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* Licensed to Elasticsearch under one or more contributor
* license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright
* ownership. Elasticsearch licenses this file to you 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.
*/
package org.elasticsearch.action.support.replication;
import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import org.apache.logging.log4j.message.ParameterizedMessage;
import org.apache.lucene.store.AlreadyClosedException;
import org.elasticsearch.ElasticsearchException;
import org.elasticsearch.ExceptionsHelper;
import org.elasticsearch.action.ActionListener;
import org.elasticsearch.action.ActionListenerResponseHandler;
import org.elasticsearch.action.UnavailableShardsException;
import org.elasticsearch.action.support.ActiveShardCount;
import org.elasticsearch.action.support.TransportAction;
import org.elasticsearch.action.support.TransportActions;
import org.elasticsearch.client.transport.NoNodeAvailableException;
import org.elasticsearch.cluster.ClusterState;
import org.elasticsearch.cluster.ClusterStateObserver;
import org.elasticsearch.cluster.action.shard.ShardStateAction;
import org.elasticsearch.cluster.block.ClusterBlockException;
import org.elasticsearch.cluster.block.ClusterBlockLevel;
import org.elasticsearch.cluster.metadata.IndexMetaData;
import org.elasticsearch.cluster.metadata.IndexNameExpressionResolver;
import org.elasticsearch.cluster.node.DiscoveryNode;
import org.elasticsearch.cluster.routing.AllocationId;
import org.elasticsearch.cluster.routing.IndexShardRoutingTable;
import org.elasticsearch.cluster.routing.ShardRouting;
import org.elasticsearch.cluster.service.ClusterService;
import javax.annotation.Nullable;
import org.elasticsearch.common.io.stream.StreamInput;
import org.elasticsearch.common.io.stream.StreamOutput;
import org.elasticsearch.common.io.stream.Writeable;
import org.elasticsearch.common.lease.Releasable;
import org.elasticsearch.common.lease.Releasables;
import io.crate.common.unit.TimeValue;
import org.elasticsearch.common.util.concurrent.AbstractRunnable;
import org.elasticsearch.index.IndexNotFoundException;
import org.elasticsearch.index.IndexService;
import org.elasticsearch.index.seqno.SequenceNumbers;
import org.elasticsearch.index.shard.IndexShard;
import org.elasticsearch.index.shard.IndexShardClosedException;
import org.elasticsearch.index.shard.ReplicationGroup;
import org.elasticsearch.index.shard.ShardId;
import org.elasticsearch.index.shard.ShardNotFoundException;
import org.elasticsearch.indices.IndexClosedException;
import org.elasticsearch.indices.IndicesService;
import org.elasticsearch.node.NodeClosedException;
import org.elasticsearch.tasks.Task;
import org.elasticsearch.tasks.TaskId;
import org.elasticsearch.threadpool.ThreadPool;
import org.elasticsearch.transport.ConnectTransportException;
import org.elasticsearch.transport.TransportChannel;
import org.elasticsearch.transport.TransportChannelResponseHandler;
import org.elasticsearch.transport.TransportException;
import org.elasticsearch.transport.TransportRequest;
import org.elasticsearch.transport.TransportRequestHandler;
import org.elasticsearch.transport.TransportRequestOptions;
import org.elasticsearch.transport.TransportResponse;
import org.elasticsearch.transport.TransportResponse.Empty;
import org.elasticsearch.transport.TransportResponseHandler;
import org.elasticsearch.transport.TransportService;
import java.io.IOException;
import java.util.Objects;
import java.util.concurrent.atomic.AtomicBoolean;
/**
* Base class for requests that should be executed on a primary copy followed by replica copies.
* Subclasses can resolve the target shard and provide implementation for primary and replica operations.
*
* The action samples cluster state on the receiving node to reroute to node with primary copy and on the
* primary node to validate request before primary operation followed by sampling state again for resolving
* nodes with replica copies to perform replication.
