/**
* 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.mapred;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.io.Writer;
import java.net.BindException;
import java.net.InetSocketAddress;
import java.net.UnknownHostException;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.Comparator;
import java.util.Date;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;
import java.util.LinkedHashMap;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Properties;
import java.util.Queue;
import java.util.Set;
import java.util.TreeMap;
import java.util.TreeSet;
import java.util.Vector;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.CopyOnWriteArrayList;
import java.util.concurrent.atomic.AtomicInteger;
import javax.management.ObjectName;
import javax.security.auth.login.LoginException;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.conf.Reconfigurable;
import org.apache.hadoop.conf.ReconfigurationServlet;
import org.apache.hadoop.fs.FileStatus;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.LocalDirAllocator;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.fs.permission.FsPermission;
import org.apache.hadoop.http.HttpServer;
import org.apache.hadoop.ipc.ProtocolSignature;
import org.apache.hadoop.ipc.RPC;
import org.apache.hadoop.ipc.RPC.VersionMismatch;
import org.apache.hadoop.ipc.Server;
import org.apache.hadoop.mapred.CleanupQueue.PathDeletionContext;
import org.apache.hadoop.mapred.JobInProgress.KillInterruptedException;
import org.apache.hadoop.mapred.JobStatusChangeEvent.EventType;
import org.apache.hadoop.mapred.TaskTrackerStatus.TaskTrackerHealthStatus;
import org.apache.hadoop.mapreduce.ClusterMetrics;
import org.apache.hadoop.mapreduce.CounterNames;
import org.apache.hadoop.mapreduce.TaskType;
import org.apache.hadoop.mapreduce.server.jobtracker.TaskTracker;
import org.apache.hadoop.metrics.util.MBeanUtil;
import org.apache.hadoop.net.DNSToSwitchMapping;
import org.apache.hadoop.net.NetUtils;
import org.apache.hadoop.net.NetworkTopology;
import org.apache.hadoop.net.Node;
import org.apache.hadoop.net.NodeBase;
import org.apache.hadoop.net.ScriptBasedMapping;
import org.apache.hadoop.security.AccessControlException;
import org.apache.hadoop.security.PermissionChecker;
import org.apache.hadoop.security.SecurityUtil;
import org.apache.hadoop.security.UnixUserGroupInformation;
import org.apache.hadoop.security.UserGroupInformation;
import org.apache.hadoop.security.authorize.AuthorizationException;
import org.apache.hadoop.security.authorize.ConfiguredPolicy;
import org.apache.hadoop.security.authorize.PolicyProvider;
import org.apache.hadoop.security.authorize.RefreshAuthorizationPolicyProtocol;
import org.apache.hadoop.security.authorize.ServiceAuthorizationManager;
import org.apache.hadoop.util.HostsFileReader;
import org.apache.hadoop.util.MRAsyncDiskService;
import org.apache.hadoop.util.ReflectionUtils;
import org.apache.hadoop.util.StringUtils;
import org.apache.hadoop.util.VersionInfo;
/*******************************************************
* JobTracker is the central location for submitting and
* tracking MR jobs in a network environment.
*
*******************************************************/
public class JobTracker extends JobTrackerTraits implements MRConstants,
InterTrackerProtocol,
JobSubmissionProtocol, TaskTrackerManager,
RefreshAuthorizationPolicyProtocol, AdminOperationsProtocol,
JobHistoryObserver {
public static final String DEFAULT_MAPRED_SYSTEM_DIR = "/tmp/hadoop/mapred/system";
public static final String MAPRED_SYSTEM_DIR_KEY = "mapred.system.dir";
public static final String MAPRED_SYSTEM_DIR_CLEAN_KEY = "mapred.system.dir.clean";
static{
Configuration.addDefaultResource("mapred-default.xml");
Configuration.addDefaultResource("mapred-site.xml");
}
static long TASKTRACKER_EXPIRY_INTERVAL = 10 * 60 * 1000;
static long RETIRE_JOB_INTERVAL;
static long RETIRE_JOB_CHECK_INTERVAL;
// The interval after which one fault of a tracker will be discarded,
// if there are no faults during this.
private long UpdateFaultyTrackerInterval;
// The maximum percentage of trackers in cluster added
// to the 'blacklist' across all the jobs.
private final static double MAX_BLACKLIST_PERCENT = 0.50;
// A tracker is blacklisted across jobs only if number of
// blacklists are X% above the average number of blacklists.
// X is the blacklist threshold here.
private double AverageBlacklistThreshold;
// Approximate number of heartbeats that could arrive JobTracker
// in a second
static final String JT_HEARTBEATS_IN_SECOND = "mapred.heartbeats.in.second";
private int NUM_HEARTBEATS_IN_SECOND;
private final int DEFAULT_NUM_HEARTBEATS_IN_SECOND = 100;
private final int MIN_NUM_HEARTBEATS_IN_SECOND = 1;
// Scaling factor for heartbeats, used for testing only
static final String JT_HEARTBEATS_SCALING_FACTOR =
"mapreduce.jobtracker.heartbeats.scaling.factor";
private float HEARTBEATS_SCALING_FACTOR;
private final float MIN_HEARTBEATS_SCALING_FACTOR = 0.01f;
private final float DEFAULT_HEARTBEATS_SCALING_FACTOR = 1.0f;
public static enum State { INITIALIZING, RUNNING }
State state = State.INITIALIZING;
private static final int FS_ACCESS_RETRY_PERIOD = 10000;
private DNSToSwitchMapping dnsToSwitchMapping;
NetworkTopology clusterMap = new NetworkTopology();
private int numTaskCacheLevels; // the max level to which we cache tasks
static Clock clock = null;
static final Clock DEFAULT_CLOCK = new Clock();
/**
* {@link #nodesAtMaxLevel} is using the keySet from {@link ConcurrentHashMap}
* so that it can be safely written to and iterated on via 2 separate threads.
* Note: It can only be iterated from a single thread which is feasible since
* the only iteration is done in {@link JobInProgress} under the
* {@link JobTracker} lock.
*/
private Set<Node> nodesAtMaxLevel =
Collections.newSetFromMap(new ConcurrentHashMap<Node, Boolean>());
final TaskScheduler taskScheduler;
private final ResourceReporter resourceReporter;
private final List<JobInProgressListener> jobInProgressListeners =
new CopyOnWriteArrayList<JobInProgressListener>();
private static final LocalDirAllocator lDirAlloc =
new LocalDirAllocator("mapred.local.dir");
// system directories are world-wide readable and owner readable
final static FsPermission SYSTEM_DIR_PERMISSION =
FsPermission.createImmutable((short) 0733); // rwx-wx-wx
// system files should have 700 permission
final static FsPermission SYSTEM_FILE_PERMISSION =
FsPermission.createImmutable((short) 0700); // rwx------
private MRAsyncDiskService asyncDiskService;
// set before starting JobTracker shutdown
private volatile boolean shutdown = false;
/**
* The maximum no. of 'completed' (successful/failed/killed)
* jobs kept in memory per-user.
*/
final int MAX_COMPLETE_USER_JOBS_IN_MEMORY;
/**
* The minimum time (in ms) that a job's information has to remain
* in the JobTracker's memory before it is retired.
*/
static int MIN_TIME_BEFORE_RETIRE = 0;
/**
* If this is set, then the next iteration of RetireJob thread will
* retire most completed jobs
*/
static volatile boolean RETIRE_COMPLETED_JOBS = false;
private final AtomicInteger nextJobId = new AtomicInteger(1);
public static final Log LOG = LogFactory.getLog(JobTracker.class);
private final TaskErrorCollector taskErrorCollector;
/**
* Returns JobTracker's clock. Note that the correct clock implementation will
* be obtained only when the JobTracker is initialized. If the JobTracker is
* not initialized then the default clock i.e {@link Clock} is returned.
*/
static Clock getClock() {
return clock == null ? DEFAULT_CLOCK : clock;
}
/**
* Start the JobTracker with given configuration.
*
* The conf will be modified to reflect the actual ports on which
* the JobTracker is up and running if the user passes the port as
* <code>zero</code>.
*
* @param conf configuration for the JobTracker.
* @throws IOException
*/
public static JobTracker startTracker(JobConf conf
) throws IOException,
InterruptedException {
return startTracker(conf, generateNewIdentifier());
}
public static JobTracker startTracker(JobConf conf, String identifier)
throws IOException, InterruptedException {
JobTracker result = null;
while (true) {
try {
result = new JobTracker(conf, identifier);
result.taskScheduler.setTaskTrackerManager(result);
break;
} catch (VersionMismatch e) {
throw e;
} catch (BindException e) {
throw e;
} catch (UnknownHostException e) {
throw e;
} catch (AccessControlException ace) {
// in case of jobtracker not having right access
// bail out
throw ace;
} catch (IOException e) {
LOG.warn("Error starting tracker: " +
StringUtils.stringifyException(e));
}
Thread.sleep(1000);
}
if (result != null) {
JobEndNotifier.startNotifier();
}
return result;
}
public void stopTracker() throws IOException {
JobEndNotifier.stopNotifier();
close();
}
public long getProtocolVersion(String protocol,
long clientVersion) throws IOException {
if (protocol.equals(InterTrackerProtocol.class.getName())) {
return InterTrackerProtocol.versionID;
} else if (protocol.equals(JobSubmissionProtocol.class.getName())){
return JobSubmissionProtocol.versionID;
} else if (protocol.equals(RefreshAuthorizationPolicyProtocol.class.getName())){
return RefreshAuthorizationPolicyProtocol.versionID;
} else if (protocol.equals(AdminOperationsProtocol.class.getName())){
return AdminOperationsProtocol.versionID;
} else {
throw new IOException("Unknown protocol to job tracker: " + protocol);
}
}
public ProtocolSignature getProtocolSignature(String protocol,
long clientVersion, int clientMethodsHash) throws IOException {
return ProtocolSignature.getProtocolSignature(
this, protocol, clientVersion, clientMethodsHash);
}
/**
* A thread to update information for all Jobs
*/
private class JobUpdater implements Runnable {
public void run() {
long iter = 0;
while (!shutdown) {
iter++;
if (iter % 60 == 0) {
// Every 60 iterations.
CounterNames.clearIfNecessary(
jobTrackerReconfigurable.getMaxUniqueCounterNames());
}
try {
// Check every second if jobs speculation stats need update
Thread.sleep(1000L);
List<JobInProgress> cachedJobs = new ArrayList<JobInProgress> ();
long startTime = JobTracker.getClock().getTime();
// get a snapshot of all the jobs in the system
synchronized (jobs) {
cachedJobs.addAll(jobs.values());
}
for (JobInProgress job: cachedJobs) {
job.refreshIfNecessary();
}
long runTime = JobTracker.getClock().getTime() - startTime;
LOG.info("JobUpdater updated. runtime:" + runTime);
} catch (InterruptedException ie) {
// ignore. if shutting down, while cond. will catch it
} catch (Exception e) {
LOG.error("JobUpdater Thread got exception: " +
StringUtils.stringifyException(e));
}
}
}
}
/**
* A thread to timeout tasks that have been assigned to task trackers,
* but that haven't reported back yet.
* Note that I included a stop() method, even though there is no place
* where JobTrackers are cleaned up.
*/
private class ExpireLaunchingTasks implements Runnable {
/**
* This is a map of the tasks that have been assigned to task trackers,
* but that have not yet been seen in a status report.
* map: task-id -> time-assigned
*/
private Map<TaskAttemptID, Long> launchingTasks =
new LinkedHashMap<TaskAttemptID, Long>();
public void run() {
while (!shutdown) {
try {
// Every 3 minutes check for any tasks that are overdue
Thread.sleep(TASKTRACKER_EXPIRY_INTERVAL/3);
long now = getClock().getTime();
LOG.debug("Starting launching task sweep");
synchronized (JobTracker.this) {
synchronized (launchingTasks) {
Iterator<Map.Entry<TaskAttemptID, Long>> itr =
launchingTasks.entrySet().iterator();
while (itr.hasNext()) {
Map.Entry<TaskAttemptID, Long> pair = itr.next();
TaskAttemptID taskId = pair.getKey();
long age = now - (pair.getValue()).longValue();
LOG.info(taskId + " is " + age + " ms debug.");
if (age > TASKTRACKER_EXPIRY_INTERVAL) {
LOG.info("Launching task " + taskId + " timed out.");
TaskInProgress tip = null;
tip = taskidToTIPMap.get(taskId);
if (tip != null) {
JobInProgress job = (JobInProgress) tip.getJob();
String trackerName = getAssignedTracker(taskId);
TaskTrackerStatus trackerStatus =
getTaskTrackerStatus(trackerName);
// This might happen when the tasktracker has already
// expired and this thread tries to call failedtask
// again. expire tasktracker should have called failed
// task!
if (trackerStatus != null)
job.failedTask(tip, taskId, "Error launching task",
tip.isMapTask()? TaskStatus.Phase.MAP:
TaskStatus.Phase.STARTING,
TaskStatus.State.FAILED,
trackerName);
}
itr.remove();
} else {
// the tasks are sorted by start time, so once we find
// one that we want to keep, we are done for this cycle.
break;
}
}
}
}
} catch (InterruptedException ie) {
// ignore. if shutting down, while cond. will catch it
} catch (Exception e) {
LOG.error("Expire Launching Task Thread got exception: " +
StringUtils.stringifyException(e));
}
}
}
public void addNewTask(TaskAttemptID taskName) {
synchronized (launchingTasks) {
launchingTasks.put(taskName,
getClock().getTime());
}
}
public void removeTask(TaskAttemptID taskName) {
synchronized (launchingTasks) {
launchingTasks.remove(taskName);
}
}
}
///////////////////////////////////////////////////////
// Used to expire TaskTrackers that have gone down
///////////////////////////////////////////////////////
class ExpireTrackers implements Runnable {
public ExpireTrackers() {
}
/**
* The run method lives for the life of the JobTracker, and removes TaskTrackers
* that have not checked in for some time.
*/
public void run() {
while (!shutdown) {
try {
//
// Thread runs periodically to check whether trackers should be expired.
// The sleep interval must be no more than half the maximum expiry time
// for a task tracker.
//
Thread.sleep(TASKTRACKER_EXPIRY_INTERVAL / 3);
//
// Loop through all expired items in the queue
//
// Need to lock the JobTracker here since we are
// manipulating it's data-structures via
// ExpireTrackers.run -> JobTracker.lostTaskTracker ->
// JobInProgress.failedTask -> JobTracker.markCompleteTaskAttempt
// Also need to lock JobTracker before locking 'taskTracker' &
// 'trackerExpiryQueue' to prevent deadlock:
// @see {@link JobTracker.processHeartbeat(TaskTrackerStatus, boolean)}
synchronized (JobTracker.this) {
synchronized (taskTrackers) {
synchronized (trackerExpiryQueue) {
long now = getClock().getTime();
TaskTrackerStatus leastRecent = null;
while ((trackerExpiryQueue.size() > 0) &&
(leastRecent = trackerExpiryQueue.first()) != null &&
((now - leastRecent.getLastSeen()) > TASKTRACKER_EXPIRY_INTERVAL)) {
// Remove profile from head of queue
trackerExpiryQueue.remove(leastRecent);
String trackerName = leastRecent.getTrackerName();
// Figure out if last-seen time should be updated, or if tracker is dead
TaskTracker current = getTaskTracker(trackerName);
TaskTrackerStatus newProfile =
(current == null ) ? null : current.getStatus();
// Items might leave the taskTracker set through other means; the
// status stored in 'taskTrackers' might be null, which means the
// tracker has already been destroyed.
