Prevent delete policy for active executing policy (#45472)

This commit adds a lock to the delete policy, in the same way that the
locking is done for policy execution. It also creates a test to exercise
the delete transport action, and modifies an existing test to provide a
common set of functions for saving and deleting policies.

Author: hub-cap

x-pack/plugin/enrich/src/main/java/org/elasticsearch/xpack/enrich/EnrichPolicyLocks.java

@@ -19,20 +19,24 @@
  * state of any policy executions in flight. This execution state can be captured and then later be used to verify that no policy
  * executions have started in the time between the first state capturing.
  */
-class EnrichPolicyLocks {
+public class EnrichPolicyLocks {
 
     /**
      * A snapshot in time detailing if any policy executions are in flight and total number of local executions that
      * have been kicked off since the node has started
      */
-    static class EnrichPolicyExecutionState {
-        final boolean arePoliciesInFlight;
+    public static class EnrichPolicyExecutionState {
+        final boolean anyPolicyInFlight;
         final long executions;
 
-        EnrichPolicyExecutionState(boolean arePoliciesInFlight, long executions) {
-            this.arePoliciesInFlight = arePoliciesInFlight;
+        EnrichPolicyExecutionState(boolean anyPolicyInFlight, long executions) {
+            this.anyPolicyInFlight = anyPolicyInFlight;
             this.executions = executions;
         }
+
+        public boolean isAnyPolicyInFlight() {
+            return anyPolicyInFlight;
+        }
     }
 
     /**
@@ -54,19 +58,19 @@ static class EnrichPolicyExecutionState {
     private final AtomicLong policyRunCounter = new AtomicLong(0L);
 
     /**
-     * Locks a policy for execution. If the policy is currently executing, this method will immediately throw without waiting.
-     * This method only blocks if another thread is currently capturing the current policy execution state.
+     * Locks a policy to prevent concurrent execution. If the policy is currently executing, this method will immediately
+     * throw without waiting. This method only blocks if another thread is currently capturing the current policy execution state.
      * @param policyName The policy name to lock for execution
      * @throws EsRejectedExecutionException if the policy is locked already or if the maximum number of concurrent policy executions
      *                                      has been reached
      */
-    void lockPolicy(String policyName) {
+    public void lockPolicy(String policyName) {
         currentStateLock.readLock().lock();
         try {
             Semaphore runLock = policyLocks.computeIfAbsent(policyName, (name) -> new Semaphore(1));
             boolean acquired = runLock.tryAcquire();
             if (acquired == false) {
-                throw new EsRejectedExecutionException("Policy execution failed. Policy execution for [" + policyName +
+                throw new EsRejectedExecutionException("Could not obtain lock because policy execution for ["  + policyName +
                     "] is already in progress.");
             }
             policyRunCounter.incrementAndGet();
@@ -80,7 +84,7 @@ void lockPolicy(String policyName) {
      * currently starting its execution and returns an appropriate state.
      * @return The current state of in-flight policy executions
      */
-    EnrichPolicyExecutionState captureExecutionState() {
+    public EnrichPolicyExecutionState captureExecutionState() {
         if (currentStateLock.writeLock().tryLock()) {
             try {
                 long revision = policyRunCounter.get();
@@ -101,15 +105,15 @@ EnrichPolicyExecutionState captureExecutionState() {
      */
     boolean isSameState(EnrichPolicyExecutionState previousState) {
         EnrichPolicyExecutionState currentState = captureExecutionState();
-        return currentState.arePoliciesInFlight == previousState.arePoliciesInFlight &&
+        return currentState.anyPolicyInFlight == previousState.anyPolicyInFlight &&
             currentState.executions == previousState.executions;
     }
 
     /**
      * Releases the lock for a given policy name, allowing it to be executed.
      * @param policyName The policy to release.
      */
-    void releasePolicy(String policyName) {
+    public void releasePolicy(String policyName) {
         currentStateLock.readLock().lock();
         try {
             policyLocks.remove(policyName);

x-pack/plugin/enrich/src/main/java/org/elasticsearch/xpack/enrich/EnrichPolicyMaintenanceService.java

