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[Segment Replication] Trigger a round of replication for replica shar…
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…ds during peer recovery when segment replication is enabled (#5332)

* Fix new added replica shards falling behind primary.

Signed-off-by: Rishikesh1159 <[email protected]>

* Trigger a round of replication during peer recovery when segment replication is enabled.

Signed-off-by: Rishikesh1159 <[email protected]>

* Remove unnecessary start replication overloaded method.

Signed-off-by: Rishikesh1159 <[email protected]>

* Add test for failure case and refactor some code.

Signed-off-by: Rishikesh1159 <[email protected]>

* Apply spotless check.

Signed-off-by: Rishikesh1159 <[email protected]>

* Addressing comments on the PR.

Signed-off-by: Rishikesh1159 <[email protected]>

* Remove unnecessary condition check.

Signed-off-by: Rishikesh1159 <[email protected]>

* Apply spotless check.

Signed-off-by: Rishikesh1159 <[email protected]>

* Add step listeners to resolve forcing round of segment replication.

Signed-off-by: Rishikesh1159 <[email protected]>

Signed-off-by: Rishikesh1159 <[email protected]>
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Rishikesh1159 authored Dec 12, 2022
1 parent bceb40c commit 0cf6797
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86 changes: 78 additions & 8 deletions ...src/internalClusterTest/java/org/opensearch/indices/replication/SegmentReplicationIT.java
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Expand Up @@ -10,6 +10,8 @@

import com.carrotsearch.randomizedtesting.RandomizedTest;
import org.junit.BeforeClass;
import org.opensearch.OpenSearchCorruptionException;
import org.opensearch.action.admin.cluster.health.ClusterHealthResponse;
import org.opensearch.action.admin.indices.segments.IndexShardSegments;
import org.opensearch.action.admin.indices.segments.IndicesSegmentResponse;
import org.opensearch.action.admin.indices.segments.IndicesSegmentsRequest;
Expand All @@ -24,7 +26,9 @@
import org.opensearch.cluster.routing.ShardRouting;
import org.opensearch.cluster.routing.allocation.command.CancelAllocationCommand;
import org.opensearch.common.Nullable;
import org.opensearch.common.Priority;
import org.opensearch.common.settings.Settings;
import org.opensearch.common.unit.TimeValue;
import org.opensearch.common.util.FeatureFlags;
import org.opensearch.index.Index;
import org.opensearch.index.IndexModule;
Expand Down Expand Up @@ -53,6 +57,7 @@
import java.util.function.Function;
import java.util.stream.Collectors;

import static org.hamcrest.Matchers.equalTo;
import static org.opensearch.index.query.QueryBuilders.matchQuery;
import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertHitCount;
import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertAcked;
Expand Down Expand Up @@ -194,6 +199,75 @@ public void testCancelPrimaryAllocation() throws Exception {
assertSegmentStats(REPLICA_COUNT);
}

/**
* This test verfies that replica shard is not added to the cluster when doing a round of segment replication fails during peer recovery.
*/
public void testAddNewReplicaFailure() throws Exception {
logger.info("--> starting [Primary Node] ...");
final String primaryNode = internalCluster().startNode();

logger.info("--> creating test index ...");
prepareCreate(
INDEX_NAME,
Settings.builder().put(IndexMetadata.SETTING_NUMBER_OF_SHARDS, 1).put(IndexMetadata.SETTING_NUMBER_OF_REPLICAS, 0)
).get();

logger.info("--> index 10 docs");
for (int i = 0; i < 10; i++) {
client().prepareIndex(INDEX_NAME).setId(Integer.toString(i)).setSource("field", "value" + i).execute().actionGet();
}
logger.info("--> flush so we have some segment files on disk");
flush(INDEX_NAME);
logger.info("--> index more docs so we have something in the translog");
for (int i = 10; i < 20; i++) {
client().prepareIndex(INDEX_NAME).setId(Integer.toString(i)).setSource("field", "value" + i).execute().actionGet();
}
refresh(INDEX_NAME);
logger.info("--> verifying count");
assertThat(client().prepareSearch(INDEX_NAME).setSize(0).execute().actionGet().getHits().getTotalHits().value, equalTo(20L));

logger.info("--> start empty node to add replica shard");
final String replicaNode = internalCluster().startNode();

