/*
* 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.hadoop.corona;
import org.apache.hadoop.net.NetUtils;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.thrift.TException;
import org.apache.thrift.protocol.TBinaryProtocol;
import org.apache.thrift.transport.TFramedTransport;
import org.apache.thrift.transport.TSocket;
import java.io.IOException;
import java.net.InetSocketAddress;
/**
* Has helper method(s) related to the availability of the ClusterManager
*/
public class ClusterManagerAvailabilityChecker {
static final Log LOG =
LogFactory.getLog(ClusterManagerAvailabilityChecker.class);
/**
* Used for getting a client to the CoronaProxyJobTracker
* @param conf
* @return Returns a client to the CPJT
* @throws IOException
*/
public static CoronaProxyJobTrackerService.Client
getPJTClient(CoronaConf conf) throws IOException {
InetSocketAddress address =
NetUtils.createSocketAddr(conf.getProxyJobTrackerThriftAddress());
TFramedTransport transport = new TFramedTransport(
new TSocket(address.getHostName(), address.getPort()));
CoronaProxyJobTrackerService.Client client =
new CoronaProxyJobTrackerService.Client(new TBinaryProtocol(transport));
try {
transport.open();
} catch (TException e) {
LOG.info("Transport Exception: ", e);
}
return client;
}
/**
* This helper method simply polls the ProxyJobTracker if and until the
* clusterManagerSafeMode flag is set there.
* @param conf
* @throws IOException
*/
public static void waitWhileClusterManagerInSafeMode(CoronaConf conf)
throws IOException {
while (true) {
try {
/**
* If this condition holds true, then two things can happen:
* 1. The CM was never in Safe Mode
* 2. CM was in Safe Mode, just before we made this method call, and
* came out of Safe Mode before the RPC call.
*/
if (!getPJTClient(conf).getClusterManagerSafeModeFlag()) {
break;
}
// If the safe mode flag is indeed set
LOG.info("Safe mode flag is set on the ProxyJobTracker");
try {
Thread.sleep(1000);
} catch (InterruptedException e) {
continue;
}
} catch (IOException e) {
throw new IOException(
"Could not check the safe mode flag on the ProxyJobTracker", e);
} catch (TException e) {
throw new IOException(
"Could not check the safe mode flag on the ProxyJobTracker", e);
}
}
}
}