if (newProfile != null) {
if ((now - newProfile.getLastSeen()) > TASKTRACKER_EXPIRY_INTERVAL) {
removeTracker(current);
// remove the mapping from the hosts list
String hostname = newProfile.getHost();
hostnameToTaskTracker.get(hostname).remove(trackerName);
} else {
// Update time by inserting latest profile
trackerExpiryQueue.add(newProfile);
}
}
}
}
}
}
} catch (InterruptedException iex) {
// ignore. if shutting down, while cond. will catch it
} catch (Exception t) {
LOG.error("Tracker Expiry Thread got exception: " +
StringUtils.stringifyException(t));
}
}
}
}
@Override
public synchronized void historyFileCopied(JobID jobid, String historyFile) {
JobInProgress job = getJob(jobid);
if (job != null) { //found in main cache
job.setHistoryFileCopied();
if (historyFile != null) {
job.setHistoryFile(historyFile);
}
return;
}
RetireJobInfo jobInfo = retireJobs.get(jobid);
if (jobInfo != null) { //found in retired cache
if (historyFile != null) {
jobInfo.setHistoryFile(historyFile);
}
}
}
/**
* An Attempt and it's corresponding TaskInProgress
* There is a unique TIP per Attempt. Hence the attempt
* can be used as the unique key to identify this tuple
* (in a Collection for example)
*/
public static final class TaskAttemptIDWithTip
implements Comparable<TaskAttemptIDWithTip> {
public final TaskAttemptID attemptId;
public final TaskInProgress tip;
public TaskAttemptIDWithTip(TaskAttemptID attemptId, TaskInProgress tip) {
this.attemptId = attemptId;
this.tip = tip;
}
public boolean equals(Object o) {
TaskAttemptIDWithTip that = (TaskAttemptIDWithTip)o;
return this.attemptId.equals(that.attemptId);
}
public int hashCode() {
return attemptId.hashCode();
}
public int compareTo(TaskAttemptIDWithTip that) {
return this.attemptId.compareTo(that.attemptId);
}
}
static class RetireJobInfo {
final JobStatus status;
final JobProfile profile;
final long finishTime;
private String historyFile;
RetireJobInfo(JobStatus status, JobProfile profile, long finishTime,
String historyFile) {
this.status = status;
this.profile = profile;
this.finishTime = finishTime;
this.historyFile = historyFile;
}
void setHistoryFile(String file) {
this.historyFile = file;
}
String getHistoryFile() {
return historyFile;
}
}
///////////////////////////////////////////////////////
// Used to remove old finished Jobs that have been around for too long
///////////////////////////////////////////////////////
class RetireJobs implements Runnable {
private final Map<JobID, RetireJobInfo> jobIDStatusMap =
new HashMap<JobID, RetireJobInfo>();
private final LinkedList<RetireJobInfo> jobRetireInfoQ =
new LinkedList<RetireJobInfo>();
public RetireJobs() {
}
synchronized void addToCache(JobInProgress job) {
RetireJobInfo info = new RetireJobInfo(job.getStatus(),
job.getProfile(), job.getFinishTime(), job.getHistoryFile());
jobRetireInfoQ.add(info);
jobIDStatusMap.put(info.status.getJobID(), info);
if (jobRetireInfoQ.size() > retiredJobsCacheSize) {
RetireJobInfo removed = jobRetireInfoQ.remove();
jobIDStatusMap.remove(removed.status.getJobID());
LOG.info("Retired job removed from cache " + removed.status.getJobID());
}
}
synchronized RetireJobInfo get(JobID jobId) {
return jobIDStatusMap.get(jobId);
}
@SuppressWarnings("unchecked")
synchronized LinkedList<RetireJobInfo> getAll() {
return (LinkedList<RetireJobInfo>) jobRetireInfoQ.clone();
}
synchronized LinkedList<JobStatus> getAllJobStatus() {
LinkedList<JobStatus> list = new LinkedList<JobStatus>();
for (RetireJobInfo info : jobRetireInfoQ) {
list.add(info.status);
}
return list;
}
private boolean minConditionToRetire(JobInProgress job, long now) {
return job.getStatus().getRunState() != JobStatus.RUNNING &&
job.getStatus().getRunState() != JobStatus.PREP &&
(job.getFinishTime() + MIN_TIME_BEFORE_RETIRE < now) &&
(job.isHistoryFileCopied() || JobHistory.isDisableHistory());
}
/**
* The run method lives for the life of the JobTracker,
* and removes Jobs that are not still running, but which
* finished a long time ago.
*/
public void run() {
while (!shutdown) {
try {
Thread.sleep(RETIRE_JOB_CHECK_INTERVAL);
List<JobInProgress> retiredJobs = new ArrayList<JobInProgress>();
long now = getClock().getTime();
long retireBefore = now - RETIRE_JOB_INTERVAL;
synchronized (jobs) {
for(JobInProgress job: jobs.values()) {
if (minConditionToRetire(job, now) &&
(RETIRE_COMPLETED_JOBS || (job.getFinishTime() < retireBefore))) {
retiredJobs.add(job);
}
}
RETIRE_COMPLETED_JOBS = false; // all completed jobs are now almost retired.
}
synchronized (userToJobsMap) {
Iterator<Map.Entry<String, ArrayList<JobInProgress>>>
userToJobsMapIt = userToJobsMap.entrySet().iterator();
while (userToJobsMapIt.hasNext()) {
Map.Entry<String, ArrayList<JobInProgress>> entry =
userToJobsMapIt.next();
ArrayList<JobInProgress> userJobs = entry.getValue();
Iterator<JobInProgress> it = userJobs.iterator();
while (it.hasNext() &&
userJobs.size() > MAX_COMPLETE_USER_JOBS_IN_MEMORY) {
JobInProgress jobUser = it.next();
if (retiredJobs.contains(jobUser)) {
LOG.info("Removing from userToJobsMap: " +
jobUser.getJobID());
it.remove();
} else if (minConditionToRetire(jobUser, now)) {
LOG.info("User limit exceeded. Marking job: " +
jobUser.getJobID() + " for retire.");
retiredJobs.add(jobUser);
it.remove();
}
}
if (userJobs.isEmpty()) {
userToJobsMapIt.remove();
}
}
}
if (!retiredJobs.isEmpty()) {
List<JobID> toBeDeleted = new ArrayList<JobID>();
synchronized (JobTracker.this) {
synchronized (jobs) {
synchronized (taskScheduler) {
for (JobInProgress job: retiredJobs) {
removeJobTasks(job);
jobs.remove(job.getProfile().getJobID());
for (JobInProgressListener l : jobInProgressListeners) {
l.jobRemoved(job);
}
String jobUser = job.getProfile().getUser();
LOG.info("Retired job with id: '" +
job.getProfile().getJobID() + "' of user '" +
jobUser + "'");
toBeDeleted.add(job.getProfile().getJobID());
addToCache(job);
}
}
}
}
for (JobID id : toBeDeleted) {
// clean up job files from the local disk
JobHistory.JobInfo.cleanupJob(id);
}
}
} catch (InterruptedException t) {
// ignore. if shutting down, while cond. will catch it
} catch (Throwable t) {
LOG.error("Error in retiring job:\n" +
StringUtils.stringifyException(t));
}
}
}
}
enum ReasonForBlackListing {
EXCEEDING_FAILURES,
NODE_UNHEALTHY
}
// The FaultInfo which indicates the number of faults of a tracker
// and when the last fault occurred
// and whether the tracker is blacklisted across all jobs or not
protected static class FaultInfo {
static final String FAULT_FORMAT_STRING = "%d failures on the tracker";
private Queue<JobFault> jobFaults;
long lastUpdated;
boolean blacklisted;
private boolean isHealthy;
private HashMap<ReasonForBlackListing, String>rfbMap;
FaultInfo() {
jobFaults = new LinkedList<JobFault>();
lastUpdated = getClock().getTime();
blacklisted = false;
rfbMap = new HashMap<ReasonForBlackListing, String>();
}
void addFault(JobFault jf) {
jobFaults.add(jf);
}
JobFault forgiveOneFault() {
return jobFaults.poll();
}
JobFault[] getFaults() {
return jobFaults.toArray(new JobFault[0]);
}
void setLastUpdated(long timeStamp) {
lastUpdated = timeStamp;
}
int getFaultCount() {
return jobFaults.size();
}
long getLastUpdated() {
return lastUpdated;
}
boolean isBlacklisted() {
return blacklisted;
}
void setBlacklist(ReasonForBlackListing rfb,
String trackerFaultReport) {
blacklisted = true;
this.rfbMap.put(rfb, trackerFaultReport);
}
public void setHealthy(boolean isHealthy) {
this.isHealthy = isHealthy;
}
public boolean isHealthy() {
return isHealthy;
}
public String getTrackerFaultReport() {
StringBuffer sb = new StringBuffer();
for(String reasons : rfbMap.values()) {
sb.append(reasons);
sb.append("\n");
}
return sb.toString();
}
Set<ReasonForBlackListing> getReasonforblacklisting() {
return this.rfbMap.keySet();
}
public void unBlacklist() {
this.blacklisted = false;
this.rfbMap.clear();
}
public boolean removeBlackListedReason(ReasonForBlackListing rfb) {
String str = rfbMap.remove(rfb);
return str!=null;
}
public void addBlackListedReason(ReasonForBlackListing rfb, String reason) {
this.rfbMap.put(rfb, reason);
}
}
public static class JobFault {
final String tasktracker;
final String job;
final String[] taskExceptions;
JobFault (String tt, String job, String[] exs) {
this.tasktracker = tt;
this.job = job;
this.taskExceptions = exs.clone();
}
}
protected class FaultyTrackersInfo {
// A map from hostName to its faults
private Map<String, FaultInfo> potentiallyFaultyTrackers =
new HashMap<String, FaultInfo>();
// This count gives the number of blacklisted trackers in the cluster
// at any time. This is maintained to avoid iteration over
// the potentiallyFaultyTrackers to get blacklisted trackers. And also
// this count doesn't include blacklisted trackers which are lost,
// although the fault info is maintained for lost trackers.
private volatile int numBlacklistedTrackers = 0;
/**
* Increments faults(blacklist by job) for the tracker by one.
*
* Adds the tracker to the potentially faulty list.
* Assumes JobTracker is locked on the entry.
*
* @param hostName
*/
void incrementFaults(String hostName, JobFault jf) {
synchronized (potentiallyFaultyTrackers) {
FaultInfo fi = getFaultInfo(hostName, true);
fi.addFault(jf);
fi.setLastUpdated(getClock().getTime());
if (exceedsFaults(fi)) {
LOG.info("Adding " + hostName + " to the blacklist"
+ " across all jobs");
String reason = String.format(FaultInfo.FAULT_FORMAT_STRING,
fi.getFaultCount());
blackListTracker(hostName, reason,
ReasonForBlackListing.EXCEEDING_FAILURES);
}
}
}
private void incrBlackListedTrackers(int count) {
numBlacklistedTrackers += count;
getInstrumentation().addBlackListedTrackers(count);
}
private void decrBlackListedTrackers(int count) {
numBlacklistedTrackers -= count;
getInstrumentation().decBlackListedTrackers(count);
}
private void blackListTracker(String hostName, String reason, ReasonForBlackListing rfb) {
FaultInfo fi = getFaultInfo(hostName, true);
boolean blackListed = fi.isBlacklisted();
if(blackListed) {
if (LOG.isDebugEnabled()) {
LOG.debug("Adding blacklisted reason for tracker : " + hostName
+ " Reason for blacklisting is : " + rfb);
}
if (!fi.getReasonforblacklisting().contains(rfb)) {
LOG.info("Adding blacklisted reason for tracker : " + hostName
+ " Reason for blacklisting is : " + rfb);
}
fi.addBlackListedReason(rfb, reason);
} else {
LOG.info("Blacklisting tracker : " + hostName
+ " Reason for blacklisting is : " + rfb);
Set<TaskTracker> trackers =
hostnameToTaskTracker.get(hostName);
synchronized (trackers) {
for (TaskTracker tracker : trackers) {
tracker.cancelAllReservations();
}
}
removeHostCapacity(hostName);
fi.setBlacklist(rfb, reason);
}
}
private boolean canUnBlackListTracker(String hostName,
ReasonForBlackListing rfb) {
FaultInfo fi = getFaultInfo(hostName, false);
if(fi == null) {
return false;
}
Set<ReasonForBlackListing> rfbSet = fi.getReasonforblacklisting();
return fi.isBlacklisted() && rfbSet.contains(rfb);
}
private void unBlackListTracker(String hostName,
ReasonForBlackListing rfb) {
// check if you can black list the tracker then call this methods
FaultInfo fi = getFaultInfo(hostName, false);
if(fi.removeBlackListedReason(rfb)) {
if(fi.getReasonforblacklisting().isEmpty()) {
addHostCapacity(hostName);
LOG.info("Unblacklisting tracker : " + hostName);
fi.unBlacklist();
//We have unBlackListed tracker, so tracker should
//definitely be healthy. Check fault count if fault count
//is zero don't keep it memory.
if(fi.getFaultCount() == 0) {
potentiallyFaultyTrackers.remove(hostName);
}
}
}
}
// Assumes JobTracker is locked on the entry
protected FaultInfo getFaultInfo(String hostName,
boolean createIfNeccessary) {
FaultInfo fi = null;
synchronized (potentiallyFaultyTrackers) {
fi = potentiallyFaultyTrackers.get(hostName);
if (fi == null && createIfNeccessary) {
fi = new FaultInfo();
potentiallyFaultyTrackers.put(hostName, fi);
}
}
return fi;
}
/**
* Blacklists the tracker across all jobs if
* <ol>
* <li>#faults are more than
* MaxBlacklistsPerTracker (configurable) blacklists</li>
* <li>#faults is 50% (configurable) above the average #faults</li>
* <li>50% the cluster is not blacklisted yet </li>
* </ol>
*/
private boolean exceedsFaults(FaultInfo fi) {
int faultCount = fi.getFaultCount();
if (faultCount >= jobTrackerReconfigurable.getMaxBlacklistsPerTracker()) {
// calculate avgBlackLists
long clusterSize = getClusterStatus().getTaskTrackers();
long sum = 0;
for (FaultInfo f : potentiallyFaultyTrackers.values()) {
sum += f.getFaultCount();
}
double avg = (double) sum / clusterSize;
long totalCluster = clusterSize + numBlacklistedTrackers;
if ((faultCount - avg) > (AverageBlacklistThreshold * avg) &&
numBlacklistedTrackers < (totalCluster * MAX_BLACKLIST_PERCENT)) {
return true;
}
}
return false;
}
/**
* Removes the tracker from blacklist and
* from potentially faulty list, when it is restarted.
*
* Assumes JobTracker is locked on the entry.
*
* @param hostName
*/
void markTrackerHealthy(String hostName) {
synchronized (potentiallyFaultyTrackers) {
FaultInfo fi = potentiallyFaultyTrackers.remove(hostName);
if (fi != null && fi.isBlacklisted()) {
LOG.info("Removing " + hostName + " from blacklist");
addHostCapacity(hostName);
}
}
}
/**
* Check whether tasks can be assigned to the tracker.
*
* One fault of the tracker is discarded if there
* are no faults during one day. So, the tracker will get a
* chance again to run tasks of a job.
* Assumes JobTracker is locked on the entry.
*
* @param hostName The tracker name
* @param now The current time
*
* @return true if the tracker is blacklisted
* false otherwise
*/
boolean shouldAssignTasksToTracker(String hostName, long now) {
synchronized (potentiallyFaultyTrackers) {
FaultInfo fi = potentiallyFaultyTrackers.get(hostName);
if (fi != null &&
(now - fi.getLastUpdated()) > UpdateFaultyTrackerInterval) {
fi.forgiveOneFault();
fi.setLastUpdated(now);
if (canUnBlackListTracker(hostName,
ReasonForBlackListing.EXCEEDING_FAILURES)) {
unBlackListTracker(hostName,
ReasonForBlackListing.EXCEEDING_FAILURES);
}
}
return (fi != null && fi.isBlacklisted());
}
}
private void removeHostCapacity(String hostName) {
synchronized (taskTrackers) {
// remove the capacity of trackers on this host
int numTrackersOnHost = 0;
for (TaskTrackerStatus status : getStatusesOnHost(hostName)) {
updateTotalTaskCapacity(status);
removeTaskTrackerCapacity(status);
int mapSlots = taskScheduler.getMaxSlots(status, TaskType.MAP);
int reduceSlots = taskScheduler.getMaxSlots(status, TaskType.REDUCE);
++numTrackersOnHost;
getInstrumentation().addBlackListedMapSlots(
mapSlots);
getInstrumentation().addBlackListedReduceSlots(
reduceSlots);
}
uniqueHostsMap.remove(hostName);
incrBlackListedTrackers(numTrackersOnHost);
}
}
// This is called on tracker's restart or after a day of blacklist.
private void addHostCapacity(String hostName) {
synchronized (taskTrackers) {
int numTrackersOnHost = 0;
// add the capacity of trackers on the host
for (TaskTrackerStatus status : getStatusesOnHost(hostName)) {
updateTotalTaskCapacity(status);
int mapSlots = taskScheduler.getMaxSlots(status, TaskType.MAP);
int reduceSlots = taskScheduler.getMaxSlots(status, TaskType.REDUCE);
numTrackersOnHost++;
getInstrumentation().decBlackListedMapSlots(mapSlots);
getInstrumentation().decBlackListedReduceSlots(reduceSlots);
}
uniqueHostsMap.put(hostName,
numTrackersOnHost);
decrBlackListedTrackers(numTrackersOnHost);
}
}
/**
* Whether a host is blacklisted across all the jobs.
*
* Assumes JobTracker is locked on the entry.
* @param hostName
* @return
*/
boolean isBlacklisted(String hostName) {
synchronized (potentiallyFaultyTrackers) {
FaultInfo fi = null;
if ((fi = potentiallyFaultyTrackers.get(hostName)) != null) {
return fi.isBlacklisted();
}
}
return false;
}
// Assumes JobTracker is locked on the entry.
int getFaultCount(String hostName) {
synchronized (potentiallyFaultyTrackers) {
FaultInfo fi = null;
if ((fi = potentiallyFaultyTrackers.get(hostName)) != null) {
return fi.getFaultCount();
}
}
return 0;
}
// Assumes JobTracker is locked on the entry.