*/
public abstract class TransportReplicationAction<
Request extends ReplicationRequest<Request>,
ReplicaRequest extends ReplicationRequest<ReplicaRequest>,
Response extends ReplicationResponse
> extends TransportAction<Request, Response> {
protected final Logger logger = LogManager.getLogger(getClass());
protected final TransportService transportService;
protected final ClusterService clusterService;
protected final ShardStateAction shardStateAction;
protected final IndicesService indicesService;
protected final TransportRequestOptions transportOptions;
protected final String executor;
// package private for testing
protected final String transportReplicaAction;
protected final String transportPrimaryAction;
private final boolean syncGlobalCheckpointAfterOperation;
protected TransportReplicationAction(String actionName,
TransportService transportService,
ClusterService clusterService,
IndicesService indicesService,
ThreadPool threadPool,
ShardStateAction shardStateAction,
IndexNameExpressionResolver indexNameExpressionResolver,
Writeable.Reader<Request> reader,
Writeable.Reader<ReplicaRequest> replicaReader,
String executor) {
this(actionName, transportService, clusterService, indicesService, threadPool, shardStateAction,
indexNameExpressionResolver, reader, replicaReader, executor, false);
}
protected TransportReplicationAction(String actionName,
TransportService transportService,
ClusterService clusterService,
IndicesService indicesService,
ThreadPool threadPool,
ShardStateAction shardStateAction,
IndexNameExpressionResolver indexNameExpressionResolver,
Writeable.Reader<Request> reader,
Writeable.Reader<ReplicaRequest> replicaReader,
String executor,
boolean syncGlobalCheckpointAfterOperation) {
super(actionName, threadPool, indexNameExpressionResolver, transportService.getTaskManager());
this.transportService = transportService;
this.clusterService = clusterService;
this.indicesService = indicesService;
this.shardStateAction = shardStateAction;
this.executor = executor;
this.transportPrimaryAction = actionName + "[p]";
this.transportReplicaAction = actionName + "[r]";
registerRequestHandlers(actionName, transportService, reader, replicaReader, executor);
this.transportOptions = transportOptions();
this.syncGlobalCheckpointAfterOperation = syncGlobalCheckpointAfterOperation;
}
protected void registerRequestHandlers(String actionName,
TransportService transportService,
Writeable.Reader<Request> reader,
Writeable.Reader<ReplicaRequest> replicaRequestReader,
String executor) {
transportService.registerRequestHandler(actionName, reader, ThreadPool.Names.SAME, new OperationTransportHandler());
transportService.registerRequestHandler(
transportPrimaryAction, in -> new ConcreteShardRequest<>(in, reader), executor, new PrimaryOperationTransportHandler());
// we must never reject on because of thread pool capacity on replicas
transportService.registerRequestHandler(
transportReplicaAction,
in -> new ConcreteReplicaRequest<>(in, replicaRequestReader),
executor,
true,
true,
new ReplicaOperationTransportHandler());
}
@Override
protected final void doExecute(Request request, ActionListener<Response> listener) {
throw new UnsupportedOperationException("the task parameter is required for this operation");
}
@Override
protected void doExecute(Task task, Request request, ActionListener<Response> listener) {
new ReroutePhase((ReplicationTask) task, request, listener).run();
}
protected ReplicationOperation.Replicas<ReplicaRequest> newReplicasProxy(long primaryTerm) {
return new ReplicasProxy(primaryTerm);
}
protected abstract Response read(StreamInput in) throws IOException;
/**
* Resolves derived values in the request. For example, the target shard id of the incoming request, if not set at request construction.
* Additional processing or validation of the request should be done here.
*
* @param indexMetaData index metadata of the concrete index this request is going to operate on
* @param request the request to resolve
*/
protected void resolveRequest(final IndexMetaData indexMetaData, final Request request) {
if (request.waitForActiveShards() == ActiveShardCount.DEFAULT) {
// if the wait for active shard count has not been set in the request,
// resolve it from the index settings
request.waitForActiveShards(indexMetaData.getWaitForActiveShards());
}
}
/**
* Primary operation on node with primary copy.
*
* @param shardRequest the request to the primary shard
* @param primary the primary shard to perform the operation on
*/
protected abstract PrimaryResult<ReplicaRequest, Response> shardOperationOnPrimary(
Request shardRequest, IndexShard primary) throws Exception;
/**
* Synchronously execute the specified replica operation. This is done under a permit from
* {@link IndexShard#acquireReplicaOperationPermit(long, long, long, ActionListener, String, Object)}.
*
* @param shardRequest the request to the replica shard
* @param replica the replica shard to perform the operation on
*/
protected abstract ReplicaResult shardOperationOnReplica(ReplicaRequest shardRequest, IndexShard replica) throws Exception;
/**
* Cluster level block to check before request execution. Returning null means that no blocks need to be checked.
*/
@Nullable
protected ClusterBlockLevel globalBlockLevel() {
return null;
}
/**
* Index level block to check before request execution. Returning null means that no blocks need to be checked.
*/
@Nullable
protected ClusterBlockLevel indexBlockLevel() {
return null;
}
/**
* True if provided index should be resolved when resolving request
*/
protected boolean resolveIndex() {
return true;
}
protected TransportRequestOptions transportOptions() {
return TransportRequestOptions.EMPTY;
}
protected boolean retryPrimaryException(final Throwable e) {
return e.getClass() == ReplicationOperation.RetryOnPrimaryException.class
|| TransportActions.isShardNotAvailableException(e);
}
protected class OperationTransportHandler implements TransportRequestHandler<Request> {
public OperationTransportHandler() {
}
@Override
public void messageReceived(final Request request, final TransportChannel channel, Task task) throws Exception {
execute(task, request, new ActionListener<Response>() {
@Override
public void onResponse(Response result) {
try {
channel.sendResponse(result);
} catch (Exception e) {
onFailure(e);
}
}
@Override
public void onFailure(Exception e) {
try {
channel.sendResponse(e);
} catch (Exception inner) {
inner.addSuppressed(e);
logger.warn(() -> new ParameterizedMessage("Failed to send response for {}", actionName), inner);
}
}
});
}
}
protected class PrimaryOperationTransportHandler implements TransportRequestHandler<ConcreteShardRequest<Request>> {
public PrimaryOperationTransportHandler() {
}
@Override
public void messageReceived(ConcreteShardRequest<Request> request, TransportChannel channel, Task task) {
new AsyncPrimaryAction(request.request, request.targetAllocationID, request.primaryTerm, channel, (ReplicationTask) task).run();
}
}
class AsyncPrimaryAction extends AbstractRunnable implements ActionListener<PrimaryShardReference> {
private final Request request;
// targetAllocationID of the shard this request is meant for
private final String targetAllocationID;
// primary term of the shard this request is meant for
private final long primaryTerm;
private final TransportChannel channel;
private final ReplicationTask replicationTask;
AsyncPrimaryAction(Request request, String targetAllocationID, long primaryTerm, TransportChannel channel,
ReplicationTask replicationTask) {
this.request = request;
this.targetAllocationID = targetAllocationID;
this.primaryTerm = primaryTerm;
this.channel = channel;
this.replicationTask = replicationTask;
}
@Override
protected void doRun() throws Exception {
acquirePrimaryShardReference(request.shardId(), targetAllocationID, primaryTerm, this, request);
}
@Override
public void onResponse(PrimaryShardReference primaryShardReference) {
try {
if (primaryShardReference.isRelocated()) {
primaryShardReference.close(); // release shard operation lock as soon as possible
setPhase(replicationTask, "primary_delegation");
// delegate primary phase to relocation target
// it is safe to execute primary phase on relocation target as there are no more in-flight operations where primary
// phase is executed on local shard and all subsequent operations are executed on relocation target as primary phase.
