/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF 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.apache.cassandra.streaming;
import java.io.IOException;
import java.net.InetAddress;
import java.net.Socket;
import java.net.SocketException;
import java.nio.ByteBuffer;
import java.nio.channels.Channels;
import java.nio.channels.ReadableByteChannel;
import java.nio.channels.WritableByteChannel;
import java.util.Collection;
import java.util.Comparator;
import java.util.concurrent.PriorityBlockingQueue;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicReference;
import com.google.common.util.concurrent.Futures;
import com.google.common.util.concurrent.ListenableFuture;
import com.google.common.util.concurrent.SettableFuture;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.apache.cassandra.config.DatabaseDescriptor;
import org.apache.cassandra.io.util.DataOutputStreamAndChannel;
import org.apache.cassandra.net.OutboundTcpConnectionPool;
import org.apache.cassandra.streaming.messages.StreamInitMessage;
import org.apache.cassandra.streaming.messages.StreamMessage;
import org.apache.cassandra.utils.FBUtilities;
/**
* ConnectionHandler manages incoming/outgoing message exchange for the {@link StreamSession}.
*
* <p>
* Internally, ConnectionHandler manages thread to receive incoming {@link StreamMessage} and thread to
* send outgoing message. Messages are encoded/decoded on those thread and handed to
* {@link StreamSession#messageReceived(org.apache.cassandra.streaming.messages.StreamMessage)}.
*/
public class ConnectionHandler
{
private static final Logger logger = LoggerFactory.getLogger(ConnectionHandler.class);
private static final int MAX_CONNECT_ATTEMPTS = 3;
private final StreamSession session;
private IncomingMessageHandler incoming;
private OutgoingMessageHandler outgoing;
ConnectionHandler(StreamSession session)
{
this.session = session;
this.incoming = new IncomingMessageHandler(session);
this.outgoing = new OutgoingMessageHandler(session);
}
/**
* Set up incoming message handler and initiate streaming.
*
* This method is called once on initiator.
*
* @throws IOException
*/
public void initiate() throws IOException
{
logger.debug("[Stream #{}] Sending stream init for incoming stream", session.planId());
Socket incomingSocket = connect(session.peer);
incoming.start(incomingSocket, StreamMessage.CURRENT_VERSION);
incoming.sendInitMessage(incomingSocket, true);
logger.debug("[Stream #{}] Sending stream init for outgoing stream", session.planId());
Socket outgoingSocket = connect(session.peer);
outgoing.start(outgoingSocket, StreamMessage.CURRENT_VERSION);
outgoing.sendInitMessage(outgoingSocket, false);
}
/**
* Set up outgoing message handler on receiving side.
*
* @param socket socket to use for {@link org.apache.cassandra.streaming.ConnectionHandler.OutgoingMessageHandler}.
* @param version Streaming message version
* @throws IOException
*/
public void initiateOnReceivingSide(Socket socket, boolean isForOutgoing, int version) throws IOException
{
if (isForOutgoing)
outgoing.start(socket, version);
else
incoming.start(socket, version);
}
/**
* Connect to peer and start exchanging message.
* When connect attempt fails, this retries for maximum of MAX_CONNECT_ATTEMPTS times.
*
* @param peer the peer to connect to.
* @return the created socket.
*
* @throws IOException when connection failed.
*/
private static Socket connect(InetAddress peer) throws IOException
{
int attempts = 0;
while (true)
{
try
{
Socket socket = OutboundTcpConnectionPool.newSocket(peer);
socket.setSoTimeout(DatabaseDescriptor.getStreamingSocketTimeout());
socket.setKeepAlive(true);
return socket;
}
catch (IOException e)
{
if (++attempts >= MAX_CONNECT_ATTEMPTS)
throw e;
long waitms = DatabaseDescriptor.getRpcTimeout() * (long)Math.pow(2, attempts);
logger.warn("Failed attempt {} to connect to {}. Retrying in {} ms. ({})", attempts, peer, waitms, e);
try
{
Thread.sleep(waitms);
}
catch (InterruptedException wtf)
{
throw new IOException("interrupted", wtf);
}
}
}
}
public ListenableFuture<?> close()
{
logger.debug("[Stream #{}] Closing stream connection handler on {}", session.planId(), session.peer);
ListenableFuture<?> inClosed = incoming == null ? Futures.immediateFuture(null) : incoming.close();
ListenableFuture<?> outClosed = outgoing == null ? Futures.immediateFuture(null) : outgoing.close();
return Futures.allAsList(inClosed, outClosed);
}
/**
* Enqueue messages to be sent.
