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A driver for Apache Cassandra 1.2+ that works exclusively with the Cassandra Query Language version 3
(CQL3) and Cassandra's binary protocol.
/*
* Copyright (C) 2012-2015 DataStax Inc.
*
* 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 com.datastax.driver.core;
import com.datastax.driver.core.Responses.Result.SetKeyspace;
import com.datastax.driver.core.exceptions.*;
import com.datastax.driver.core.utils.MoreFutures;
import com.google.common.annotations.VisibleForTesting;
import com.google.common.base.Objects;
import com.google.common.collect.Lists;
import com.google.common.collect.MapMaker;
import com.google.common.util.concurrent.*;
import io.netty.bootstrap.Bootstrap;
import io.netty.channel.*;
import io.netty.channel.group.ChannelGroup;
import io.netty.channel.group.DefaultChannelGroup;
import io.netty.channel.socket.SocketChannel;
import io.netty.handler.codec.DecoderException;
import io.netty.handler.timeout.IdleStateEvent;
import io.netty.handler.timeout.IdleStateHandler;
import io.netty.util.Timeout;
import io.netty.util.Timer;
import io.netty.util.TimerTask;
import io.netty.util.concurrent.GlobalEventExecutor;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.lang.ref.WeakReference;
import java.net.InetSocketAddress;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;
import java.util.Queue;
import java.util.concurrent.*;
import java.util.concurrent.atomic.AtomicBoolean;
import java.util.concurrent.atomic.AtomicInteger;
import java.util.concurrent.atomic.AtomicReference;
import static com.datastax.driver.core.Message.Response.Type.ERROR;
import static io.netty.handler.timeout.IdleState.READER_IDLE;
// For LoggingHandler
//import org.jboss.netty.handler.logging.LoggingHandler;
//import org.jboss.netty.logging.InternalLogLevel;
/**
* A connection to a Cassandra Node.
*/
class Connection {
private static final Logger logger = LoggerFactory.getLogger(Connection.class);
private static final byte[] EMPTY_BYTE_ARRAY = new byte[0];
private static final boolean DISABLE_COALESCING = SystemProperties.getBoolean("com.datastax.driver.DISABLE_COALESCING", false);
enum State {OPEN, TRASHED, RESURRECTING, GONE}
final AtomicReference state = new AtomicReference(State.OPEN);
volatile long maxIdleTime;
final InetSocketAddress address;
private final String name;
@VisibleForTesting
volatile Channel channel;
private final Factory factory;
@VisibleForTesting
final Dispatcher dispatcher;
// Used by connection pooling to count how many requests are "in flight" on that connection.
final AtomicInteger inFlight = new AtomicInteger(0);
private final AtomicInteger writer = new AtomicInteger(0);
private final AtomicReference targetKeyspace;
private final SetKeyspaceAttempt defaultKeyspaceAttempt;
private volatile boolean isInitialized;
private final AtomicBoolean isDefunct = new AtomicBoolean();
private final AtomicBoolean signaled = new AtomicBoolean();
private final AtomicReference closeFuture = new AtomicReference();
private final AtomicReference ownerRef = new AtomicReference();
private final ListenableFuture thisFuture;
/**
* Create a new connection to a Cassandra node and associate it with the given pool.
*
* @param name the connection name
* @param address the remote address
* @param factory the connection factory to use
* @param owner the component owning this connection (may be null).
* Note that an existing connection can also be associated to an owner later with {@link #setOwner(Owner)}.
*/
protected Connection(String name, InetSocketAddress address, Factory factory, Owner owner) {
this.address = address;
this.factory = factory;
this.dispatcher = new Dispatcher();
this.name = name;
this.ownerRef.set(owner);
this.thisFuture = Futures.immediateFuture(this);
this.defaultKeyspaceAttempt = new SetKeyspaceAttempt(null, thisFuture);
this.targetKeyspace = new AtomicReference(defaultKeyspaceAttempt);
}
/**
* Create a new connection to a Cassandra node.
*/
Connection(String name, InetSocketAddress address, Factory factory) {
this(name, address, factory, null);
}
ListenableFuture initAsync() {
if (factory.isShutdown)
return Futures.immediateFailedFuture(new ConnectionException(address, "Connection factory is shut down"));
ProtocolVersion protocolVersion = factory.protocolVersion == null ? ProtocolVersion.NEWEST_SUPPORTED : factory.protocolVersion;
final SettableFuture channelReadyFuture = SettableFuture.create();
try {
Bootstrap bootstrap = factory.newBootstrap();
ProtocolOptions protocolOptions = factory.configuration.getProtocolOptions();
bootstrap.handler(
new Initializer(this, protocolVersion, protocolOptions.getCompression().compressor(), protocolOptions.getSSLOptions(),
factory.configuration.getPoolingOptions().getHeartbeatIntervalSeconds(),
factory.configuration.getNettyOptions(),
factory.configuration.getCodecRegistry()));
ChannelFuture future = bootstrap.connect(address);
writer.incrementAndGet();
future.addListener(new ChannelFutureListener() {
@Override
public void operationComplete(ChannelFuture future) throws Exception {
writer.decrementAndGet();
channel = future.channel();
if (isClosed()) {
channel.close().addListener(new ChannelFutureListener() {
@Override
public void operationComplete(ChannelFuture future) throws Exception {
channelReadyFuture.setException(new TransportException(Connection.this.address, "Connection closed during initialization."));
}
});
} else {
Connection.this.factory.allChannels.add(channel);
if (!future.isSuccess()) {
if (logger.isDebugEnabled())
logger.debug(String.format("%s Error connecting to %s%s", Connection.this, Connection.this.address, extractMessage(future.cause())));
channelReadyFuture.setException(new TransportException(Connection.this.address, "Cannot connect", future.cause()));
} else {
logger.debug("{} Connection established, initializing transport", Connection.this);
channel.closeFuture().addListener(new ChannelCloseListener());
channelReadyFuture.set(null);
}
}
}
});
} catch (RuntimeException e) {
closeAsync().force();
throw e;
}
Executor initExecutor = factory.manager.configuration.getPoolingOptions().getInitializationExecutor();
ListenableFuture initializeTransportFuture = Futures.transform(channelReadyFuture,
onChannelReady(protocolVersion, initExecutor), initExecutor);
// Fallback on initializeTransportFuture so we can properly propagate specific exceptions.
