org.elasticsearch.transport.TransportHandshaker Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of elasticsearch Show documentation
Show all versions of elasticsearch Show documentation
Elasticsearch subproject :server
/*
* 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.transport;
import org.elasticsearch.Version;
import org.elasticsearch.action.ActionListener;
import org.elasticsearch.cluster.node.DiscoveryNode;
import org.elasticsearch.common.bytes.BytesReference;
import org.elasticsearch.common.io.stream.BytesStreamOutput;
import org.elasticsearch.common.io.stream.StreamInput;
import org.elasticsearch.common.io.stream.StreamOutput;
import org.elasticsearch.common.metrics.CounterMetric;
import org.elasticsearch.common.unit.TimeValue;
import org.elasticsearch.threadpool.ThreadPool;
import java.io.EOFException;
import java.io.IOException;
import java.util.Set;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;
import java.util.concurrent.atomic.AtomicBoolean;
/**
* Sends and receives transport-level connection handshakes. This class will send the initial handshake,
* manage state/timeouts while the handshake is in transit, and handle the eventual response.
*/
final class TransportHandshaker {
static final String HANDSHAKE_ACTION_NAME = "internal:tcp/handshake";
private final ConcurrentMap pendingHandshakes = new ConcurrentHashMap<>();
private final CounterMetric numHandshakes = new CounterMetric();
private final Version version;
private final ThreadPool threadPool;
private final HandshakeRequestSender handshakeRequestSender;
private final HandshakeResponseSender handshakeResponseSender;
TransportHandshaker(Version version, ThreadPool threadPool, HandshakeRequestSender handshakeRequestSender,
HandshakeResponseSender handshakeResponseSender) {
this.version = version;
this.threadPool = threadPool;
this.handshakeRequestSender = handshakeRequestSender;
this.handshakeResponseSender = handshakeResponseSender;
}
void sendHandshake(long requestId, DiscoveryNode node, TcpChannel channel, TimeValue timeout, ActionListener listener) {
numHandshakes.inc();
final HandshakeResponseHandler handler = new HandshakeResponseHandler(requestId, version, listener);
pendingHandshakes.put(requestId, handler);
channel.addCloseListener(ActionListener.wrap(
() -> handler.handleLocalException(new TransportException("handshake failed because connection reset"))));
boolean success = false;
try {
// for the request we use the minCompatVersion since we don't know what's the version of the node we talk to
// we also have no payload on the request but the response will contain the actual version of the node we talk
// to as the payload.
final Version minCompatVersion = version.minimumCompatibilityVersion();
handshakeRequestSender.sendRequest(node, channel, requestId, minCompatVersion);
threadPool.schedule(
() -> handler.handleLocalException(new ConnectTransportException(node, "handshake_timeout[" + timeout + "]")),
timeout,
ThreadPool.Names.GENERIC);
success = true;
} catch (Exception e) {
handler.handleLocalException(new ConnectTransportException(node, "failure to send " + HANDSHAKE_ACTION_NAME, e));
} finally {
if (success == false) {
TransportResponseHandler removed = pendingHandshakes.remove(requestId);
assert removed == null : "Handshake should not be pending if exception was thrown";
}
}
}
void handleHandshake(Version version, Set features, TcpChannel channel, long requestId, StreamInput stream) throws IOException {
// Must read the handshake request to exhaust the stream
HandshakeRequest handshakeRequest = new HandshakeRequest(stream);
final int nextByte = stream.read();
if (nextByte != -1) {
throw new IllegalStateException("Handshake request not fully read for requestId [" + requestId + "], action ["
+ TransportHandshaker.HANDSHAKE_ACTION_NAME + "], available [" + stream.available() + "]; resetting");
}
HandshakeResponse response = new HandshakeResponse(this.version);
handshakeResponseSender.sendResponse(version, features, channel, response, requestId);
}
TransportResponseHandler removeHandlerForHandshake(long requestId) {
return pendingHandshakes.remove(requestId);
}
int getNumPendingHandshakes() {
return pendingHandshakes.size();
}
long getNumHandshakes() {
return numHandshakes.count();
}
private class HandshakeResponseHandler implements TransportResponseHandler {
private final long requestId;
private final Version currentVersion;
private final ActionListener listener;
private final AtomicBoolean isDone = new AtomicBoolean(false);
private HandshakeResponseHandler(long requestId, Version currentVersion, ActionListener listener) {
this.requestId = requestId;
this.currentVersion = currentVersion;
this.listener = listener;
}
@Override
public HandshakeResponse read(StreamInput in) throws IOException {
return new HandshakeResponse(in);
}
@Override
public void handleResponse(HandshakeResponse response) {
if (isDone.compareAndSet(false, true)) {
Version version = response.responseVersion;
if (currentVersion.isCompatible(version) == false) {
listener.onFailure(new IllegalStateException("Received message from unsupported version: [" + version
+ "] minimal compatible version is: [" + currentVersion.minimumCompatibilityVersion() + "]"));
} else {
listener.onResponse(version);
}
}
}
@Override
public void handleException(TransportException e) {
if (isDone.compareAndSet(false, true)) {
listener.onFailure(new IllegalStateException("handshake failed", e));
}
}
void handleLocalException(TransportException e) {
if (removeHandlerForHandshake(requestId) != null && isDone.compareAndSet(false, true)) {
listener.onFailure(e);
}
}
@Override
public String executor() {
return ThreadPool.Names.SAME;
}
}
static final class HandshakeRequest extends TransportRequest {
private final Version version;
HandshakeRequest(Version version) {
this.version = version;
}
HandshakeRequest(StreamInput streamInput) throws IOException {
super(streamInput);
BytesReference remainingMessage;
try {
remainingMessage = streamInput.readBytesReference();
} catch (EOFException e) {
remainingMessage = null;
}
if (remainingMessage == null) {
version = null;
} else {
try (StreamInput messageStreamInput = remainingMessage.streamInput()) {
this.version = Version.readVersion(messageStreamInput);
}
}
}
@Override
public void writeTo(StreamOutput streamOutput) throws IOException {
super.writeTo(streamOutput);
assert version != null;
try (BytesStreamOutput messageStreamOutput = new BytesStreamOutput(4)) {
Version.writeVersion(version, messageStreamOutput);
BytesReference reference = messageStreamOutput.bytes();
streamOutput.writeBytesReference(reference);
}
}
}
static final class HandshakeResponse extends TransportResponse {
private final Version responseVersion;
HandshakeResponse(Version responseVersion) {
this.responseVersion = responseVersion;
}
private HandshakeResponse(StreamInput in) throws IOException {
super(in);
responseVersion = Version.readVersion(in);
}
@Override
public void writeTo(StreamOutput out) throws IOException {
assert responseVersion != null;
Version.writeVersion(responseVersion, out);
}
Version getResponseVersion() {
return responseVersion;
}
}
@FunctionalInterface
interface HandshakeRequestSender {
void sendRequest(DiscoveryNode node, TcpChannel channel, long requestId, Version version) throws IOException;
}
@FunctionalInterface
interface HandshakeResponseSender {
void sendResponse(Version version, Set features, TcpChannel channel, TransportResponse response, long requestId)
throws IOException;
}
}