final ShardRouting primary = primaryShardReference.routingEntry();
assert primary.relocating() : "indexShard is marked as relocated but routing isn't" + primary;
DiscoveryNode relocatingNode = clusterService.state().nodes().get(primary.relocatingNodeId());
transportService.sendRequest(relocatingNode, transportPrimaryAction,
new ConcreteShardRequest<>(request, primary.allocationId().getRelocationId(), primaryTerm),
transportOptions,
new TransportChannelResponseHandler<>(logger, channel, "rerouting indexing to target primary " + primary,
TransportReplicationAction.this::read) {
@Override
public void handleResponse(Response response) {
setPhase(replicationTask, "finished");
super.handleResponse(response);
}
@Override
public void handleException(TransportException exp) {
setPhase(replicationTask, "finished");
super.handleException(exp);
}
});
} else {
setPhase(replicationTask, "primary");
final ActionListener<Response> listener = createResponseListener(primaryShardReference);
createReplicatedOperation(request,
ActionListener.wrap(result -> result.respond(listener), listener::onFailure),
primaryShardReference)
.execute();
}
} catch (Exception e) {
Releasables.closeWhileHandlingException(primaryShardReference); // release shard operation lock before responding to caller
onFailure(e);
}
}
@Override
public void onFailure(Exception e) {
setPhase(replicationTask, "finished");
try {
channel.sendResponse(e);
} catch (IOException inner) {
inner.addSuppressed(e);
logger.warn("failed to send response", inner);
}
}
private ActionListener<Response> createResponseListener(final PrimaryShardReference primaryShardReference) {
return new ActionListener<Response>() {
@Override
public void onResponse(Response response) {
if (syncGlobalCheckpointAfterOperation) {
final IndexShard shard = primaryShardReference.indexShard;
try {
shard.maybeSyncGlobalCheckpoint("post-operation");
} catch (final Exception e) {
// only log non-closed exceptions
if (ExceptionsHelper.unwrap(e, AlreadyClosedException.class, IndexShardClosedException.class) == null) {
logger.info(
new ParameterizedMessage(
"{} failed to execute post-operation global checkpoint sync",
shard.shardId()),
e);
// intentionally swallow, a missed global checkpoint sync should not fail this operation
}
}
}
primaryShardReference.close(); // release shard operation lock before responding to caller
setPhase(replicationTask, "finished");
try {
channel.sendResponse(response);
} catch (IOException e) {
onFailure(e);
}
}
@Override
public void onFailure(Exception e) {
primaryShardReference.close(); // release shard operation lock before responding to caller
setPhase(replicationTask, "finished");
try {
channel.sendResponse(e);
} catch (IOException e1) {
logger.warn("failed to send response", e);
}
}
};
}
protected ReplicationOperation<Request, ReplicaRequest, PrimaryResult<ReplicaRequest, Response>> createReplicatedOperation(
Request request, ActionListener<PrimaryResult<ReplicaRequest, Response>> listener,
PrimaryShardReference primaryShardReference) {
return new ReplicationOperation<>(request, primaryShardReference, listener,
newReplicasProxy(primaryTerm), logger, actionName);
}
}
protected static class PrimaryResult<ReplicaRequest extends ReplicationRequest<ReplicaRequest>,
Response extends ReplicationResponse>
implements ReplicationOperation.PrimaryResult<ReplicaRequest> {
final ReplicaRequest replicaRequest;
public final Response finalResponseIfSuccessful;
public final Exception finalFailure;
/**
* Result of executing a primary operation
* expects <code>finalResponseIfSuccessful</code> or <code>finalFailure</code> to be not-null
*/
public PrimaryResult(ReplicaRequest replicaRequest, Response finalResponseIfSuccessful, Exception finalFailure) {
assert finalFailure != null ^ finalResponseIfSuccessful != null
: "either a response or a failure has to be not null, " +
"found [" + finalFailure + "] failure and [" + finalResponseIfSuccessful + "] response";
this.replicaRequest = replicaRequest;
this.finalResponseIfSuccessful = finalResponseIfSuccessful;
this.finalFailure = finalFailure;
}
public PrimaryResult(ReplicaRequest replicaRequest, Response replicationResponse) {
this(replicaRequest, replicationResponse, null);
}
@Override
public ReplicaRequest replicaRequest() {
return replicaRequest;
}
@Override
public void setShardInfo(ReplicationResponse.ShardInfo shardInfo) {
if (finalResponseIfSuccessful != null) {
finalResponseIfSuccessful.setShardInfo(shardInfo);
}
}
public void respond(ActionListener<Response> listener) {
if (finalResponseIfSuccessful != null) {
listener.onResponse(finalResponseIfSuccessful);
} else {
listener.onFailure(finalFailure);
}
}
}
protected static class ReplicaResult {
final Exception finalFailure;
public ReplicaResult(Exception finalFailure) {
this.finalFailure = finalFailure;
}
public ReplicaResult() {
this(null);
}
public void respond(ActionListener<TransportResponse.Empty> listener) {
if (finalFailure == null) {
listener.onResponse(TransportResponse.Empty.INSTANCE);
} else {
