Merge pull request #74 from ashwing/ltr_1_fix_for_premature_childshard_creation

Ltr 1 fix for premature childshard creation

amazon-kinesis-client/src/main/java/software/amazon/kinesis/lifecycle/ShutdownTask.java

@@ -17,6 +17,7 @@ package software.amazon.kinesis.lifecycle;
 import com.google.common.annotations.VisibleForTesting;
 
 import java.util.List;
+import java.util.Objects;
 import java.util.Optional;
 
 import lombok.NonNull;
@@ -24,11 +25,11 @@ import lombok.RequiredArgsConstructor;
 import lombok.extern.slf4j.Slf4j;
 import software.amazon.awssdk.services.kinesis.model.ChildShard;
 import software.amazon.awssdk.utils.CollectionUtils;
-import software.amazon.awssdk.utils.Validate;
 import software.amazon.kinesis.annotations.KinesisClientInternalApi;
 import software.amazon.kinesis.checkpoint.ShardRecordProcessorCheckpointer;
 import software.amazon.kinesis.common.InitialPositionInStreamExtended;
 import software.amazon.kinesis.common.StreamIdentifier;
+import software.amazon.kinesis.exceptions.internal.BlockedOnParentShardException;
 import software.amazon.kinesis.leases.HierarchicalShardSyncer;
 import software.amazon.kinesis.leases.Lease;
 import software.amazon.kinesis.leases.LeaseCleanupManager;
@@ -52,7 +53,6 @@ import software.amazon.kinesis.retrieval.RecordsPublisher;
 import software.amazon.kinesis.retrieval.kpl.ExtendedSequenceNumber;
 
 import java.util.Set;
-import java.util.UUID;
 import java.util.function.Function;
 import java.util.stream.Collectors;
 
@@ -99,6 +99,7 @@ public class ShutdownTask implements ConsumerTask {
     private final LeaseCleanupManager leaseCleanupManager;
 
     private static final Function<ShardInfo, String> leaseKeyProvider = shardInfo -> ShardInfo.getLeaseKey(shardInfo);
+    private int retryLeftForValidParentState = 10;
 
     /*
      * Invokes ShardRecordProcessor shutdown() API.
@@ -120,26 +121,21 @@ public class ShutdownTask implements ConsumerTask {
 
                 final long startTime = System.currentTimeMillis();
                 final Lease currentShardLease = leaseCoordinator.getCurrentlyHeldLease(leaseKeyProvider.apply(shardInfo));
-                final ShutdownReason localReason = attemptPersistingChildShardInfoAndOverrideShutdownReasonOnFailure(reason, currentShardLease);
+                final Runnable leaseLostAction = () -> shardRecordProcessor.leaseLost(LeaseLostInput.builder().build());
 
-                if (localReason == ShutdownReason.SHARD_END) {
+                if (reason == ShutdownReason.SHARD_END) {
-                    final LeasePendingDeletion leasePendingDeletion = new LeasePendingDeletion(streamIdentifier, currentShardLease, shardInfo);
+                    try {
-                    if (!leaseCleanupManager.isEnqueuedForDeletion(leasePendingDeletion)) {
+                        takeShardEndAction(currentShardLease, scope, startTime);
-                        boolean isSuccess = false;
+                    } catch (InvalidStateException e) {
-                        try {
+                        // If InvalidStateException happens, it indicates we have a non recoverable error in short term.
-                            isSuccess = attemptShardEndCheckpointing(scope, startTime);
+                        // In this scenario, we should shutdown the shardConsumer with LEASE_LOST reason to allow other worker to take the lease and retry shutting down.
-                        } finally {
+                        log.warn("Lease {}: Invalid state encountered while shutting down shardConsumer with SHARD_END reason. " +
-                            // Check if either the shard end ddb persist is successful or
+                                "Dropping the lease and shutting down shardConsumer using LEASE_LOST reason. ", currentShardLease.leaseKey(), e);
-                            // if childshards is empty. When child shards is empty then either it is due to
+                        dropLease(currentShardLease);
-                            // completed shard being reprocessed or we got RNF from service.
+                        throwOnApplicationException(leaseLostAction, scope, startTime);
-                            // For these cases enqueue the lease for deletion.
-                            if (isSuccess || CollectionUtils.isNullOrEmpty(childShards)) {
-                                leaseCleanupManager.enqueueForDeletion(leasePendingDeletion);
-                            }
-                        }
                     }
                 } else {
-                    throwOnApplicationException(() -> shardRecordProcessor.leaseLost(LeaseLostInput.builder().build()), scope, startTime);
+                    throwOnApplicationException(leaseLostAction, scope, startTime);
                 }
 
                 log.debug("Shutting down retrieval strategy for shard {}.", leaseKeyProvider.apply(shardInfo));
@@ -168,41 +164,47 @@ public class ShutdownTask implements ConsumerTask {
         return new TaskResult(exception);
     }
 