Set<ReasonForBlackListing> getReasonForBlackListing(String hostName) {
synchronized (potentiallyFaultyTrackers) {
FaultInfo fi = null;
if ((fi = potentiallyFaultyTrackers.get(hostName)) != null) {
return fi.getReasonforblacklisting();
}
}
return null;
}
// Assumes JobTracker is locked on the entry.
void setNodeHealthStatus(String hostName, boolean isHealthy, String reason) {
FaultInfo fi = null;
// If tracker is not healthy, create a fault info object
// blacklist it.
if (!isHealthy) {
fi = getFaultInfo(hostName, true);
fi.setHealthy(isHealthy);
synchronized (potentiallyFaultyTrackers) {
blackListTracker(hostName, reason,
ReasonForBlackListing.NODE_UNHEALTHY);
}
} else {
fi = getFaultInfo(hostName, false);
if (fi == null) {
return;
} else {
if (canUnBlackListTracker(hostName,
ReasonForBlackListing.NODE_UNHEALTHY)) {
unBlackListTracker(hostName, ReasonForBlackListing.NODE_UNHEALTHY);
}
}
}
}
}
/**
* Get all task tracker statuses on given host
*
* Assumes JobTracker is locked on the entry
* @param hostName
* @return {@link java.util.List} of {@link TaskTrackerStatus}
*/
private List<TaskTrackerStatus> getStatusesOnHost(String hostName) {
List<TaskTrackerStatus> statuses = new ArrayList<TaskTrackerStatus>();
synchronized (taskTrackers) {
for (TaskTracker tt : taskTrackers.values()) {
TaskTrackerStatus status = tt.getStatus();
if (hostName.equals(status.getHost())) {
statuses.add(status);
}
}
}
return statuses;
}
private final JobTrackerInstrumentation myInstrumentation;
private ObjectName versionBeanName;
/////////////////////////////////////////////////////////////////
// The real JobTracker
////////////////////////////////////////////////////////////////
int port;
String localMachine;
private String trackerIdentifier;
long startTime;
int totalSubmissions = 0;
private int totalMapTaskCapacity;
private int totalReduceTaskCapacity;
// Remember the last number of slots for updating total map and reduce
// capacity
private Map<String, Integer> trackerNameToMapSlots =
new HashMap<String, Integer>();
private Map<String, Integer> trackerNameToReduceSlots =
new HashMap<String, Integer>();
private HostsFileReader hostsReader;
//
// Properties to maintain while running Jobs and Tasks:
//
// 1. Each Task is always contained in a single Job. A Job succeeds when all its
// Tasks are complete.
//
// 2. Every running or successful Task is assigned to a Tracker. Idle Tasks are not.
//
// 3. When a Tracker fails, all of its assigned Tasks are marked as failures.
//
// 4. A Task might need to be reexecuted if it (or the machine it's hosted on) fails
// before the Job is 100% complete. Sometimes an upstream Task can fail without
// reexecution if all downstream Tasks that require its output have already obtained
// the necessary files.
//
// All the known jobs. (jobid->JobInProgress)
Map<JobID, JobInProgress> jobs =
Collections.synchronizedMap(new TreeMap<JobID, JobInProgress>());
// (user -> list of JobInProgress)
TreeMap<String, ArrayList<JobInProgress>> userToJobsMap =
new TreeMap<String, ArrayList<JobInProgress>>();
// (trackerID --> list of jobs to cleanup)
Map<String, Set<JobID>> trackerToJobsToCleanup =
new HashMap<String, Set<JobID>>();
// (trackerID --> list of tasks to cleanup)
Map<String, Set<TaskAttemptID>> trackerToTasksToCleanup =
new HashMap<String, Set<TaskAttemptID>>();
// All the known TaskInProgress items, mapped to by taskids (taskid->TIP)
Map<TaskAttemptID, TaskInProgress> taskidToTIPMap =
new TreeMap<TaskAttemptID, TaskInProgress>();
// This is used to keep track of all trackers running on one host. While
// decommissioning the host, all the trackers on the host will be lost.
Map<String, Set<TaskTracker>> hostnameToTaskTracker =
Collections.synchronizedMap(new TreeMap<String, Set<TaskTracker>>());
// (taskid --> trackerID)
TreeMap<TaskAttemptID, String> taskidToTrackerMap = new TreeMap<TaskAttemptID, String>();
// (trackerID->TreeSet of taskids running at that tracker)
HashMap<String, Set<TaskAttemptIDWithTip>> trackerToTaskMap =
new HashMap<String, Set<TaskAttemptIDWithTip>>();
// (trackerID -> TreeSet of completed taskids running at that tracker)
TreeMap<String, Set<TaskAttemptID>> trackerToMarkedTasksMap =
new TreeMap<String, Set<TaskAttemptID>>();
// (trackerID --> last sent HeartBeatResponse)
Map<String, HeartbeatResponse> trackerToHeartbeatResponseMap =
new TreeMap<String, HeartbeatResponse>();
// (hostname --> Node (NetworkTopology))
Map<String, Node> hostnameToNodeMap =
Collections.synchronizedMap(new TreeMap<String, Node>());
// job-id->username during staging
Map<JobID, String> jobToUserMap =
Collections.synchronizedMap(new TreeMap<JobID, String>());
// Number of resolved entries
int numResolved;
protected FaultyTrackersInfo faultyTrackers = new FaultyTrackersInfo();
private JobTrackerStatistics statistics =
new JobTrackerStatistics();
//
// Watch and expire TaskTracker objects using these structures.
// We can map from Name->TaskTrackerStatus, or we can expire by time.
//
int totalMaps = 0;
int totalReduces = 0;
private int occupiedMapSlots = 0;
private int occupiedReduceSlots = 0;
private int reservedMapSlots = 0;
private int reservedReduceSlots = 0;
private HashMap<String, TaskTracker> taskTrackers =
new HashMap<String, TaskTracker>();
Map<String,Integer>uniqueHostsMap = new ConcurrentHashMap<String, Integer>();
ExpireTrackers expireTrackers = new ExpireTrackers();
Thread expireTrackersThread = null;
RetireJobs retireJobs = new RetireJobs();
Thread retireJobsThread = null;
final int retiredJobsCacheSize;
ExpireLaunchingTasks expireLaunchingTasks = new ExpireLaunchingTasks();
JobUpdater jobUpdater = new JobUpdater();
Thread expireLaunchingTaskThread = new Thread(expireLaunchingTasks,
"expireLaunchingTasks");
Thread jobUpdaterThread = new Thread(jobUpdater, "jobUpdater");
CompletedJobStatusStore completedJobStatusStore = null;
Thread completedJobsStoreThread = null;
/**
* It might seem like a bug to maintain a TreeSet of tasktracker objects,
* which can be updated at any time. But that's not what happens! We
* only update status objects in the taskTrackers table. Status objects
* are never updated once they enter the expiry queue. Instead, we wait
* for them to expire and remove them from the expiry queue. If a status
* object has been updated in the taskTracker table, the latest status is
* reinserted. Otherwise, we assume the tracker has expired.
*/
TreeSet<TaskTrackerStatus> trackerExpiryQueue =
new TreeSet<TaskTrackerStatus>(
new Comparator<TaskTrackerStatus>() {
public int compare(TaskTrackerStatus p1, TaskTrackerStatus p2) {
if (p1.getLastSeen() < p2.getLastSeen()) {
return -1;
} else if (p1.getLastSeen() > p2.getLastSeen()) {
return 1;
} else {
return (p1.getTrackerName().compareTo(p2.getTrackerName()));
}
}
}
);
// Used to provide an HTML view on Job, Task, and TaskTracker structures
final HttpServer infoServer;
int infoPort;
Server interTrackerServer;
// Some jobs are stored in a local system directory. We can delete
// the files when we're done with the job.
public static final String SUBDIR = "jobTracker";
FileSystem fs = null;
Path systemDir = null;
JobConf conf;
private JobTrackerReconfigurable jobTrackerReconfigurable;
private final UserGroupInformation mrOwner;
private final String supergroup;
long limitMaxMemForMapTasks;
long limitMaxMemForReduceTasks;
long memSizeForMapSlotOnJT;
long memSizeForReduceSlotOnJT;
private QueueManager queueManager;
/**
* Start the JobTracker process, listen on the indicated port
*/
JobTracker(JobConf conf) throws IOException, InterruptedException {
this(conf, generateNewIdentifier());
}
/**
* Start the JobTracker process, listen on the indicated port
*/
JobTracker(JobConf conf, Clock clock)
throws IOException, InterruptedException {
this(conf, generateNewIdentifier());
JobTracker.clock = clock;
}
JobTracker(JobConf conf, String identifier)
throws IOException, InterruptedException {
// find the owner of the process
if (conf.getBoolean("hadoop.disable.shell",false)){
conf.setStrings(UnixUserGroupInformation.UGI_PROPERTY_NAME, new String[]{"hadoop", "hadoop"});
}
try {
mrOwner = UnixUserGroupInformation.login(conf);
} catch (LoginException e) {
throw new IOException(StringUtils.stringifyException(e));
}
supergroup = conf.get("mapred.permissions.supergroup", "supergroup");
LOG.info("Starting jobtracker with owner as " + mrOwner.getUserName()
+ " and supergroup as " + supergroup);
//
// Grab some static constants
//
TASKTRACKER_EXPIRY_INTERVAL =
conf.getLong("mapred.tasktracker.expiry.interval", 10 * 60 * 1000);
RETIRE_JOB_INTERVAL = conf.getLong("mapred.jobtracker.retirejob.interval", 24 * 60 * 60 * 1000);
RETIRE_JOB_CHECK_INTERVAL = conf.getLong("mapred.jobtracker.retirejob.check", 60 * 1000);
retiredJobsCacheSize =
conf.getInt("mapred.job.tracker.retiredjobs.cache.size", 1000);
MAX_COMPLETE_USER_JOBS_IN_MEMORY = conf.getInt("mapred.jobtracker.completeuserjobs.maximum", 100);
MIN_TIME_BEFORE_RETIRE = conf.getInt("mapred.jobtracker.mintime.before.retirejob", 0);
UpdateFaultyTrackerInterval =
conf.getInt("mapred.tasktracker.blacklist.reevaluation.interval", 24 * 60 * 60 * 1000);
NUM_HEARTBEATS_IN_SECOND =
conf.getInt(JT_HEARTBEATS_IN_SECOND, DEFAULT_NUM_HEARTBEATS_IN_SECOND);
if (NUM_HEARTBEATS_IN_SECOND < MIN_NUM_HEARTBEATS_IN_SECOND) {
NUM_HEARTBEATS_IN_SECOND = DEFAULT_NUM_HEARTBEATS_IN_SECOND;
}
HEARTBEATS_SCALING_FACTOR =
conf.getFloat(JT_HEARTBEATS_SCALING_FACTOR,
DEFAULT_HEARTBEATS_SCALING_FACTOR);
if (HEARTBEATS_SCALING_FACTOR < MIN_HEARTBEATS_SCALING_FACTOR) {
HEARTBEATS_SCALING_FACTOR = DEFAULT_HEARTBEATS_SCALING_FACTOR;
}
//This configuration is there solely for tuning purposes and
//once this feature has been tested in real clusters and an appropriate
//value for the threshold has been found, this config might be taken out.
AverageBlacklistThreshold =
conf.getFloat("mapred.cluster.average.blacklist.threshold", 0.5f);
// This is a directory of temporary submission files. We delete it
// on startup, and can delete any files that we're done with
this.conf = conf;
this.jobTrackerReconfigurable = new JobTrackerReconfigurable(conf);
JobConf jobConf = new JobConf(conf);
initializeTaskMemoryRelatedConfig();
// Read the hosts/exclude files to restrict access to the jobtracker.
this.hostsReader = new HostsFileReader(conf.get("mapred.hosts", ""),
conf.get("mapred.hosts.exclude", ""));
Configuration queuesConf = new Configuration(this.conf);
queueManager = new QueueManager(queuesConf);
// Create the scheduler
Class<? extends TaskScheduler> schedulerClass
= conf.getClass("mapred.jobtracker.taskScheduler",
JobQueueTaskScheduler.class, TaskScheduler.class);
taskScheduler = (TaskScheduler) ReflectionUtils.newInstance(schedulerClass, conf);
// Create the resourceReporter
Class<? extends ResourceReporter> reporterClass
= conf.getClass("mapred.jobtracker.resourceReporter", null,
ResourceReporter.class);
if (reporterClass != null) {
resourceReporter =
(ResourceReporter) ReflectionUtils.newInstance(reporterClass, conf);
LOG.info("Resource reporter: " + reporterClass.getClass() +
" is created");
} else {
resourceReporter = null;
LOG.warn("Resource reporter is not configured. It will be disabled.");
}
// Set ports, start RPC servers, setup security policy etc.
InetSocketAddress addr = getAddress(conf);
this.localMachine = addr.getHostName();
this.port = addr.getPort();
// Set service-level authorization security policy
if (conf.getBoolean(
ServiceAuthorizationManager.SERVICE_AUTHORIZATION_CONFIG, false)) {
PolicyProvider policyProvider =
(PolicyProvider)(ReflectionUtils.newInstance(
conf.getClass(PolicyProvider.POLICY_PROVIDER_CONFIG,
MapReducePolicyProvider.class, PolicyProvider.class),
conf));
SecurityUtil.setPolicy(new ConfiguredPolicy(conf, policyProvider));
}
int handlerCount = conf.getInt("mapred.job.tracker.handler.count", 10);
this.interTrackerServer = RPC.getServer(this, addr.getHostName(), addr.getPort(), handlerCount, false, conf);
if (LOG.isDebugEnabled()) {
Properties p = System.getProperties();
for (Iterator it = p.keySet().iterator(); it.hasNext();) {
String key = (String) it.next();
String val = p.getProperty(key);
LOG.debug("Property '" + key + "' is " + val);
}
}
String infoAddr =
NetUtils.getServerAddress(conf, "mapred.job.tracker.info.bindAddress",
"mapred.job.tracker.info.port",
"mapred.job.tracker.http.address");
InetSocketAddress infoSocAddr = NetUtils.createSocketAddr(infoAddr);
String infoBindAddress = infoSocAddr.getHostName();
int tmpInfoPort = infoSocAddr.getPort();
this.startTime = getClock().getTime();
infoServer = new HttpServer("job", infoBindAddress, tmpInfoPort,
tmpInfoPort == 0, conf);
infoServer.setAttribute("job.tracker", this);
// initialize history parameters.
boolean historyInitialized = JobHistory.init(this, conf, this.localMachine,
this.startTime);
infoServer.addServlet("reducegraph", "/taskgraph", TaskGraphServlet.class);
jobTrackerReconfigurable = new JobTrackerReconfigurable(conf);
infoServer.setAttribute(ReconfigurationServlet.
CONF_SERVLET_RECONFIGURABLE_PREFIX +
"/jtconfchange", jobTrackerReconfigurable);
infoServer.addInternalServlet("jtconfchange", "/jtconfchange",
ReconfigurationServlet.class);
if (taskScheduler instanceof Reconfigurable) {
infoServer.setAttribute(ReconfigurationServlet.
CONF_SERVLET_RECONFIGURABLE_PREFIX +
"/fsconfchange", taskScheduler);
infoServer.addInternalServlet("fsconfchange", "/fsconfchange",
ReconfigurationServlet.class);
}
infoServer.start();
this.trackerIdentifier = identifier;
// Initialize instrumentation
JobTrackerInstrumentation tmp;
Class<? extends JobTrackerInstrumentation> metricsInst =
getInstrumentationClass(jobConf);
try {
java.lang.reflect.Constructor<? extends JobTrackerInstrumentation> c =
metricsInst.getConstructor(new Class[] {JobTracker.class, JobConf.class} );
tmp = c.newInstance(this, jobConf);
} catch(Exception e) {
//Reflection can throw lots of exceptions -- handle them all by
//falling back on the default.
LOG.error("failed to initialize job tracker metrics", e);
tmp = new JobTrackerMetricsInst(this, jobConf);
}
myInstrumentation = tmp;
versionBeanName = VersionInfo.registerJMX("JobTracker");
int excludedAtStart = hostsReader.getExcludedHosts().size();
myInstrumentation.setDecommissionedTrackers(excludedAtStart);
// The rpc/web-server ports can be ephemeral ports...
