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* 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.single.instance;
import org.elasticsearch.action.ActionListener;
import org.elasticsearch.action.ActionResponse;
import org.elasticsearch.action.UnavailableShardsException;
import org.elasticsearch.action.support.ActionFilters;
import org.elasticsearch.action.support.HandledTransportAction;
import org.elasticsearch.cluster.ClusterState;
import org.elasticsearch.cluster.ClusterStateObserver;
import org.elasticsearch.cluster.block.ClusterBlockException;
import org.elasticsearch.cluster.block.ClusterBlockLevel;
import org.elasticsearch.cluster.metadata.IndexNameExpressionResolver;
import org.elasticsearch.cluster.node.DiscoveryNode;
import org.elasticsearch.cluster.node.DiscoveryNodes;
import org.elasticsearch.cluster.routing.ShardIterator;
import org.elasticsearch.cluster.routing.ShardRouting;
import org.elasticsearch.cluster.service.ClusterService;
import org.elasticsearch.common.Nullable;
import org.elasticsearch.common.settings.Settings;
import org.elasticsearch.common.unit.TimeValue;
import org.elasticsearch.node.NodeClosedException;
import org.elasticsearch.threadpool.ThreadPool;
import org.elasticsearch.transport.ConnectTransportException;
import org.elasticsearch.transport.TransportChannel;
import org.elasticsearch.transport.TransportException;
import org.elasticsearch.transport.TransportRequestHandler;
import org.elasticsearch.transport.TransportRequestOptions;
import org.elasticsearch.transport.TransportResponseHandler;
import org.elasticsearch.transport.TransportService;
import java.util.function.Supplier;
public abstract class TransportInstanceSingleOperationAction<Request extends InstanceShardOperationRequest<Request>, Response extends ActionResponse>
extends HandledTransportAction<Request, Response> {
protected final ClusterService clusterService;
protected final TransportService transportService;
final String executor;
final String shardActionName;
protected TransportInstanceSingleOperationAction(Settings settings, String actionName, ThreadPool threadPool,
ClusterService clusterService, TransportService transportService,
ActionFilters actionFilters, IndexNameExpressionResolver indexNameExpressionResolver, Supplier<Request> request) {
super(settings, actionName, threadPool, transportService, actionFilters, indexNameExpressionResolver, request);
this.clusterService = clusterService;
this.transportService = transportService;
this.executor = executor();
this.shardActionName = actionName + "[s]";
transportService.registerRequestHandler(shardActionName, request, executor, new ShardTransportHandler());
}
@Override
protected void doExecute(Request request, ActionListener<Response> listener) {
new AsyncSingleAction(request, listener).start();
}
protected abstract String executor();
protected abstract void shardOperation(Request request, ActionListener<Response> listener);
protected abstract Response newResponse();
protected ClusterBlockException checkGlobalBlock(ClusterState state) {
return state.blocks().globalBlockedException(ClusterBlockLevel.WRITE);
}
protected ClusterBlockException checkRequestBlock(ClusterState state, Request request) {
return state.blocks().indexBlockedException(ClusterBlockLevel.WRITE, request.concreteIndex());
}
/**
* Resolves the request. Throws an exception if the request cannot be resolved.
*/
protected abstract void resolveRequest(ClusterState state, Request request);
protected boolean retryOnFailure(Exception e) {
return false;
}
protected TransportRequestOptions transportOptions() {
return TransportRequestOptions.EMPTY;
}
/**
* Should return an iterator with a single shard!
*/
protected abstract ShardIterator shards(ClusterState clusterState, Request request);
class AsyncSingleAction {
private final ActionListener<Response> listener;
private final Request request;
private volatile ClusterStateObserver observer;
private ShardIterator shardIt;
AsyncSingleAction(Request request, ActionListener<Response> listener) {
this.request = request;
this.listener = listener;
}
public void start() {
ClusterState state = clusterService.state();
this.observer = new ClusterStateObserver(state, clusterService, request.timeout(), logger, threadPool.getThreadContext());
doStart(state);
}
protected void doStart(ClusterState clusterState) {
try {
ClusterBlockException blockException = checkGlobalBlock(clusterState);
if (blockException != null) {
if (blockException.retryable()) {
retry(blockException);
return;
} else {
throw blockException;
}
}
request.concreteIndex(indexNameExpressionResolver.concreteSingleIndex(clusterState, request).getName());
resolveRequest(clusterState, request);
blockException = checkRequestBlock(clusterState, request);
if (blockException != null) {
if (blockException.retryable()) {
retry(blockException);
return;
} else {
throw blockException;
}
}
shardIt = shards(clusterState, request);
} catch (Exception e) {
listener.onFailure(e);
return;
}
// no shardIt, might be in the case between index gateway recovery and shardIt initialization
if (shardIt.size() == 0) {
retry(null);
return;
}
// this transport only make sense with an iterator that returns a single shard routing (like primary)
assert shardIt.size() == 1;
ShardRouting shard = shardIt.nextOrNull();
assert shard != null;
if (!shard.active()) {
retry(null);
return;
}
request.shardId = shardIt.shardId();
DiscoveryNode node = clusterState.nodes().get(shard.currentNodeId());
transportService.sendRequest(node, shardActionName, request, transportOptions(), new TransportResponseHandler<Response>() {
@Override
public Response newInstance() {
return newResponse();
}
@Override
public String executor() {
return ThreadPool.Names.SAME;
}
@Override
public void handleResponse(Response response) {
listener.onResponse(response);
}
@Override
public void handleException(TransportException exp) {
final Throwable cause = exp.unwrapCause();
// if we got disconnected from the node, or the node / shard is not in the right state (being closed)
if (cause instanceof ConnectTransportException || cause instanceof NodeClosedException ||
retryOnFailure(exp)) {
retry((Exception) cause);
} else {
listener.onFailure(exp);
}
}
});
}
void retry(@Nullable final Exception failure) {
if (observer.isTimedOut()) {
// we running as a last attempt after a timeout has happened. don't retry
Exception listenFailure = failure;
if (listenFailure == null) {
if (shardIt == null) {
listenFailure = new UnavailableShardsException(request.concreteIndex(), -1, "Timeout waiting for [{}], request: {}", request.timeout(), actionName);
} else {
listenFailure = new UnavailableShardsException(shardIt.shardId(), "[{}] shardIt, [{}] active : Timeout waiting for [{}], request: {}", shardIt.size(), shardIt.sizeActive(), request.timeout(), actionName);
}
}
listener.onFailure(listenFailure);
return;
}
observer.waitForNextChange(new ClusterStateObserver.Listener() {
@Override
public void onNewClusterState(ClusterState state) {
doStart(state);
}
@Override
public void onClusterServiceClose() {
listener.onFailure(new NodeClosedException(clusterService.localNode()));
}
@Override
public void onTimeout(TimeValue timeout) {
// just to be on the safe side, see if we can start it now?
doStart(observer.setAndGetObservedState());
}
}, request.timeout());
}
}
private class ShardTransportHandler implements TransportRequestHandler<Request> {
@Override
public void messageReceived(final Request request, final TransportChannel channel) throws Exception {
shardOperation(request, new ActionListener<Response>() {
@Override
public void onResponse(Response response) {
try {
channel.sendResponse(response);
} catch (Exception e) {
onFailure(e);
}
}
@Override
public void onFailure(Exception e) {
try {
channel.sendResponse(e);
} catch (Exception inner) {
inner.addSuppressed(e);
logger.warn("failed to send response for get", inner);
}
}
});
}
}
}