listener.onFailure(finalFailure);
}
}
}
public class ReplicaOperationTransportHandler implements TransportRequestHandler<ConcreteReplicaRequest<ReplicaRequest>> {
@Override
public void messageReceived(
final ConcreteReplicaRequest<ReplicaRequest> replicaRequest,
final TransportChannel channel,
final Task task)
throws Exception {
new AsyncReplicaAction(
replicaRequest.getRequest(),
replicaRequest.getTargetAllocationID(),
replicaRequest.getPrimaryTerm(),
replicaRequest.getGlobalCheckpoint(),
replicaRequest.getMaxSeqNoOfUpdatesOrDeletes(),
channel,
(ReplicationTask) task).run();
}
}
public static class RetryOnReplicaException extends ElasticsearchException {
public RetryOnReplicaException(ShardId shardId, String msg) {
super(msg);
setShard(shardId);
}
public RetryOnReplicaException(StreamInput in) throws IOException {
super(in);
}
}
private final class AsyncReplicaAction extends AbstractRunnable implements ActionListener<Releasable> {
private final ReplicaRequest request;
// allocation id of the replica this request is meant for
private final String targetAllocationID;
private final long primaryTerm;
private final long globalCheckpoint;
private final long maxSeqNoOfUpdatesOrDeletes;
private final TransportChannel channel;
private final IndexShard replica;
/**
* The task on the node with the replica shard.
*/
private final ReplicationTask task;
// important: we pass null as a timeout as failing a replica is
// something we want to avoid at all costs
private final ClusterStateObserver observer = new ClusterStateObserver(clusterService, null, logger);
AsyncReplicaAction(
ReplicaRequest request,
String targetAllocationID,
long primaryTerm,
long globalCheckpoint,
long maxSeqNoOfUpdatesOrDeletes,
TransportChannel channel,
ReplicationTask task) {
this.request = request;
this.channel = channel;
this.task = task;
this.targetAllocationID = targetAllocationID;
this.primaryTerm = primaryTerm;
this.globalCheckpoint = globalCheckpoint;
this.maxSeqNoOfUpdatesOrDeletes = maxSeqNoOfUpdatesOrDeletes;
final ShardId shardId = request.shardId();
assert shardId != null : "request shardId must be set";
this.replica = getIndexShard(shardId);
}
@Override
public void onResponse(Releasable releasable) {
try {
final ReplicaResult replicaResult = shardOperationOnReplica(request, replica);
releasable.close(); // release shard operation lock before responding to caller
final TransportReplicationAction.ReplicaResponse response =
new ReplicaResponse(replica.getLocalCheckpoint(), replica.getLastSyncedGlobalCheckpoint());
replicaResult.respond(new ResponseListener(response));
} catch (final Exception e) {
Releasables.closeWhileHandlingException(releasable); // release shard operation lock before responding to caller
AsyncReplicaAction.this.onFailure(e);
}
}
@Override
public void onFailure(Exception e) {
if (e instanceof RetryOnReplicaException) {
logger.trace(
() -> new ParameterizedMessage(
"Retrying operation on replica, action [{}], request [{}]",
transportReplicaAction,
request
),
e
);
request.onRetry();
observer.waitForNextChange(new ClusterStateObserver.Listener() {
@Override
public void onNewClusterState(ClusterState state) {
// Forking a thread on local node via transport service so that custom transport service have an
// opportunity to execute custom logic before the replica operation begins
String extraMessage = "action [" + transportReplicaAction + "], request[" + request + "]";
TransportChannelResponseHandler<TransportResponse.Empty> handler =
new TransportChannelResponseHandler<>(logger, channel, extraMessage, in -> TransportResponse.Empty.INSTANCE);
transportService.sendRequest(clusterService.localNode(), transportReplicaAction,
new ConcreteReplicaRequest<>(request, targetAllocationID, primaryTerm,
globalCheckpoint, maxSeqNoOfUpdatesOrDeletes),
handler);
}
@Override
public void onClusterServiceClose() {
responseWithFailure(new NodeClosedException(clusterService.localNode()));
}
@Override
public void onTimeout(TimeValue timeout) {
throw new AssertionError("Cannot happen: there is not timeout");
}
});
} else {
responseWithFailure(e);
}
}
protected void responseWithFailure(Exception e) {
try {
setPhase(task, "finished");
channel.sendResponse(e);
} catch (IOException responseException) {
responseException.addSuppressed(e);
logger.warn(() -> new ParameterizedMessage(
"failed to send error message back to client for action [{}]", transportReplicaAction), responseException);
}
}
@Override
protected void doRun() throws Exception {
setPhase(task, "replica");
final String actualAllocationId = this.replica.routingEntry().allocationId().getId();
if (actualAllocationId.equals(targetAllocationID) == false) {
throw new ShardNotFoundException(this.replica.shardId(), "expected aID [{}] but found [{}]", targetAllocationID,
actualAllocationId);
}
replica.acquireReplicaOperationPermit(primaryTerm, globalCheckpoint, maxSeqNoOfUpdatesOrDeletes, this, executor, request);
}
/**
* Listens for the response on the replica and sends the response back to the primary.
