;
 import org.apache.hadoop.hdds.client.ReplicationType;
 import org.apache.hadoop.hdds.conf.OzoneConfiguration;
+import org.apache.hadoop.hdds.utils.TransactionInfo;
+import org.apache.hadoop.hdds.utils.db.Table;
 import org.apache.hadoop.ozone.MiniOzoneCluster;
 import org.apache.hadoop.ozone.OmUtils;
 import org.apache.hadoop.ozone.client.ObjectStore;
@@ -42,11 +44,13 @@
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.Timeout;
 
+import static org.apache.hadoop.ozone.OzoneConsts.TRANSACTION_INFO_KEY;
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static java.nio.charset.StandardCharsets.UTF_8;
 import static org.apache.hadoop.ozone.OmUtils.EPOCH_ID_SHIFT;
 import static org.apache.hadoop.ozone.OmUtils.EPOCH_WHEN_RATIS_NOT_ENABLED;
 import static org.apache.hadoop.ozone.om.OMConfigKeys.OZONE_OM_RATIS_ENABLE_KEY;
+import static org.junit.jupiter.api.Assertions.assertTrue;
 
 /**
  * Tests OM epoch generation for when Ratis is not enabled.
@@ -145,6 +149,48 @@ public void testUniqueTrxnIndexOnOMRestart() throws Exception {
     assertEquals(4, om.getLastTrxnIndexForNonRatis());
   }
 
+  @Test
+  public void testIncreaseTrxnIndexBasedOnExistingDB() throws Exception {
+    // Set transactionInfo.getTerm() not -1 to mock the DB migrated from ratis cluster.
+    // When OM is first started from the existing ratis DB, the transaction index for
+    // requests should not start from 0. It should incrementally increase from the last
+    // transaction index which was stored in DB transactionInfoTable before started.
+
+    String volumeName = "volume" + RandomStringUtils.randomNumeric(5);
+    String bucketName = "bucket" + RandomStringUtils.randomNumeric(5);
+    String keyName = "key" + RandomStringUtils.randomNumeric(5);
+
+    OzoneManager om = cluster.getOzoneManager();
+    ObjectStore objectStore = client.getObjectStore();
+
+    objectStore.createVolume(volumeName);
+    OzoneVolume ozoneVolume = objectStore.getVolume(volumeName);
+    ozoneVolume.createBucket(bucketName);
+
+    Table<String, TransactionInfo> transactionInfoTable = om.getMetadataManager().getTransactionInfoTable();
+    long initIndex = transactionInfoTable.get(TRANSACTION_INFO_KEY).getTransactionIndex();
+    // Set transactionInfo.getTerm() = 1 to mock the DB migrated from ratis cluster
+    transactionInfoTable.put(TRANSACTION_INFO_KEY, TransactionInfo.valueOf(1, initIndex));
+    TransactionInfo transactionInfo = transactionInfoTable.get(TRANSACTION_INFO_KEY);
+    // Verify transaction term != -1 and index > 1
+    assertEquals(1, transactionInfo.getTerm());
+    assertTrue(initIndex > 1);
+
+    // Restart the OM and create new object
+    cluster.restartOzoneManager();
+
+    String data = "random data";
+    OzoneOutputStream ozoneOutputStream = ozoneVolume.getBucket(bucketName).createKey(keyName, data.length());
+    ozoneOutputStream.write(data.getBytes(UTF_8), 0, data.length());
+    ozoneOutputStream.close();
+
+    // Transaction index after OM restart is incremented by 2 (create and commit op) from the last
+    // transaction index before OM restart rather than from 0.
+    // So, the transactionIndex should be (initIndex + 2) rather than (0 + 2)
+    assertEquals(initIndex + 2,
+        om.getMetadataManager().getTransactionInfoTable().get(TRANSACTION_INFO_KEY).getTransactionIndex());
+  }
+
   @Test
   public void testEpochIntegrationInObjectID() throws Exception {
     // Create a volume and check the objectID has the epoch as

hadoop-ozone/ozone-manager/src/main/java/org/apache/hadoop/ozone/om/OzoneManager.java

@@ -2153,15 +2153,16 @@ public long getObjectIdFromTxId(long trxnId) {
   long getLastTrxnIndexForNonRatis() throws IOException {
     TransactionInfo transactionInfo =
         TransactionInfo.readTransactionInfo(metadataManager);
-    // If the OMTransactionInfo does not exist in DB or if the term is not -1
-    // (corresponding to non-Ratis cluster), return 0 so that new incoming
+    // If the OMTransactionInfo does not exist in DB, return 0 so that new incoming
     // requests can have transaction index starting from 1.
-    if (transactionInfo == null || transactionInfo.getTerm() != -1) {
+    if (transactionInfo == null) {
       return 0;
     }
-    // If there exists a last transaction index in DB, the new incoming
-    // requests in non-Ratis cluster must have transaction index
-    // incrementally increasing from the stored transaction index onwards.
+    // If there exists a last transaction index in DB, including two cases:
+    // 1. transactionInfo.getTerm() == -1 corresponds to a non-Ratis cluster
+    // 2. transactionInfo.getTerm() != -1 indicates that the DB may be migrated from Ratis cluster
+    // For both cases above, the new incoming requests in non-Ratis cluster must have
+    // transaction index incrementally increasing from the stored transaction index onwards.
     return transactionInfo.getTransactionIndex();
   }