// ... ensure we have the correct info
this.port = interTrackerServer.getListenerAddress().getPort();
this.conf.set("mapred.job.tracker", (this.localMachine + ":" + this.port));
LOG.info("JobTracker up at: " + this.port);
this.infoPort = this.infoServer.getPort();
this.conf.set("mapred.job.tracker.http.address",
infoBindAddress + ":" + this.infoPort);
LOG.info("JobTracker webserver: " + this.infoServer.getPort());
// start async disk service for asynchronous deletion service
asyncDiskService = new MRAsyncDiskService(FileSystem.getLocal(jobConf),
jobConf.getLocalDirs(), conf);
while (!Thread.currentThread().isInterrupted()) {
try {
// if we haven't contacted the namenode go ahead and do it
if (fs == null) {
fs = FileSystem.get(conf);
}
// clean up the system dir, which will only work if hdfs is out of
// safe mode
if(systemDir == null) {
systemDir = new Path(getSystemDir());
}
if (conf.getBoolean(MAPRED_SYSTEM_DIR_CLEAN_KEY, false)) {
LOG.info("Recreating system dir to start clean");
if (fs.exists(systemDir)) {
fs.delete(systemDir, true);
}
}
// make the systemdir if it doesn't exist already
if (!fs.isDirectory(systemDir)) {
// if systemdir is a file, delete it
if (fs.exists(systemDir)) {
fs.delete(systemDir, true);
}
if (!FileSystem.mkdirs(fs, systemDir,
new FsPermission(SYSTEM_DIR_PERMISSION))) {
LOG.error("Mkdirs failed to create " + systemDir);
} else {
// point of success
break;
}
} else {
// system dir exists
// Make sure that the backup data is preserved
FileStatus[] systemDirData = fs.listStatus(this.systemDir);
LOG.info("Cleaning up the system directory");
for (FileStatus status: systemDirData) {
// spare the CAR directory - shared cache files are immutable and reusable
if (status.isDir() &&
status.getPath().getName().equals(JobSubmissionProtocol.CAR)) {
LOG.info("Preserving shared cache in system directory");
continue;
}
fs.delete(status.getPath(), true);
}
break;
}
} catch (AccessControlException ace) {
LOG.warn("Failed to operate on mapred.system.dir (" + systemDir
+ ") because of permissions.");
LOG.warn("Manually delete the mapred.system.dir (" + systemDir
+ ") and then start the JobTracker.");
LOG.warn("Bailing out ... ");
throw ace;
} catch (IOException ie) {
LOG.info("problem cleaning system directory: " + systemDir, ie);
}
Thread.sleep(FS_ACCESS_RETRY_PERIOD);
}
if (Thread.currentThread().isInterrupted()) {
throw new InterruptedException();
}
asyncDiskService.moveAndDeleteFromEachVolume(SUBDIR);
// Initialize history DONE folder
if (historyInitialized) {
JobHistory.initDone(conf, fs);
String historyLogDir =
JobHistory.getCompletedJobHistoryLocation().toString();
infoServer.setAttribute("historyLogDir", historyLogDir);
FileSystem historyFS = new Path(historyLogDir).getFileSystem(conf);
infoServer.setAttribute("fileSys", historyFS);
}
this.dnsToSwitchMapping = ReflectionUtils.newInstance(
conf.getClass("topology.node.switch.mapping.impl", ScriptBasedMapping.class,
DNSToSwitchMapping.class), conf);
this.numTaskCacheLevels = conf.getInt("mapred.task.cache.levels",
NetworkTopology.DEFAULT_HOST_LEVEL);
//initializes the job status store
completedJobStatusStore = new CompletedJobStatusStore(conf);
ExpireUnusedFilesInCache eufic = new ExpireUnusedFilesInCache(
conf, getClock(), new Path(getSystemDir()));
taskErrorCollector = new TaskErrorCollector(conf);
}
private static SimpleDateFormat getDateFormat() {
return new SimpleDateFormat("yyyyMMddHHmm");
}
private static String generateNewIdentifier() {
return getDateFormat().format(new Date());
}
static boolean validateIdentifier(String id) {
try {
// the jobtracker id should be 'date' parseable
getDateFormat().parse(id);
return true;
} catch (ParseException pe) {}
return false;
}
static boolean validateJobNumber(String id) {
try {
// the job number should be integer parseable
Integer.parseInt(id);
return true;
} catch (IllegalArgumentException pe) {}
return false;
}
public static Class<? extends JobTrackerInstrumentation> getInstrumentationClass(Configuration conf) {
return conf.getClass("mapred.jobtracker.instrumentation",
JobTrackerMetricsInst.class, JobTrackerInstrumentation.class);
}
public static void setInstrumentationClass(Configuration conf, Class<? extends JobTrackerInstrumentation> t) {
conf.setClass("mapred.jobtracker.instrumentation",
t, JobTrackerInstrumentation.class);
}
JobTrackerInstrumentation getInstrumentation() {
return myInstrumentation;
}
public static InetSocketAddress getAddress(Configuration conf) {
String jobTrackerStr =
conf.get("mapred.job.tracker", "localhost:8012");
return NetUtils.createSocketAddr(jobTrackerStr);
}
JobTrackerReconfigurable getJobTrackerReconfigurable() {
return jobTrackerReconfigurable;
}
/**
* Run forever
*/
public void offerService() throws InterruptedException, IOException {
taskScheduler.start();
// refresh the node list as the recovery manager might have added
// disallowed trackers
refreshHosts();
this.expireTrackersThread = new Thread(this.expireTrackers,
"expireTrackers");
this.expireTrackersThread.setDaemon(true);
this.expireTrackersThread.start();
this.retireJobsThread = new Thread(this.retireJobs, "retireJobs");
this.retireJobsThread.setDaemon(true);
this.retireJobsThread.start();
expireLaunchingTaskThread.setDaemon(true);
expireLaunchingTaskThread.start();
jobUpdaterThread.setDaemon(true);
jobUpdaterThread.start();
if (completedJobStatusStore.isActive()) {
completedJobsStoreThread = new Thread(completedJobStatusStore,
"completedjobsStore-housekeeper");
completedJobsStoreThread.start();
}
// start the inter-tracker server once the jt is ready
this.interTrackerServer.start();
synchronized (this) {
state = State.RUNNING;
}
LOG.info("Starting RUNNING");
this.interTrackerServer.join();
LOG.info("Stopped interTrackerServer");
}
private void closeThread(Thread t) {
if (t != null && t.isAlive()) {
LOG.info("Stopping " + t.getName());
t.interrupt();
try {
t.join();
} catch (InterruptedException ex) {
ex.printStackTrace();
}
}
}
void close() throws IOException {
if (this.infoServer != null) {
LOG.info("Stopping infoServer");
try {
this.infoServer.stop();
} catch (Exception ex) {
LOG.warn("Exception shutting down JobTracker", ex);
}
}
if (this.interTrackerServer != null) {
LOG.info("Stopping interTrackerServer");
this.interTrackerServer.stop();
}
shutdown = true;
closeThread(this.expireTrackersThread);
closeThread(this.retireJobsThread);
closeThread(this.jobUpdaterThread);
if (taskScheduler != null) {
taskScheduler.terminate();
}
closeThread(this.expireLaunchingTaskThread);
closeThread(this.completedJobsStoreThread);
if (versionBeanName != null) {
MBeanUtil.unregisterMBean(versionBeanName);
}
LOG.info("stopped all jobtracker services");
return;
}
///////////////////////////////////////////////////////
// Maintain lookup tables; called by JobInProgress
// and TaskInProgress
///////////////////////////////////////////////////////
void createTaskEntry(TaskAttemptID taskid, String taskTracker, TaskInProgress tip) {
LOG.info("Adding task (" + tip.getAttemptType(taskid) + ") " +
"'" + taskid + "' to tip " +
tip.getTIPId() + ", for tracker '" + taskTracker + "'");
// taskid --> tracker
taskidToTrackerMap.put(taskid, taskTracker);
// tracker --> taskid
Set<TaskAttemptIDWithTip> taskset = trackerToTaskMap.get(taskTracker);
if (taskset == null) {
taskset = new HashSet<TaskAttemptIDWithTip>();
trackerToTaskMap.put(taskTracker, taskset);
}
taskset.add(new TaskAttemptIDWithTip(taskid, tip));
// taskid --> TIP
taskidToTIPMap.put(taskid, tip);
}
void removeTaskEntry(TaskAttemptID taskid) {
// taskid --> tracker
String tracker = taskidToTrackerMap.remove(taskid);
// tracker --> taskid
if (tracker != null) {
Set<TaskAttemptIDWithTip> taskset = trackerToTaskMap.get(tracker);
if (taskset != null) {
taskset.remove(new TaskAttemptIDWithTip(taskid, null));
}
}
// taskid --> TIP
if (taskidToTIPMap.remove(taskid) != null) {
LOG.info("Removing task '" + taskid + "'");
}
}
/**
* Mark a 'task' for removal later.
* This function assumes that the JobTracker is locked on entry.
*
* @param taskTracker the tasktracker at which the 'task' was running
* @param taskid completed (success/failure/killed) task
*/
void markCompletedTaskAttempt(String taskTracker, TaskAttemptID taskid) {
// tracker --> taskid
Set<TaskAttemptID> taskset = trackerToMarkedTasksMap.get(taskTracker);
if (taskset == null) {
taskset = new TreeSet<TaskAttemptID>();
trackerToMarkedTasksMap.put(taskTracker, taskset);
}
taskset.add(taskid);
LOG.debug("Marked '" + taskid + "' from '" + taskTracker + "'");
}
/**
* Mark all 'non-running' jobs of the job for pruning.
* This function assumes that the JobTracker is locked on entry.
*
* @param job the completed job
*/
void markCompletedJob(JobInProgress job) {
for (TaskInProgress tip : job.getTasks(TaskType.JOB_SETUP)) {
for (TaskStatus taskStatus : tip.getTaskStatuses()) {
if (taskStatus.getRunState() != TaskStatus.State.RUNNING &&
taskStatus.getRunState() != TaskStatus.State.COMMIT_PENDING &&
taskStatus.getRunState() != TaskStatus.State.UNASSIGNED) {
markCompletedTaskAttempt(taskStatus.getTaskTracker(),
taskStatus.getTaskID());
}
}
}
for (TaskInProgress tip : job.getTasks(TaskType.MAP)) {
for (TaskStatus taskStatus : tip.getTaskStatuses()) {
if (taskStatus.getRunState() != TaskStatus.State.RUNNING &&
taskStatus.getRunState() != TaskStatus.State.COMMIT_PENDING &&
taskStatus.getRunState() != TaskStatus.State.FAILED_UNCLEAN &&
taskStatus.getRunState() != TaskStatus.State.KILLED_UNCLEAN &&
taskStatus.getRunState() != TaskStatus.State.UNASSIGNED) {
markCompletedTaskAttempt(taskStatus.getTaskTracker(),
taskStatus.getTaskID());
}
}
}
for (TaskInProgress tip : job.getTasks(TaskType.REDUCE)) {
for (TaskStatus taskStatus : tip.getTaskStatuses()) {
if (taskStatus.getRunState() != TaskStatus.State.RUNNING &&
taskStatus.getRunState() != TaskStatus.State.COMMIT_PENDING &&
taskStatus.getRunState() != TaskStatus.State.FAILED_UNCLEAN &&
taskStatus.getRunState() != TaskStatus.State.KILLED_UNCLEAN &&
taskStatus.getRunState() != TaskStatus.State.UNASSIGNED) {
markCompletedTaskAttempt(taskStatus.getTaskTracker(),
taskStatus.getTaskID());
}
}
}
}
/**
* Remove all 'marked' tasks running on a given {@link TaskTracker}
* from the {@link JobTracker}'s data-structures.
* This function assumes that the JobTracker is locked on entry.
*
* @param taskTracker tasktracker whose 'non-running' tasks are to be purged
*/
void removeMarkedTasks(String taskTracker) {
// Purge all the 'marked' tasks which were running at taskTracker
Set<TaskAttemptID> markedTaskSet =
trackerToMarkedTasksMap.get(taskTracker);
if (markedTaskSet != null) {
for (TaskAttemptID taskid : markedTaskSet) {
removeTaskEntry(taskid);
if (LOG.isDebugEnabled()) {
LOG.debug("Removed marked completed task '" + taskid + "' from '" +
taskTracker + "'");
}
}
// Clear
trackerToMarkedTasksMap.remove(taskTracker);
}
}
/**
* Call {@link #removeTaskEntry(org.apache.hadoop.mapred.TaskAttemptID)}
* for each of the
* job's tasks.
* When the JobTracker is retiring the long-completed
* job, either because it has outlived {@link #RETIRE_JOB_INTERVAL}
* or the limit of {@link #MAX_COMPLETE_USER_JOBS_IN_MEMORY} jobs
* has been reached, we can afford to nuke all it's tasks; a little
* unsafe, but practically feasible.
*
* @param job the job about to be 'retired'
*/
synchronized void removeJobTasks(JobInProgress job) {
// iterate over all the task types
for (TaskType type : TaskType.values()) {
// iterate over all the tips of the type under consideration
for (TaskInProgress tip : job.getTasks(type)) {
// iterate over all the task-ids in the tip under consideration
for (TaskAttemptID id : tip.getAllTaskAttemptIDs()) {
// remove the task-id entry from the jobtracker
removeTaskEntry(id);
}
}
}
}
/**
* Safe clean-up all data structures at the end of the
* job (success/failure/killed).
* Here we also ensure that for a given user we maintain
* information for only MAX_COMPLETE_USER_JOBS_IN_MEMORY jobs
* on the JobTracker.
*
* @param job completed job.
*/
synchronized void finalizeJob(JobInProgress job) {
// Mark the 'non-running' tasks for pruning
markCompletedJob(job);
JobEndNotifier.registerNotification(job.getJobConf(), job.getStatus());
// start the merge of log files
JobID id = job.getStatus().getJobID();
// mark the job as completed
try {
JobHistory.JobInfo.markCompleted(id);
} catch (IOException ioe) {
LOG.info("Failed to mark job " + id + " as completed!", ioe);
}
final JobTrackerInstrumentation metrics = getInstrumentation();
metrics.finalizeJob(conf, id);
long now = getClock().getTime();
// mark the job for cleanup at all the trackers
addJobForCleanup(id);
try {
File userFileForJob =
new File(lDirAlloc.getLocalPathToRead(SUBDIR + "/" + id,
conf).toString());
if (userFileForJob != null) {
userFileForJob.delete();
}
} catch (IOException ioe) {
LOG.info("Failed to delete job id mapping for job " + id, ioe);
}
// add the blacklisted trackers to potentially faulty list
if (job.getStatus().getRunState() == JobStatus.SUCCEEDED) {
if (job.getNoOfBlackListedTrackers() > 0) {
for (Entry<String, List<String>> e : job.getBlackListedTrackers().entrySet()) {
String tt = e.getKey();
String jobName = job.getJobID().toString();
String[] exceptions = e.getValue().toArray(new String[0]);
faultyTrackers.incrementFaults(tt, new JobFault(tt, jobName, exceptions));
}
}
}
String jobUser = job.getProfile().getUser();
//add to the user to jobs mapping
synchronized (userToJobsMap) {
ArrayList<JobInProgress> userJobs = userToJobsMap.get(jobUser);
if (userJobs == null) {
userJobs = new ArrayList<JobInProgress>();
userToJobsMap.put(jobUser, userJobs);
}
userJobs.add(job);
}
}
///////////////////////////////////////////////////////
// Accessors for objects that want info on jobs, tasks,
// trackers, etc.
///////////////////////////////////////////////////////
public int getTotalSubmissions() {
return totalSubmissions;
}
public String getJobTrackerMachine() {
return localMachine;
}
/**
* Get the unique identifier (ie. timestamp) of this job tracker start.
* @return a string with a unique identifier
*/
public String getTrackerIdentifier() {
return trackerIdentifier;
}
public int getTrackerPort() {
return port;
}
public int getInfoPort() {
return infoPort;
}
public long getStartTime() {
return startTime;
}
public Vector<JobInProgress> runningJobs() {
Vector<JobInProgress> v = new Vector<JobInProgress>();
for (Iterator it = jobs.values().iterator(); it.hasNext();) {
JobInProgress jip = (JobInProgress) it.next();
JobStatus status = jip.getStatus();
if (status.getRunState() == JobStatus.RUNNING) {
v.add(jip);
}
}
return v;
}
/**
* Version that is called from a timer thread, and therefore needs to be
* careful to synchronize.