@@ -137,7 +137,7 @@ void cleanUpEnrichIndices() {
             .indicesOptions(IndicesOptions.lenientExpand());
         // Check that no enrich policies are being executed
         final EnrichPolicyLocks.EnrichPolicyExecutionState executionState = enrichPolicyLocks.captureExecutionState();
-        if (executionState.arePoliciesInFlight == false) {
+        if (executionState.isAnyPolicyInFlight() == false) {
             client.admin().indices().getIndex(indices, new ActionListener<GetIndexResponse>() {
                 @Override
                 public void onResponse(GetIndexResponse getIndexResponse) {

x-pack/plugin/enrich/src/main/java/org/elasticsearch/xpack/enrich/action/TransportDeleteEnrichPolicyAction.java

@@ -25,6 +25,7 @@
 import org.elasticsearch.xpack.core.enrich.EnrichPolicy;
 import org.elasticsearch.xpack.core.enrich.action.DeleteEnrichPolicyAction;
 import org.elasticsearch.xpack.enrich.AbstractEnrichProcessor;
+import org.elasticsearch.xpack.enrich.EnrichPolicyLocks;
 import org.elasticsearch.xpack.enrich.EnrichStore;
 
 import java.io.IOException;
@@ -33,6 +34,7 @@
 
 public class TransportDeleteEnrichPolicyAction extends TransportMasterNodeAction<DeleteEnrichPolicyAction.Request, AcknowledgedResponse> {
 
+    private final EnrichPolicyLocks enrichPolicyLocks;
     private final IngestService ingestService;
 
     @Inject
@@ -41,9 +43,11 @@ public TransportDeleteEnrichPolicyAction(TransportService transportService,
                                              ThreadPool threadPool,
                                              ActionFilters actionFilters,
                                              IndexNameExpressionResolver indexNameExpressionResolver,
+                                             EnrichPolicyLocks enrichPolicyLocks,
                                              IngestService ingestService) {
         super(DeleteEnrichPolicyAction.NAME, transportService, clusterService, threadPool, actionFilters,
             DeleteEnrichPolicyAction.Request::new, indexNameExpressionResolver);
+        this.enrichPolicyLocks = enrichPolicyLocks;
         this.ingestService = ingestService;
     }
 
@@ -64,6 +68,7 @@ protected AcknowledgedResponse read(StreamInput in) throws IOException {
     @Override
     protected void masterOperation(DeleteEnrichPolicyAction.Request request, ClusterState state,
                                    ActionListener<AcknowledgedResponse> listener) throws Exception {
+        enrichPolicyLocks.lockPolicy(request.getName());
         List<PipelineConfiguration> pipelines = IngestService.getPipelines(state);
         EnrichPolicy policy = EnrichStore.getPolicy(request.getName(), state);
         List<String> pipelinesWithProcessors = new ArrayList<>();
@@ -79,13 +84,15 @@ protected void masterOperation(DeleteEnrichPolicyAction.Request request, Cluster
         }
 
         if (pipelinesWithProcessors.isEmpty() == false) {
+            enrichPolicyLocks.releasePolicy(request.getName());
             listener.onFailure(
                 new ElasticsearchStatusException("Could not delete policy [{}] because a pipeline is referencing it {}",
                     RestStatus.CONFLICT, request.getName(), pipelinesWithProcessors));
             return;
         }
 
         EnrichStore.deletePolicy(request.getName(), clusterService, e -> {
+            enrichPolicyLocks.releasePolicy(request.getName());
            if (e == null) {
                listener.onResponse(new AcknowledgedResponse(true));
            } else {

x-pack/plugin/enrich/src/test/java/org/elasticsearch/xpack/enrich/AbstractEnrichTestCase.java

