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io.atomix.cluster.messaging.impl.NettyMessagingService Maven / Gradle / Ivy
/*
* Copyright 2015-present Open Networking Foundation
* Copyright © 2020 camunda services GmbH ([email protected] )
*
* Licensed 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 io.atomix.cluster.messaging.impl;
import static io.atomix.utils.concurrent.Threads.namedThreads;
import com.google.common.base.Throwables;
import com.google.common.collect.Maps;
import com.google.common.util.concurrent.MoreExecutors;
import io.atomix.cluster.messaging.ManagedMessagingService;
import io.atomix.cluster.messaging.MessagingConfig;
import io.atomix.cluster.messaging.MessagingException;
import io.atomix.cluster.messaging.MessagingService;
import io.atomix.utils.concurrent.OrderedFuture;
import io.atomix.utils.net.Address;
import io.netty.bootstrap.Bootstrap;
import io.netty.bootstrap.ServerBootstrap;
import io.netty.buffer.ByteBuf;
import io.netty.buffer.PooledByteBufAllocator;
import io.netty.channel.Channel;
import io.netty.channel.ChannelFutureListener;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelInboundHandlerAdapter;
import io.netty.channel.ChannelInitializer;
import io.netty.channel.ChannelOption;
import io.netty.channel.EventLoopGroup;
import io.netty.channel.ServerChannel;
import io.netty.channel.SimpleChannelInboundHandler;
import io.netty.channel.WriteBufferWaterMark;
import io.netty.channel.epoll.Epoll;
import io.netty.channel.epoll.EpollEventLoopGroup;
import io.netty.channel.epoll.EpollServerSocketChannel;
import io.netty.channel.epoll.EpollSocketChannel;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.SocketChannel;
import io.netty.channel.socket.nio.NioServerSocketChannel;
import io.netty.channel.socket.nio.NioSocketChannel;
import io.netty.util.concurrent.DefaultThreadFactory;
import io.netty.util.concurrent.Future;
import java.net.ConnectException;
import java.net.InetAddress;
import java.time.Duration;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Optional;
import java.util.OptionalInt;
import java.util.concurrent.CompletableFuture;
import java.util.concurrent.CopyOnWriteArrayList;
import java.util.concurrent.Executor;
import java.util.concurrent.Executors;
import java.util.concurrent.RejectedExecutionException;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;
import java.util.concurrent.atomic.AtomicBoolean;
import java.util.concurrent.atomic.AtomicLong;
import java.util.function.BiConsumer;
import java.util.function.BiFunction;
import java.util.function.Function;
import java.util.stream.Collectors;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/** Netty based MessagingService. */
public final class NettyMessagingService implements ManagedMessagingService {
private static final Duration DEFAULT_TIMEOUT = Duration.ofSeconds(5);
private final Logger log = LoggerFactory.getLogger(getClass());
private final Address advertisedAddress;
private final Collection bindingAddresses = new ArrayList<>();
private final int preamble;
private final ProtocolVersion protocolVersion;
private final AtomicBoolean started = new AtomicBoolean(false);
private final HandlerRegistry handlers = new HandlerRegistry();
private volatile LocalClientConnection localConnection;
private final Map connections = Maps.newConcurrentMap();
private final AtomicLong messageIdGenerator = new AtomicLong(0);
private final ChannelPool channelPool;
private EventLoopGroup serverGroup;
private EventLoopGroup clientGroup;
private Class serverChannelClass;
private Class clientChannelClass;
private Channel serverChannel;
private final List openFutures;
private final MessagingConfig config;
// a single thread executor which silently rejects tasks being submitted when it's shutdown
private ScheduledExecutorService timeoutExecutor;
public NettyMessagingService(
final String cluster, final Address advertisedAddress, final MessagingConfig config) {
this(cluster, advertisedAddress, config, ProtocolVersion.latest());
}
NettyMessagingService(
final String cluster,
final Address advertisedAddress,
final MessagingConfig config,
final ProtocolVersion protocolVersion) {
preamble = cluster.hashCode();
this.advertisedAddress = advertisedAddress;
this.protocolVersion = protocolVersion;
this.config = config;
openFutures = new CopyOnWriteArrayList<>();
channelPool = new ChannelPool(this::openChannel, config.getConnectionPoolSize());
initAddresses(config);
}
private void initAddresses(final MessagingConfig config) {
final int port = config.getPort() != null ? config.getPort() : advertisedAddress.port();
if (config.getInterfaces().isEmpty()) {