ListenableFuture initFuture = Futures.withFallback(initializeTransportFuture, new FutureFallback() {
@Override
public ListenableFuture create(Throwable t) throws Exception {
SettableFuture future = SettableFuture.create();
// Make sure the connection gets properly closed.
if (t instanceof ClusterNameMismatchException || t instanceof UnsupportedProtocolVersionException) {
// Just propagate
closeAsync().force();
future.setException(t);
} else {
// Defunct to ensure that the error will be signaled (marking the host down)
Exception e = (t instanceof ConnectionException || t instanceof DriverException || t instanceof InterruptedException)
? (Exception) t
: new ConnectionException(Connection.this.address,
String.format("Unexpected error during transport initialization (%s)", t),
t);
future.setException(defunct(e));
}
return future;
}
}, initExecutor);
// Ensure the connection gets closed if the caller cancels the returned future.
Futures.addCallback(initFuture, new MoreFutures.FailureCallback() {
@Override
public void onFailure(Throwable t) {
if (!isClosed()) {
closeAsync().force();
}
}
}, initExecutor);
return initFuture;
}
private static String extractMessage(Throwable t) {
if (t == null)
return "";
String msg = t.getMessage() == null || t.getMessage().isEmpty()
? t.toString()
: t.getMessage();
return " (" + msg + ')';
}
private AsyncFunction onChannelReady(final ProtocolVersion protocolVersion, final Executor initExecutor) {
return new AsyncFunction() {
@Override
public ListenableFuture apply(Void input) throws Exception {
ProtocolOptions.Compression compression = factory.configuration.getProtocolOptions().getCompression();
Future startupResponseFuture = write(new Requests.Startup(compression));
return Futures.transform(startupResponseFuture,
onStartupResponse(protocolVersion, initExecutor), initExecutor);
}
};
}
private AsyncFunction onStartupResponse(final ProtocolVersion protocolVersion, final Executor initExecutor) {
return new AsyncFunction() {
@Override
public ListenableFuture apply(Message.Response response) throws Exception {
switch (response.type) {
case READY:
return checkClusterName(protocolVersion, initExecutor);
case ERROR:
Responses.Error error = (Responses.Error) response;
// Testing for a specific string is a tad fragile but well, we don't have much choice
// C* 2.1 reports a server error instead of protocol error, see CASSANDRA-9451
if ((error.code == ExceptionCode.PROTOCOL_ERROR || error.code == ExceptionCode.SERVER_ERROR) &&
error.message.contains("Invalid or unsupported protocol version"))
throw unsupportedProtocolVersionException(protocolVersion, error.serverProtocolVersion);
throw new TransportException(address, String.format("Error initializing connection: %s", error.message));
case AUTHENTICATE:
Responses.Authenticate authenticate = (Responses.Authenticate) response;
Authenticator authenticator;
try {
authenticator = factory.authProvider.newAuthenticator(address, authenticate.authenticator);
} catch (AuthenticationException e) {
incrementAuthErrorMetric();
throw e;
}
switch (protocolVersion) {
case V1:
if (authenticator instanceof ProtocolV1Authenticator)
return authenticateV1(authenticator, protocolVersion, initExecutor);
else
// DSE 3.x always uses SASL authentication backported from protocol v2
return authenticateV2(authenticator, protocolVersion, initExecutor);
case V2:
case V3:
case V4:
return authenticateV2(authenticator, protocolVersion, initExecutor);
default:
throw defunct(protocolVersion.unsupported());
}
default:
throw new TransportException(address, String.format("Unexpected %s response message from server to a STARTUP message", response.type));
}
}
};
}
// Due to C* gossip bugs, system.peers may report nodes that are gone from the cluster.
// If these nodes have been recommissionned to another cluster and are up, nothing prevents the driver from connecting
// to them. So we check that the cluster the node thinks it belongs to is our cluster (JAVA-397).
private ListenableFuture checkClusterName(ProtocolVersion protocolVersion, final Executor executor) {
final String expected = factory.manager.metadata.clusterName;
// At initialization, the cluster is not known yet
if (expected == null) {
markInitialized();
return MoreFutures.VOID_SUCCESS;
}
DefaultResultSetFuture clusterNameFuture = new DefaultResultSetFuture(null, protocolVersion, new Requests.Query("select cluster_name from system.local"));
try {
write(clusterNameFuture);
return Futures.transform(clusterNameFuture,
new AsyncFunction() {
@Override
public ListenableFuture apply(ResultSet rs) throws Exception {
Row row = rs.one();
String actual = row.getString("cluster_name");
if (!expected.equals(actual))
throw new ClusterNameMismatchException(address, actual, expected);
markInitialized();
return MoreFutures.VOID_SUCCESS;
}
}, executor);
} catch (Exception e) {
return Futures.immediateFailedFuture(e);
}
}
private void markInitialized() {
isInitialized = true;
Host.statesLogger.debug("[{}] {} Transport initialized, connection ready", address, this);
}
private ListenableFuture authenticateV1(Authenticator authenticator, final ProtocolVersion protocolVersion, final Executor executor) {
Requests.Credentials creds = new Requests.Credentials(((ProtocolV1Authenticator) authenticator).getCredentials());
try {
Future authResponseFuture = write(creds);
return Futures.transform(authResponseFuture,
new AsyncFunction() {
@Override
public ListenableFuture apply(Message.Response authResponse) throws Exception {
switch (authResponse.type) {
case READY:
return checkClusterName(protocolVersion, executor);
case ERROR:
incrementAuthErrorMetric();
throw new AuthenticationException(address, ((Responses.Error) authResponse).message);
default:
throw new TransportException(address, String.format("Unexpected %s response message from server to a CREDENTIALS message", authResponse.type));
}
}
}, executor);
} catch (Exception e) {
return Futures.immediateFailedFuture(e);
}
}
private ListenableFuture authenticateV2(final Authenticator authenticator, final ProtocolVersion protocolVersion, final Executor executor) {
byte[] initialResponse = authenticator.initialResponse();
if (null == initialResponse)
initialResponse = EMPTY_BYTE_ARRAY;
try {
Future authResponseFuture = write(new Requests.AuthResponse(initialResponse));
return Futures.transform(authResponseFuture, onV2AuthResponse(authenticator, protocolVersion, executor), executor);
} catch (Exception e) {
return Futures.immediateFailedFuture(e);
}
}
private AsyncFunction onV2AuthResponse(final Authenticator authenticator, final ProtocolVersion protocolVersion, final Executor executor) {
return new AsyncFunction() {
@Override
public ListenableFuture apply(Message.Response authResponse) throws Exception {
switch (authResponse.type) {
case AUTH_SUCCESS:
logger.trace("{} Authentication complete", this);
authenticator.onAuthenticationSuccess(((Responses.AuthSuccess) authResponse).token);
return checkClusterName(protocolVersion, executor);
case AUTH_CHALLENGE:
byte[] responseToServer = authenticator.evaluateChallenge(((Responses.AuthChallenge) authResponse).token);
if (responseToServer == null) {
// If we generate a null response, then authentication has completed, proceed without
// sending a further response back to the server.
