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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.nodes;
import org.apache.logging.log4j.message.ParameterizedMessage;
import org.elasticsearch.action.ActionListener;
import org.elasticsearch.action.FailedNodeException;
import org.elasticsearch.action.NoSuchNodeException;
import org.elasticsearch.action.support.ActionFilters;
import org.elasticsearch.action.support.HandledTransportAction;
import org.elasticsearch.cluster.ClusterState;
import org.elasticsearch.cluster.metadata.IndexNameExpressionResolver;
import org.elasticsearch.cluster.node.DiscoveryNode;
import org.elasticsearch.cluster.service.ClusterService;
import org.elasticsearch.common.settings.Settings;
import org.elasticsearch.tasks.Task;
import org.elasticsearch.threadpool.ThreadPool;
import org.elasticsearch.transport.NodeShouldNotConnectException;
import org.elasticsearch.transport.TransportChannel;
import org.elasticsearch.transport.TransportException;
import org.elasticsearch.transport.TransportRequest;
import org.elasticsearch.transport.TransportRequestHandler;
import org.elasticsearch.transport.TransportRequestOptions;
import org.elasticsearch.transport.TransportResponseHandler;
import org.elasticsearch.transport.TransportService;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.Objects;
import java.util.concurrent.atomic.AtomicInteger;
import java.util.concurrent.atomic.AtomicReferenceArray;
import java.util.function.Supplier;
public abstract class TransportNodesAction<NodesRequest extends BaseNodesRequest<NodesRequest>,
NodesResponse extends BaseNodesResponse,
NodeRequest extends BaseNodeRequest,
NodeResponse extends BaseNodeResponse>
extends HandledTransportAction<NodesRequest, NodesResponse> {
protected final ClusterService clusterService;
protected final TransportService transportService;
protected final Class<NodeResponse> nodeResponseClass;
final String transportNodeAction;
protected TransportNodesAction(Settings settings, String actionName, ThreadPool threadPool,
ClusterService clusterService, TransportService transportService, ActionFilters actionFilters,
IndexNameExpressionResolver indexNameExpressionResolver,
Supplier<NodesRequest> request, Supplier<NodeRequest> nodeRequest,
String nodeExecutor,
Class<NodeResponse> nodeResponseClass) {
super(settings, actionName, threadPool, transportService, actionFilters, indexNameExpressionResolver, request);
this.clusterService = Objects.requireNonNull(clusterService);
this.transportService = Objects.requireNonNull(transportService);
this.nodeResponseClass = Objects.requireNonNull(nodeResponseClass);
this.transportNodeAction = actionName + "[n]";
transportService.registerRequestHandler(
transportNodeAction, nodeRequest, nodeExecutor, new NodeTransportHandler());
}
@Override
protected final void doExecute(NodesRequest request, ActionListener<NodesResponse> listener) {
logger.warn("attempt to execute a transport nodes operation without a task");
throw new UnsupportedOperationException("task parameter is required for this operation");
}
@Override
protected void doExecute(Task task, NodesRequest request, ActionListener<NodesResponse> listener) {
new AsyncAction(task, request, listener).start();
}
protected boolean transportCompress() {
return false;
}
/**
* Map the responses into {@code nodeResponseClass} responses and {@link FailedNodeException}s.
*
* @param request The associated request.
* @param nodesResponses All node-level responses
* @return Never {@code null}.
* @throws NullPointerException if {@code nodesResponses} is {@code null}
* @see #newResponse(BaseNodesRequest, List, List)
*/
protected NodesResponse newResponse(NodesRequest request, AtomicReferenceArray nodesResponses) {
final List<NodeResponse> responses = new ArrayList<>();
final List<FailedNodeException> failures = new ArrayList<>();
final boolean accumulateExceptions = accumulateExceptions();
for (int i = 0; i < nodesResponses.length(); ++i) {
Object response = nodesResponses.get(i);
if (response instanceof FailedNodeException) {
if (accumulateExceptions) {
failures.add((FailedNodeException)response);
} else {
logger.warn("not accumulating exceptions, excluding exception from response", (FailedNodeException)response);
}
} else {
responses.add(nodeResponseClass.cast(response));
}
}
return newResponse(request, responses, failures);
}
/**
* Create a new {@link NodesResponse} (multi-node response).
*
* @param request The associated request.
* @param responses All successful node-level responses.
* @param failures All node-level failures.