bindingAddresses.add(Address.from(advertisedAddress.host(), port));
} else {
final List addresses =
config.getInterfaces().stream()
.map(iface -> Address.from(iface, port))
.collect(Collectors.toList());
bindingAddresses.addAll(addresses);
}
}
@Override
public Address address() {
return advertisedAddress;
}
@Override
public Collection bindingAddresses() {
return bindingAddresses;
}
@Override
public CompletableFuture sendAsync(
final Address address, final String type, final byte[] payload, final boolean keepAlive) {
final long messageId = messageIdGenerator.incrementAndGet();
final ProtocolRequest message =
new ProtocolRequest(messageId, advertisedAddress, type, payload);
return executeOnPooledConnection(
address, type, c -> c.sendAsync(message), MoreExecutors.directExecutor());
}
@Override
public CompletableFuture sendAndReceive(
final Address address, final String type, final byte[] payload, final boolean keepAlive) {
return sendAndReceive(
address, type, payload, keepAlive, DEFAULT_TIMEOUT, MoreExecutors.directExecutor());
}
@Override
public CompletableFuture sendAndReceive(
final Address address,
final String type,
final byte[] payload,
final boolean keepAlive,
final Executor executor) {
return sendAndReceive(address, type, payload, keepAlive, DEFAULT_TIMEOUT, executor);
}
@Override
public CompletableFuture sendAndReceive(
final Address address,
final String type,
final byte[] payload,
final boolean keepAlive,
final Duration timeout) {
return sendAndReceive(
address, type, payload, keepAlive, timeout, MoreExecutors.directExecutor());
}
@Override
public CompletableFuture sendAndReceive(
final Address address,
final String type,
final byte[] payload,
final boolean keepAlive,
final Duration timeout,
final Executor executor) {
if (!started.get()) {
return CompletableFuture.failedFuture(
new IllegalStateException("MessagingService is closed."));
}
final long messageId = messageIdGenerator.incrementAndGet();
final ProtocolRequest message =
new ProtocolRequest(messageId, advertisedAddress, type, payload);
final CompletableFuture responseFuture;
if (keepAlive) {
responseFuture =
executeOnPooledConnection(address, type, c -> c.sendAndReceive(message), executor);
} else {
responseFuture =
executeOnTransientConnection(address, c -> c.sendAndReceive(message), executor);
}
final var timeoutFuture =
timeoutExecutor.schedule(
() ->
responseFuture.completeExceptionally(
new TimeoutException(
String.format(
"Request %s to %s timed out in %s", message, address, timeout))),
timeout.toNanos(),
TimeUnit.NANOSECONDS);
responseFuture.whenComplete((ignored, error) -> timeoutFuture.cancel(true));
return responseFuture;
}
@Override
public void registerHandler(
final String type, final BiConsumer handler, final Executor executor) {
handlers.register(
type,
(message, connection) ->
executor.execute(() -> handler.accept(message.sender(), message.payload())));
}
@Override
public void registerHandler(
final String type,
final BiFunction handler,
final Executor executor) {
handlers.register(
type,
(message, connection) ->
executor.execute(
() -> {
byte[] responsePayload = null;
ProtocolReply.Status status = ProtocolReply.Status.OK;
try {
responsePayload = handler.apply(message.sender(), message.payload());
} catch (final Exception e) {
log.warn("An error occurred in a message handler:", e);
status = ProtocolReply.Status.ERROR_HANDLER_EXCEPTION;
}
connection.reply(message, status, Optional.ofNullable(responsePayload));
}));
}
@Override
public void registerHandler(
final String type, final BiFunction> handler) {
handlers.register(
type,
(message, connection) ->
handler
.apply(message.sender(), message.payload())
.whenComplete(
(result, error) -> {
final ProtocolReply.Status status;
if (error == null) {
status = ProtocolReply.Status.OK;
} else {
log.warn("An error occurred in a message handler:", error);
status = ProtocolReply.Status.ERROR_HANDLER_EXCEPTION;
}
connection.reply(message, status, Optional.ofNullable(result));
}));
}
@Override
public void unregisterHandler(final String type) {
handlers.unregister(type);
}
@Override
public CompletableFuture start() {
if (started.get()) {
log.warn("Already running at local address: {}", advertisedAddress);
return CompletableFuture.completedFuture(this);
}
initTransport();
return bootstrapServer()
.thenRun(
() -> {
timeoutExecutor =
Executors.newSingleThreadScheduledExecutor(
new DefaultThreadFactory("netty-messaging-timeout-"));
localConnection = new LocalClientConnection(handlers);
started.set(true);
log.info("Started");
})
.thenApply(v -> this);
}
@Override
public boolean isRunning() {
return started.get();