*/
private class ResponseListener implements ActionListener<TransportResponse.Empty> {
private final ReplicaResponse replicaResponse;
ResponseListener(ReplicaResponse replicaResponse) {
this.replicaResponse = replicaResponse;
}
@Override
public void onResponse(Empty response) {
if (logger.isTraceEnabled()) {
logger.trace("action [{}] completed on shard [{}] for request [{}]", transportReplicaAction, request.shardId(),
request);
}
setPhase(task, "finished");
try {
channel.sendResponse(replicaResponse);
} catch (Exception e) {
onFailure(e);
}
}
@Override
public void onFailure(Exception e) {
responseWithFailure(e);
}
}
}
protected IndexShard getIndexShard(ShardId shardId) {
IndexService indexService = indicesService.indexServiceSafe(shardId.getIndex());
return indexService.getShard(shardId.id());
}
/**
* Responsible for routing and retrying failed operations on the primary.
* The actual primary operation is done in {@link ReplicationOperation} on the
* node with primary copy.
*
* Resolves index and shard id for the request before routing it to target node
*/
final class ReroutePhase extends AbstractRunnable {
private final ActionListener<Response> listener;
private final Request request;
private final ReplicationTask task;
private final ClusterStateObserver observer;
private final AtomicBoolean finished = new AtomicBoolean();
ReroutePhase(ReplicationTask task, Request request, ActionListener<Response> listener) {
this.request = request;
if (task != null) {
this.request.setParentTask(clusterService.localNode().getId(), task.getId());
}
this.listener = listener;
this.task = task;
this.observer = new ClusterStateObserver(clusterService, request.timeout(), logger);
}
@Override
public void onFailure(Exception e) {
finishWithUnexpectedFailure(e);
}
@Override
protected void doRun() {
setPhase(task, "routing");
final ClusterState state = observer.setAndGetObservedState();
if (handleBlockExceptions(state)) {
return;
}
// request does not have a shardId yet, we need to pass the concrete index to resolve shardId
final String concreteIndex = concreteIndex(state);
final IndexMetaData indexMetaData = state.metaData().index(concreteIndex);
if (indexMetaData == null) {
retry(new IndexNotFoundException(concreteIndex));
return;
}
if (indexMetaData.getState() == IndexMetaData.State.CLOSE) {
throw new IndexClosedException(indexMetaData.getIndex());
}
// resolve all derived request fields, so we can route and apply it
resolveRequest(indexMetaData, request);
assert request.shardId() != null : "request shardId must be set in resolveRequest";
assert request.waitForActiveShards() != ActiveShardCount.DEFAULT : "request waitForActiveShards must be set in resolveRequest";
final ShardRouting primary = primary(state);
if (retryIfUnavailable(state, primary)) {
return;
}
final DiscoveryNode node = state.nodes().get(primary.currentNodeId());
if (primary.currentNodeId().equals(state.nodes().getLocalNodeId())) {
performLocalAction(state, primary, node, indexMetaData);
} else {
performRemoteAction(state, primary, node);
}
}
private void performLocalAction(ClusterState state, ShardRouting primary, DiscoveryNode node, IndexMetaData indexMetaData) {
setPhase(task, "waiting_on_primary");
if (logger.isTraceEnabled()) {
logger.trace("send action [{}] to local primary [{}] for request [{}] with cluster state version [{}] to [{}] ",
transportPrimaryAction, request.shardId(), request, state.version(), primary.currentNodeId());
}
performAction(node, transportPrimaryAction, true,
new ConcreteShardRequest<>(request, primary.allocationId().getId(), indexMetaData.primaryTerm(primary.id())));
}
private void performRemoteAction(ClusterState state, ShardRouting primary, DiscoveryNode node) {
if (state.version() < request.routedBasedOnClusterVersion()) {
logger.trace("failed to find primary [{}] for request [{}] despite sender thinking it would be here. Local cluster state "
+ "version [{}]] is older than on sending node (version [{}]), scheduling a retry...", request.shardId(), request,
state.version(), request.routedBasedOnClusterVersion());
retryBecauseUnavailable(request.shardId(), "failed to find primary as current cluster state with version ["
+ state.version() + "] is stale (expected at least [" + request.routedBasedOnClusterVersion() + "]");
return;
} else {
// chasing the node with the active primary for a second hop requires that we are at least up-to-date with the current
// cluster state version this prevents redirect loops between two nodes when a primary was relocated and the relocation
// target is not aware that it is the active primary shard already.
