/**
* 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.hive.hcatalog.templeton;
import java.io.IOException;
import java.net.URL;
import java.net.MalformedURLException;
import java.util.Date;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hive.hcatalog.templeton.tool.JobState;
import org.apache.hive.hcatalog.templeton.tool.TempletonUtils;
/**
* Complete a job. This will run the callback if
*
* - the job is done
* - there is a callback
* - the callback has not yet been called
*
* There is a small chance for a race condition if two callers run
* this at the same time. That should never happen.
*
* We use a Hadoop config var to notify this class on the completion
* of a job. Hadoop will call use multiple times in the event of
* failure. Even if the failure is that the client callback failed.
*
* See LauncherDelegator for the HADOOP_END_RETRY* vars that are set.
*/
public class CompleteDelegator extends TempletonDelegator {
private static final Log LOG = LogFactory.getLog(CompleteDelegator.class);
public CompleteDelegator(AppConfig appConf) {
super(appConf);
}
public CompleteBean run(String id)
throws CallbackFailedException, IOException {
if (id == null)
acceptWithError("No jobid given");
JobState state = null;
try {
state = new JobState(id, Main.getAppConfigInstance());
if (state.getCompleteStatus() == null)
failed("Job not yet complete. jobId=" + id, null);
Long notified = state.getNotifiedTime();
if (notified != null)
return acceptWithError("Callback already run for jobId=" + id +
" at " + new Date(notified));
String callback = state.getCallback();
if (callback == null)
return new CompleteBean("No callback registered");
try {
doCallback(state.getId(), callback);
} catch (Exception e) {
failed("Callback failed " + callback + " for " + id, e);
}
state.setNotifiedTime(System.currentTimeMillis());
return new CompleteBean("Callback sent");
} finally {
if (state != null)
state.close();
}
}
/**
* Call the callback url with the jobid to let them know it's
* finished. If the url has the string $jobId in it, it will be
* replaced with the completed jobid.
*/
public static void doCallback(String jobid, String url)
throws MalformedURLException, IOException {
if (url.contains("$jobId"))
url = url.replace("$jobId", jobid);
TempletonUtils.fetchUrl(new URL(url));
}
private void failed(String msg, Exception e)
throws CallbackFailedException {
if (e != null)
LOG.error(msg, e);
else
LOG.error(msg);
throw new CallbackFailedException(msg);
}
private CompleteBean acceptWithError(String msg) {
LOG.error(msg);
return new CompleteBean(msg);
}
}