logger.trace("{} Authentication complete (No response to server)", this);
return checkClusterName(protocolVersion, executor);
} else {
// Otherwise, send the challenge response back to the server
logger.trace("{} Sending Auth response to challenge", this);
Future nextResponseFuture = write(new Requests.AuthResponse(responseToServer));
return Futures.transform(nextResponseFuture, onV2AuthResponse(authenticator, protocolVersion, executor), executor);
}
case ERROR:
// This is not very nice, but we're trying to identify if we
// attempted v2 auth against a server which only supports v1
// The AIOOBE indicates that the server didn't recognise the
// initial AuthResponse message
String message = ((Responses.Error) authResponse).message;
if (message.startsWith("java.lang.ArrayIndexOutOfBoundsException: 15"))
message = String.format("Cannot use authenticator %s with protocol version 1, "
+ "only plain text authentication is supported with this protocol version", authenticator);
incrementAuthErrorMetric();
throw new AuthenticationException(address, message);
default:
throw new TransportException(address, String.format("Unexpected %s response message from server to authentication message", authResponse.type));
}
}
};
}
private void incrementAuthErrorMetric() {
if (factory.manager.configuration.getMetricsOptions().isEnabled()) {
factory.manager.metrics.getErrorMetrics().getAuthenticationErrors().inc();
}
}
private UnsupportedProtocolVersionException unsupportedProtocolVersionException(ProtocolVersion triedVersion, ProtocolVersion serverProtocolVersion) {
logger.debug("Got unsupported protocol version error from {} for version {} server supports version {}", address, triedVersion, serverProtocolVersion);
return new UnsupportedProtocolVersionException(address, triedVersion, serverProtocolVersion);
}
boolean isDefunct() {
return isDefunct.get();
}
int maxAvailableStreams() {
return dispatcher.streamIdHandler.maxAvailableStreams();
}
E defunct(E e) {
if (isDefunct.compareAndSet(false, true)) {
if (Host.statesLogger.isTraceEnabled())
Host.statesLogger.trace("Defuncting " + this, e);
else if (Host.statesLogger.isDebugEnabled())
Host.statesLogger.debug("Defuncting {} because: {}", this, e.getMessage());
Host host = factory.manager.metadata.getHost(address);
if (host != null) {
// Sometimes close() can be called before defunct(); avoid decrementing the connection count twice, but
// we still want to signal the error to the conviction policy.
boolean decrement = signaled.compareAndSet(false, true);
boolean hostDown = host.convictionPolicy.signalConnectionFailure(this, decrement);
if (hostDown) {
factory.manager.signalHostDown(host, host.wasJustAdded());
} else {
notifyOwnerWhenDefunct();
}
}
// Force the connection to close to make sure the future completes. Otherwise force() might never get called and
// threads will wait on the future forever.
// (this also errors out pending handlers)
closeAsync().force();
}
return e;
}
private void notifyOwnerWhenDefunct() {
// If an error happens during initialization, the owner will detect it and take appropriate action
if (!isInitialized)
return;
Owner owner = this.ownerRef.get();
if (owner != null)
owner.onConnectionDefunct(this);
}
String keyspace() {
return targetKeyspace.get().keyspace;
}
void setKeyspace(String keyspace) throws ConnectionException {
if (keyspace == null)
return;
if (Objects.equal(keyspace(), keyspace))
return;
try {
Uninterruptibles.getUninterruptibly(setKeyspaceAsync(keyspace));
} catch (ConnectionException e) {
throw defunct(e);
} catch (BusyConnectionException e) {
logger.warn("Tried to set the keyspace on busy {}. "
+ "This should not happen but is not critical (it will be retried)", this);
throw new ConnectionException(address, "Tried to set the keyspace on busy connection");
} catch (ExecutionException e) {
Throwable cause = e.getCause();
if (cause instanceof OperationTimedOutException) {
// Rethrow so that the caller doesn't try to use the connection, but do not defunct as we don't want to mark down
logger.warn("Timeout while setting keyspace on {}. "
+ "This should not happen but is not critical (it will be retried)", this);
throw new ConnectionException(address, "Timeout while setting keyspace on connection");
} else {
throw defunct(new ConnectionException(address, "Error while setting keyspace", cause));
}
}
}
ListenableFuture setKeyspaceAsync(final String keyspace) throws ConnectionException, BusyConnectionException {
SetKeyspaceAttempt existingAttempt = targetKeyspace.get();
if (Objects.equal(existingAttempt.keyspace, keyspace))
return existingAttempt.future;
final SettableFuture ksFuture = SettableFuture.create();
final SetKeyspaceAttempt attempt = new SetKeyspaceAttempt(keyspace, ksFuture);
// Check for an existing keyspace attempt.
while (true) {
existingAttempt = targetKeyspace.get();
// if existing attempts' keyspace matches what we are trying to set, use it.
if (attempt.equals(existingAttempt)) {
return existingAttempt.future;
} else if (!existingAttempt.future.isDone()) {
// If the existing attempt is still in flight, fail this attempt immediately.