*/
public synchronized List<JobInProgress> getRunningJobs() {
synchronized (jobs) {
return runningJobs();
}
}
public Vector<JobInProgress> failedJobs() {
Vector<JobInProgress> v = new Vector<JobInProgress>();
for (Iterator it = jobs.values().iterator(); it.hasNext();) {
JobInProgress jip = (JobInProgress) it.next();
JobStatus status = jip.getStatus();
if ((status.getRunState() == JobStatus.FAILED)
|| (status.getRunState() == JobStatus.KILLED)) {
v.add(jip);
}
}
return v;
}
public synchronized List<JobInProgress> getFailedJobs() {
synchronized (jobs) {
return failedJobs();
}
}
public Vector<JobInProgress> completedJobs() {
Vector<JobInProgress> v = new Vector<JobInProgress>();
for (Iterator it = jobs.values().iterator(); it.hasNext();) {
JobInProgress jip = (JobInProgress) it.next();
JobStatus status = jip.getStatus();
if (status.getRunState() == JobStatus.SUCCEEDED) {
v.add(jip);
}
}
return v;
}
public synchronized List<JobInProgress> getCompletedJobs() {
synchronized (jobs) {
return completedJobs();
}
}
private Vector<JobInProgress> preparingJobs() {
Vector<JobInProgress> v = new Vector<JobInProgress>();
for (Iterator it = jobs.values().iterator(); it.hasNext();) {
JobInProgress jip = (JobInProgress) it.next();
JobStatus status = jip.getStatus();
if (status.getRunState() == JobStatus.PREP) {
v.add(jip);
}
}
return v;
}
public synchronized List<JobInProgress> getPreparingJobs() {
synchronized (jobs) {
return preparingJobs();
}
}
/**
* Get all the task trackers in the cluster
*
* @return {@link Collection} of {@link TaskTrackerStatus}
*/
// lock to taskTrackers should hold JT lock first.
public synchronized Collection<TaskTrackerStatus> taskTrackers() {
Collection<TaskTrackerStatus> ttStatuses;
synchronized (taskTrackers) {
ttStatuses =
new ArrayList<TaskTrackerStatus>(taskTrackers.values().size());
for (TaskTracker tt : taskTrackers.values()) {
ttStatuses.add(tt.getStatus());
}
}
return ttStatuses;
}
/**
* Get the active task tracker statuses in the cluster
*
* @return {@link Collection} of active {@link TaskTrackerStatus}
*/
// This method is synchronized to make sure that the locking order
// "taskTrackers lock followed by faultyTrackers.potentiallyFaultyTrackers
// lock" is under JobTracker lock to avoid deadlocks.
synchronized public Collection<TaskTrackerStatus> activeTaskTrackers() {
Collection<TaskTrackerStatus> activeTrackers =
new ArrayList<TaskTrackerStatus>();
synchronized (taskTrackers) {
for ( TaskTracker tt : taskTrackers.values()) {
TaskTrackerStatus status = tt.getStatus();
if (!faultyTrackers.isBlacklisted(status.getHost())) {
activeTrackers.add(status);
}
}
}
return activeTrackers;
}
/**
* Get the active and blacklisted task tracker names in the cluster. The first
* element in the returned list contains the list of active tracker names.
* The second element in the returned list contains the list of blacklisted
* tracker names.
*/
// This method is synchronized to make sure that the locking order
// "taskTrackers lock followed by faultyTrackers.potentiallyFaultyTrackers
// lock" is under JobTracker lock to avoid deadlocks.
synchronized public List<List<String>> taskTrackerNames() {
List<String> activeTrackers =
new ArrayList<String>();
List<String> blacklistedTrackers =
new ArrayList<String>();
synchronized (taskTrackers) {
for (TaskTracker tt : taskTrackers.values()) {
TaskTrackerStatus status = tt.getStatus();
if (!faultyTrackers.isBlacklisted(status.getHost())) {
activeTrackers.add(status.getTrackerName());
} else {
blacklistedTrackers.add(status.getTrackerName());
}
}
}
List<List<String>> result = new ArrayList<List<String>>(2);
result.add(activeTrackers);
result.add(blacklistedTrackers);
return result;
}
/**
* Get the blacklisted task tracker statuses in the cluster
*
* @return {@link Collection} of blacklisted {@link TaskTrackerStatus}
*/
// This method is synchronized to make sure that the locking order
// "taskTrackers lock followed by faultyTrackers.potentiallyFaultyTrackers
// lock" is under JobTracker lock to avoid deadlocks.
synchronized public Collection<TaskTrackerStatus> blacklistedTaskTrackers() {
Collection<TaskTrackerStatus> blacklistedTrackers =
new ArrayList<TaskTrackerStatus>();
synchronized (taskTrackers) {
for (TaskTracker tt : taskTrackers.values()) {
TaskTrackerStatus status = tt.getStatus();
if (faultyTrackers.isBlacklisted(status.getHost())) {
blacklistedTrackers.add(status);
}
}
}
return blacklistedTrackers;
}
synchronized int getFaultCount(String hostName) {
return faultyTrackers.getFaultCount(hostName);
}
/**
* Get the number of blacklisted trackers across all the jobs
*
* @return
*/
int getBlacklistedTrackerCount() {
return faultyTrackers.numBlacklistedTrackers;
}
/**
* Whether the tracker is blacklisted or not
*
* @param trackerID
*
* @return true if blacklisted, false otherwise
*/
synchronized public boolean isBlacklisted(String trackerID) {
TaskTrackerStatus status = getTaskTrackerStatus(trackerID);
if (status != null) {
return faultyTrackers.isBlacklisted(status.getHost());
}
return false;
}
// lock to taskTrackers should hold JT lock first.
synchronized public TaskTrackerStatus getTaskTrackerStatus(String trackerID) {
TaskTracker taskTracker;
synchronized (taskTrackers) {
taskTracker = taskTrackers.get(trackerID);
}
return (taskTracker == null) ? null : taskTracker.getStatus();
}
// lock to taskTrackers should hold JT lock first.
synchronized public TaskTracker getTaskTracker(String trackerID) {
synchronized (taskTrackers) {
return taskTrackers.get(trackerID);
}
}
JobTrackerStatistics getStatistics() {
return statistics;
}
/**
* Adds a new node to the jobtracker. It involves adding it to the expiry
* thread and adding it for resolution
*
* Assumes JobTracker, taskTrackers and trackerExpiryQueue is locked on entry
*
* @param taskTracker Task Tracker
*/
void addNewTracker(TaskTracker taskTracker) {
TaskTrackerStatus status = taskTracker.getStatus();
trackerExpiryQueue.add(status);
// Register the tracker if its not registered
String hostname = status.getHost();
if (getNode(status.getTrackerName()) == null) {
// Making the network location resolution inline ..
resolveAndAddToTopology(hostname);
}
// add it to the set of tracker per host
Set<TaskTracker> trackers = hostnameToTaskTracker.get(hostname);
if (trackers == null) {
trackers = Collections.synchronizedSet(new HashSet<TaskTracker>());
hostnameToTaskTracker.put(hostname, trackers);
}
statistics.taskTrackerAdded(status.getTrackerName());
getInstrumentation().addTrackers(1);
LOG.info("Adding tracker " + status.getTrackerName() + " to host "
+ hostname);
trackers.add(taskTracker);
}
public Node resolveAndAddToTopology(String name) {
List <String> tmpList = new ArrayList<String>(1);
tmpList.add(name);
List <String> rNameList = dnsToSwitchMapping.resolve(tmpList);
String rName = rNameList.get(0);
String networkLoc = NodeBase.normalize(rName);
return addHostToNodeMapping(name, networkLoc);
}
private Node addHostToNodeMapping(String host, String networkLoc) {
Node node = null;
synchronized (nodesAtMaxLevel) {
if ((node = clusterMap.getNode(networkLoc+"/"+host)) == null) {
node = new NodeBase(host, networkLoc);
clusterMap.add(node);
if (node.getLevel() < getNumTaskCacheLevels()) {
LOG.fatal("Got a host whose level is: " + node.getLevel() + "."
+ " Should get at least a level of value: "
+ getNumTaskCacheLevels());
try {
stopTracker();
} catch (IOException ie) {
LOG.warn("Exception encountered during shutdown: "
+ StringUtils.stringifyException(ie));
System.exit(-1);
}
}
hostnameToNodeMap.put(host, node);
// Make an entry for the node at the max level in the cache
nodesAtMaxLevel.add(getParentNode(node, getNumTaskCacheLevels() - 1));
}
}
return node;
}
/**
* Returns a collection of nodes at the max level
*/
public Collection<Node> getNodesAtMaxLevel() {
return nodesAtMaxLevel;
}
public static Node getParentNode(Node node, int level) {
for (int i = 0; i < level; ++i) {
node = node.getParent();
}
return node;
}
/**
* Return the Node in the network topology that corresponds to the hostname
*/
public Node getNode(String name) {
return hostnameToNodeMap.get(name);
}
public int getNumTaskCacheLevels() {
return numTaskCacheLevels;
}
public int getNumResolvedTaskTrackers() {
return numResolved;
}
public int getNumberOfUniqueHosts() {
return uniqueHostsMap.size();
}
public void addJobInProgressListener(JobInProgressListener listener) {
jobInProgressListeners.add(listener);
}
public void removeJobInProgressListener(JobInProgressListener listener) {
jobInProgressListeners.remove(listener);
}
// Update the listeners about the job
// Assuming JobTracker is locked on entry.
void updateJobInProgressListeners(JobChangeEvent event) {
for (JobInProgressListener listener : jobInProgressListeners) {
listener.jobUpdated(event);
}
}
/**
* Return the {@link QueueManager} associated with the JobTracker.
*/
public QueueManager getQueueManager() {
return queueManager;
}
////////////////////////////////////////////////////
// InterTrackerProtocol
////////////////////////////////////////////////////
public String getBuildVersion() throws IOException{
return VersionInfo.getBuildVersion();
}
/**
* The periodic heartbeat mechanism between the {@link TaskTracker} and
* the {@link JobTracker}.
*
* The {@link JobTracker} processes the status information sent by the
* {@link TaskTracker} and responds with instructions to start/stop
* tasks or jobs, and also 'reset' instructions during contingencies.
*/
public HeartbeatResponse heartbeat(TaskTrackerStatus status,
boolean restarted,
boolean initialContact,
boolean acceptNewTasks,
short responseId)
throws IOException {
if (LOG.isDebugEnabled()) {
LOG.debug("Got heartbeat from: " + status.getTrackerName() +
" (restarted: " + restarted +
" initialContact: " + initialContact +
" acceptNewTasks: " + acceptNewTasks + ")" +
" with responseId: " + responseId);
}
short newResponseId;
boolean shouldSchedule = false;
TaskTrackerStatus taskTrackerStatus;
String trackerName;
synchronized (this) {
// Make sure heartbeat is from a tasktracker allowed by the jobtracker.
if (!acceptTaskTracker(status)) {
throw new DisallowedTaskTrackerException(status);
}
// First check if the last heartbeat response got through
trackerName = status.getTrackerName();
long now = getClock().getTime();
if (restarted) {
faultyTrackers.markTrackerHealthy(status.getHost());
} else {
// This updates faulty tracker information.
faultyTrackers.shouldAssignTasksToTracker(status.getHost(), now);
}
HeartbeatResponse prevHeartbeatResponse =
trackerToHeartbeatResponseMap.get(trackerName);
if (initialContact != true) {
// If this isn't the 'initial contact' from the tasktracker,
// there is something seriously wrong if the JobTracker has
// no record of the 'previous heartbeat'; if so, ask the
// tasktracker to re-initialize itself.
if (prevHeartbeatResponse == null) {
// Jobtracker might have restarted but no recovery is needed
// otherwise this code should not be reached
LOG.warn("Serious problem, cannot find record of 'previous' " +
"heartbeat for '" + trackerName +
"'; reinitializing the tasktracker");
return new HeartbeatResponse(responseId,
new TaskTrackerAction[] {new ReinitTrackerAction()});
} else {
// It is completely safe to not process a 'duplicate' heartbeat from a
// {@link TaskTracker} since it resends the heartbeat when rpcs are
// lost see {@link TaskTracker.transmitHeartbeat()};
// acknowledge it by re-sending the previous response to let the
// {@link TaskTracker} go forward.
if (prevHeartbeatResponse.getResponseId() != responseId) {
LOG.info("Ignoring 'duplicate' heartbeat from '" +
trackerName + "'; resending the previous 'lost' response");
return prevHeartbeatResponse;
}
}
}
// Process this heartbeat
newResponseId = (short)(responseId + 1);
status.setLastSeen(now);
if (!processHeartbeat(status, initialContact)) {
if (prevHeartbeatResponse != null) {
trackerToHeartbeatResponseMap.remove(trackerName);
}
return new HeartbeatResponse(newResponseId,
new TaskTrackerAction[] {new ReinitTrackerAction()});
}
shouldSchedule = acceptNewTasks &&
!faultyTrackers.isBlacklisted(status.getHost());
taskTrackerStatus =
shouldSchedule ? getTaskTrackerStatus(trackerName) : null;
} // synchronized JobTracker
// Initialize the response to be sent for the heartbeat
HeartbeatResponse response = new HeartbeatResponse(newResponseId, null);
List<TaskTrackerAction> actions = new ArrayList<TaskTrackerAction>();
List<Task> setupCleanupTasks = null;
// Check for setup/cleanup tasks to be executed on the tasktracker
if (shouldSchedule) {
if (taskTrackerStatus == null) {
LOG.warn("Unknown task tracker polling; ignoring: " + trackerName);
} else {
setupCleanupTasks = getSetupAndCleanupTasks(taskTrackerStatus);
}
}
synchronized (this) {
// Check for tasks to be killed
// we compute this first so that additional tasks can be scheduled
// to compensate for the kill actions
List<TaskTrackerAction> killTasksList = getTasksToKill(trackerName);
if (killTasksList != null) {
actions.addAll(killTasksList);
}
List<Task> tasks = null;
// Check for map/reduce tasks to be executed on the tasktracker
// ignore any contribution by setup/cleanup tasks - it's ok to try
// and overschedule since setup/cleanup tasks are super fast
if (taskTrackerStatus != null) {
// This tells Scheduler how many MAP/REDUCE slots will be released after
// heartbeat. So that the Scheduler can pre-schedule them.
int mapsReleased = countSlotsReleased
(killTasksList, setupCleanupTasks, taskTrackerStatus, TaskType.MAP);
int reducesReleased = countSlotsReleased
(killTasksList, setupCleanupTasks, taskTrackerStatus, TaskType.REDUCE);
status.setMapsReleased(mapsReleased);
status.setReducesReleased(reducesReleased);
List<Task> assignedTasks = taskScheduler.assignTasks(taskTrackers.get(trackerName));
if ((setupCleanupTasks != null) && (assignedTasks != null)) {
// tasks is immutable. so merge the tasks and assignedTasks into a new list
// make sure that the setup/cleanup tasks go first since we can be overscheduling
// tasks here and we need to make sure that the setup/cleanup is run first
tasks = new ArrayList<Task> (assignedTasks.size() +
setupCleanupTasks.size());
tasks.addAll(setupCleanupTasks);
tasks.addAll(assignedTasks);
} else {
tasks = (setupCleanupTasks != null) ? setupCleanupTasks : assignedTasks;
}
}
if (tasks != null) {
for (Task task : tasks) {
TaskAttemptID taskid = task.getTaskID();
JobInProgress job = getJob(taskid.getJobID());
if (job != null) {
createTaskEntry (taskid, taskTrackerStatus.getTrackerName(),
job.getTaskInProgress(taskid.getTaskID()));
} else {
// because we do not hold the jobtracker lock throughout this
// routine - there is a small chance that the job for the task
// we are trying to schedule no longer exists. ignore such tasks
LOG.warn("Unable to find job corresponding to task: " + taskid.toString());
}
expireLaunchingTasks.addNewTask(task.getTaskID());
LOG.debug(trackerName + " -> LaunchTask: " + task.getTaskID());
actions.add(new LaunchTaskAction(task));
}
}
// Check for jobs to be killed/cleanedup
List<TaskTrackerAction> killJobsList = getJobsForCleanup(trackerName);
if (killJobsList != null) {
actions.addAll(killJobsList);
}
// Check for tasks whose outputs can be saved
List<TaskTrackerAction> commitTasksList = getTasksToSave(status);
if (commitTasksList != null) {
actions.addAll(commitTasksList);
}
// calculate next heartbeat interval and put in heartbeat response
int nextInterval = getNextHeartbeatInterval();
response.setHeartbeatInterval(nextInterval);
response.setActions(
actions.toArray(new TaskTrackerAction[actions.size()]));
// Update the trackerToHeartbeatResponseMap
trackerToHeartbeatResponseMap.put(trackerName, response);
// Done processing the hearbeat, now remove 'marked' tasks
removeMarkedTasks(trackerName);
return response;
} // synchronized JobTracker
}
/**
* Calculate how many MAP/REDUCE (non-setup/cleanup) slots will be released
* right after the heartbeat
*
* @param killTasksList Kill actions the TT received by heartbeat
* @param setupCleanupTasks SetupCleanup tasks TT received by heartbeat
* @param taskTrackerStatus The status of the TT
* @param type The type of the task (MAP/REDUCE)
* @return Number of slots will be released
*/
private int countSlotsReleased(List<TaskTrackerAction> killTasksList,
Collection<Task> setupCleanupTasks, TaskTrackerStatus taskTrackerStatus,
TaskType type) {
Map<TaskAttemptID, TaskStatus.State> taskState =
new HashMap<TaskAttemptID, TaskStatus.State>();
if (taskTrackerStatus.getTaskReports() != null) {
for (TaskStatus ts : taskTrackerStatus.getTaskReports()) {
taskState.put(ts.getTaskID(), ts.getRunState());
}
}
int released = 0;
for (TaskTrackerAction action : killTasksList) {
TaskAttemptID tid = ((KillTaskAction)action).getTaskID();
if (type == TaskType.MAP && tid.isMap() ||
type == TaskType.REDUCE && !tid.isMap()) {
TaskStatus.State state = taskState.get(tid);
if (TaskStatus.TERMINATING_STATES.contains(state)) {
// If we are killing a tasks that's already failed, it doesn't count.
continue;
}
released += 1;
}
}
if (setupCleanupTasks != null) {
released -= setupCleanupTasks.size();
}
return released;
}
/**
* Calculates next heartbeat interval using cluster size.