-    private ShutdownReason attemptPersistingChildShardInfoAndOverrideShutdownReasonOnFailure(ShutdownReason originalReason, Lease currentShardLease)
+    // Involves persisting child shard info, attempt to checkpoint and enqueueing lease for cleanup.
-            throws DependencyException, ProvisionedThroughputException {
+    private void takeShardEndAction(Lease currentShardLease,
-        ShutdownReason localReason = originalReason;
+            MetricsScope scope, long startTime)
-        if (originalReason == ShutdownReason.SHARD_END) {
+            throws DependencyException, ProvisionedThroughputException, InvalidStateException,
-            // Create new lease for the child shards if they don't exist.
+            CustomerApplicationException {
-            // We have one valid scenario that shutdown task got created with SHARD_END reason and an empty list of childShards.
+        // Create new lease for the child shards if they don't exist.
-            // This would happen when KinesisDataFetcher(for polling mode) or FanOutRecordsPublisher(for StoS mode) catches ResourceNotFound exception.
+        // We have one valid scenario that shutdown task got created with SHARD_END reason and an empty list of childShards.
-            // In this case, KinesisDataFetcher and FanOutRecordsPublisher will send out SHARD_END signal to trigger a shutdown task with empty list of childShards.
+        // This would happen when KinesisDataFetcher(for polling mode) or FanOutRecordsPublisher(for StoS mode) catches ResourceNotFound exception.
-            // This scenario could happen when customer deletes the stream while leaving the KCL application running.
+        // In this case, KinesisDataFetcher and FanOutRecordsPublisher will send out SHARD_END signal to trigger a shutdown task with empty list of childShards.
-            Validate.validState(currentShardLease != null,
+        // This scenario could happen when customer deletes the stream while leaving the KCL application running.
-                                "%s : Lease not owned by the current worker. Leaving ShardEnd handling to new owner.",
+        if (currentShardLease == null) {
-                                leaseKeyProvider.apply(shardInfo));
+            throw new InvalidStateException(leaseKeyProvider.apply(shardInfo)
+                    + " : Lease not owned by the current worker. Leaving ShardEnd handling to new owner.");
+        }
+        if (!CollectionUtils.isNullOrEmpty(childShards)) {
+            createLeasesForChildShardsIfNotExist();
+            updateLeaseWithChildShards(currentShardLease);
+        }
+        final LeasePendingDeletion leasePendingDeletion = new LeasePendingDeletion(streamIdentifier, currentShardLease,
+                shardInfo);
+        if (!leaseCleanupManager.isEnqueuedForDeletion(leasePendingDeletion)) {
+            boolean isSuccess = false;
             try {
-                if (!CollectionUtils.isNullOrEmpty(childShards)) {
+                isSuccess = attemptShardEndCheckpointing(scope, startTime);
-                    createLeasesForChildShardsIfNotExist();
+            } finally {
-                    updateLeaseWithChildShards(currentShardLease);
+                // Check if either the shard end ddb persist is successful or
+                // if childshards is empty. When child shards is empty then either it is due to
+                // completed shard being reprocessed or we got RNF from service.
+                // For these cases enqueue the lease for deletion.
+                if (isSuccess || CollectionUtils.isNullOrEmpty(childShards)) {
+                    leaseCleanupManager.enqueueForDeletion(leasePendingDeletion);
                 }
-            } catch (InvalidStateException e) {
-                // If InvalidStateException happens, it indicates we are missing childShard related information.
-                // In this scenario, we should shutdown the shardConsumer with LEASE_LOST reason to allow other worker to take the lease and retry getting
-                // childShard information in the processTask.
-                localReason = ShutdownReason.LEASE_LOST;
-                log.warn("Lease {}: Exception happened while shutting down shardConsumer with SHARD_END reason. " +
-                                 "Dropping the lease and shutting down shardConsumer using LEASE_LOST reason. Exception: ", currentShardLease.leaseKey(), e);
-                dropLease(currentShardLease);
             }
         }
-        return localReason;
     }
 