ksFuture.setException(new DriverException("Aborting attempt to set keyspace to '" + keyspace + "' since there is already an in flight attempt to set keyspace to '" + existingAttempt.keyspace + "'. "
+ "This can happen if you try to USE different keyspaces from the same session simultaneously."));
return ksFuture;
} else if (targetKeyspace.compareAndSet(existingAttempt, attempt)) {
// Otherwise, if the existing attempt is done, start a new set keyspace attempt for the new keyspace.
logger.debug("{} Setting keyspace {}", this, keyspace);
// Note: we quote the keyspace below, because the name is the one coming from Cassandra, so it's in the right case already
Future future = write(new Requests.Query("USE \"" + keyspace + '"'));
Futures.addCallback(future, new FutureCallback() {
@Override
public void onSuccess(Message.Response response) {
if (response instanceof SetKeyspace) {
logger.debug("{} Keyspace set to {}", Connection.this, keyspace);
ksFuture.set(Connection.this);
} else {
// Unset this attempt so new attempts may be made for the same keyspace.
targetKeyspace.compareAndSet(attempt, defaultKeyspaceAttempt);
if (response.type == ERROR) {
Responses.Error error = (Responses.Error) response;
ksFuture.setException(defunct(error.asException(address)));
} else {
ksFuture.setException(defunct(new DriverInternalError("Unexpected response while setting keyspace: " + response)));
}
}
}
@Override
public void onFailure(Throwable t) {
targetKeyspace.compareAndSet(attempt, defaultKeyspaceAttempt);
ksFuture.setException(t);
}
}, factory.manager.configuration.getPoolingOptions().getInitializationExecutor());
return ksFuture;
}
}
}
/**
* Write a request on this connection.
*
* @param request the request to send
* @return a future on the server response
* @throws ConnectionException if the connection is closed
* @throws TransportException if an I/O error while sending the request
*/
Future write(Message.Request request) throws ConnectionException, BusyConnectionException {
Future future = new Future(request);
write(future);
return future;
}
ResponseHandler write(ResponseCallback callback) throws ConnectionException, BusyConnectionException {
return write(callback, -1, true);
}
ResponseHandler write(ResponseCallback callback, long statementReadTimeoutMillis, boolean startTimeout) throws ConnectionException, BusyConnectionException {
ResponseHandler handler = new ResponseHandler(this, statementReadTimeoutMillis, callback);
dispatcher.add(handler);
Message.Request request = callback.request().setStreamId(handler.streamId);
/*
* We check for close/defunct *after* having set the handler because closing/defuncting
* will set their flag and then error out handler if need. So, by doing the check after
* having set the handler, we guarantee that even if we race with defunct/close, we may
* never leave a handler that won't get an answer or be errored out.
*/
if (isDefunct.get()) {
dispatcher.removeHandler(handler, true);
throw new ConnectionException(address, "Write attempt on defunct connection");
}
if (isClosed()) {
dispatcher.removeHandler(handler, true);
throw new ConnectionException(address, "Connection has been closed");
}
logger.trace("{}, stream {}, writing request {}", this, request.getStreamId(), request);
writer.incrementAndGet();
if (DISABLE_COALESCING) {
channel.writeAndFlush(request).addListener(writeHandler(request, handler));
} else {
flush(new FlushItem(channel, request, writeHandler(request, handler)));
}
if (startTimeout)
handler.startTimeout();
return handler;
}
private ChannelFutureListener writeHandler(final Message.Request request, final ResponseHandler handler) {
return new ChannelFutureListener() {
@Override
public void operationComplete(ChannelFuture writeFuture) {
writer.decrementAndGet();
if (!writeFuture.isSuccess()) {
logger.debug("{}, stream {}, Error writing request {}", Connection.this, request.getStreamId(), request);
// Remove this handler from the dispatcher so it don't get notified of the error
// twice (we will fail that method already)
dispatcher.removeHandler(handler, true);
final ConnectionException ce;
if (writeFuture.cause() instanceof java.nio.channels.ClosedChannelException) {
ce = new TransportException(address, "Error writing: Closed channel");
} else {
ce = new TransportException(address, "Error writing", writeFuture.cause());
}
final long latency = System.nanoTime() - handler.startTime;
// This handler is executed while holding the writeLock of the channel.
// defunct might close the pool, which will close all of its connections; closing a connection also
// requires its writeLock.
// Therefore if multiple connections in the same pool get a write error, they could deadlock;
// we run defunct on a separate thread to avoid that.
ListeningExecutorService executor = factory.manager.executor;
if (!executor.isShutdown())
executor.execute(new Runnable() {
@Override
public void run() {
handler.callback.onException(Connection.this, defunct(ce), latency, handler.retryCount);
}
});
} else {
logger.trace("{}, stream {}, request sent successfully", Connection.this, request.getStreamId());
}
}
};
}
boolean hasOwner() {
return this.ownerRef.get() != null;
}
/**
* @return whether the connection was already associated with an owner
*/
boolean setOwner(Owner owner) {
return ownerRef.compareAndSet(null, owner);
}
/**
* If the connection is part of a pool, return it to the pool.
* The connection should generally not be reused after that.
*/
void release() {
Owner owner = ownerRef.get();
if (owner instanceof HostConnectionPool)
((HostConnectionPool) owner).returnConnection(this);
}
boolean isClosed() {
return closeFuture.get() != null;
}
/**
* Closes the connection: no new writes will be accepted after this method has returned.
*
* However, a closed connection might still have ongoing queries awaiting for their result.
* When all these ongoing queries have completed, the underlying channel will be closed; we
* refer to this final state as "terminated".
*
* @return a future that will complete once the connection has terminated.
* @see #tryTerminate(boolean)
*/
CloseFuture closeAsync() {
ConnectionCloseFuture future = new ConnectionCloseFuture();
if (!closeFuture.compareAndSet(null, future)) {
// close had already been called, return the existing future
return closeFuture.get();
}
logger.debug("{} closing connection", this);
// Only signal if defunct hasn't done it already
if (signaled.compareAndSet(false, true)) {
Host host = factory.manager.metadata.getHost(address);
if (host != null) {
host.convictionPolicy.signalConnectionClosed(this);
}
}
boolean terminated = tryTerminate(false);
if (!terminated) {
// The time by which all pending requests should have normally completed (use twice the read timeout for a generous
// estimate -- note that this does not cover the eventuality that read timeout is updated dynamically, but we can live
// with that).
long terminateTime = System.currentTimeMillis() + 2 * factory.getReadTimeoutMillis();
factory.reaper.register(this, terminateTime);
}
return future;
}
/**
* Tries to terminate a closed connection, i.e. release system resources.