// Mock transport service to add behaviour of throwing corruption exception during segment replication process.
MockTransportService mockTransportService = ((MockTransportService) internalCluster().getInstance(
TransportService.class,
primaryNode
));
mockTransportService.addSendBehavior(
internalCluster().getInstance(TransportService.class, replicaNode),
(connection, requestId, action, request, options) -> {
if (action.equals(SegmentReplicationTargetService.Actions.FILE_CHUNK)) {
throw new OpenSearchCorruptionException("expected");
}
connection.sendRequest(requestId, action, request, options);
}
);
ensureGreen(INDEX_NAME);
// Add Replica shard to the new empty replica node
assertAcked(
client().admin()
.indices()
.prepareUpdateSettings(INDEX_NAME)
.setSettings(Settings.builder().put(IndexMetadata.SETTING_NUMBER_OF_REPLICAS, 1))
);

// Verify that cluster state is not green and replica shard failed during a round of segment replication is not added to the cluster
ClusterHealthResponse clusterHealthResponse = client().admin()
.cluster()
.prepareHealth()
.setWaitForEvents(Priority.LANGUID)
.setWaitForNodes("2")
.setWaitForGreenStatus()
.setTimeout(TimeValue.timeValueSeconds(2))
.execute()
.actionGet();
assertTrue(clusterHealthResponse.isTimedOut());
ensureYellow(INDEX_NAME);
IndicesService indicesService = internalCluster().getInstance(IndicesService.class, replicaNode);
assertFalse(indicesService.hasIndex(resolveIndex(INDEX_NAME)));
}

public void testReplicationAfterPrimaryRefreshAndFlush() throws Exception {
final String nodeA = internalCluster().startNode();
final String nodeB = internalCluster().startNode();
Expand Down Expand Up @@ -452,18 +526,14 @@ public void testStartReplicaAfterPrimaryIndexesDocs() throws Exception {
final String replicaNode = internalCluster().startNode();
ensureGreen(INDEX_NAME);

client().prepareIndex(INDEX_NAME).setId("3").setSource("foo", "bar").get();
assertHitCount(client(primaryNode).prepareSearch(INDEX_NAME).setSize(0).setPreference("_only_local").get(), 2);
assertHitCount(client(replicaNode).prepareSearch(INDEX_NAME).setSize(0).setPreference("_only_local").get(), 2);

client().prepareIndex(INDEX_NAME).setId("3").setSource("foo", "bar").get();
refresh(INDEX_NAME);
waitForReplicaUpdate();
assertHitCount(client(primaryNode).prepareSearch(INDEX_NAME).setSize(0).setPreference("_only_local").get(), 3);
assertHitCount(client(replicaNode).prepareSearch(INDEX_NAME).setSize(0).setPreference("_only_local").get(), 3);

IndexShard primaryShard = getIndexShard(primaryNode);
IndexShard replicaShard = getIndexShard(replicaNode);
assertEquals(
primaryShard.translogStats().estimatedNumberOfOperations(),
replicaShard.translogStats().estimatedNumberOfOperations()
);
assertSegmentStats(REPLICA_COUNT);
}

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93 changes: 88 additions & 5 deletions server/src/main/java/org/opensearch/indices/cluster/IndicesClusterStateService.java
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Expand Up @@ -37,6 +37,7 @@
import org.apache.logging.log4j.message.ParameterizedMessage;
import org.opensearch.ResourceAlreadyExistsException;
import org.opensearch.action.ActionListener;
import org.opensearch.action.StepListener;
import org.opensearch.cluster.ClusterChangedEvent;
import org.opensearch.cluster.ClusterState;
import org.opensearch.cluster.ClusterStateApplier;
Expand All @@ -45,11 +46,12 @@
import org.opensearch.cluster.metadata.IndexMetadata;
import org.opensearch.cluster.node.DiscoveryNode;
import org.opensearch.cluster.node.DiscoveryNodes;
import org.opensearch.cluster.routing.ShardRouting;
import org.opensearch.cluster.routing.ShardRoutingState;
import org.opensearch.cluster.routing.RoutingTable;
import org.opensearch.cluster.routing.IndexShardRoutingTable;
import org.opensearch.cluster.routing.RecoverySource.Type;
import org.opensearch.cluster.routing.RoutingNode;
import org.opensearch.cluster.routing.RoutingTable;
import org.opensearch.cluster.routing.ShardRouting;
import org.opensearch.cluster.routing.RecoverySource.Type;
import org.opensearch.cluster.service.ClusterService;
import org.opensearch.common.Nullable;
import org.opensearch.common.component.AbstractLifecycleComponent;
Expand Down Expand Up @@ -82,8 +84,11 @@
import org.opensearch.indices.recovery.RecoveryListener;
import org.opensearch.indices.recovery.RecoveryState;
import org.opensearch.indices.replication.SegmentReplicationSourceService;
import org.opensearch.indices.replication.SegmentReplicationState;
import org.opensearch.indices.replication.SegmentReplicationTargetService;
import org.opensearch.indices.replication.checkpoint.ReplicationCheckpoint;
import org.opensearch.indices.replication.checkpoint.SegmentReplicationCheckpointPublisher;
import org.opensearch.indices.replication.common.ReplicationFailedException;
import org.opensearch.indices.replication.common.ReplicationState;
import org.opensearch.repositories.RepositoriesService;
import org.opensearch.search.SearchService;
Expand Down Expand Up @@ -143,6 +148,8 @@ public class IndicesClusterStateService extends AbstractLifecycleComponent imple
private final Consumer<ShardId> globalCheckpointSyncer;
private final RetentionLeaseSyncer retentionLeaseSyncer;