* Heartbeat interval is incremented by 1 second for every 100 nodes by default.
* @return next heartbeat interval.
*/
public int getNextHeartbeatInterval() {
// get the no of task trackers
int clusterSize = getClusterStatus().getTaskTrackers();
int heartbeatInterval = Math.max(
(int)(1000 * HEARTBEATS_SCALING_FACTOR *
Math.ceil((double)clusterSize /
NUM_HEARTBEATS_IN_SECOND)),
HEARTBEAT_INTERVAL_MIN) ;
return heartbeatInterval;
}
/**
* Return if the specified tasktracker is in the hosts list,
* if one was configured. If none was configured, then this
* returns true.
*/
private boolean inHostsList(TaskTrackerStatus status) {
Set<String> hostsList = hostsReader.getHosts();
return (hostsList.isEmpty() || hostsList.contains(status.getHost()));
}
/**
* Return if the specified tasktracker is in the exclude list.
*/
private boolean inExcludedHostsList(TaskTrackerStatus status) {
Set<String> excludeList = hostsReader.getExcludedHosts();
return excludeList.contains(status.getHost());
}
/**
* Returns true if the tasktracker is in the hosts list and
* not in the exclude list.
*/
private boolean acceptTaskTracker(TaskTrackerStatus status) {
return (inHostsList(status) && !inExcludedHostsList(status));
}
/**
* Update the last recorded status for the given task tracker.
* It assumes that the taskTrackers are locked on entry.
* @param trackerName The name of the tracker
* @param status The new status for the task tracker
* @return Was an old status found?
*/
boolean updateTaskTrackerStatus(String trackerName,
TaskTrackerStatus status) {
TaskTracker tt = getTaskTracker(trackerName);
TaskTrackerStatus oldStatus = (tt == null) ? null : tt.getStatus();
// update the total cluster capacity first
if (status != null) {
// we have a fresh tasktracker status
if (!faultyTrackers.isBlacklisted(status.getHost())) {
// if the task tracker host is not blacklisted - then
// we update the cluster capacity with the capacity
// reported by the tasktracker
updateTotalTaskCapacity(status);
} else {
// if the tasktracker is blacklisted - then it's capacity
// is already removed and will only be added back to the
// cluster capacity when it's unblacklisted
}
} else {
if (oldStatus != null) {
// old status exists - but no new status. in this case
// we are removing the tracker from the cluster.
if (!faultyTrackers.isBlacklisted(oldStatus.getHost())) {
// we update the total task capacity based on the old status
// this seems redundant - but this call is idempotent - so just
// make it. the danger of not making it is that we may accidentally
// remove something we never had
updateTotalTaskCapacity(oldStatus);
removeTaskTrackerCapacity(oldStatus);
} else {
// if the host is blacklisted - then the tracker's capacity
// has already been removed and there's nothing to do
}
}
}
if (oldStatus != null) {
totalMaps -= oldStatus.countMapTasks();
totalReduces -= oldStatus.countReduceTasks();
occupiedMapSlots -= oldStatus.countOccupiedMapSlots();
occupiedReduceSlots -= oldStatus.countOccupiedReduceSlots();
getInstrumentation().decRunningMaps(oldStatus.countMapTasks());
getInstrumentation().decRunningReduces(oldStatus.countReduceTasks());
getInstrumentation().decOccupiedMapSlots(oldStatus.countOccupiedMapSlots());
getInstrumentation().decOccupiedReduceSlots(oldStatus.countOccupiedReduceSlots());
if (status == null) {
taskTrackers.remove(trackerName);
Integer numTaskTrackersInHost =
uniqueHostsMap.get(oldStatus.getHost());
if (numTaskTrackersInHost != null) {
numTaskTrackersInHost --;
if (numTaskTrackersInHost > 0) {
uniqueHostsMap.put(oldStatus.getHost(), numTaskTrackersInHost);
}
else {
uniqueHostsMap.remove(oldStatus.getHost());
}
}
}
}
if (status != null) {
totalMaps += status.countMapTasks();
totalReduces += status.countReduceTasks();
occupiedMapSlots += status.countOccupiedMapSlots();
occupiedReduceSlots += status.countOccupiedReduceSlots();
getInstrumentation().addRunningMaps(status.countMapTasks());
getInstrumentation().addRunningReduces(status.countReduceTasks());
getInstrumentation().addOccupiedMapSlots(status.countOccupiedMapSlots());
getInstrumentation().addOccupiedReduceSlots(status.countOccupiedReduceSlots());
boolean alreadyPresent = false;
TaskTracker taskTracker = taskTrackers.get(trackerName);
if (taskTracker != null) {
alreadyPresent = true;
} else {
taskTracker = new TaskTracker(trackerName);
}
taskTracker.setStatus(status);
taskTrackers.put(trackerName, taskTracker);
if (LOG.isDebugEnabled()) {
int runningMaps = 0, runningReduces = 0;
int commitPendingMaps = 0, commitPendingReduces = 0;
int unassignedMaps = 0, unassignedReduces = 0;
int miscMaps = 0, miscReduces = 0;
List<TaskStatus> taskReports = status.getTaskReports();
for (Iterator<TaskStatus> it = taskReports.iterator(); it.hasNext();) {
TaskStatus ts = (TaskStatus) it.next();
boolean isMap = ts.getIsMap();
TaskStatus.State state = ts.getRunState();
if (state == TaskStatus.State.RUNNING) {
if (isMap) { ++runningMaps; }
else { ++runningReduces; }
} else if (state == TaskStatus.State.UNASSIGNED) {
if (isMap) { ++unassignedMaps; }
else { ++unassignedReduces; }
} else if (state == TaskStatus.State.COMMIT_PENDING) {
if (isMap) { ++commitPendingMaps; }
else { ++commitPendingReduces; }
} else {
if (isMap) { ++miscMaps; }
else { ++miscReduces; }
}
}
LOG.debug(trackerName + ": Status -" +
" running(m) = " + runningMaps +
" unassigned(m) = " + unassignedMaps +
" commit_pending(m) = " + commitPendingMaps +
" misc(m) = " + miscMaps +
" running(r) = " + runningReduces +
" unassigned(r) = " + unassignedReduces +
" commit_pending(r) = " + commitPendingReduces +
" misc(r) = " + miscReduces);
}
if (!alreadyPresent) {
Integer numTaskTrackersInHost =
uniqueHostsMap.get(status.getHost());
if (numTaskTrackersInHost == null) {
numTaskTrackersInHost = 0;
}
numTaskTrackersInHost ++;
uniqueHostsMap.put(status.getHost(), numTaskTrackersInHost);
}
}
getInstrumentation().setMapSlots(totalMapTaskCapacity);
getInstrumentation().setReduceSlots(totalReduceTaskCapacity);
return oldStatus != null;
}
// Increment the number of reserved slots in the cluster.
// This method assumes the caller has JobTracker lock.
void incrementReservations(TaskType type, int reservedSlots) {
if (type.equals(TaskType.MAP)) {
reservedMapSlots += reservedSlots;
} else if (type.equals(TaskType.REDUCE)) {
reservedReduceSlots += reservedSlots;
}
}
// Decrement the number of reserved slots in the cluster.
// This method assumes the caller has JobTracker lock.
void decrementReservations(TaskType type, int reservedSlots) {
if (type.equals(TaskType.MAP)) {
reservedMapSlots -= reservedSlots;
} else if (type.equals(TaskType.REDUCE)) {
reservedReduceSlots -= reservedSlots;
}
}
private void updateNodeHealthStatus(TaskTrackerStatus trackerStatus) {
TaskTrackerHealthStatus status = trackerStatus.getHealthStatus();
synchronized (faultyTrackers) {
faultyTrackers.setNodeHealthStatus(trackerStatus.getHost(),
status.isNodeHealthy(), status.getHealthReport());
}
}
/**
* Process incoming heartbeat messages from the task trackers.
*/
synchronized boolean processHeartbeat(
TaskTrackerStatus trackerStatus,
boolean initialContact) {
String trackerName = trackerStatus.getTrackerName();
synchronized (taskTrackers) {
synchronized (trackerExpiryQueue) {
boolean seenBefore = updateTaskTrackerStatus(trackerName,
trackerStatus);
TaskTracker taskTracker = getTaskTracker(trackerName);
if (initialContact) {
// If it's first contact, then clear out
// any state hanging around
if (seenBefore) {
LOG.warn("initialContact but seenBefore from Tracker : " + trackerName);
lostTaskTracker(taskTracker);
}
} else {
// If not first contact, there should be some record of the tracker
if (!seenBefore) {
LOG.warn("Status from unknown Tracker : " + trackerName);
updateTaskTrackerStatus(trackerName, null);
return false;
}
}
if (initialContact) {
// if this is lost tracker that came back now, and if it blacklisted
// increment the count of blacklisted trackers in the cluster
if (isBlacklisted(trackerName)) {
faultyTrackers.incrBlackListedTrackers(1);
}
addNewTracker(taskTracker);
}
}
}
updateTaskStatuses(trackerStatus);
updateNodeHealthStatus(trackerStatus);
return true;
}
/**
* A tracker wants to know if any of its Tasks have been
* closed (because the job completed, whether successfully or not)
*/
synchronized List<TaskTrackerAction> getTasksToKill(String taskTracker) {
Set<TaskAttemptIDWithTip> taskset = trackerToTaskMap.get(taskTracker);
List<TaskTrackerAction> killList = new ArrayList<TaskTrackerAction>();
if (taskset != null) {
for (TaskAttemptIDWithTip onetask : taskset) {
TaskAttemptID killTaskId = onetask.attemptId;
TaskInProgress tip = onetask.tip;
if (tip == null) {
continue;
}
if (tip.shouldClose(killTaskId)) {
//
// This is how the JobTracker ends a task at the TaskTracker.
// It may be successfully completed, or may be killed in
// mid-execution.
//
if (!((JobInProgress)tip.getJob()).isComplete()) {
killList.add(new KillTaskAction(killTaskId));
LOG.debug(taskTracker + " -> KillTaskAction: " + killTaskId);
}
}
}
}
// add the stray attempts for uninited jobs
synchronized (trackerToTasksToCleanup) {
Set<TaskAttemptID> set = trackerToTasksToCleanup.remove(taskTracker);
if (set != null) {
for (TaskAttemptID id : set) {
killList.add(new KillTaskAction(id));
}
}
}
return killList;
}
/**
* Add a job to cleanup for the tracker.
*/
private void addJobForCleanup(JobID id) {
for (String taskTracker : taskTrackers.keySet()) {
LOG.debug("Marking job " + id + " for cleanup by tracker " + taskTracker);
synchronized (trackerToJobsToCleanup) {
Set<JobID> jobsToKill = trackerToJobsToCleanup.get(taskTracker);
if (jobsToKill == null) {
jobsToKill = new HashSet<JobID>();
trackerToJobsToCleanup.put(taskTracker, jobsToKill);
}
jobsToKill.add(id);
}
}
}
/**
* A tracker wants to know if any job needs cleanup because the job completed.
*/
private List<TaskTrackerAction> getJobsForCleanup(String taskTracker) {
Set<JobID> jobs = null;
synchronized (trackerToJobsToCleanup) {
jobs = trackerToJobsToCleanup.remove(taskTracker);
}
if (jobs != null) {
// prepare the actions list
List<TaskTrackerAction> killList = new ArrayList<TaskTrackerAction>();
for (JobID killJobId : jobs) {
killList.add(new KillJobAction(killJobId));
LOG.debug(taskTracker + " -> KillJobAction: " + killJobId);
}
return killList;
}
return null;
}
/**
* A tracker wants to know if any of its Tasks can be committed
*/
synchronized List<TaskTrackerAction> getTasksToSave(
TaskTrackerStatus tts) {
List<TaskStatus> taskStatuses = tts.getTaskReports();
if (taskStatuses != null) {
List<TaskTrackerAction> saveList = new ArrayList<TaskTrackerAction>();
for (TaskStatus taskStatus : taskStatuses) {
if (taskStatus.getRunState() == TaskStatus.State.COMMIT_PENDING) {
TaskAttemptID taskId = taskStatus.getTaskID();
TaskInProgress tip = taskidToTIPMap.get(taskId);
if (tip == null) {
continue;
}
if (tip.shouldCommit(taskId)) {
saveList.add(new CommitTaskAction(taskId));
LOG.info(tts.getTrackerName() +
" -> CommitTaskAction: " + taskId);
}
}
}
return saveList;
}
return null;
}
// returns cleanup tasks first, then setup tasks.
List<Task> getSetupAndCleanupTasks(
TaskTrackerStatus taskTracker) throws IOException {
int maxMapTasks = taskScheduler.getMaxSlots(taskTracker, TaskType.MAP);
int maxReduceTasks =
taskScheduler.getMaxSlots(taskTracker, TaskType.REDUCE);
int numMaps = taskTracker.countOccupiedMapSlots();
int numReduces = taskTracker.countOccupiedReduceSlots();
int numTaskTrackers = getClusterStatus().getTaskTrackers();
int numUniqueHosts = getNumberOfUniqueHosts();
List<JobInProgress> cachedJobs = new ArrayList<JobInProgress> ();
// get a snapshot of all the jobs in the system
synchronized (jobs) {
cachedJobs.addAll(jobs.values());
}
Task t = null;
if (numMaps < maxMapTasks) {
for (JobInProgress job: cachedJobs) {
t = job.obtainJobCleanupTask(taskTracker, numTaskTrackers,
numUniqueHosts, true);
if (t != null) {
return Collections.singletonList(t);
}
}
for (JobInProgress job: cachedJobs) {
t = job.obtainTaskCleanupTask(taskTracker, true);
if (t != null) {
return Collections.singletonList(t);
}
}
for (JobInProgress job: cachedJobs) {
t = job.obtainJobSetupTask(taskTracker, numTaskTrackers,
numUniqueHosts, true);
if (t != null) {
return Collections.singletonList(t);
}
}
}
if (numReduces < maxReduceTasks) {
for (JobInProgress job: cachedJobs) {
t = job.obtainJobCleanupTask(taskTracker, numTaskTrackers,
numUniqueHosts, false);
if (t != null) {
return Collections.singletonList(t);
}
}
for (JobInProgress job: cachedJobs) {
t = job.obtainTaskCleanupTask(taskTracker, false);
if (t != null) {
return Collections.singletonList(t);
}
}
for (JobInProgress job: cachedJobs) {
t = job.obtainJobSetupTask(taskTracker, numTaskTrackers,
numUniqueHosts, false);
if (t != null) {
return Collections.singletonList(t);
}
}
}
return null;
}
/**
* Grab the local fs name
*/
public synchronized String getFilesystemName() throws IOException {
if (fs == null) {
throw new IllegalStateException("FileSystem object not available yet");
}
return fs.getUri().toString();
}
public void reportTaskTrackerError(String taskTracker,
String errorClass,
String errorMessage) throws IOException {
LOG.warn("Report from " + taskTracker + ": " + errorMessage);
}
/**
* Remove the job_ from jobids to get the unique string.
*/
static String getJobUniqueString(String jobid) {
return jobid.substring(4);
}
////////////////////////////////////////////////////
// JobSubmissionProtocol
////////////////////////////////////////////////////
/**
* Allocates a new JobId string.
*/
public JobID getNewJobId() throws IOException {
JobID id = new JobID(getTrackerIdentifier(), nextJobId.getAndIncrement());
// get the user group info
UserGroupInformation ugi = UserGroupInformation.getCurrentUGI();
// mark the user for this id
jobToUserMap.put(id, ugi.getUserName());
LOG.info("Job id " + id + " assigned to user " + ugi.getUserName());
return id;
}
private File persistUserName(JobID jobId, UserGroupInformation ugi)
throws IOException {
// persist
File userFileForJob = new File(
lDirAlloc.getLocalPathForWrite(
SUBDIR + "/" + jobId, conf).toString());
if (userFileForJob == null) {
LOG.info("Failed to create job-id file for job " +
jobId + " at " + userFileForJob);
} else {
FileOutputStream fout = new FileOutputStream(userFileForJob);
BufferedWriter writer = null;
try {
writer = new BufferedWriter(new OutputStreamWriter(fout));
writer.write(ugi.getUserName() + "\n");
} finally {
if (writer != null) {
writer.close();
}
fout.close();
}
LOG.info("Job " + jobId +
" user info persisted to file : " + userFileForJob);
}
return userFileForJob;
}
/**
* JobTracker.submitJob() kicks off a new job.
*
* Create a 'JobInProgress' object, which contains both JobProfile
* and JobStatus. Those two sub-objects are sometimes shipped outside
* of the JobTracker. But JobInProgress adds info that's useful for
* the JobTracker alone.