request.routedBasedOnClusterVersion(state.version());
}
if (logger.isTraceEnabled()) {
logger.trace("send action [{}] on primary [{}] for request [{}] with cluster state version [{}] to [{}]", actionName,
request.shardId(), request, state.version(), primary.currentNodeId());
}
setPhase(task, "rerouted");
performAction(node, actionName, false, request);
}
private boolean retryIfUnavailable(ClusterState state, ShardRouting primary) {
if (primary == null || primary.active() == false) {
logger.trace("primary shard [{}] is not yet active, scheduling a retry: action [{}], request [{}], "
+ "cluster state version [{}]", request.shardId(), actionName, request, state.version());
retryBecauseUnavailable(request.shardId(), "primary shard is not active");
return true;
}
if (state.nodes().nodeExists(primary.currentNodeId()) == false) {
logger.trace("primary shard [{}] is assigned to an unknown node [{}], scheduling a retry: action [{}], request [{}], "
+ "cluster state version [{}]", request.shardId(), primary.currentNodeId(), actionName, request, state.version());
retryBecauseUnavailable(request.shardId(), "primary shard isn't assigned to a known node.");
return true;
}
return false;
}
private String concreteIndex(ClusterState state) {
return resolveIndex() ? indexNameExpressionResolver.concreteSingleIndex(state, request).getName() : request.index();
}
private ShardRouting primary(ClusterState state) {
IndexShardRoutingTable indexShard = state.getRoutingTable().shardRoutingTable(request.shardId());
return indexShard.primaryShard();
}
private boolean handleBlockExceptions(ClusterState state) {
ClusterBlockLevel globalBlockLevel = globalBlockLevel();
if (globalBlockLevel != null) {
ClusterBlockException blockException = state.blocks().globalBlockedException(globalBlockLevel);
if (blockException != null) {
handleBlockException(blockException);
return true;
}
}
ClusterBlockLevel indexBlockLevel = indexBlockLevel();
if (indexBlockLevel != null) {
ClusterBlockException blockException = state.blocks().indexBlockedException(indexBlockLevel, concreteIndex(state));
if (blockException != null) {
handleBlockException(blockException);
return true;
}
}
return false;
}
private void handleBlockException(ClusterBlockException blockException) {
if (blockException.retryable()) {
logger.trace("cluster is blocked, scheduling a retry", blockException);
retry(blockException);
} else {
finishAsFailed(blockException);
}
}
private void performAction(final DiscoveryNode node, final String action, final boolean isPrimaryAction,
final TransportRequest requestToPerform) {
transportService.sendRequest(node, action, requestToPerform, transportOptions, new TransportResponseHandler<Response>() {
@Override
public Response read(StreamInput in) throws IOException {
return TransportReplicationAction.this.read(in);
}
@Override
public String executor() {
return ThreadPool.Names.SAME;
}
@Override
public void handleResponse(Response response) {
finishOnSuccess(response);
}
@Override
public void handleException(TransportException exp) {
try {
// if we got disconnected from the node, or the node / shard is not in the right state (being closed)
final Throwable cause = exp.unwrapCause();
if (cause instanceof ConnectTransportException || cause instanceof NodeClosedException ||
(isPrimaryAction && retryPrimaryException(cause))) {
logger.trace(() -> new ParameterizedMessage(
"received an error from node [{}] for request [{}], scheduling a retry",
node.getId(), requestToPerform), exp);
retry(exp);
} else {
finishAsFailed(exp);
}
} catch (Exception e) {
e.addSuppressed(exp);
finishWithUnexpectedFailure(e);
}
}
});
}
void retry(Exception failure) {
assert failure != null;
if (observer.isTimedOut()) {
// we running as a last attempt after a timeout has happened. don't retry
finishAsFailed(failure);
return;
}
setPhase(task, "waiting_for_retry");
request.onRetry();
observer.waitForNextChange(new ClusterStateObserver.Listener() {
@Override
public void onNewClusterState(ClusterState state) {
run();
}
@Override
public void onClusterServiceClose() {
finishAsFailed(new NodeClosedException(clusterService.localNode()));
}
@Override
public void onTimeout(TimeValue timeout) {
// Try one more time...
run();
}
});
}
void finishAsFailed(Exception failure) {
if (finished.compareAndSet(false, true)) {
setPhase(task, "failed");
logger.trace(() -> new ParameterizedMessage("operation failed. action [{}], request [{}]", actionName, request), failure);
listener.onFailure(failure);
} else {
assert false : "finishAsFailed called but operation is already finished";
}
}
void finishWithUnexpectedFailure(Exception failure) {
logger.warn(() -> new ParameterizedMessage(
"unexpected error during the primary phase for action [{}], request [{}]",
actionName, request), failure);
if (finished.compareAndSet(false, true)) {
setPhase(task, "failed");
listener.onFailure(failure);
} else {
assert false : "finishWithUnexpectedFailure called but operation is already finished";
}
}
void finishOnSuccess(Response response) {
if (finished.compareAndSet(false, true)) {
setPhase(task, "finished");
if (logger.isTraceEnabled()) {
logger.trace("operation succeeded. action [{}],request [{}]", actionName, request);
}
listener.onResponse(response);
} else {
assert false : "finishOnSuccess called but operation is already finished";
}
}
void retryBecauseUnavailable(ShardId shardId, String message) {
retry(new UnavailableShardsException(shardId, "{} Timeout: [{}], request: [{}]", message, request.timeout(), request));
}
}
/**
* Tries to acquire reference to {@link IndexShard} to perform a primary operation. Released after performing primary operation locally
* and replication of the operation to all replica shards is completed / failed (see {@link ReplicationOperation}).
