/*
* 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.thrift.server;
import java.util.Random;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.RejectedExecutionException;
import java.util.concurrent.SynchronousQueue;
import java.util.concurrent.ThreadPoolExecutor;
import java.util.concurrent.TimeUnit;
import org.apache.thrift.TException;
import org.apache.thrift.TProcessor;
import org.apache.thrift.protocol.TProtocol;
import org.apache.thrift.transport.TSaslTransportException;
import org.apache.thrift.transport.TServerTransport;
import org.apache.thrift.transport.TTransport;
import org.apache.thrift.transport.TTransportException;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* Server which uses Java's built in ThreadPool management to spawn off
* a worker pool that
*
*/
public class TThreadPoolServer extends TServer {
private static final Logger LOGGER = LoggerFactory.getLogger(TThreadPoolServer.class.getName());
public static class Args extends AbstractServerArgs<Args> {
public int minWorkerThreads = 5;
public int maxWorkerThreads = Integer.MAX_VALUE;
public ExecutorService executorService;
public int stopTimeoutVal = 60;
public TimeUnit stopTimeoutUnit = TimeUnit.SECONDS;
public int requestTimeout = 20;
public TimeUnit requestTimeoutUnit = TimeUnit.SECONDS;
public int beBackoffSlotLength = 100;
public TimeUnit beBackoffSlotLengthUnit = TimeUnit.MILLISECONDS;
public Args(TServerTransport transport) {
super(transport);
}
public Args minWorkerThreads(int n) {
minWorkerThreads = n;
return this;
}
public Args maxWorkerThreads(int n) {
maxWorkerThreads = n;
return this;
}
public Args requestTimeout(int n) {
requestTimeout = n;
return this;
}
public Args requestTimeoutUnit(TimeUnit tu) {
requestTimeoutUnit = tu;
return this;
}
//Binary exponential backoff slot length
public Args beBackoffSlotLength(int n) {
beBackoffSlotLength = n;
return this;
}
//Binary exponential backoff slot time unit
public Args beBackoffSlotLengthUnit(TimeUnit tu) {
beBackoffSlotLengthUnit = tu;
return this;
}
public Args executorService(ExecutorService executorService) {
this.executorService = executorService;
return this;
}
}
// Executor service for handling client connections
private ExecutorService executorService_;
// Flag for stopping the server
// Please see THRIFT-1795 for the usage of this flag
private volatile boolean stopped_ = false;
private final TimeUnit stopTimeoutUnit;
private final long stopTimeoutVal;
private final TimeUnit requestTimeoutUnit;
private final long requestTimeout;
private final long beBackoffSlotInMillis;
private Random random = new Random(System.currentTimeMillis());
public TThreadPoolServer(Args args) {
super(args);
stopTimeoutUnit = args.stopTimeoutUnit;
stopTimeoutVal = args.stopTimeoutVal;
requestTimeoutUnit = args.requestTimeoutUnit;
requestTimeout = args.requestTimeout;
beBackoffSlotInMillis = args.beBackoffSlotLengthUnit.toMillis(args.beBackoffSlotLength);
executorService_ = args.executorService != null ?