}
@Override
public CompletableFuture stop() {
if (started.compareAndSet(true, false)) {
return CompletableFuture.supplyAsync(
() -> {
boolean interrupted = false;
try {
try {
serverChannel.close().sync();
} catch (final InterruptedException e) {
interrupted = true;
}
final Future serverShutdownFuture =
serverGroup.shutdownGracefully(
config.getShutdownQuietPeriod().toMillis(),
config.getShutdownTimeout().toMillis(),
TimeUnit.MILLISECONDS);
final Future clientShutdownFuture =
clientGroup.shutdownGracefully(
config.getShutdownQuietPeriod().toMillis(),
config.getShutdownTimeout().toMillis(),
TimeUnit.MILLISECONDS);
try {
serverShutdownFuture.sync();
} catch (final InterruptedException e) {
interrupted = true;
}
try {
clientShutdownFuture.sync();
} catch (final InterruptedException e) {
interrupted = true;
}
timeoutExecutor.shutdown();
for (final var entry : connections.entrySet()) {
final var channel = entry.getKey();
channel.close();
final var connection = entry.getValue();
connection.close();
}
for (final CompletableFuture openFuture : openFutures) {
openFuture.completeExceptionally(
new IllegalStateException("MessagingService has been closed."));
}
openFutures.clear();
} finally {
log.info("Stopped");
if (interrupted) {
Thread.currentThread().interrupt();
}
}
return null;
});
}
return CompletableFuture.completedFuture(null);
}
private void initTransport() {
if (Epoll.isAvailable()) {
initEpollTransport();
} else {
initNioTransport();
}
}
private void initEpollTransport() {
clientGroup =
new EpollEventLoopGroup(0, namedThreads("netty-messaging-event-epoll-client-%d", log));
serverGroup =
new EpollEventLoopGroup(0, namedThreads("netty-messaging-event-epoll-server-%d", log));
serverChannelClass = EpollServerSocketChannel.class;
clientChannelClass = EpollSocketChannel.class;
}
private void initNioTransport() {
clientGroup =
new NioEventLoopGroup(0, namedThreads("netty-messaging-event-nio-client-%d", log));
serverGroup =
new NioEventLoopGroup(0, namedThreads("netty-messaging-event-nio-server-%d", log));
serverChannelClass = NioServerSocketChannel.class;
clientChannelClass = NioSocketChannel.class;
}
/**
* Executes the given callback on a pooled connection.
*
* @param address the connection address
* @param type the message type to map to the connection
* @param callback the callback to execute
* @param executor an executor on which to complete the callback future
* @param the callback response type
* @return a future to be completed once the callback future is complete
*/
private CompletableFuture executeOnPooledConnection(
final Address address,
final String type,
final Function> callback,
final Executor executor) {
final CompletableFuture future = new CompletableFuture<>();
executeOnPooledConnection(address, type, callback, executor, future);
return future;
}
/**
* Executes the given callback on a pooled connection.
*
* @param address the connection address
* @param type the message type to map to the connection
* @param callback the callback to execute
* @param executor an executor on which to complete the callback future
* @param future the future to be completed once the callback future is complete
* @param the callback response type
*/
private void executeOnPooledConnection(
final Address address,
final String type,
final Function> callback,
final Executor executor,
final CompletableFuture future) {
if (address.equals(advertisedAddress)) {
callback
.apply(localConnection)
.whenComplete(
(result, error) -> {
if (error == null) {
executor.execute(() -> future.complete(result));
} else {
executor.execute(() -> future.completeExceptionally(error));
}
});
return;
}
openFutures.add(future);
channelPool
.getChannel(address, type)
.whenComplete(
(channel, channelError) -> {
if (channelError == null) {
final ClientConnection connection = getOrCreateClientConnection(channel);
callback
.apply(connection)
.whenComplete(
(result, sendError) -> {
if (sendError == null) {
executor.execute(
() -> {
future.complete(result);
openFutures.remove(future);
});
} else {
final Throwable cause = Throwables.getRootCause(sendError);
if (!(cause instanceof TimeoutException)
&& !(cause instanceof MessagingException)) {
channel
.close()
.addListener(
f -> {
log.debug(
"Closing connection to {}", channel.remoteAddress());
connection.close();
connections.remove(channel);
});
}
executor.execute(
() -> {
future.completeExceptionally(sendError);
openFutures.remove(future);
});
}
});
} else {
executor.execute(
() -> {
future.completeExceptionally(channelError);
openFutures.remove(future);
});
}
});
}
/**
* Executes the given callback on a transient connection.