*/
private void acquirePrimaryShardReference(ShardId shardId, String allocationId, long primaryTerm,
ActionListener<PrimaryShardReference> onReferenceAcquired, Object debugInfo) {
IndexShard indexShard = getIndexShard(shardId);
// we may end up here if the cluster state used to route the primary is so stale that the underlying
// index shard was replaced with a replica. For example - in a two node cluster, if the primary fails
// the replica will take over and a replica will be assigned to the first node.
if (indexShard.routingEntry().primary() == false) {
throw new ReplicationOperation.RetryOnPrimaryException(indexShard.shardId(),
"actual shard is not a primary " + indexShard.routingEntry());
}
final String actualAllocationId = indexShard.routingEntry().allocationId().getId();
if (actualAllocationId.equals(allocationId) == false) {
throw new ShardNotFoundException(shardId, "expected aID [{}] but found [{}]", allocationId, actualAllocationId);
}
final long actualTerm = indexShard.getPendingPrimaryTerm();
if (actualTerm != primaryTerm) {
throw new ShardNotFoundException(shardId, "expected aID [{}] with term [{}] but found [{}]", allocationId,
primaryTerm, actualTerm);
}
ActionListener<Releasable> onAcquired = new ActionListener<Releasable>() {
@Override
public void onResponse(Releasable releasable) {
onReferenceAcquired.onResponse(new PrimaryShardReference(indexShard, releasable));
}
@Override
public void onFailure(Exception e) {
onReferenceAcquired.onFailure(e);
}
};
indexShard.acquirePrimaryOperationPermit(onAcquired, executor, debugInfo);
}
class ShardReference implements Releasable {
protected final IndexShard indexShard;
private final Releasable operationLock;
ShardReference(IndexShard indexShard, Releasable operationLock) {
this.indexShard = indexShard;
this.operationLock = operationLock;
}
@Override
public void close() {
operationLock.close();
}
public long getLocalCheckpoint() {
return indexShard.getLocalCheckpoint();
}
public ShardRouting routingEntry() {
return indexShard.routingEntry();
}
}
class PrimaryShardReference extends ShardReference
implements ReplicationOperation.Primary<Request, ReplicaRequest, PrimaryResult<ReplicaRequest, Response>> {
PrimaryShardReference(IndexShard indexShard, Releasable operationLock) {
super(indexShard, operationLock);
}
public boolean isRelocated() {
return indexShard.isRelocatedPrimary();
}
@Override
public void failShard(String reason, Exception e) {
try {
indexShard.failShard(reason, e);
} catch (Exception inner) {
e.addSuppressed(inner);
}
}
@Override
public PrimaryResult perform(Request request) throws Exception {
PrimaryResult result = shardOperationOnPrimary(request, indexShard);
assert result.replicaRequest() == null || result.finalFailure == null : "a replica request [" + result.replicaRequest()
+ "] with a primary failure [" + result.finalFailure + "]";
return result;
}
@Override
public void updateLocalCheckpointForShard(String allocationId, long checkpoint) {
indexShard.updateLocalCheckpointForShard(allocationId, checkpoint);
}
@Override
public void updateGlobalCheckpointForShard(final String allocationId, final long globalCheckpoint) {
indexShard.updateGlobalCheckpointForShard(allocationId, globalCheckpoint);
}
@Override
public long localCheckpoint() {
return indexShard.getLocalCheckpoint();
}
@Override
public long globalCheckpoint() {
return indexShard.getLastSyncedGlobalCheckpoint();
}
@Override
public long computedGlobalCheckpoint() {
return indexShard.getLastKnownGlobalCheckpoint();
}
@Override
public long maxSeqNoOfUpdatesOrDeletes() {
return indexShard.getMaxSeqNoOfUpdatesOrDeletes();
}
@Override
public ReplicationGroup getReplicationGroup() {
return indexShard.getReplicationGroup();
}
}
public static class ReplicaResponse extends TransportResponse implements ReplicationOperation.ReplicaResponse {
private final long localCheckpoint;
private final long globalCheckpoint;
public ReplicaResponse(long localCheckpoint, long globalCheckpoint) {
/*
* A replica should always know its own local checkpoints so this should always be a valid sequence number or the pre-6.0
* checkpoint value when simulating responses to replication actions that pre-6.0 nodes are not aware of (e.g., the global
* checkpoint background sync, and the primary/replica resync).
*/
assert localCheckpoint != SequenceNumbers.UNASSIGNED_SEQ_NO;
this.localCheckpoint = localCheckpoint;
this.globalCheckpoint = globalCheckpoint;
}
public ReplicaResponse(StreamInput in) throws IOException {
localCheckpoint = in.readZLong();
globalCheckpoint = in.readZLong();
}
@Override
public void writeTo(StreamOutput out) throws IOException {
out.writeZLong(localCheckpoint);
out.writeZLong(globalCheckpoint);
}
@Override
public long localCheckpoint() {
return localCheckpoint;
}
@Override
public long globalCheckpoint() {
return globalCheckpoint;
}
}
/**
* The {@code ReplicasProxy} is an implementation of the {@code Replicas}
* interface that performs the actual {@code ReplicaRequest} on the replica
* shards. It also encapsulates the logic required for failing the replica
* if deemed necessary as well as marking it as stale when needed.