     private boolean attemptShardEndCheckpointing(MetricsScope scope, long startTime)
             throws DependencyException, ProvisionedThroughputException, InvalidStateException,
             CustomerApplicationException {
         final Lease leaseFromDdb = Optional.ofNullable(leaseCoordinator.leaseRefresher().getLease(leaseKeyProvider.apply(shardInfo)))
-                .orElseThrow(() -> new IllegalStateException("Lease for shard " + leaseKeyProvider.apply(shardInfo) + " does not exist."));
+                .orElseThrow(() -> new InvalidStateException("Lease for shard " + leaseKeyProvider.apply(shardInfo) + " does not exist."));
         if (!leaseFromDdb.checkpoint().equals(ExtendedSequenceNumber.SHARD_END)) {
             // Call the shardRecordsProcessor to checkpoint with SHARD_END sequence number.
             // The shardEnded is implemented by customer. We should validate if the SHARD_END checkpointing is successful after calling shardEnded.
@@ -237,6 +239,33 @@ public class ShutdownTask implements ConsumerTask {
 
     private void createLeasesForChildShardsIfNotExist()
             throws DependencyException, InvalidStateException, ProvisionedThroughputException {
+        // For child shard resulted from merge of two parent shards, verify if both the parents are either present or
+        // not present in the lease table before creating the lease entry.
+        if (!CollectionUtils.isNullOrEmpty(childShards) && childShards.size() == 1) {
+            final ChildShard childShard = childShards.get(0);
+            final List<String> parentLeaseKeys = childShard.parentShards().stream()
+                    .map(parentShardId -> ShardInfo.getLeaseKey(shardInfo, parentShardId)).collect(Collectors.toList());
+            if (parentLeaseKeys.size() != 2) {
+                throw new InvalidStateException("Shard " + shardInfo.shardId() + "'s only child shard " + childShard
+                        + " does not contain other parent information.");
+            } else {
+                boolean isValidLeaseTableState =
+                        Objects.isNull(leaseCoordinator.leaseRefresher().getLease(parentLeaseKeys.get(0))) == Objects
+                                .isNull(leaseCoordinator.leaseRefresher().getLease(parentLeaseKeys.get(1)));
+                if (!isValidLeaseTableState) {
+                    if (--retryLeftForValidParentState >= 0) {
+                        throw new BlockedOnParentShardException(
+                                "Shard " + shardInfo.shardId() + "'s only child shard " + childShard
+                                        + " has partial parent information in lease table. Hence deferring lease creation of child shard.");
+                    } else {
+                        throw new InvalidStateException(
+                                "Shard " + shardInfo.shardId() + "'s only child shard " + childShard
+                                        + " has partial parent information in lease table. Hence deferring lease creation of child shard.");
+                    }
+                }
+            }
+        }
+        // Attempt create leases for child shards.
         for(ChildShard childShard : childShards) {
             final String leaseKey = ShardInfo.getLeaseKey(shardInfo, childShard.shardId());
             if(leaseCoordinator.leaseRefresher().getLease(leaseKey) == null) {

amazon-kinesis-client/src/test/java/software/amazon/kinesis/lifecycle/ShutdownTaskTest.java

@@ -17,6 +17,7 @@ package software.amazon.kinesis.lifecycle;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertNotNull;
 import static org.junit.Assert.assertNull;
+import static org.junit.Assert.assertThat;
 import static org.junit.Assert.assertTrue;
 import static org.mockito.Matchers.any;
 import static org.mockito.Mockito.doNothing;
@@ -30,6 +31,7 @@ import java.util.Collections;
 import java.util.List;
 import java.util.UUID;
 
+import com.google.common.collect.ImmutableList;
 import org.junit.Before;
 import org.junit.Test;
 import org.junit.runner.RunWith;
@@ -42,6 +44,7 @@ import software.amazon.kinesis.checkpoint.ShardRecordProcessorCheckpointer;
 import software.amazon.kinesis.common.InitialPositionInStream;
 import software.amazon.kinesis.common.InitialPositionInStreamExtended;
 import software.amazon.kinesis.common.StreamIdentifier;
+import software.amazon.kinesis.exceptions.internal.BlockedOnParentShardException;
 import software.amazon.kinesis.exceptions.internal.KinesisClientLibIOException;
 import software.amazon.kinesis.leases.HierarchicalShardSyncer;
 import software.amazon.kinesis.leases.Lease;
@@ -194,6 +197,108 @@ public class ShutdownTaskTest {
         verify(leaseCleanupManager, times(1)).enqueueForDeletion(any(LeasePendingDeletion.class));
     }
 