*
* @param address the connection address
* @param callback the callback to execute
* @param executor an executor on which to complete the callback future
* @param the callback response type
*/
private CompletableFuture executeOnTransientConnection(
final Address address,
final Function> callback,
final Executor executor) {
final CompletableFuture future = new CompletableFuture<>();
if (address.equals(advertisedAddress)) {
callback
.apply(localConnection)
.whenComplete(
(result, error) -> {
if (error == null) {
executor.execute(() -> future.complete(result));
} else {
executor.execute(() -> future.completeExceptionally(error));
}
});
return future;
}
openChannel(address)
.whenComplete(
(channel, channelError) -> {
if (channelError == null) {
callback
.apply(getOrCreateClientConnection(channel))
.whenComplete(
(result, sendError) -> {
if (sendError == null) {
executor.execute(() -> future.complete(result));
} else {
executor.execute(() -> future.completeExceptionally(sendError));
}
channel.close();
});
} else {
executor.execute(() -> future.completeExceptionally(channelError));
}
});
return future;
}
private RemoteClientConnection getOrCreateClientConnection(final Channel channel) {
RemoteClientConnection connection = connections.get(channel);
if (connection == null) {
connection = connections.computeIfAbsent(channel, RemoteClientConnection::new);
channel
.closeFuture()
.addListener(
f -> {
final RemoteClientConnection removedConnection = connections.remove(channel);
if (removedConnection != null) {
removedConnection.close();
}
});
}
return connection;
}
/**
* Opens a new Netty channel to the given address.
*
* @param address the address to which to open the channel
* @return a future to be completed once the channel has been opened and the handshake is complete
*/
private CompletableFuture openChannel(final Address address) {
return bootstrapClient(address);
}
/**
* Bootstraps a new channel to the given address.
*
* @param address the address to which to connect
* @return a future to be completed with the connected channel
*/
private CompletableFuture bootstrapClient(final Address address) {
final CompletableFuture future = new OrderedFuture<>();
final InetAddress resolvedAddress = address.address(true);
if (resolvedAddress == null) {
future.completeExceptionally(
new IllegalStateException(
"Failed to bootstrap client (address "
+ address.toString()
+ " cannot be resolved)"));
return future;
}
final Bootstrap bootstrap = new Bootstrap();
bootstrap.option(ChannelOption.ALLOCATOR, PooledByteBufAllocator.DEFAULT);
bootstrap.option(
ChannelOption.WRITE_BUFFER_WATER_MARK,
new WriteBufferWaterMark(10 * 32 * 1024, 10 * 64 * 1024));
bootstrap.option(ChannelOption.SO_RCVBUF, 1024 * 1024);
bootstrap.option(ChannelOption.SO_SNDBUF, 1024 * 1024);
bootstrap.option(ChannelOption.SO_KEEPALIVE, true);
bootstrap.option(ChannelOption.TCP_NODELAY, true);
bootstrap.option(ChannelOption.CONNECT_TIMEOUT_MILLIS, 1000);
bootstrap.group(clientGroup);
// TODO: Make this faster:
// http://normanmaurer.me/presentations/2014-facebook-eng-netty/slides.html#37.0
bootstrap.channel(clientChannelClass);
bootstrap.remoteAddress(resolvedAddress, address.port());
bootstrap.handler(new BasicClientChannelInitializer(future));
final Channel channel =
bootstrap
.connect()
.addListener(
onConnect -> {
if (!onConnect.isSuccess()) {
future.completeExceptionally(
new ConnectException(
String.format("Failed to connect channel for address %s", address)));
}
})
.channel();
// immediately ensure we're notified of the channel being closed. the common case is that the
// channel is closed after we've handled the request (and response in the case of a
// sendAndReceive operation), so the future is already completed by then. If it isn't, then the
// channel was closed too early, which should be handled as a failure from the consumer point
// of view.
channel
.closeFuture()
.addListener(
onClose ->
future.completeExceptionally(
new ConnectException(
String.format(
"Channel %s for address %s was closed unexpectedly before the request was handled",
channel, address))));
return future;
}
/**
* Bootstraps a server.