*/
protected class ReplicasProxy implements ReplicationOperation.Replicas<ReplicaRequest> {
protected final long primaryTerm;
public ReplicasProxy(long primaryTerm) {
this.primaryTerm = primaryTerm;
}
@Override
public void performOn(
final ShardRouting replica,
final ReplicaRequest request,
final long globalCheckpoint,
final long maxSeqNoOfUpdatesOrDeletes,
final ActionListener<ReplicationOperation.ReplicaResponse> listener) {
String nodeId = replica.currentNodeId();
final DiscoveryNode node = clusterService.state().nodes().get(nodeId);
if (node == null) {
listener.onFailure(new NoNodeAvailableException("unknown node [" + nodeId + "]"));
return;
}
final ConcreteReplicaRequest<ReplicaRequest> replicaRequest = new ConcreteReplicaRequest<>(
request, replica.allocationId().getId(), primaryTerm, globalCheckpoint, maxSeqNoOfUpdatesOrDeletes);
sendReplicaRequest(replicaRequest, node, listener);
}
@Override
public void failShardIfNeeded(ShardRouting replica, String message, Exception exception, ActionListener<Void> listener) {
// This does not need to fail the shard. The idea is that this
// is a non-write operation (something like a refresh or a global
// checkpoint sync) and therefore the replica should still be
// "alive" if it were to fail.
listener.onResponse(null);
}
@Override
public void markShardCopyAsStaleIfNeeded(ShardId shardId, String allocationId, ActionListener<Void> listener) {
// This does not need to make the shard stale. The idea is that this
// is a non-write operation (something like a refresh or a global
// checkpoint sync) and therefore the replica should still be
// "alive" if it were to be marked as stale.
listener.onResponse(null);
}
}
/**
* Sends the specified replica request to the specified node.
*
* @param replicaRequest the replica request
* @param node the node to send the request to
* @param listener callback for handling the response or failure
*/
protected void sendReplicaRequest(
final ConcreteReplicaRequest<ReplicaRequest> replicaRequest,
final DiscoveryNode node,
final ActionListener<ReplicationOperation.ReplicaResponse> listener) {
final ActionListenerResponseHandler<ReplicaResponse> handler = new ActionListenerResponseHandler<>(listener, ReplicaResponse::new);
transportService.sendRequest(node, transportReplicaAction, replicaRequest, transportOptions, handler);
}
/** a wrapper class to encapsulate a request when being sent to a specific allocation id **/
public static class ConcreteShardRequest<R extends TransportRequest> extends TransportRequest {
/** {@link AllocationId#getId()} of the shard this request is sent to **/
private final String targetAllocationID;
private final long primaryTerm;
private final R request;
public ConcreteShardRequest(R request, String targetAllocationID, long primaryTerm) {
Objects.requireNonNull(request);
Objects.requireNonNull(targetAllocationID);
this.request = request;
this.targetAllocationID = targetAllocationID;
this.primaryTerm = primaryTerm;
}
@Override
public void setParentTask(String parentTaskNode, long parentTaskId) {
request.setParentTask(parentTaskNode, parentTaskId);
}
@Override
public void setParentTask(TaskId taskId) {
request.setParentTask(taskId);
}
@Override
public TaskId getParentTask() {
return request.getParentTask();
}
@Override
public Task createTask(long id, String type, String action, TaskId parentTaskId) {
return request.createTask(id, type, action, parentTaskId);
}
@Override
public String getDescription() {
return "[" + request.getDescription() + "] for aID [" + targetAllocationID + "] and term [" + primaryTerm + "]";
}
public ConcreteShardRequest(StreamInput in, Reader<R> reader) throws IOException {
targetAllocationID = in.readString();
primaryTerm = in.readVLong();
request = reader.read(in);
}
@Override
public void writeTo(StreamOutput out) throws IOException {
out.writeString(targetAllocationID);
out.writeVLong(primaryTerm);
request.writeTo(out);
}
public R getRequest() {
return request;
}
public String getTargetAllocationID() {
return targetAllocationID;
}
public long getPrimaryTerm() {
return primaryTerm;
}
@Override
public String toString() {
return "request: " + request + ", target allocation id: " + targetAllocationID + ", primary term: " + primaryTerm;
}
}
protected static final class ConcreteReplicaRequest<R extends TransportRequest> extends ConcreteShardRequest<R> {
private final long globalCheckpoint;
private final long maxSeqNoOfUpdatesOrDeletes;
public ConcreteReplicaRequest(final R request, final String targetAllocationID, final long primaryTerm,
final long globalCheckpoint, final long maxSeqNoOfUpdatesOrDeletes) {
super(request, targetAllocationID, primaryTerm);
this.globalCheckpoint = globalCheckpoint;
this.maxSeqNoOfUpdatesOrDeletes = maxSeqNoOfUpdatesOrDeletes;
}
public ConcreteReplicaRequest(StreamInput in, Reader<R> reader) throws IOException {
super(in, reader);
globalCheckpoint = in.readZLong();
maxSeqNoOfUpdatesOrDeletes = in.readZLong();
}
@Override
public void writeTo(StreamOutput out) throws IOException {
super.writeTo(out);
out.writeZLong(globalCheckpoint);
out.writeZLong(maxSeqNoOfUpdatesOrDeletes);
}
public long getGlobalCheckpoint() {
return globalCheckpoint;
}
public long getMaxSeqNoOfUpdatesOrDeletes() {
return maxSeqNoOfUpdatesOrDeletes;
}
@Override
public String toString() {
return "ConcreteReplicaRequest{" +
"targetAllocationID='" + getTargetAllocationID() + '\'' +
", primaryTerm='" + getPrimaryTerm() + '\'' +
", request=" + getRequest() +
", globalCheckpoint=" + globalCheckpoint +
", maxSeqNoOfUpdatesOrDeletes=" + maxSeqNoOfUpdatesOrDeletes +
'}';
}
}
/**
* Sets the current phase on the task if it isn't null. Pulled into its own
* method because its more convenient that way.
*/
static void setPhase(ReplicationTask task, String phase) {
if (task != null) {
task.setPhase(phase);
}
}
}