+    @Test
+    public final void testCallThrowsUntilParentInfoNotPresentInLease() throws DependencyException, InvalidStateException, ProvisionedThroughputException {
+        shardInfo = new ShardInfo("shardId-0", concurrencyToken, Collections.emptySet(),
+                ExtendedSequenceNumber.LATEST);
+        task = new ShutdownTask(shardInfo, shardDetector, shardRecordProcessor, recordProcessorCheckpointer,
+                SHARD_END_SHUTDOWN_REASON, INITIAL_POSITION_TRIM_HORIZON, cleanupLeasesOfCompletedShards,
+                ignoreUnexpectedChildShards, leaseCoordinator, TASK_BACKOFF_TIME_MILLIS, recordsPublisher,
+                hierarchicalShardSyncer, NULL_METRICS_FACTORY, constructChildShard(), streamIdentifier, leaseCleanupManager);
+
+        when(recordProcessorCheckpointer.lastCheckpointValue()).thenReturn(ExtendedSequenceNumber.SHARD_END);
+        Lease heldLease = LeaseHelper.createLease("shardId-0", "leaseOwner", ImmutableList.of("parent1", "parent2"));
+        Lease parentLease = LeaseHelper.createLease("shardId-1", "leaseOwner", Collections.emptyList());
+        when(leaseCoordinator.getCurrentlyHeldLease("shardId-0")).thenReturn(heldLease);
+        when(leaseCoordinator.getCurrentlyHeldLease("shardId-1"))
+                .thenReturn(null, null, null, null, null, parentLease);
+        when(leaseCoordinator.leaseRefresher()).thenReturn(leaseRefresher);
+        when(leaseCoordinator.updateLease(Matchers.any(Lease.class), Matchers.any(UUID.class), Matchers.anyString(), Matchers.anyString())).thenReturn(true);
+        when(leaseRefresher.getLease("shardId-0")).thenReturn(heldLease);
+        // Return null lease first time to simulate partial parent lease info
+        when(leaseRefresher.getLease("shardId-1"))
+                .thenReturn(null, null, null, null, null, parentLease);
+
+        // Make first 5 attempts with partial parent info in lease table
+        for (int i = 0; i < 5; i++) {
+            TaskResult result = task.call();
+            assertNotNull(result.getException());
+            assertTrue(result.getException() instanceof BlockedOnParentShardException);
+            assertTrue(result.getException().getMessage().contains("has partial parent information in lease table"));
+            verify(recordsPublisher, never()).shutdown();
+            verify(shardRecordProcessor, never())
+                    .shardEnded(ShardEndedInput.builder().checkpointer(recordProcessorCheckpointer).build());
+            verify(shardRecordProcessor, never()).leaseLost(LeaseLostInput.builder().build());
+            verify(leaseCoordinator, never())
+                    .updateLease(Matchers.any(Lease.class), Matchers.any(UUID.class), Matchers.anyString(), Matchers.anyString());
+            verify(leaseRefresher, never()).createLeaseIfNotExists(Matchers.any(Lease.class));
+            verify(leaseCoordinator, never()).dropLease(Matchers.any(Lease.class));
+            verify(leaseCleanupManager, never()).enqueueForDeletion(any(LeasePendingDeletion.class));
+        }
+
+        // make next attempt with complete parent info in lease table
+        TaskResult result = task.call();
+        assertNull(result.getException());
+        verify(recordsPublisher).shutdown();
+        verify(shardRecordProcessor).shardEnded(ShardEndedInput.builder().checkpointer(recordProcessorCheckpointer).build());
+        verify(shardRecordProcessor, never()).leaseLost(LeaseLostInput.builder().build());
+        verify(leaseRefresher).updateLeaseWithMetaInfo(Matchers.any(Lease.class), Matchers.any(UpdateField.class));
+        verify(leaseRefresher, times(1)).createLeaseIfNotExists(Matchers.any(Lease.class));
+        verify(leaseCoordinator, never()).dropLease(Matchers.any(Lease.class));
+        verify(leaseCleanupManager, times(1)).enqueueForDeletion(any(LeasePendingDeletion.class));
+    }
+
+    @Test
+    public final void testCallTriggersLeaseLossWhenParentInfoNotPresentInLease() throws DependencyException, InvalidStateException, ProvisionedThroughputException {
+        shardInfo = new ShardInfo("shardId-0", concurrencyToken, Collections.emptySet(),
+                ExtendedSequenceNumber.LATEST);
+        task = new ShutdownTask(shardInfo, shardDetector, shardRecordProcessor, recordProcessorCheckpointer,