*
* @return a future to be completed once the server has been bound to all interfaces
*/
private CompletableFuture bootstrapServer() {
final ServerBootstrap b = new ServerBootstrap();
b.option(ChannelOption.SO_REUSEADDR, true);
b.option(ChannelOption.SO_BACKLOG, 128);
b.childOption(
ChannelOption.WRITE_BUFFER_WATER_MARK, new WriteBufferWaterMark(8 * 1024, 32 * 1024));
b.childOption(ChannelOption.SO_RCVBUF, 1024 * 1024);
b.childOption(ChannelOption.SO_SNDBUF, 1024 * 1024);
b.childOption(ChannelOption.SO_KEEPALIVE, true);
b.childOption(ChannelOption.TCP_NODELAY, true);
b.childOption(ChannelOption.ALLOCATOR, PooledByteBufAllocator.DEFAULT);
b.group(serverGroup, clientGroup);
b.channel(serverChannelClass);
b.childHandler(new BasicServerChannelInitializer());
return bind(b);
}
/**
* Binds the given bootstrap to the appropriate interfaces.
*
* @param bootstrap the bootstrap to bind
* @return a future to be completed once the bootstrap has been bound to all interfaces
*/
private CompletableFuture bind(final ServerBootstrap bootstrap) {
final CompletableFuture future = new CompletableFuture<>();
bind(bootstrap, bindingAddresses.iterator(), future);
return future;
}
/**
* Recursively binds the given bootstrap to the given interfaces.
*
* @param bootstrap the bootstrap to bind
* @param addressIterator an iterator of Addresses to which to bind
* @param future the future to completed once the bootstrap has been bound to all provided
* interfaces
*/
private void bind(
final ServerBootstrap bootstrap,
final Iterator addressIterator,
final CompletableFuture future) {
if (addressIterator.hasNext()) {
final Address address = addressIterator.next();
bootstrap
.bind(address.host(), address.port())
.addListener(
(ChannelFutureListener)
f -> {
if (f.isSuccess()) {
log.info("TCP server listening for connections on {}", address);
serverChannel = f.channel();
bind(bootstrap, addressIterator, future);
} else {
log.warn(
"Failed to bind TCP server to port {} due to {}", address, f.cause());
future.completeExceptionally(f.cause());
}
});
} else {
future.complete(null);
}
}
/** Channel initializer for basic connections. */
private class BasicClientChannelInitializer extends ChannelInitializer {
private final CompletableFuture future;
BasicClientChannelInitializer(final CompletableFuture future) {
this.future = future;
}
@Override
protected void initChannel(final SocketChannel channel) throws Exception {
channel.pipeline().addLast("handshake", new ClientHandshakeHandlerAdapter(future));
}
}
/** Channel initializer for basic connections. */
private class BasicServerChannelInitializer extends ChannelInitializer {
@Override
protected void initChannel(final SocketChannel channel) throws Exception {
channel.pipeline().addLast("handshake", new ServerHandshakeHandlerAdapter());
}
}
/** Base class for handshake handlers. */
private abstract class HandshakeHandlerAdapter
extends ChannelInboundHandlerAdapter {
/**
* Writes the protocol version to the given context.
*
* @param context the context to which to write the version
* @param version the version to write
*/
void writeProtocolVersion(final ChannelHandlerContext context, final ProtocolVersion version) {
final ByteBuf buffer = context.alloc().buffer(6);
buffer.writeInt(preamble);
buffer.writeShort(version.version());
context.writeAndFlush(buffer);
}
/**
* Reads the protocol version from the given buffer.
*
* @param context the buffer context
* @param buffer the buffer from which to read the version
* @return the read protocol version
*/
OptionalInt readProtocolVersion(final ChannelHandlerContext context, final ByteBuf buffer) {
try {
final int preamble = buffer.readInt();
if (preamble != NettyMessagingService.this.preamble) {
log.warn("Received invalid handshake, closing connection");
context.close();
return OptionalInt.empty();
}
return OptionalInt.of(buffer.readShort());
} finally {
buffer.release();
}
}
/**
* Activates the given version of the messaging protocol.