private final SegmentReplicationTargetService segmentReplicationTargetService;

private final SegmentReplicationCheckpointPublisher checkpointPublisher;

@Inject
Expand Down Expand Up @@ -217,6 +224,7 @@ public IndicesClusterStateService(
indexEventListeners.add(segmentReplicationTargetService);
indexEventListeners.add(segmentReplicationSourceService);
}
this.segmentReplicationTargetService = segmentReplicationTargetService;
this.builtInIndexListener = Collections.unmodifiableList(indexEventListeners);
this.indicesService = indicesService;
this.clusterService = clusterService;
Expand Down Expand Up @@ -773,8 +781,83 @@ public synchronized void handleRecoveryFailure(ShardRouting shardRouting, boolea
}

public void handleRecoveryDone(ReplicationState state, ShardRouting shardRouting, long primaryTerm) {
RecoveryState RecState = (RecoveryState) state;
shardStateAction.shardStarted(shardRouting, primaryTerm, "after " + RecState.getRecoverySource(), SHARD_STATE_ACTION_LISTENER);
RecoveryState recoveryState = (RecoveryState) state;
AllocatedIndex<? extends Shard> indexService = indicesService.indexService(shardRouting.shardId().getIndex());
StepListener<Void> forceSegRepListener = new StepListener<>();
// For Segment Replication enabled indices, we want replica shards to start a replication event to fetch latest segments before
// it is marked as Started.
if (indexService.getIndexSettings().isSegRepEnabled()) {
forceSegmentReplication(indexService, shardRouting, forceSegRepListener);
} else {
forceSegRepListener.onResponse(null);
}
forceSegRepListener.whenComplete(
v -> shardStateAction.shardStarted(
shardRouting,
primaryTerm,
"after " + recoveryState.getRecoverySource(),
SHARD_STATE_ACTION_LISTENER
),
e -> handleRecoveryFailure(shardRouting, true, e)
);
}

/**
* Forces a round of Segment Replication with empty checkpoint, so that replicas could fetch latest segment files from primary.
*/
private void forceSegmentReplication(
AllocatedIndex<? extends Shard> indexService,
ShardRouting shardRouting,
StepListener<Void> forceSegRepListener
) {
IndexShard indexShard = (IndexShard) indexService.getShardOrNull(shardRouting.id());
if (indexShard != null
&& indexShard.indexSettings().isSegRepEnabled()
&& shardRouting.primary() == false
&& shardRouting.state() == ShardRoutingState.INITIALIZING
&& indexShard.state() == IndexShardState.POST_RECOVERY) {
segmentReplicationTargetService.startReplication(
ReplicationCheckpoint.empty(shardRouting.shardId()),
indexShard,
new SegmentReplicationTargetService.SegmentReplicationListener() {
@Override
public void onReplicationDone(SegmentReplicationState state) {
logger.trace(
() -> new ParameterizedMessage(
"[shardId {}] [replication id {}] Replication complete, timing data: {}",
indexShard.shardId().getId(),
state.getReplicationId(),
state.getTimingData()
)
);
forceSegRepListener.onResponse(null);
}

@Override
public void onReplicationFailure(
SegmentReplicationState state,
ReplicationFailedException e,
boolean sendShardFailure
) {
logger.trace(
() -> new ParameterizedMessage(
"[shardId {}] [replication id {}] Replication failed, timing data: {}",
indexShard.shardId().getId(),
state.getReplicationId(),
state.getTimingData()
)
);
if (sendShardFailure == true) {
logger.error("replication failure", e);
indexShard.failShard("replication failure", e);
}
forceSegRepListener.onFailure(e);
}
}
);
} else {
forceSegRepListener.onResponse(null);
}
}

private void failAndRemoveShard(
Expand Down

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