+                SHARD_END_SHUTDOWN_REASON, INITIAL_POSITION_TRIM_HORIZON, cleanupLeasesOfCompletedShards,
+                ignoreUnexpectedChildShards, leaseCoordinator, TASK_BACKOFF_TIME_MILLIS, recordsPublisher,
+                hierarchicalShardSyncer, NULL_METRICS_FACTORY, constructChildShard(), streamIdentifier, leaseCleanupManager);
+
+        when(recordProcessorCheckpointer.lastCheckpointValue()).thenReturn(ExtendedSequenceNumber.SHARD_END);
+        Lease heldLease = LeaseHelper.createLease("shardId-0", "leaseOwner", ImmutableList.of("parent1", "parent2"));
+        Lease parentLease = LeaseHelper.createLease("shardId-1", "leaseOwner", Collections.emptyList());
+        when(leaseCoordinator.getCurrentlyHeldLease("shardId-0")).thenReturn(heldLease);
+        when(leaseCoordinator.getCurrentlyHeldLease("shardId-1"))
+                .thenReturn(null, null, null, null, null, null, null, null, null, null, null);
+        when(leaseCoordinator.leaseRefresher()).thenReturn(leaseRefresher);
+        when(leaseCoordinator.updateLease(Matchers.any(Lease.class), Matchers.any(UUID.class), Matchers.anyString(), Matchers.anyString())).thenReturn(true);
+        when(leaseRefresher.getLease("shardId-0")).thenReturn(heldLease);
+        // Return null lease first time to simulate partial parent lease info
+        when(leaseRefresher.getLease("shardId-1"))
+                .thenReturn(null, null, null, null, null, null, null, null, null, null, null);
+
+        // Make first 10 attempts with partial parent info in lease table
+        for (int i = 0; i < 10; i++) {
+            TaskResult result = task.call();
+            assertNotNull(result.getException());
+            assertTrue(result.getException() instanceof BlockedOnParentShardException);
+            assertTrue(result.getException().getMessage().contains("has partial parent information in lease table"));
+            verify(recordsPublisher, never()).shutdown();
+            verify(shardRecordProcessor, never())
+                    .shardEnded(ShardEndedInput.builder().checkpointer(recordProcessorCheckpointer).build());
+            verify(shardRecordProcessor, never()).leaseLost(LeaseLostInput.builder().build());
+            verify(leaseCoordinator, never())
+                    .updateLease(Matchers.any(Lease.class), Matchers.any(UUID.class), Matchers.anyString(), Matchers.anyString());
+            verify(leaseRefresher, never()).createLeaseIfNotExists(Matchers.any(Lease.class));
+            verify(leaseCoordinator, never()).dropLease(Matchers.any(Lease.class));
+            verify(leaseCleanupManager, never()).enqueueForDeletion(any(LeasePendingDeletion.class));
+        }
+
+        // make final attempt with incomplete parent info in lease table
+        TaskResult result = task.call();
+        assertNull(result.getException());
+        verify(recordsPublisher).shutdown();
+        verify(shardRecordProcessor, never()).shardEnded(ShardEndedInput.builder().checkpointer(recordProcessorCheckpointer).build());
+        verify(shardRecordProcessor).leaseLost(LeaseLostInput.builder().build());
+        verify(leaseRefresher, never()).updateLeaseWithMetaInfo(Matchers.any(Lease.class), Matchers.any(UpdateField.class));
+        verify(leaseRefresher, never()).createLeaseIfNotExists(Matchers.any(Lease.class));
+        verify(leaseCoordinator).dropLease(Matchers.any(Lease.class));
+        verify(leaseCleanupManager, never()).enqueueForDeletion(any(LeasePendingDeletion.class));
+    }
+
     /**
      * Test method for {@link ShutdownTask#call()}.
      * This test is for the scenario that a ShutdownTask is created for detecting a false Shard End.
@@ -269,4 +374,18 @@ public class ShutdownTaskTest {
         childShards.add(rightChild);
         return  childShards;
     }
+
+    private List<ChildShard> constructChildShard() {
+        List<ChildShard> childShards = new ArrayList<>();
+        List<String> parentShards = new ArrayList<>();
+        parentShards.add(shardId);
+        parentShards.add("shardId-1");
+        ChildShard leftChild = ChildShard.builder()
+                .shardId("shardId-2")
+                .parentShards(parentShards)
+                .hashKeyRange(ShardObjectHelper.newHashKeyRange("0", "49"))
+                .build();
+        childShards.add(leftChild);
+        return  childShards;
+    }
 }