*
* This is called both by "normal" code and by {@link Cluster.ConnectionReaper}.
*
* @param force whether to proceed if there are still outstanding requests.
* @return whether the connection has actually terminated.
* @see #closeAsync()
*/
boolean tryTerminate(boolean force) {
assert isClosed();
ConnectionCloseFuture future = closeFuture.get();
if (future.isDone()) {
logger.debug("{} has already terminated", this);
return true;
} else {
if (force || dispatcher.pending.isEmpty()) {
if (force)
logger.warn("Forcing termination of {}. This should not happen and is likely a bug, please report.", this);
future.force();
return true;
} else {
logger.debug("Not terminating {}: there are still pending requests", this);
return false;
}
}
}
@Override
public String toString() {
return String.format("Connection[%s, inFlight=%d, closed=%b]", name, inFlight.get(), isClosed());
}
static class Factory {
final Timer timer;
final EventLoopGroup eventLoopGroup;
private final Class channelClass;
private final ChannelGroup allChannels = new DefaultChannelGroup(GlobalEventExecutor.INSTANCE);
private final ConcurrentMap idGenerators = new ConcurrentHashMap();
final DefaultResponseHandler defaultHandler;
final Cluster.Manager manager;
final Cluster.ConnectionReaper reaper;
final Configuration configuration;
final AuthProvider authProvider;
private volatile boolean isShutdown;
volatile ProtocolVersion protocolVersion;
private final NettyOptions nettyOptions;
Factory(Cluster.Manager manager, Configuration configuration) {
this.defaultHandler = manager;
this.manager = manager;
this.reaper = manager.reaper;
this.configuration = configuration;
this.authProvider = configuration.getProtocolOptions().getAuthProvider();
this.protocolVersion = configuration.getProtocolOptions().initialProtocolVersion;
this.nettyOptions = configuration.getNettyOptions();
this.eventLoopGroup = nettyOptions.eventLoopGroup(
manager.configuration.getThreadingOptions().createThreadFactory(manager.clusterName, "nio-worker"));
this.channelClass = nettyOptions.channelClass();
this.timer = nettyOptions.timer(
manager.configuration.getThreadingOptions().createThreadFactory(manager.clusterName, "timeouter"));
}
int getPort() {
return configuration.getProtocolOptions().getPort();
}
/**
* Opens a new connection to the node this factory points to.
*
* @return the newly created (and initialized) connection.
* @throws ConnectionException if connection attempt fails.
*/
Connection open(Host host) throws ConnectionException, InterruptedException, UnsupportedProtocolVersionException, ClusterNameMismatchException {
InetSocketAddress address = host.getSocketAddress();
if (isShutdown)
throw new ConnectionException(address, "Connection factory is shut down");
host.convictionPolicy.signalConnectionsOpening(1);
Connection connection = new Connection(buildConnectionName(host), address, this);
// This method opens the connection synchronously, so wait until it's initialized
try {
connection.initAsync().get();
return connection;
} catch (ExecutionException e) {
throw launderAsyncInitException(e);
}
}
/**
* Same as open, but associate the created connection to the provided connection pool.
*/
Connection open(HostConnectionPool pool) throws ConnectionException, InterruptedException, UnsupportedProtocolVersionException, ClusterNameMismatchException {
pool.host.convictionPolicy.signalConnectionsOpening(1);
Connection connection = new Connection(buildConnectionName(pool.host), pool.host.getSocketAddress(), this, pool);
try {
connection.initAsync().get();
return connection;
} catch (ExecutionException e) {
throw launderAsyncInitException(e);
}
}
/**
* Creates new connections and associate them to the provided connection pool, but does not start them.
*/
List newConnections(HostConnectionPool pool, int count) {
pool.host.convictionPolicy.signalConnectionsOpening(count);
List connections = Lists.newArrayListWithCapacity(count);
for (int i = 0; i < count; i++)
connections.add(new Connection(buildConnectionName(pool.host), pool.host.getSocketAddress(), this, pool));
return connections;
}
private String buildConnectionName(Host host) {
return host.getSocketAddress().toString() + '-' + getIdGenerator(host).getAndIncrement();
}
static RuntimeException launderAsyncInitException(ExecutionException e) throws ConnectionException, InterruptedException, UnsupportedProtocolVersionException, ClusterNameMismatchException {
Throwable t = e.getCause();
if (t instanceof ConnectionException)
throw (ConnectionException) t;
if (t instanceof InterruptedException)
throw (InterruptedException) t;
if (t instanceof UnsupportedProtocolVersionException)
throw (UnsupportedProtocolVersionException) t;
if (t instanceof ClusterNameMismatchException)
throw (ClusterNameMismatchException) t;
if (t instanceof DriverException)
throw (DriverException) t;
return new RuntimeException("Unexpected exception during connection initialization", t);
}
private AtomicInteger getIdGenerator(Host host) {
AtomicInteger g = idGenerators.get(host);
if (g == null) {
g = new AtomicInteger(1);
AtomicInteger old = idGenerators.putIfAbsent(host, g);
if (old != null)
g = old;
}
return g;
}
long getReadTimeoutMillis() {
return configuration.getSocketOptions().getReadTimeoutMillis();
}
private Bootstrap newBootstrap() {
Bootstrap b = new Bootstrap();
b.group(eventLoopGroup)
.channel(channelClass);
SocketOptions options = configuration.getSocketOptions();
b.option(ChannelOption.CONNECT_TIMEOUT_MILLIS, options.getConnectTimeoutMillis());
Boolean keepAlive = options.getKeepAlive();
if (keepAlive != null)
b.option(ChannelOption.SO_KEEPALIVE, keepAlive);
Boolean reuseAddress = options.getReuseAddress();
if (reuseAddress != null)
b.option(ChannelOption.SO_REUSEADDR, reuseAddress);
Integer soLinger = options.getSoLinger();
if (soLinger != null)
b.option(ChannelOption.SO_LINGER, soLinger);
Boolean tcpNoDelay = options.getTcpNoDelay();
if (tcpNoDelay != null)
b.option(ChannelOption.TCP_NODELAY, tcpNoDelay);
Integer receiveBufferSize = options.getReceiveBufferSize();
if (receiveBufferSize != null)
b.option(ChannelOption.SO_RCVBUF, receiveBufferSize);
Integer sendBufferSize = options.getSendBufferSize();
if (sendBufferSize != null)
b.option(ChannelOption.SO_SNDBUF, sendBufferSize);
nettyOptions.afterBootstrapInitialized(b);
return b;
}
void shutdown() {
// Make sure we skip creating connection from now on.