*/
public JobStatus submitJob(JobID jobId) throws IOException {
final UserGroupInformation ugi;
final Path jobDir;
synchronized (this) {
if (jobs.containsKey(jobId)) {
//job already running, don't start twice
return jobs.get(jobId).getStatus();
}
// check if the owner is uploding the splits or not
// get the user group info
ugi = UserGroupInformation.getCurrentUGI();
// check if the user invoking this api is the owner of this job
if (!jobToUserMap.get(jobId).equals(ugi.getUserName())) {
throw new IOException("User " + ugi.getUserName() +
" is not the owner of the job " + jobId);
}
jobDir = this.getSystemDirectoryForJob(jobId);
jobToUserMap.remove(jobId);
}
File userFileForJob = persistUserName(jobId, ugi);
JobInProgress.copyJobFileLocally(jobDir, jobId, this.conf);
synchronized (this) {
JobInProgress job = null;
try {
job = new JobInProgress(jobId, this,
jobTrackerReconfigurable.getJobConf(), ugi.getUserName(), 0);
} catch (Exception e) {
if (userFileForJob != null) {
userFileForJob.delete();
}
throw new IOException(e);
}
String queue = job.getProfile().getQueueName();
if (!(queueManager.getQueues().contains(queue))) {
new CleanupQueue().addToQueue(new PathDeletionContext(
FileSystem.get(conf),
getSystemDirectoryForJob(jobId).toUri().getPath()));
job.fail();
if (userFileForJob != null) {
userFileForJob.delete();
}
throw new IOException("Queue \"" + queue + "\" does not exist");
}
// The task scheduler should validate the job configuration
taskScheduler.checkJob(job);
// check for access
try {
checkAccess(job, QueueManager.QueueOperation.SUBMIT_JOB);
} catch (IOException ioe) {
LOG.warn("Access denied for user " + job.getJobConf().getUser() +
". Ignoring job " + jobId, ioe);
job.fail();
if (userFileForJob != null) {
userFileForJob.delete();
}
new CleanupQueue().addToQueue(new PathDeletionContext(
FileSystem.get(conf),
getSystemDirectoryForJob(jobId).toUri().getPath()));
throw ioe;
}
// Check the job if it cannot run in the cluster because of invalid memory
// requirements.
try {
checkMemoryRequirements(job);
} catch (IOException ioe) {
new CleanupQueue().addToQueue(new PathDeletionContext(
FileSystem.get(conf),
getSystemDirectoryForJob(jobId).toUri().getPath()));
throw ioe;
}
return addJob(jobId, job);
}
}
/**
* Adds a job to the jobtracker. Make sure that the checks are inplace before
* adding a job. This is the core job submission logic
* @param jobId The id for the job submitted which needs to be added
*/
protected synchronized JobStatus addJob(JobID jobId, JobInProgress job) {
totalSubmissions++;
synchronized (jobs) {
synchronized (taskScheduler) {
jobs.put(job.getProfile().getJobID(), job);
for (JobInProgressListener listener : jobInProgressListeners) {
try {
listener.jobAdded(job);
} catch (IOException ioe) {
LOG.warn("Failed to add and so skipping the job : "
+ job.getJobID() + ". Exception : " + ioe);
}
}
}
}
myInstrumentation.submitJob(job.getJobConf(), jobId);
String jobName = job.getJobConf().getJobName();
int jobNameLen = 64;
if (jobName.length() > jobNameLen) {
jobName = jobName.substring(0, jobNameLen); // Truncate for logging.
}
LOG.info("Job " + jobId + "(" + jobName +
") added successfully for user '" + job.getJobConf().getUser() +
"' to queue '" + job.getJobConf().getQueueName() + "'" +
", source " + job.getJobConf().getJobSource());
return job.getStatus();
}
// Check whether the specified operation can be performed
// related to the job.
private void checkAccess(JobInProgress job,
QueueManager.QueueOperation oper)
throws IOException {
// get the user group info
UserGroupInformation ugi = UserGroupInformation.getCurrentUGI();
checkAccess(job, oper, ugi);
}
// use the passed ugi for checking the access
private void checkAccess(JobInProgress job, QueueManager.QueueOperation oper,
UserGroupInformation ugi) throws IOException {
// get the queue
String queue = job.getProfile().getQueueName();
if (!queueManager.hasAccess(queue, job, oper, ugi)) {
throw new AccessControlException("User "
+ ugi.getUserName()
+ " cannot perform "
+ "operation " + oper + " on queue " + queue +
".\n Please run \"hadoop queue -showacls\" " +
"command to find the queues you have access" +
" to .");
}
}
/**@deprecated use {@link #getClusterStatus(boolean)}*/
@Deprecated
public synchronized ClusterStatus getClusterStatus() {
return getClusterStatus(false);
}
public synchronized ClusterStatus getClusterStatus(boolean detailed) {
synchronized (taskTrackers) {
if (detailed) {
List<List<String>> trackerNames = taskTrackerNames();
return new ClusterStatus(trackerNames.get(0),
trackerNames.get(1),
taskTrackers(),
getRunningJobs(),
TASKTRACKER_EXPIRY_INTERVAL,
totalMaps,
totalReduces,
totalMapTaskCapacity,
totalReduceTaskCapacity,
state, getExcludedNodes().size()
);
} else {
return new ClusterStatus(taskTrackers.size() -
getBlacklistedTrackerCount(),
getBlacklistedTrackerCount(),
TASKTRACKER_EXPIRY_INTERVAL,
totalMaps,
totalReduces,
totalMapTaskCapacity,
totalReduceTaskCapacity,
state, getExcludedNodes().size());
}
}
}
public synchronized ClusterMetrics getClusterMetrics() {
return new ClusterMetrics(totalMaps,
totalReduces, occupiedMapSlots, occupiedReduceSlots,
reservedMapSlots, reservedReduceSlots,
totalMapTaskCapacity, totalReduceTaskCapacity,
totalSubmissions,
taskTrackers.size() - getBlacklistedTrackerCount(),
getBlacklistedTrackerCount(), getExcludedNodes().size()) ;
}
public synchronized void killJob(JobID jobid) throws IOException {
if (null == jobid) {
LOG.info("Null jobid object sent to JobTracker.killJob()");
return;
}
JobInProgress job = jobs.get(jobid);
if (null == job) {
LOG.info("killJob(): JobId " + jobid.toString() + " is not a valid job");
return;
}
checkAccess(job, QueueManager.QueueOperation.ADMINISTER_JOBS);
killJob(job);
}
private synchronized void killJob(JobInProgress job) {
LOG.info("Killing job " + job.getJobID());
JobStatus prevStatus = (JobStatus)job.getStatus().clone();
job.kill();
// Inform the listeners if the job is killed
// Note :
// If the job is killed in the PREP state then the listeners will be
// invoked
// If the job is killed in the RUNNING state then cleanup tasks will be
// launched and the updateTaskStatuses() will take care of it
JobStatus newStatus = (JobStatus)job.getStatus().clone();
if (prevStatus.getRunState() != newStatus.getRunState()
&& newStatus.getRunState() == JobStatus.KILLED) {
JobStatusChangeEvent event =
new JobStatusChangeEvent(job, EventType.RUN_STATE_CHANGED, prevStatus,
newStatus);
updateJobInProgressListeners(event);
}
}
public void initJob(JobInProgress job) {
if (null == job) {
LOG.info("Init on null job is not valid");
return;
}
try {
JobStatus prevStatus = (JobStatus)job.getStatus().clone();
LOG.info("Initializing " + job.getJobID());
job.initTasks();
// Here the job *should* be in the PREP state.
// From here there are 3 ways :
// - job requires setup : the job remains in PREP state and
// setup is launched to move the job in RUNNING state
// - job is complete (no setup required and no tasks) : complete
// the job and move it to SUCCEEDED
// - job has tasks but doesnt require setup : make the job RUNNING.
if (job.isJobEmpty()) { // is the job empty?
completeEmptyJob(job); // complete it
} else if (!job.isSetupCleanupRequired()) { // setup/cleanup not required
job.completeSetup(); // complete setup and make job running
}
// Inform the listeners if the job state has changed
// Note : that the job will be in PREP state.
JobStatus newStatus = (JobStatus)job.getStatus().clone();
if (prevStatus.getRunState() != newStatus.getRunState()) {
JobStatusChangeEvent event =
new JobStatusChangeEvent(job, EventType.RUN_STATE_CHANGED, prevStatus,
newStatus);
synchronized (JobTracker.this) {
updateJobInProgressListeners(event);
}
}
} catch (KillInterruptedException kie) {
// If job was killed during initialization, job state will be KILLED
LOG.error(job.getJobID() + ": Job initialization interrupted:\n" +
StringUtils.stringifyException(kie));
killJob(job);
} catch (Throwable t) {
// If the job initialization is failed, job state will be FAILED
LOG.error(job.getJobID() + ": Job initialization failed:\n" +
StringUtils.stringifyException(t));
failJob(job);
}
}
private synchronized void completeEmptyJob(JobInProgress job) {
job.completeEmptyJob();
}
/**
* Fail a job and inform the listeners. Other components in the framework
* should use this to fail a job.
*/
public synchronized void failJob(JobInProgress job) {
if (null == job) {
LOG.info("Fail on null job is not valid");
return;
}
JobStatus prevStatus = (JobStatus)job.getStatus().clone();
LOG.info("Failing job " + job.getJobID());
job.fail();
// Inform the listeners if the job state has changed
JobStatus newStatus = (JobStatus)job.getStatus().clone();
if (prevStatus.getRunState() != newStatus.getRunState()) {
JobStatusChangeEvent event =
new JobStatusChangeEvent(job, EventType.RUN_STATE_CHANGED, prevStatus,
newStatus);
updateJobInProgressListeners(event);
}
}
/**
* Set the priority of a job
* @param jobid id of the job
* @param priority new priority of the job
*/
public synchronized void setJobPriority(JobID jobid,
String priority)
throws IOException {
JobInProgress job = jobs.get(jobid);
if (null == job) {
LOG.info("setJobPriority(): JobId " + jobid.toString()
+ " is not a valid job");
return;
}
checkAccess(job, QueueManager.QueueOperation.ADMINISTER_JOBS);
JobPriority newPriority = JobPriority.valueOf(priority);
setJobPriority(jobid, newPriority);
}
void storeCompletedJob(JobInProgress job) {
//persists the job info in DFS
completedJobStatusStore.store(job);
}
/**
* Check if the <code>job</code> has been initialized.
*
* @param job {@link JobInProgress} to be checked
* @return <code>true</code> if the job has been initialized,
* <code>false</code> otherwise
*/
private boolean isJobInited(JobInProgress job) {
return job.inited();
}
public JobProfile getJobProfile(JobID jobid) {
synchronized (this) {
JobInProgress job = jobs.get(jobid);
if (job != null) {
// Safe to call JobInProgress.getProfile while holding the lock
// on the JobTracker since it isn't a synchronized method
return job.getProfile();
} else {
RetireJobInfo info = retireJobs.get(jobid);
if (info != null) {
return info.profile;
}
}
}
return completedJobStatusStore.readJobProfile(jobid);
}
public JobStatus getJobStatus(JobID jobid) {
if (null == jobid) {
LOG.warn("JobTracker.getJobStatus() cannot get status for null jobid");
return null;
}
synchronized (this) {
JobInProgress job = jobs.get(jobid);
if (job != null) {
// Safe to call JobInProgress.getStatus while holding the lock
// on the JobTracker since it isn't a synchronized method
JobStatus stats = job.getStatus();
if (stats == null) {
LOG.warn("JobTracker.getJobStatus() returning null for jobid " +
jobid + " after non-null job");
}
return stats;
} else {
RetireJobInfo info = retireJobs.get(jobid);
if (info != null) {
if (info.status == null) {
LOG.warn("JobTracker.getJobStatus() returning null for jobid " +
jobid + " after retrieving info from retireJobs");
}
return info.status;
}
}
}
JobStatus stats = completedJobStatusStore.readJobStatus(jobid);
if (stats == null) {
LOG.warn("JobTracker.getJobStatus() returning null for jobid " + jobid +
" after getting status from completedJobStatusStore");
}
return stats;
}
private static final Counters EMPTY_COUNTERS
= new Counters();
public Counters getJobCounters(JobID jobid) {
JobInProgress job;
synchronized (this) {
job = jobs.get(jobid);
}
if (job != null) {
if (!isJobInited(job)) {
return EMPTY_COUNTERS;
}
return job.getCounters();
}
return completedJobStatusStore.readCounters(jobid);
}
public TaskReport[] getMapTaskReports(JobID jobid) {
return super.getMapTaskReportsImpl(jobid);
}
public TaskReport[] getReduceTaskReports(JobID jobid) {
return super.getReduceTaskReportsImpl(jobid);
}
public TaskReport[] getCleanupTaskReports(JobID jobid) {
return super.getCleanupTaskReportsImpl(jobid);
}
public TaskReport[] getSetupTaskReports(JobID jobid) {
return super.getSetupTaskReportsImpl(jobid);
}
static final String MAPRED_CLUSTER_MAP_MEMORY_MB_PROPERTY =
"mapred.cluster.map.memory.mb";
static final String MAPRED_CLUSTER_REDUCE_MEMORY_MB_PROPERTY =
"mapred.cluster.reduce.memory.mb";
static final String MAPRED_CLUSTER_MAX_MAP_MEMORY_MB_PROPERTY =
"mapred.cluster.max.map.memory.mb";
static final String MAPRED_CLUSTER_MAX_REDUCE_MEMORY_MB_PROPERTY =
"mapred.cluster.max.reduce.memory.mb";
/*
* Returns a list of TaskCompletionEvent for the given job,
* starting from fromEventId.
* @see org.apache.hadoop.mapred.JobSubmissionProtocol#getTaskCompletionEvents(java.lang.String, int, int)
*/
public TaskCompletionEvent[] getTaskCompletionEvents(
JobID jobid, int fromEventId, int maxEvents) throws IOException{
JobInProgress job = this.jobs.get(jobid);
if (null != job) {
return job.inited() ? job.getTaskCompletionEvents(fromEventId, maxEvents)
: TaskCompletionEvent.EMPTY_ARRAY;
}
return completedJobStatusStore.readJobTaskCompletionEvents(jobid, fromEventId, maxEvents);
}
public synchronized String[] getTaskDiagnostics(TaskAttemptID taskId)
throws IOException {
return super.getTaskDiagnosticsImpl(taskId);
}
/** Get all the TaskStatuses from the tipid. */
TaskStatus[] getTaskStatuses(TaskID tipid) {
TaskInProgress tip = getTip(tipid);
return (tip == null ? new TaskStatus[0]
: tip.getTaskStatuses());
}
/** Returns the TaskStatus for a particular taskid. */
TaskStatus getTaskStatus(TaskAttemptID taskid) {
TaskInProgress tip = getTip(taskid.getTaskID());
return (tip == null ? null
: tip.getTaskStatus(taskid));
}
/**
* Returns the counters for the specified task in progress.
*/
Counters getTipCounters(TaskID tipid) {
TaskInProgress tip = getTip(tipid);
return (tip == null ? null : tip.getCounters());
}
/**
* Returns the configured task scheduler for this job tracker.
* @return the configured task scheduler
*/
TaskScheduler getTaskScheduler() {
return taskScheduler;
}
@Override
// This is for JobSubmissionProtocol
public boolean killTask(TaskAttemptID taskid, boolean shouldFail) throws IOException{
return this.killTask(taskid, shouldFail,
"Request received to " + (shouldFail ? "fail" : "kill")
+ " task '" + taskid + "' from JobClient" );
}
@Override
// This is for TaskTrackerManager
public synchronized boolean killTask(
TaskAttemptID taskid, boolean shouldFail, String reason) throws IOException{
TaskInProgress tip = taskidToTIPMap.get(taskid);
if(tip != null) {
checkAccess((JobInProgress)tip.getJob(), QueueManager.QueueOperation.ADMINISTER_JOBS);
return tip.killTask(taskid, shouldFail, reason);
}
else {
LOG.info("Kill task attempt failed since task " + taskid + " was not found");
return false;
}
}
/**
* Get tracker name for a given task id.
* @param taskId the name of the task
* @return The name of the task tracker
*/
public synchronized String getAssignedTracker(TaskAttemptID taskId) {
return taskidToTrackerMap.get(taskId);
}
public JobStatus[] jobsToComplete() {
return getJobStatus(jobs.values(), true);
}
public JobStatus[] getAllJobs() {
List<JobStatus> list = new ArrayList<JobStatus>();
list.addAll(Arrays.asList(getJobStatus(jobs.values(),false)));
list.addAll(retireJobs.getAllJobStatus());
return list.toArray(new JobStatus[list.size()]);
}
/**
* @see org.apache.hadoop.mapred.JobSubmissionProtocol#getSystemDir()
*/
public String getSystemDir() {
Path sysDir = new Path(conf.get(MAPRED_SYSTEM_DIR_KEY, DEFAULT_MAPRED_SYSTEM_DIR));
return fs.makeQualified(sysDir).toString();
}
///////////////////////////////////////////////////////////////
// JobTracker methods
///////////////////////////////////////////////////////////////
public JobInProgress getJob(JobID jobid) {
return jobs.get(jobid);
}
public JobInProgressTraits getJobInProgress(JobID jobid) {
return (JobInProgressTraits)jobs.get(jobid);
}
// Get the job directory in system directory
Path getSystemDirectoryForJob(JobID id) {
return new Path(getSystemDir(), id.toString());
}
/**
* Change the run-time priority of the given job.