@@ -0,0 +1,49 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License;
+ * you may not use this file except in compliance with the Elastic License.
+ */
+package org.elasticsearch.xpack.enrich;
+
+import org.elasticsearch.cluster.service.ClusterService;
+import org.elasticsearch.plugins.Plugin;
+import org.elasticsearch.test.ESSingleNodeTestCase;
+import org.elasticsearch.xpack.core.enrich.EnrichPolicy;
+
+import java.util.Collection;
+import java.util.Collections;
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.atomic.AtomicReference;
+
+public abstract class AbstractEnrichTestCase extends ESSingleNodeTestCase {
+
+    @Override
+    protected Collection<Class<? extends Plugin>> getPlugins() {
+        return Collections.singletonList(LocalStateEnrich.class);
+    }
+
+    protected AtomicReference<Exception> saveEnrichPolicy(String name, EnrichPolicy policy,
+                                                          ClusterService clusterService) throws InterruptedException {
+        CountDownLatch latch = new CountDownLatch(1);
+        AtomicReference<Exception> error = new AtomicReference<>();
+        EnrichStore.putPolicy(name, policy, clusterService, e -> {
+            error.set(e);
+            latch.countDown();
+        });
+        latch.await();
+        return error;
+    }
+
+    void deleteEnrichPolicy(String name, ClusterService clusterService) throws Exception {
+        CountDownLatch latch = new CountDownLatch(1);
+        AtomicReference<Exception> error = new AtomicReference<>();
+        EnrichStore.deletePolicy(name, clusterService, e -> {
+            error.set(e);
+            latch.countDown();
+        });
+        latch.await();
+        if (error.get() != null){
+            throw error.get();
+        }
+    }
+}

x-pack/plugin/enrich/src/test/java/org/elasticsearch/xpack/enrich/EnrichPolicyExecutorTests.java

@@ -127,7 +127,7 @@ public void testNonConcurrentPolicyExecution() throws InterruptedException {
         firstTaskComplete.await();
 
         // Validate exception from second run
-        assertThat(expected.getMessage(), containsString("Policy execution failed. Policy execution for [" + testPolicyName +
+        assertThat(expected.getMessage(), containsString("Could not obtain lock because policy execution for [" + testPolicyName +
             "] is already in progress."));
 
         // Ensure that the lock from the previous run has been cleared

x-pack/plugin/enrich/src/test/java/org/elasticsearch/xpack/enrich/EnrichPolicyLocksTests.java

@@ -24,14 +24,14 @@ public void testLockPolicy() {
         // Ensure that locked policies are rejected
         EsRejectedExecutionException exception1 = expectThrows(EsRejectedExecutionException.class,
             () -> policyLocks.lockPolicy(policy1));
-        assertThat(exception1.getMessage(), is(equalTo("Policy execution failed. Policy execution for [policy1]" +
+        assertThat(exception1.getMessage(), is(equalTo("Could not obtain lock because policy execution for [policy1]" +
             " is already in progress.")));
 
         policyLocks.lockPolicy(policy2);
         EsRejectedExecutionException exception2 = expectThrows(EsRejectedExecutionException.class,
             () -> policyLocks.lockPolicy(policy2));
 
-        assertThat(exception2.getMessage(), is(equalTo("Policy execution failed. Policy execution for [policy2]" +
+        assertThat(exception2.getMessage(), is(equalTo("Could not obtain lock because policy execution for [policy2]" +
             " is already in progress.")));
     }
 
@@ -42,13 +42,13 @@ public void testSafePoint() {
 
         // Get exec state - should note as safe and revision 1 since nothing has happened yet
         executionState = policyLocks.captureExecutionState();
-        assertThat(executionState.arePoliciesInFlight, is(false));
+        assertThat(executionState.anyPolicyInFlight, is(false));
         assertThat(executionState.executions, is(0L));
         assertThat(policyLocks.isSameState(executionState), is(true));
 
         // Get another exec state - should still note as safe and revision 1 since nothing has happened yet
         executionState = policyLocks.captureExecutionState();
-        assertThat(executionState.arePoliciesInFlight, is(false));
+        assertThat(executionState.anyPolicyInFlight, is(false));
         assertThat(executionState.executions, is(0L));
         assertThat(policyLocks.isSameState(executionState), is(true));
 