isShutdown = true;
// All channels should be closed already, we call this just to be sure. And we know
// we're not on an I/O thread or anything, so just call await.
allChannels.close().awaitUninterruptibly();
nettyOptions.onClusterClose(eventLoopGroup);
nettyOptions.onClusterClose(timer);
}
}
private static final class Flusher implements Runnable {
final WeakReference eventLoopRef;
final Queue queued = new ConcurrentLinkedQueue();
final AtomicBoolean running = new AtomicBoolean(false);
final HashSet channels = new HashSet();
int runsWithNoWork = 0;
private Flusher(EventLoop eventLoop) {
this.eventLoopRef = new WeakReference(eventLoop);
}
void start() {
if (!running.get() && running.compareAndSet(false, true)) {
EventLoop eventLoop = eventLoopRef.get();
if (eventLoop != null)
eventLoop.execute(this);
}
}
@Override
public void run() {
boolean doneWork = false;
FlushItem flush;
while (null != (flush = queued.poll())) {
Channel channel = flush.channel;
if (channel.isActive()) {
channels.add(channel);
channel.write(flush.request).addListener(flush.listener);
doneWork = true;
}
}
// Always flush what we have (don't artificially delay to try to coalesce more messages)
for (Channel channel : channels)
channel.flush();
channels.clear();
if (doneWork) {
runsWithNoWork = 0;
} else {
// either reschedule or cancel
if (++runsWithNoWork > 5) {
running.set(false);
if (queued.isEmpty() || !running.compareAndSet(false, true))
return;
}
}
EventLoop eventLoop = eventLoopRef.get();
if (eventLoop != null && !eventLoop.isShuttingDown()) {
eventLoop.schedule(this, 10000, TimeUnit.NANOSECONDS);
}
}
}
private static final ConcurrentMap flusherLookup = new MapMaker()
.concurrencyLevel(16)
.weakKeys()
.makeMap();
private static class FlushItem {
final Channel channel;
final Object request;
final ChannelFutureListener listener;
private FlushItem(Channel channel, Object request, ChannelFutureListener listener) {
this.channel = channel;
this.request = request;
this.listener = listener;
}
}
private void flush(FlushItem item) {
EventLoop loop = item.channel.eventLoop();
Flusher flusher = flusherLookup.get(loop);
if (flusher == null) {
Flusher alt = flusherLookup.putIfAbsent(loop, flusher = new Flusher(loop));
if (alt != null)
flusher = alt;
}
flusher.queued.add(item);
flusher.start();
}
class Dispatcher extends SimpleChannelInboundHandler {
final StreamIdGenerator streamIdHandler;
private final ConcurrentMap pending = new ConcurrentHashMap();
Dispatcher() {
ProtocolVersion protocolVersion = factory.protocolVersion;
if (protocolVersion == null) {
// This happens for the first control connection because the protocol version has not been
// negociated yet.
protocolVersion = ProtocolVersion.V2;
}
streamIdHandler = StreamIdGenerator.newInstance(protocolVersion);
}
void add(ResponseHandler handler) {
ResponseHandler old = pending.put(handler.streamId, handler);
assert old == null;
}
void removeHandler(ResponseHandler handler, boolean releaseStreamId) {
// If we don't release the ID, mark first so that we can rely later on the fact that if
// we receive a response for an ID with no handler, it's that this ID has been marked.
if (!releaseStreamId)
streamIdHandler.mark(handler.streamId);
// If a RequestHandler is cancelled right when the response arrives, this method (called with releaseStreamId=false) will race with messageReceived.
// messageReceived could have already released the streamId, which could have already been reused by another request. We must not remove the handler
// if it's not ours, because that would cause the other request to hang forever.
boolean removed = pending.remove(handler.streamId, handler);
if (!removed) {
// We raced, so if we marked the streamId above, that was wrong.
if (!releaseStreamId)
streamIdHandler.unmark(handler.streamId);
return;
}
handler.cancelTimeout();
if (releaseStreamId)
streamIdHandler.release(handler.streamId);
if (isClosed())
tryTerminate(false);
}
@Override
protected void channelRead0(ChannelHandlerContext ctx, Message.Response response) throws Exception {
int streamId = response.getStreamId();
if (logger.isTraceEnabled())
logger.trace("{}, stream {}, received: {}", Connection.this, streamId, asDebugString(response));
if (streamId < 0) {
factory.defaultHandler.handle(response);
return;
}
ResponseHandler handler = pending.remove(streamId);
streamIdHandler.release(streamId);
if (handler == null) {
/*
* During normal operation, we should not receive responses for which we don't have a handler. There is
* two cases however where this can happen:
* 1) The connection has been defuncted due to some internal error and we've raced between removing the
* handler and actually closing the connection; since the original error has been logged, we're fine
* ignoring this completely.
* 2) This request has timed out. In that case, we've already switched to another host (or errored out
* to the user). So log it for debugging purpose, but it's fine ignoring otherwise.
