/*
* Copyright 2012-2014 Continuuity, 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.continuuity.tephra.distributed;
import com.continuuity.tephra.TransactionManager;
import com.continuuity.tephra.distributed.thrift.TTransactionServer;
import com.continuuity.tephra.inmemory.InMemoryTransactionService;
import com.continuuity.tephra.rpc.ThriftRPCServer;
import com.google.common.util.concurrent.MoreExecutors;
import com.google.common.util.concurrent.Uninterruptibles;
import com.google.inject.Inject;
import com.google.inject.Provider;
import org.apache.hadoop.conf.Configuration;
import org.apache.twill.api.ElectionHandler;
import org.apache.twill.common.ServiceListenerAdapter;
import org.apache.twill.discovery.DiscoveryService;
import org.apache.twill.internal.zookeeper.LeaderElection;
import org.apache.twill.zookeeper.ZKClient;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.net.InetSocketAddress;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;
/**
*
*/
public final class TransactionService extends InMemoryTransactionService {
private static final Logger LOG = LoggerFactory.getLogger(TransactionService.class);
private LeaderElection leaderElection;
private final ZKClient zkClient;
private ThriftRPCServer<TransactionServiceThriftHandler, TTransactionServer> server;
@Inject
public TransactionService(Configuration conf,
ZKClient zkClient,
DiscoveryService discoveryService,
Provider<TransactionManager> txManagerProvider) {
super(conf, discoveryService, txManagerProvider);
this.zkClient = zkClient;
}
@Override
protected InetSocketAddress getAddress() {
return server.getBindAddress();
}
@Override
protected void doStart() {
leaderElection = new LeaderElection(zkClient, "/tx.service/leader", new ElectionHandler() {
@Override
public void leader() {
// if the txManager fails, we should stop the server
txManager = txManagerProvider.get();
txManager.addListener(new ServiceListenerAdapter() {
@Override
public void failed(State from, Throwable failure) {
LOG.error("Transaction manager aborted, stopping transaction service");
stopAndWait();
}
}, MoreExecutors.sameThreadExecutor());
server = ThriftRPCServer.builder(TTransactionServer.class)
.setHost(address)
.setWorkerThreads(threads)
.setMaxReadBufferBytes(maxReadBufferBytes)
.setIOThreads(ioThreads)
.build(new TransactionServiceThriftHandler(txManager));
try {
server.startAndWait();
doRegister();
LOG.info("Transaction Thrift Service started successfully on " + getAddress());
} catch (Throwable t) {
LOG.info("Transaction Thrift Service didn't start on " + server.getBindAddress());
leaderElection.stop();
notifyFailed(t);
}
}
@Override
public void follower() {
undoRegiser();
if (server != null && server.isRunning()) {
server.stopAndWait();
}
}
});
leaderElection.start();
notifyStarted();
}
@Override
protected void doStop() {
if (leaderElection != null) {
// NOTE: if was a leader this will cause loosing of leadership which in callback above will
// de-register service in discovery service and stop the service if needed
try {
Uninterruptibles.getUninterruptibly(leaderElection.stop(), 5, TimeUnit.SECONDS);
} catch (TimeoutException te) {
LOG.warn("Timed out waiting for leader election cancellation to complete");
} catch (ExecutionException e) {
LOG.error("Exception when cancelling leader election.", e);
}
}
notifyStopped();
}
}