/**
* 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.ambari.view.pig.resources.jobs.utils;
import org.apache.ambari.view.ViewContext;
import org.apache.ambari.view.pig.persistence.utils.ItemNotFound;
import org.apache.ambari.view.pig.resources.jobs.JobResourceManager;
import org.apache.ambari.view.pig.resources.jobs.models.PigJob;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.util.HashMap;
import java.util.Map;
import java.util.Observable;
import java.util.concurrent.Executors;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.ScheduledFuture;
import java.util.concurrent.TimeUnit;
/**
* Polling manager
* Makes scheduled repeated polling of templeton to
* be aware of happen events like job finished,
* killed, changed progress and so on.
*/
public class JobPolling implements Runnable {
private final static Logger LOG =
LoggerFactory.getLogger(JobPolling.class);
/**
* We should limit count of concurrent calls to templeton
* to avoid high load on component
*/
private static final int WORKER_COUNT = 2;
private static final int POLLING_DELAY = 10*60; // 10 minutes
/**
* In LONG_JOB_THRESHOLD seconds job reschedules polling from POLLING_DELAY to LONG_POLLING_DELAY
*/
private static final int LONG_POLLING_DELAY = 60*60; // 1 hour
private static final int LONG_JOB_THRESHOLD = 60*60; // 1 hour
private static final ScheduledExecutorService pollWorkersPool = Executors.newScheduledThreadPool(WORKER_COUNT);
private static final Map<String, JobPolling> jobPollers = new HashMap<String, JobPolling>();
private JobResourceManager resourceManager = null;
private final ViewContext context;
private PigJob job;
private volatile ScheduledFuture<?> thisFuture;
private JobPolling(ViewContext context, PigJob job) {
this.context = context;
this.job = job;
}
protected synchronized JobResourceManager getResourceManager() {
if (resourceManager == null) {
resourceManager = new JobResourceManager(context);
}
return resourceManager;
}
/**
* Do polling
*/
public void run() {
LOG.debug("Polling job status " + job.getJobId() + " #" + job.getId());
try {
job = getResourceManager().read(job.getId());
} catch (ItemNotFound itemNotFound) {
LOG.error("Job " + job.getJobId() + " does not exist! Polling canceled");
thisFuture.cancel(false);
return;
}
getResourceManager().retrieveJobStatus(job);
Long time = System.currentTimeMillis() / 1000L;
if (time - job.getDateStarted() > LONG_JOB_THRESHOLD) {
LOG.debug("Job becomes long.. Rescheduling polling to longer period");
// If job running longer than LONG_JOB_THRESHOLD, reschedule
// it to poll every LONG_POLLING_DELAY instead of POLLING_DELAY
thisFuture.cancel(false);
scheduleJobPolling(true);
}
switch (job.getStatus()) {
case SUBMIT_FAILED:
case COMPLETED:
case FAILED:
case KILLED:
LOG.debug("Job finished. Polling canceled");
thisFuture.cancel(false);
break;
default:
}
}
private void scheduleJobPolling(boolean longDelay) {
if (!longDelay) {
thisFuture = pollWorkersPool.scheduleWithFixedDelay(this,
POLLING_DELAY, POLLING_DELAY, TimeUnit.SECONDS);
} else {
thisFuture = pollWorkersPool.scheduleWithFixedDelay(this,
LONG_POLLING_DELAY, LONG_POLLING_DELAY, TimeUnit.SECONDS);
}
}
private void scheduleJobPolling() {
scheduleJobPolling(false);
}
/**
* Schedule job polling
* @param context ViewContext of web app
* @param job job instance
* @return returns false if already scheduled
*/
public static boolean pollJob(ViewContext context, PigJob job) {
if (jobPollers.get(job.getJobId()) == null) {
LOG.debug("Setting up polling for " + job.getJobId());
JobPolling polling = new JobPolling(context, job);
polling.scheduleJobPolling();
jobPollers.put(job.getJobId(), polling);
return true;
}
return false;
}
}