*/
streamIdHandler.unmark(streamId);
if (logger.isDebugEnabled())
logger.debug("{} Response received on stream {} but no handler set anymore (either the request has "
+ "timed out or it was closed due to another error). Received message is {}", Connection.this, streamId, asDebugString(response));
return;
}
handler.cancelTimeout();
handler.callback.onSet(Connection.this, response, System.nanoTime() - handler.startTime, handler.retryCount);
// If we happen to be closed and we're the last outstanding request, we need to terminate the connection
// (note: this is racy as the signaling can be called more than once, but that's not a problem)
if (isClosed())
tryTerminate(false);
}
@Override
public void userEventTriggered(ChannelHandlerContext ctx, Object evt) throws Exception {
if (!isClosed() && evt instanceof IdleStateEvent && ((IdleStateEvent) evt).state() == READER_IDLE) {
logger.debug("{} was inactive for {} seconds, sending heartbeat", Connection.this, factory.configuration.getPoolingOptions().getHeartbeatIntervalSeconds());
write(HEARTBEAT_CALLBACK);
}
}
// Make sure we don't print huge responses in debug/error logs.
private String asDebugString(Object obj) {
if (obj == null)
return "null";
String msg = obj.toString();
if (msg.length() < 500)
return msg;
return msg.substring(0, 500) + "... [message of size " + msg.length() + " truncated]";
}
@Override
public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
if (logger.isDebugEnabled())
logger.debug(String.format("%s connection error", Connection.this), cause);
// Ignore exception while writing, this will be handled by write() directly
if (writer.get() > 0)
return;
if (cause instanceof DecoderException) {
Throwable error = cause.getCause();
// Special case, if we encountered a FrameTooLongException, raise exception on handler and don't defunct it since
// the connection is in an ok state.
if (error != null && error instanceof FrameTooLongException) {
FrameTooLongException ftle = (FrameTooLongException) error;
int streamId = ftle.getStreamId();
ResponseHandler handler = pending.remove(streamId);
streamIdHandler.release(streamId);
if (handler == null) {
streamIdHandler.unmark(streamId);
if (logger.isDebugEnabled())
logger.debug("{} FrameTooLongException received on stream {} but no handler set anymore (either the request has "
+ "timed out or it was closed due to another error).", Connection.this, streamId);
return;
}
handler.cancelTimeout();
handler.callback.onException(Connection.this, ftle, System.nanoTime() - handler.startTime, handler.retryCount);
return;
}
}
defunct(new TransportException(address, String.format("Unexpected exception triggered (%s)", cause), cause));
}
void errorOutAllHandler(ConnectionException ce) {
Iterator iter = pending.values().iterator();
while (iter.hasNext()) {
ResponseHandler handler = iter.next();
handler.cancelTimeout();
handler.callback.onException(Connection.this, ce, System.nanoTime() - handler.startTime, handler.retryCount);
iter.remove();
}
}
}
private class ChannelCloseListener implements ChannelFutureListener {
@Override
public void operationComplete(ChannelFuture future) throws Exception {
// If we've closed the channel client side then we don't really want to defunct the connection, but
// if there is remaining thread waiting on us, we still want to wake them up
if (!isInitialized || isClosed()) {
dispatcher.errorOutAllHandler(new TransportException(address, "Channel has been closed"));
// we still want to force so that the future completes
Connection.this.closeAsync().force();
} else
defunct(new TransportException(address, "Channel has been closed"));
}
}
private static final ResponseCallback HEARTBEAT_CALLBACK = new ResponseCallback() {
@Override
public Message.Request request() {
return new Requests.Options();
}
@Override
public int retryCount() {
return 0; // no retries here
}
@Override
public void onSet(Connection connection, Message.Response response, long latency, int retryCount) {
switch (response.type) {
case SUPPORTED:
logger.debug("{} heartbeat query succeeded", connection);
break;
default:
fail(connection, new ConnectionException(connection.address, "Unexpected heartbeat response: " + response));
}
}
@Override
public void onException(Connection connection, Exception exception, long latency, int retryCount) {
// Nothing to do: the connection is already defunct if we arrive here
}
@Override
public boolean onTimeout(Connection connection, long latency, int retryCount) {
fail(connection, new ConnectionException(connection.address, "Heartbeat query timed out"));
return true;
}
private void fail(Connection connection, Exception e) {
connection.defunct(e);
}
};
private class ConnectionCloseFuture extends CloseFuture {
@Override
public ConnectionCloseFuture force() {
// Note: we must not call releaseExternalResources on the bootstrap, because this shutdown the executors, which are shared
// This method can be thrown during initialization, at which point channel is not yet set. This is ok.
if (channel == null) {
set(null);
return this;
}
// We're going to close this channel. If anyone is waiting on that connection, we should defunct it otherwise it'll wait
// forever. In general this won't happen since we get there only when all ongoing query are done, but this can happen
// if the shutdown is forced. This is a no-op if there is no handler set anymore.
dispatcher.errorOutAllHandler(new TransportException(address, "Connection has been closed"));
ChannelFuture future = channel.close();
future.addListener(new ChannelFutureListener() {
public void operationComplete(ChannelFuture future) {
factory.allChannels.remove(channel);
if (future.cause() != null) {
logger.warn("Error closing channel", future.cause());
ConnectionCloseFuture.this.setException(future.cause());
} else
ConnectionCloseFuture.this.set(null);
}
});
return this;
}
}
private class SetKeyspaceAttempt {
private final String keyspace;
private final ListenableFuture future;
SetKeyspaceAttempt(String keyspace, ListenableFuture future) {
this.keyspace = keyspace;
this.future = future;
}
@Override
public boolean equals(Object o) {
if (this == o)
return true;
if (!(o instanceof SetKeyspaceAttempt))
return false;
SetKeyspaceAttempt that = (SetKeyspaceAttempt) o;
return keyspace != null ? keyspace.equals(that.keyspace) : that.keyspace == null;
}
@Override
public int hashCode() {
return keyspace != null ? keyspace.hashCode() : 0;
}
}
static class Future extends AbstractFuture implements RequestHandler.Callback {
private final Message.Request request;
private volatile InetSocketAddress address;
Future(Message.Request request) {
this.request = request;
}
@Override
public void register(RequestHandler handler) {
// noop, we don't care about the handler here so far
}
@Override
public Message.Request request() {
return request;
}
@Override
public int retryCount() {
// This is ignored, as there is no retry logic in this class
return 0;
}
@Override
public void onSet(Connection connection, Message.Response response, ExecutionInfo info, Statement statement, long latency) {
onSet(connection, response, latency, 0);
}
@Override
public void onSet(Connection connection, Message.Response response, long latency, int retryCount) {
this.address = connection.address;
super.set(response);
}
@Override
public void onException(Connection connection, Exception exception, long latency, int retryCount) {
// If all nodes are down, we will get a null connection here. This is fine, if we have
// an exception, consumers shouldn't assume the address is not null.