* @return Never {@code null}.
* @throws NullPointerException if any parameter is {@code null}.
*/
protected abstract NodesResponse newResponse(NodesRequest request, List<NodeResponse> responses, List<FailedNodeException> failures);
protected abstract NodeRequest newNodeRequest(String nodeId, NodesRequest request);
protected abstract NodeResponse newNodeResponse();
protected abstract NodeResponse nodeOperation(NodeRequest request);
protected NodeResponse nodeOperation(NodeRequest request, Task task) {
return nodeOperation(request);
}
protected abstract boolean accumulateExceptions();
/**
* resolve node ids to concrete nodes of the incoming request
**/
protected void resolveRequest(NodesRequest request, ClusterState clusterState) {
assert request.concreteNodes() == null : "request concreteNodes shouldn't be set";
String[] nodesIds = clusterState.nodes().resolveNodes(request.nodesIds());
request.setConcreteNodes(Arrays.stream(nodesIds).map(clusterState.nodes()::get).toArray(DiscoveryNode[]::new));
}
class AsyncAction {
private final NodesRequest request;
private final ActionListener<NodesResponse> listener;
private final AtomicReferenceArray<Object> responses;
private final AtomicInteger counter = new AtomicInteger();
private final Task task;
AsyncAction(Task task, NodesRequest request, ActionListener<NodesResponse> listener) {
this.task = task;
this.request = request;
this.listener = listener;
if (request.concreteNodes() == null) {
resolveRequest(request, clusterService.state());
assert request.concreteNodes() != null;
}
this.responses = new AtomicReferenceArray<>(request.concreteNodes().length);
}
void start() {
final DiscoveryNode[] nodes = request.concreteNodes();
if (nodes.length == 0) {
// nothing to notify
threadPool.generic().execute(() -> listener.onResponse(newResponse(request, responses)));
return;
}
TransportRequestOptions.Builder builder = TransportRequestOptions.builder();
if (request.timeout() != null) {
builder.withTimeout(request.timeout());
}
builder.withCompress(transportCompress());
for (int i = 0; i < nodes.length; i++) {
final int idx = i;
final DiscoveryNode node = nodes[i];
final String nodeId = node.getId();
try {
if (node == null) {
onFailure(idx, nodeId, new NoSuchNodeException(nodeId));
} else {
TransportRequest nodeRequest = newNodeRequest(nodeId, request);
if (task != null) {
nodeRequest.setParentTask(clusterService.localNode().getId(), task.getId());
}
transportService.sendRequest(node, transportNodeAction, nodeRequest, builder.build(),
new TransportResponseHandler<NodeResponse>() {
@Override
public NodeResponse newInstance() {
return newNodeResponse();
}
@Override
public void handleResponse(NodeResponse response) {
onOperation(idx, response);
}
@Override
public void handleException(TransportException exp) {
onFailure(idx, node.getId(), exp);
}
@Override
public String executor() {
return ThreadPool.Names.SAME;
}
});
}
} catch (Exception e) {
onFailure(idx, nodeId, e);
}
}
}
private void onOperation(int idx, NodeResponse nodeResponse) {
responses.set(idx, nodeResponse);
if (counter.incrementAndGet() == responses.length()) {
finishHim();
}
}
private void onFailure(int idx, String nodeId, Throwable t) {
if (logger.isDebugEnabled() && !(t instanceof NodeShouldNotConnectException)) {
logger.debug(
(org.apache.logging.log4j.util.Supplier<?>)
() -> new ParameterizedMessage("failed to execute on node [{}]", nodeId), t);
}
responses.set(idx, new FailedNodeException(nodeId, "Failed node [" + nodeId + "]", t));
if (counter.incrementAndGet() == responses.length()) {
finishHim();
}
}
private void finishHim() {
NodesResponse finalResponse;
try {
finalResponse = newResponse(request, responses);
} catch (Exception e) {
logger.debug("failed to combine responses from nodes", e);
listener.onFailure(e);
return;
}
listener.onResponse(finalResponse);
}
}
class NodeTransportHandler implements TransportRequestHandler<NodeRequest> {
@Override
public void messageReceived(NodeRequest request, TransportChannel channel, Task task) throws Exception {
channel.sendResponse(nodeOperation(request, task));
}
@Override
public void messageReceived(NodeRequest request, TransportChannel channel) throws Exception {
channel.sendResponse(nodeOperation(request));
}
}
}