*
* @param messages messages to send
*/
public void sendMessages(Collection<? extends StreamMessage> messages)
{
for (StreamMessage message : messages)
sendMessage(message);
}
public void sendMessage(StreamMessage message)
{
if (outgoing.isClosed())
throw new RuntimeException("Outgoing stream handler has been closed");
outgoing.enqueue(message);
}
/**
* @return true if outgoing connection is opened and ready to send messages
*/
public boolean isOutgoingConnected()
{
return outgoing != null && !outgoing.isClosed();
}
abstract static class MessageHandler implements Runnable
{
protected final StreamSession session;
protected int protocolVersion;
protected Socket socket;
private final AtomicReference<SettableFuture<?>> closeFuture = new AtomicReference<>();
protected MessageHandler(StreamSession session)
{
this.session = session;
}
protected abstract String name();
protected static DataOutputStreamAndChannel getWriteChannel(Socket socket) throws IOException
{
WritableByteChannel out = socket.getChannel();
// socket channel is null when encrypted(SSL)
if (out == null)
out = Channels.newChannel(socket.getOutputStream());
return new DataOutputStreamAndChannel(socket.getOutputStream(), out);
}
protected static ReadableByteChannel getReadChannel(Socket socket) throws IOException
{
ReadableByteChannel in = socket.getChannel();
// socket channel is null when encrypted(SSL)
return in == null
? Channels.newChannel(socket.getInputStream())
: in;
}
public void sendInitMessage(Socket socket, boolean isForOutgoing) throws IOException
{
StreamInitMessage message = new StreamInitMessage(
FBUtilities.getBroadcastAddress(),
session.sessionIndex(),
session.planId(),
session.description(),
isForOutgoing);
ByteBuffer messageBuf = message.createMessage(false, protocolVersion);
getWriteChannel(socket).write(messageBuf);
}
public void start(Socket socket, int protocolVersion)
{
this.socket = socket;
this.protocolVersion = protocolVersion;
new Thread(this, name() + "-" + session.peer).start();
}
public ListenableFuture<?> close()
{
// Assume it wasn't closed. Not a huge deal if we create a future on a race
SettableFuture<?> future = SettableFuture.create();
return closeFuture.compareAndSet(null, future)
? future
: closeFuture.get();
}
public boolean isClosed()
{
return closeFuture.get() != null;
}
protected void signalCloseDone()
{
closeFuture.get().set(null);
// We can now close the socket
try
{
socket.close();
}
catch (IOException ignore) {}
}
}
/**
* Incoming streaming message handler
*/
static class IncomingMessageHandler extends MessageHandler
{
IncomingMessageHandler(StreamSession session)
{
super(session);
}
protected String name()
{
return "STREAM-IN";
}
public void run()
{
try
{
ReadableByteChannel in = getReadChannel(socket);
while (!isClosed())
{
// receive message
StreamMessage message = StreamMessage.deserialize(in, protocolVersion, session);
// Might be null if there is an error during streaming (see FileMessage.deserialize). It's ok
// to ignore here since we'll have asked for a retry.
if (message != null)
{
logger.debug("[Stream #{}] Received {}", session.planId(), message);
session.messageReceived(message);
}
}
}
catch (SocketException e)
{
// socket is closed
close();
}
catch (Throwable e)
{
session.onError(e);
}
finally
{
signalCloseDone();
}
}
}
/**
* Outgoing file transfer thread
*/
static class OutgoingMessageHandler extends MessageHandler
{
/*
* All out going messages are queued up into messageQueue.
* The size will grow when received streaming request.
*
* Queue is also PriorityQueue so that prior messages can go out fast.
*/
private final PriorityBlockingQueue<StreamMessage> messageQueue = new PriorityBlockingQueue<>(64, new Comparator<StreamMessage>()
{
public int compare(StreamMessage o1, StreamMessage o2)
{
return o2.getPriority() - o1.getPriority();
}
});
OutgoingMessageHandler(StreamSession session)
{
super(session);
}
protected String name()
{
return "STREAM-OUT";
}
public void enqueue(StreamMessage message)
{
messageQueue.put(message);
}
public void run()
{
try
{
DataOutputStreamAndChannel out = getWriteChannel(socket);
StreamMessage next;
while (!isClosed())
{
if ((next = messageQueue.poll(1, TimeUnit.SECONDS)) != null)
{
logger.debug("[Stream #{}] Sending {}", session.planId(), next);
sendMessage(out, next);
if (next.type == StreamMessage.Type.SESSION_FAILED)
close();
}
}
// Sends the last messages on the queue
while ((next = messageQueue.poll()) != null)
sendMessage(out, next);
}
catch (InterruptedException e)
{
throw new AssertionError(e);
}
catch (Throwable e)
{
session.onError(e);
}
finally
{
signalCloseDone();
}
}
private void sendMessage(DataOutputStreamAndChannel out, StreamMessage message)
{
try
{
StreamMessage.serialize(message, out, protocolVersion, session);
}
catch (SocketException e)
{
session.onError(e);
close();
}
catch (IOException e)
{
session.onError(e);
}
}
}
}