if (connection != null)
this.address = connection.address;
super.setException(exception);
}
@Override
public boolean onTimeout(Connection connection, long latency, int retryCount) {
assert connection != null; // We always timeout on a specific connection, so this shouldn't be null
this.address = connection.address;
return super.setException(new OperationTimedOutException(connection.address));
}
InetSocketAddress getAddress() {
return address;
}
}
interface ResponseCallback {
Message.Request request();
int retryCount();
void onSet(Connection connection, Message.Response response, long latency, int retryCount);
void onException(Connection connection, Exception exception, long latency, int retryCount);
boolean onTimeout(Connection connection, long latency, int retryCount);
}
static class ResponseHandler {
final Connection connection;
final int streamId;
final ResponseCallback callback;
final int retryCount;
private final long readTimeoutMillis;
private final long startTime;
private volatile Timeout timeout;
private final AtomicBoolean isCancelled = new AtomicBoolean();
ResponseHandler(Connection connection, long statementReadTimeoutMillis, ResponseCallback callback) throws BusyConnectionException {
this.connection = connection;
this.readTimeoutMillis = (statementReadTimeoutMillis >= 0) ? statementReadTimeoutMillis : connection.factory.getReadTimeoutMillis();
this.streamId = connection.dispatcher.streamIdHandler.next();
if (streamId == -1)
throw new BusyConnectionException(connection.address);
this.callback = callback;
this.retryCount = callback.retryCount();
this.startTime = System.nanoTime();
}
void startTimeout() {
this.timeout = this.readTimeoutMillis <= 0 ? null : connection.factory.timer.newTimeout(onTimeoutTask(), this.readTimeoutMillis, TimeUnit.MILLISECONDS);
}
void cancelTimeout() {
if (timeout != null)
timeout.cancel();
}
boolean cancelHandler() {
if (!isCancelled.compareAndSet(false, true))
return false;
// We haven't really received a response: we want to remove the handle because we gave up on that
// request and there is no point in holding the handler, but we don't release the streamId. If we
// were, a new request could reuse that ID but get the answer to the request we just gave up on instead
// of its own answer, and we would have no way to detect that.
connection.dispatcher.removeHandler(this, false);
return true;
}
private TimerTask onTimeoutTask() {
return new TimerTask() {
@Override
public void run(Timeout timeout) {
if (callback.onTimeout(connection, System.nanoTime() - startTime, retryCount))
cancelHandler();
}
};
}
}
interface DefaultResponseHandler {
void handle(Message.Response response);
}
private static class Initializer extends ChannelInitializer {
// Stateless handlers
private static final Message.ProtocolDecoder messageDecoder = new Message.ProtocolDecoder();
private static final Message.ProtocolEncoder messageEncoderV1 = new Message.ProtocolEncoder(ProtocolVersion.V1);
private static final Message.ProtocolEncoder messageEncoderV2 = new Message.ProtocolEncoder(ProtocolVersion.V2);
private static final Message.ProtocolEncoder messageEncoderV3 = new Message.ProtocolEncoder(ProtocolVersion.V3);
private static final Message.ProtocolEncoder messageEncoderV4 = new Message.ProtocolEncoder(ProtocolVersion.V4);
private static final Frame.Encoder frameEncoder = new Frame.Encoder();
private final ProtocolVersion protocolVersion;
private final Connection connection;
private final FrameCompressor compressor;
private final SSLOptions sslOptions;
private final NettyOptions nettyOptions;
private final ChannelHandler idleStateHandler;
private final CodecRegistry codecRegistry;
Initializer(Connection connection, ProtocolVersion protocolVersion, FrameCompressor compressor, SSLOptions sslOptions, int heartBeatIntervalSeconds, NettyOptions nettyOptions, CodecRegistry codecRegistry) {
this.connection = connection;
this.protocolVersion = protocolVersion;
this.compressor = compressor;
this.sslOptions = sslOptions;
this.nettyOptions = nettyOptions;
this.codecRegistry = codecRegistry;
this.idleStateHandler = new IdleStateHandler(heartBeatIntervalSeconds, 0, 0);
}
@Override
protected void initChannel(SocketChannel channel) throws Exception {
// set the codec registry so that it can be accessed by ProtocolDecoder
channel.attr(Message.CODEC_REGISTRY_ATTRIBUTE_KEY).set(codecRegistry);
ChannelPipeline pipeline = channel.pipeline();
if (sslOptions != null) {
pipeline.addLast("ssl", sslOptions.newSSLHandler(channel));
}
// pipeline.addLast("debug", new LoggingHandler(LogLevel.INFO));
pipeline.addLast("frameDecoder", new Frame.Decoder());
pipeline.addLast("frameEncoder", frameEncoder);
if (compressor != null) {
pipeline.addLast("frameDecompressor", new Frame.Decompressor(compressor));
pipeline.addLast("frameCompressor", new Frame.Compressor(compressor));
}
pipeline.addLast("messageDecoder", messageDecoder);
pipeline.addLast("messageEncoder", messageEncoderFor(protocolVersion));
pipeline.addLast("idleStateHandler", idleStateHandler);
pipeline.addLast("dispatcher", connection.dispatcher);
nettyOptions.afterChannelInitialized(channel);
}
private Message.ProtocolEncoder messageEncoderFor(ProtocolVersion version) {
switch (version) {
case V1:
return messageEncoderV1;
case V2:
return messageEncoderV2;
case V3:
return messageEncoderV3;
case V4:
return messageEncoderV4;
default:
throw new DriverInternalError("Unsupported protocol version " + protocolVersion);
}
}
}
/**
* A component that "owns" a connection, and should be notified when it dies.
*/
interface Owner {
void onConnectionDefunct(Connection connection);
}
}