args.executorService : createDefaultExecutorService(args);
}
private static ExecutorService createDefaultExecutorService(Args args) {
SynchronousQueue<Runnable> executorQueue =
new SynchronousQueue<Runnable>();
return new ThreadPoolExecutor(args.minWorkerThreads,
args.maxWorkerThreads,
60,
TimeUnit.SECONDS,
executorQueue);
}
public void serve() {
try {
serverTransport_.listen();
} catch (TTransportException ttx) {
LOGGER.error("Error occurred during listening.", ttx);
return;
}
// Run the preServe event
if (eventHandler_ != null) {
eventHandler_.preServe();
}
stopped_ = false;
setServing(true);
int failureCount = 0;
while (!stopped_) {
try {
TTransport client = serverTransport_.accept();
WorkerProcess wp = new WorkerProcess(client);
int retryCount = 0;
long remainTimeInMillis = requestTimeoutUnit.toMillis(requestTimeout);
while(true) {
try {
executorService_.execute(wp);
break;
} catch(Throwable t) {
if (t instanceof RejectedExecutionException) {
retryCount++;
try {
if (remainTimeInMillis > 0) {
//do a truncated 20 binary exponential backoff sleep
long sleepTimeInMillis = ((long) (random.nextDouble() *
(1L << Math.min(retryCount, 20)))) * beBackoffSlotInMillis;
sleepTimeInMillis = Math.min(sleepTimeInMillis, remainTimeInMillis);
TimeUnit.MILLISECONDS.sleep(sleepTimeInMillis);
remainTimeInMillis = remainTimeInMillis - sleepTimeInMillis;
} else {
client.close();
wp = null;
LOGGER.warn("Task has been rejected by ExecutorService " + retryCount
+ " times till timedout, reason: " + t);
break;
}
} catch (InterruptedException e) {
LOGGER.warn("Interrupted while waiting to place client on executor queue.");
Thread.currentThread().interrupt();
break;
}
} else if (t instanceof Error) {
LOGGER.error("ExecutorService threw error: " + t, t);
throw (Error)t;
} else {
//for other possible runtime errors from ExecutorService, should also not kill serve
LOGGER.warn("ExecutorService threw error: " + t, t);
break;
}
}
}
} catch (TTransportException ttx) {
if (!stopped_) {
++failureCount;
LOGGER.warn("Transport error occurred during acceptance of message.", ttx);
}
}
}
executorService_.shutdown();
// Loop until awaitTermination finally does return without a interrupted
// exception. If we don't do this, then we'll shut down prematurely. We want
// to let the executorService clear it's task queue, closing client sockets
// appropriately.
long timeoutMS = stopTimeoutUnit.toMillis(stopTimeoutVal);
long now = System.currentTimeMillis();
while (timeoutMS >= 0) {
try {
executorService_.awaitTermination(timeoutMS, TimeUnit.MILLISECONDS);
break;
} catch (InterruptedException ix) {
long newnow = System.currentTimeMillis();
timeoutMS -= (newnow - now);
now = newnow;
}
}
setServing(false);
}
public void stop() {
stopped_ = true;
serverTransport_.interrupt();
}
private class WorkerProcess implements Runnable {
/**
* Client that this services.
*/
private TTransport client_;
/**
* Default constructor.
*
* @param client Transport to process
*/
private WorkerProcess(TTransport client) {
client_ = client;
}
/**
* Loops on processing a client forever
*/
public void run() {
TProcessor processor = null;
TTransport inputTransport = null;
TTransport outputTransport = null;
TProtocol inputProtocol = null;
TProtocol outputProtocol = null;
TServerEventHandler eventHandler = null;
ServerContext connectionContext = null;
try {
processor = processorFactory_.getProcessor(client_);
inputTransport = inputTransportFactory_.getTransport(client_);
outputTransport = outputTransportFactory_.getTransport(client_);
inputProtocol = inputProtocolFactory_.getProtocol(inputTransport);
outputProtocol = outputProtocolFactory_.getProtocol(outputTransport);
eventHandler = getEventHandler();
if (eventHandler != null) {
connectionContext = eventHandler.createContext(inputProtocol, outputProtocol);
}
// we check stopped_ first to make sure we're not supposed to be shutting
// down. this is necessary for graceful shutdown.
while (true) {
if (eventHandler != null) {
eventHandler.processContext(connectionContext, inputTransport, outputTransport);
}
if(stopped_ || !processor.process(inputProtocol, outputProtocol)) {
break;
}
}
} catch (TSaslTransportException ttx) {
// Something thats not SASL was in the stream, continue silently
} catch (TTransportException ttx) {
// Assume the client died and continue silently
} catch (TException tx) {
LOGGER.error("Thrift error occurred during processing of message.", tx);
} catch (Exception x) {
LOGGER.error("Error occurred during processing of message.", x);
}
if (eventHandler != null) {
eventHandler.deleteContext(connectionContext, inputProtocol, outputProtocol);
}
if (inputTransport != null) {
inputTransport.close();
}
if (outputTransport != null) {
outputTransport.close();
}
}
}
}