@@ -57,7 +57,7 @@ public void testSafePoint() {
 
         // Get a third exec state - should have a new revision and report unsafe since execution is in progress
         executionState = policyLocks.captureExecutionState();
-        assertThat(executionState.arePoliciesInFlight, is(true));
+        assertThat(executionState.anyPolicyInFlight, is(true));
         assertThat(executionState.executions, is(1L));
 
         // Unlock the policy
@@ -66,13 +66,13 @@ public void testSafePoint() {
         // Get a fourth exec state - should have the same revision as third, and report no policies in flight since the previous execution
         // is complete
         executionState = policyLocks.captureExecutionState();
-        assertThat(executionState.arePoliciesInFlight, is(false));
+        assertThat(executionState.anyPolicyInFlight, is(false));
         assertThat(executionState.executions, is(1L));
 
         // Create a fifth exec state, lock and release a policy, and check if the captured exec state is the same as the current state in
         // the lock object
         executionState = policyLocks.captureExecutionState();
-        assertThat(executionState.arePoliciesInFlight, is(false));
+        assertThat(executionState.anyPolicyInFlight, is(false));
         assertThat(executionState.executions, is(1L));
         policyLocks.lockPolicy(policy);
         policyLocks.releasePolicy(policy);

x-pack/plugin/enrich/src/test/java/org/elasticsearch/xpack/enrich/EnrichStoreTests.java renamed to x-pack/plugin/enrich/src/test/java/org/elasticsearch/xpack/enrich/EnrichStoreCrudTests.java

@@ -3,31 +3,22 @@
  * or more contributor license agreements. Licensed under the Elastic License;
  * you may not use this file except in compliance with the Elastic License.
  */
+
 package org.elasticsearch.xpack.enrich;
 
 import org.elasticsearch.ResourceNotFoundException;
 import org.elasticsearch.cluster.service.ClusterService;
 import org.elasticsearch.common.xcontent.XContentType;
-import org.elasticsearch.plugins.Plugin;
-import org.elasticsearch.test.ESSingleNodeTestCase;
 import org.elasticsearch.xpack.core.enrich.EnrichPolicy;
 
-import java.util.Collection;
-import java.util.Collections;
 import java.util.Map;
-import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.atomic.AtomicReference;
 
 import static org.elasticsearch.xpack.enrich.EnrichPolicyTests.randomEnrichPolicy;
 import static org.hamcrest.Matchers.equalTo;
 import static org.hamcrest.Matchers.nullValue;
 
-public class EnrichStoreTests extends ESSingleNodeTestCase {
-
-    @Override
-    protected Collection<Class<? extends Plugin>> getPlugins() {
-        return Collections.singletonList(LocalStateEnrich.class);
-    }
+public class EnrichStoreCrudTests extends AbstractEnrichTestCase {
 
     public void testCrud() throws Exception {
         EnrichPolicy policy = randomEnrichPolicy(XContentType.JSON);
@@ -137,29 +128,4 @@ public void testListValidation()  {
         Map<String, EnrichPolicy> policies = EnrichStore.getPolicies(clusterService.state());
         assertTrue(policies.isEmpty());
     }
-
-    private AtomicReference<Exception> saveEnrichPolicy(String name, EnrichPolicy policy,
-                                                        ClusterService clusterService) throws InterruptedException {
-        CountDownLatch latch = new CountDownLatch(1);
-        AtomicReference<Exception> error = new AtomicReference<>();
-        EnrichStore.putPolicy(name, policy, clusterService, e -> {
-            error.set(e);
-            latch.countDown();
-        });
-        latch.await();
-        return error;
-    }
-
-    private void deleteEnrichPolicy(String name, ClusterService clusterService) throws Exception {
-        CountDownLatch latch = new CountDownLatch(1);
-        AtomicReference<Exception> error = new AtomicReference<>();
-        EnrichStore.deletePolicy(name, clusterService, e -> {
-            error.set(e);
-            latch.countDown();
-        });
-        latch.await();
-        if (error.get() != null){
-            throw error.get();
-        }
-    }
 }