| /** |
| * 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.raid; |
| |
| import java.io.IOException; |
| import java.util.Iterator; |
| import java.util.List; |
| import java.util.LinkedList; |
| import java.util.HashMap; |
| import java.util.Map; |
| |
| import org.apache.commons.logging.Log; |
| import org.apache.commons.logging.LogFactory; |
| import org.apache.hadoop.conf.Configuration; |
| import org.apache.hadoop.util.StringUtils; |
| |
| /** |
| * Periodically monitors the status of jobs registered with it. |
| * |
| * Jobs that are submitted for the same policy name are kept in the same list, |
| * and the list itself is kept in a map that has the policy name as the key and |
| * the list as value. |
| */ |
| class JobMonitor implements Runnable { |
| public static final Log LOG = LogFactory.getLog( |
| "org.apache.hadoop.raid.JobMonitor"); |
| |
| volatile boolean running = true; |
| |
| private Map<String, List<DistRaid>> jobs; |
| private long jobMonitorInterval; |
| private volatile long jobsMonitored = 0; |
| private volatile long jobsSucceeded = 0; |
| |
| public JobMonitor(Configuration conf) { |
| jobMonitorInterval = conf.getLong("raid.jobmonitor.interval", 60000); |
| jobs = new java.util.HashMap<String, List<DistRaid>>(); |
| } |
| |
| public void run() { |
| while (running) { |
| try { |
| LOG.info("JobMonitor thread continuing to run..."); |
| doMonitor(); |
| } catch (Throwable e) { |
| LOG.error("JobMonitor encountered exception " + |
| StringUtils.stringifyException(e)); |
| // All expected exceptions are caught by doMonitor(). It is better |
| // to exit now, this will prevent RaidNode from submitting more jobs |
| // since the number of running jobs will never decrease. |
| return; |
| } |
| } |
| } |
| |
| /** |
| * Periodically checks status of running map-reduce jobs. |
| */ |
| public void doMonitor() { |
| while (running) { |
| String[] keys = null; |
| // Make a copy of the names of the current jobs. |
| synchronized(jobs) { |
| keys = jobs.keySet().toArray(new String[0]); |
| } |
| |
| // Check all the jobs. We do not want to block access to `jobs` |
| // because that will prevent new jobs from being added. |
| // This is safe because JobMonitor.run is the only code that can |
| // remove a job from `jobs`. Thus all elements in `keys` will have |
| // valid values. |
| Map<String, List<DistRaid>> finishedJobs = |
| new HashMap<String, List<DistRaid>>(); |
| |
| for (String key: keys) { |
| // For each policy being monitored, get the list of jobs running. |
| DistRaid[] jobListCopy = null; |
| synchronized(jobs) { |
| List<DistRaid> jobList = jobs.get(key); |
| synchronized(jobList) { |
| jobListCopy = jobList.toArray(new DistRaid[jobList.size()]); |
| } |
| } |
| // The code that actually contacts the JobTracker is not synchronized, |
| // it uses copies of the list of jobs. |
| for (DistRaid job: jobListCopy) { |
| // Check each running job. |
| try { |
| boolean complete = job.checkComplete(); |
| if (complete) { |
| addJob(finishedJobs, key, job); |
| if (job.successful()) { |
| jobsSucceeded++; |
| } |
| } |
| } catch (IOException ioe) { |
| // If there was an error, consider the job finished. |
| addJob(finishedJobs, key, job); |
| } |
| } |
| } |
| |
| if (finishedJobs.size() > 0) { |
| for (String key: finishedJobs.keySet()) { |
| List<DistRaid> finishedJobList = finishedJobs.get(key); |
| // Iterate through finished jobs and remove from jobs. |
| // removeJob takes care of locking. |
| for (DistRaid job: finishedJobList) { |
| removeJob(jobs, key, job); |
| } |
| } |
| } |
| |
| try { |
| Thread.sleep(jobMonitorInterval); |
| } catch (InterruptedException ie) { |
| } |
| } |
| } |
| |
| public int runningJobsCount(String key) { |
| int count = 0; |
| synchronized(jobs) { |
| if (jobs.containsKey(key)) { |
| List<DistRaid> jobList = jobs.get(key); |
| synchronized(jobList) { |
| count = jobList.size(); |
| } |
| } |
| } |
| return count; |
| } |
| |
| public void monitorJob(String key, DistRaid job) { |
| addJob(jobs, key, job); |
| jobsMonitored++; |
| } |
| |
| public long jobsMonitored() { |
| return this.jobsMonitored; |
| } |
| |
| public long jobsSucceeded() { |
| return this.jobsSucceeded; |
| } |
| |
| private static void addJob(Map<String, List<DistRaid>> jobsMap, |
| String jobName, DistRaid job) { |
| synchronized(jobsMap) { |
| List<DistRaid> list = null; |
| if (jobsMap.containsKey(jobName)) { |
| list = jobsMap.get(jobName); |
| } else { |
| list = new LinkedList<DistRaid>(); |
| jobsMap.put(jobName, list); |
| } |
| synchronized(list) { |
| list.add(job); |
| } |
| } |
| } |
| |
| private static void removeJob(Map<String, List<DistRaid>> jobsMap, |
| String jobName, DistRaid job) { |
| synchronized(jobsMap) { |
| if (jobsMap.containsKey(jobName)) { |
| List<DistRaid> list = jobsMap.get(jobName); |
| synchronized(list) { |
| for (Iterator<DistRaid> it = list.iterator(); it.hasNext(); ) { |
| DistRaid val = it.next(); |
| if (val == job) { |
| it.remove(); |
| } |
| } |
| if (list.size() == 0) { |
| jobsMap.remove(jobName); |
| } |
| } |
| } |
| } |
| } |
| } |