*
* @param context the channel handler context
* @param connection the client or server connection for which to activate the protocol version
* @param protocolVersion the protocol version to activate
*/
void activateProtocolVersion(
final ChannelHandlerContext context,
final Connection connection,
final ProtocolVersion protocolVersion) {
final MessagingProtocol protocol = protocolVersion.createProtocol(advertisedAddress);
context.pipeline().remove(this);
context.pipeline().addLast("encoder", protocol.newEncoder());
context.pipeline().addLast("decoder", protocol.newDecoder());
context.pipeline().addLast("handler", new MessageDispatcher<>(connection));
}
}
/** Client handshake handler. */
private class ClientHandshakeHandlerAdapter extends HandshakeHandlerAdapter {
private final CompletableFuture future;
ClientHandshakeHandlerAdapter(final CompletableFuture future) {
this.future = future;
}
@Override
public void channelActive(final ChannelHandlerContext context) throws Exception {
log.debug(
"Writing client protocol version {} for connection to {}",
protocolVersion,
context.channel().remoteAddress());
writeProtocolVersion(context, protocolVersion);
}
@Override
public void channelRead(final ChannelHandlerContext context, final Object message)
throws Exception {
// Read the protocol version from the server.
readProtocolVersion(context, (ByteBuf) message)
.ifPresent(
version -> {
// If the protocol version is a valid protocol version for the client, activate the
// protocol.
// Otherwise, close the connection and log an error.
final ProtocolVersion protocolVersion = ProtocolVersion.valueOf(version);
if (protocolVersion != null) {
activateProtocolVersion(
context, getOrCreateClientConnection(context.channel()), protocolVersion);
} else {
log.error("Failed to negotiate protocol version");
context.close();
}
});
}
@Override
public void exceptionCaught(final ChannelHandlerContext ctx, final Throwable cause)
throws Exception {
future.completeExceptionally(cause);
}
@Override
void activateProtocolVersion(
final ChannelHandlerContext context,
final Connection connection,
final ProtocolVersion protocolVersion) {
log.debug(
"Activating client protocol version {} for connection to {}",
protocolVersion,
context.channel().remoteAddress());
super.activateProtocolVersion(context, connection, protocolVersion);
future.complete(context.channel());
}
}
/** Server handshake handler. */
private class ServerHandshakeHandlerAdapter extends HandshakeHandlerAdapter {
@Override
public void channelRead(final ChannelHandlerContext context, final Object message)
throws Exception {
// Read the protocol version from the client handshake. If the client's protocol version is
// unknown
// to the server, use the latest server protocol version.
readProtocolVersion(context, (ByteBuf) message)
.ifPresent(
version -> {
ProtocolVersion protocolVersion = ProtocolVersion.valueOf(version);
if (protocolVersion == null) {
protocolVersion = ProtocolVersion.latest();
}
writeProtocolVersion(context, protocolVersion);
activateProtocolVersion(
context,
new RemoteServerConnection(handlers, context.channel()),
protocolVersion);
});
}
@Override
void activateProtocolVersion(
final ChannelHandlerContext context,
final Connection connection,
final ProtocolVersion protocolVersion) {
log.debug(
"Activating server protocol version {} for connection to {}",
protocolVersion,
context.channel().remoteAddress());
super.activateProtocolVersion(context, connection, protocolVersion);
}
}
/** Connection message dispatcher. */
private class MessageDispatcher
extends SimpleChannelInboundHandler {
private final Connection connection;
MessageDispatcher(final Connection connection) {
this.connection = connection;
}
@Override
public void channelInactive(final ChannelHandlerContext context) throws Exception {
connection.close();
context.close();
}
@Override
public void exceptionCaught(final ChannelHandlerContext context, final Throwable cause) {
log.error("Exception inside channel handling pipeline", cause);
connection.close();
context.close();
}
@Override
public boolean acceptInboundMessage(final Object msg) {
return msg instanceof ProtocolMessage;
}
@Override
@SuppressWarnings("unchecked")
protected void channelRead0(final ChannelHandlerContext ctx, final Object message)
throws Exception {
try {
connection.dispatch((M) message);
} catch (final RejectedExecutionException e) {
log.warn("Unable to dispatch message due to {}", e.getMessage());
}
}
}
}