* @param jobId job id
* @param priority new {@link JobPriority} for the job
*/
synchronized void setJobPriority(JobID jobId, JobPriority priority) {
JobInProgress job = jobs.get(jobId);
if (job != null) {
synchronized (taskScheduler) {
JobStatus oldStatus = (JobStatus)job.getStatus().clone();
job.setPriority(priority);
JobStatus newStatus = (JobStatus)job.getStatus().clone();
JobStatusChangeEvent event =
new JobStatusChangeEvent(job, EventType.PRIORITY_CHANGED, oldStatus,
newStatus);
updateJobInProgressListeners(event);
}
} else {
LOG.warn("Trying to change the priority of an unknown job: " + jobId);
}
}
////////////////////////////////////////////////////
// Methods to track all the TaskTrackers
////////////////////////////////////////////////////
/**
* Accept and process a new TaskTracker profile. We might
* have known about the TaskTracker previously, or it might
* be brand-new. All task-tracker structures have already
* been updated. Just process the contained tasks and any
* jobs that might be affected.
*/
void updateTaskStatuses(TaskTrackerStatus status) {
String trackerName = status.getTrackerName();
for (TaskStatus report : status.getTaskReports()) {
report.setTaskTracker(trackerName);
TaskAttemptID taskId = report.getTaskID();
// Remove it from the expired task list
if (report.getRunState() != TaskStatus.State.UNASSIGNED) {
expireLaunchingTasks.removeTask(taskId);
}
JobInProgress job = getJob(taskId.getJobID());
if (job == null) {
// if job is not there in the cleanup list ... add it
synchronized (trackerToJobsToCleanup) {
Set<JobID> jobs = trackerToJobsToCleanup.get(trackerName);
if (jobs == null) {
jobs = new HashSet<JobID>();
trackerToJobsToCleanup.put(trackerName, jobs);
}
jobs.add(taskId.getJobID());
}
continue;
}
if (!job.inited()) {
// if job is not yet initialized ... kill the attempt
synchronized (trackerToTasksToCleanup) {
Set<TaskAttemptID> tasks = trackerToTasksToCleanup.get(trackerName);
if (tasks == null) {
tasks = new HashSet<TaskAttemptID>();
trackerToTasksToCleanup.put(trackerName, tasks);
}
tasks.add(taskId);
}
continue;
}
TaskInProgress tip = taskidToTIPMap.get(taskId);
// Check if the tip is known to the jobtracker. In case of a restarted
// jt, some tasks might join in later
if (tip != null) {
// Update the job and inform the listeners if necessary
JobStatus prevStatus = (JobStatus)job.getStatus().clone();
// Clone TaskStatus object here, because JobInProgress
// or TaskInProgress can modify this object and
// the changes should not get reflected in TaskTrackerStatus.
// An old TaskTrackerStatus is used later in countMapTasks, etc.
job.updateTaskStatus(tip, (TaskStatus)report.clone());
JobStatus newStatus = (JobStatus)job.getStatus().clone();
// Update the listeners if an incomplete job completes
if (prevStatus.getRunState() != newStatus.getRunState()) {
JobStatusChangeEvent event =
new JobStatusChangeEvent(job, EventType.RUN_STATE_CHANGED,
prevStatus, newStatus);
updateJobInProgressListeners(event);
}
} else {
LOG.info("Serious problem. While updating status, cannot find taskid "
+ report.getTaskID());
}
// Process 'failed fetch' notifications
List<TaskAttemptID> failedFetchMaps = report.getFetchFailedMaps();
if (failedFetchMaps != null) {
TaskAttemptID reportingAttempt = report.getTaskID();
for (TaskAttemptID mapTaskId : failedFetchMaps) {
TaskInProgress failedFetchMap = taskidToTIPMap.get(mapTaskId);
if (failedFetchMap != null) {
// Gather information about the map which has to be failed, if need be
String failedFetchTrackerName = getAssignedTracker(mapTaskId);
if (failedFetchTrackerName == null) {
failedFetchTrackerName = "Lost task tracker";
}
((JobInProgress)failedFetchMap.getJob()).fetchFailureNotification(
reportingAttempt, failedFetchMap, mapTaskId, failedFetchTrackerName);
}
}
}
}
}
/**
* We lost the task tracker! All task-tracker structures have
* already been updated. Just process the contained tasks and any
* jobs that might be affected.
*/
void lostTaskTracker(TaskTracker taskTracker) {
String trackerName = taskTracker.getTrackerName();
LOG.info("Lost tracker '" + trackerName + "'");
// remove the tracker from the local structures
synchronized (trackerToJobsToCleanup) {
trackerToJobsToCleanup.remove(trackerName);
}
synchronized (trackerToTasksToCleanup) {
trackerToTasksToCleanup.remove(trackerName);
}
Set<TaskAttemptIDWithTip> lostTasks = trackerToTaskMap.get(trackerName);
trackerToTaskMap.remove(trackerName);
if (lostTasks != null) {
// List of jobs which had any of their tasks fail on this tracker
Set<JobInProgress> jobsWithFailures = new HashSet<JobInProgress>();
for (TaskAttemptIDWithTip oneTask : lostTasks) {
TaskAttemptID taskId = oneTask.attemptId;
TaskInProgress tip = oneTask.tip;
JobInProgress job = (JobInProgress) tip.getJob();
// Completed reduce tasks never need to be failed, because
// their outputs go to dfs
// And completed maps with zero reducers of the job
// never need to be failed.
if (!tip.isComplete() ||
(tip.isMapTask() && !tip.isJobSetupTask() &&
job.desiredReduces() != 0)) {
// if the job is done, we don't want to change anything
if (job.getStatus().getRunState() == JobStatus.RUNNING ||
job.getStatus().getRunState() == JobStatus.PREP) {
// the state will be KILLED_UNCLEAN, if the task(map or reduce)
// was RUNNING on the tracker
TaskStatus.State killState = (tip.isRunningTask(taskId) &&
!tip.isJobSetupTask() && !tip.isJobCleanupTask()) ?
TaskStatus.State.KILLED_UNCLEAN : TaskStatus.State.KILLED;
job.failedTask(tip, taskId,
("Lost task tracker: " + trackerName +
" at " + new Date()),
(tip.isMapTask() ?
TaskStatus.Phase.MAP :
TaskStatus.Phase.REDUCE),
killState,
trackerName);
jobsWithFailures.add(job);
}
} else {
// Completed 'reduce' task and completed 'maps' with zero
// reducers of the job, not failed;
// only removed from data-structures.
markCompletedTaskAttempt(trackerName, taskId);
}
}
// Penalize this tracker for each of the jobs which
// had any tasks running on it when it was 'lost'
// Also, remove any reserved slots on this tasktracker
for (JobInProgress job : jobsWithFailures) {
String reason = "Tracker went down";
job.addTrackerTaskFailure(trackerName, taskTracker, reason);
}
// Cleanup
taskTracker.cancelAllReservations();
// Purge 'marked' tasks, needs to be done
// here to prevent hanging references!
removeMarkedTasks(trackerName);
}
}
/**
* Rereads the config to get hosts and exclude list file names.
* Rereads the files to update the hosts and exclude lists.
*/
public synchronized void refreshNodes() throws IOException {
// check access
PermissionChecker.checkSuperuserPrivilege(mrOwner, supergroup);
// call the actual api
refreshHosts();
}
private synchronized void refreshHosts() throws IOException {
// Reread the config to get mapred.hosts and mapred.hosts.exclude filenames.
// Update the file names and refresh internal includes and excludes list
LOG.info("Refreshing hosts information");
Configuration conf = new Configuration();
hostsReader.updateFileNames(conf.get("mapred.hosts",""),
conf.get("mapred.hosts.exclude", ""));
hostsReader.refresh();
Set<String> excludeSet = new HashSet<String>();
for(Map.Entry<String, TaskTracker> eSet : taskTrackers.entrySet()) {
String trackerName = eSet.getKey();
TaskTrackerStatus status = eSet.getValue().getStatus();
// Check if not include i.e not in host list or in hosts list but excluded
if (!inHostsList(status) || inExcludedHostsList(status)) {
excludeSet.add(status.getHost()); // add to rejected trackers
}
}
decommissionNodes(excludeSet);
int totalExcluded = hostsReader.getExcludedHosts().size();
getInstrumentation().setDecommissionedTrackers(totalExcluded);
}
// Remove a tracker from the system
private void removeTracker(TaskTracker tracker) {
String trackerName = tracker.getTrackerName();
// Remove completely after marking the tasks as 'KILLED'
lostTaskTracker(tracker);
TaskTrackerStatus status = tracker.getStatus();
// tracker is lost, and if it is blacklisted, remove
// it from the count of blacklisted trackers in the cluster
if (isBlacklisted(trackerName)) {
faultyTrackers.decrBlackListedTrackers(1);
}
updateTaskTrackerStatus(trackerName, null);
statistics.taskTrackerRemoved(trackerName);
getInstrumentation().decTrackers(1);
}
// main decommission
synchronized void decommissionNodes(Set<String> hosts)
throws IOException {
LOG.info("Decommissioning " + hosts.size() + " nodes");
// create a list of tracker hostnames
synchronized (taskTrackers) {
synchronized (trackerExpiryQueue) {
int trackersDecommissioned = 0;
for (String host : hosts) {
LOG.info("Decommissioning host " + host);
Set<TaskTracker> trackers = hostnameToTaskTracker.remove(host);
if (trackers != null) {
for (TaskTracker tracker : trackers) {
LOG.info("Decommission: Losing tracker " + tracker.getTrackerName() +
" on host " + host);
removeTracker(tracker);
}
trackersDecommissioned += trackers.size();
}
LOG.info("Host " + host + " is ready for decommissioning");
}
}
}
}
/**
* Returns a set of excluded nodes.
*/
Collection<String> getExcludedNodes() {
return hostsReader.getExcludedHosts();
}
/**
* Returns a set of dead nodes. (nodes that are expected to be alive)
*/
public Collection<String> getDeadNodes() {
List<String> activeHosts = new ArrayList<String>();
synchronized(taskTrackers) {
for (TaskTracker tt : taskTrackers.values()) {
activeHosts.add(tt.getStatus().getHost());
}
}
// dead hosts are the difference between active and known hosts
// We don't consider a blacklisted host to be dead.
Set<String> knownHosts = new HashSet<String>(hostsReader.getHosts());
knownHosts.removeAll(activeHosts);
// Also remove the excluded nodes as getHosts() returns them as well
knownHosts.removeAll(hostsReader.getExcludedHosts());
Set<String> deadHosts = knownHosts;
return deadHosts;
}
/**
* Get the localized job file path on the job trackers local file system
* @param jobId id of the job
* @return the path of the job conf file on the local file system
*/
public static String getLocalJobFilePath(JobID jobId){
return JobHistory.JobInfo.getLocalJobFilePath(jobId);
}
////////////////////////////////////////////////////////////
// main()
////////////////////////////////////////////////////////////
/**
* Start the JobTracker process. This is used only for debugging. As a rule,
* JobTracker should be run as part of the DFS Namenode process.
*/
public static void main(String argv[]
) throws IOException, InterruptedException {
StringUtils.startupShutdownMessage(JobTracker.class, argv, LOG);
try {
if (argv.length == 0) {
JobTracker tracker = startTracker(new JobConf());
tracker.offerService();
return;
}
if ("-instance".equals(argv[0]) && argv.length == 2) {
int instance = Integer.parseInt(argv[1]);
if (instance == 0 || instance == 1) {
JobConf conf = new JobConf();
JobConf.overrideConfiguration(conf, instance);
JobTracker tracker = startTracker(conf);
tracker.offerService();
return;
}
}
if ("-dumpConfiguration".equals(argv[0]) && argv.length == 1) {
dumpConfiguration(new PrintWriter(System.out));
return;
}
System.out.println("usage: JobTracker [-dumpConfiguration]");
System.out.println(" JobTracker [-instance <0|1>]");
System.exit(-1);
} catch (Throwable e) {
LOG.fatal(StringUtils.stringifyException(e));
System.exit(-1);
}
}
/**
* Dumps the configuration properties in Json format
* @param writer {@link}Writer object to which the output is written
* @throws IOException
*/
private static void dumpConfiguration(Writer writer) throws IOException {
Configuration.dumpConfiguration(new JobConf(), writer);
writer.write("\n");
// get the QueueManager configuration properties
QueueManager.dumpConfiguration(writer);
writer.write("\n");
}
@Override
public JobQueueInfo[] getQueues() throws IOException {
return queueManager.getJobQueueInfos();
}
@Override
public JobQueueInfo getQueueInfo(String queue) throws IOException {
return queueManager.getJobQueueInfo(queue);
}
@Override
public JobStatus[] getJobsFromQueue(String queue) throws IOException {
Collection<JobInProgress> jips = taskScheduler.getJobs(queue);
return getJobStatus(jips,false);
}
@Override
public QueueAclsInfo[] getQueueAclsForCurrentUser() throws IOException{
return queueManager.getQueueAcls(
UserGroupInformation.getCurrentUGI());
}
private synchronized JobStatus[] getJobStatus(Collection<JobInProgress> jips,
boolean toComplete) {
if(jips == null || jips.isEmpty()) {
return new JobStatus[]{};
}
ArrayList<JobStatus> jobStatusList = new ArrayList<JobStatus>();
for(JobInProgress jip : jips) {
JobStatus status = jip.getStatus();
status.setStartTime(jip.getStartTime());
status.setUsername(jip.getProfile().getUser());
if(toComplete) {
if(status.getRunState() == JobStatus.RUNNING ||
status.getRunState() == JobStatus.PREP) {
jobStatusList.add(status);
}
}else {
jobStatusList.add(status);
}
}
return (JobStatus[]) jobStatusList.toArray(
new JobStatus[jobStatusList.size()]);
}
/**
* Returns the confgiured maximum number of tasks for a single job
*/
int getMaxTasksPerJob() {
return conf.getInt("mapred.jobtracker.maxtasks.per.job", -1);
}
@Override
public void refreshServiceAcl() throws IOException {
if (!conf.getBoolean(
ServiceAuthorizationManager.SERVICE_AUTHORIZATION_CONFIG, false)) {
throw new AuthorizationException("Service Level Authorization not enabled!");
}
SecurityUtil.getPolicy().refresh();
}
private void initializeTaskMemoryRelatedConfig() {
memSizeForMapSlotOnJT =
JobConf.normalizeMemoryConfigValue(conf.getLong(
JobTracker.MAPRED_CLUSTER_MAP_MEMORY_MB_PROPERTY,
JobConf.DISABLED_MEMORY_LIMIT));
memSizeForReduceSlotOnJT =
JobConf.normalizeMemoryConfigValue(conf.getLong(
JobTracker.MAPRED_CLUSTER_REDUCE_MEMORY_MB_PROPERTY,
JobConf.DISABLED_MEMORY_LIMIT));
if (conf.get(JobConf.UPPER_LIMIT_ON_TASK_VMEM_PROPERTY) != null) {
LOG.warn(
JobConf.deprecatedString(
JobConf.UPPER_LIMIT_ON_TASK_VMEM_PROPERTY)+
" instead use "+JobTracker.MAPRED_CLUSTER_MAX_MAP_MEMORY_MB_PROPERTY+
" and " + JobTracker.MAPRED_CLUSTER_MAX_REDUCE_MEMORY_MB_PROPERTY
);
limitMaxMemForMapTasks = limitMaxMemForReduceTasks =
JobConf.normalizeMemoryConfigValue(
conf.getLong(
JobConf.UPPER_LIMIT_ON_TASK_VMEM_PROPERTY,
JobConf.DISABLED_MEMORY_LIMIT));
if (limitMaxMemForMapTasks != JobConf.DISABLED_MEMORY_LIMIT &&
limitMaxMemForMapTasks >= 0) {
limitMaxMemForMapTasks = limitMaxMemForReduceTasks =
limitMaxMemForMapTasks /
(1024 * 1024); //Converting old values in bytes to MB
}
} else {
limitMaxMemForMapTasks =
JobConf.normalizeMemoryConfigValue(
conf.getLong(
JobTracker.MAPRED_CLUSTER_MAX_MAP_MEMORY_MB_PROPERTY,
JobConf.DISABLED_MEMORY_LIMIT));
limitMaxMemForReduceTasks =
JobConf.normalizeMemoryConfigValue(
conf.getLong(
JobTracker.MAPRED_CLUSTER_MAX_REDUCE_MEMORY_MB_PROPERTY,
JobConf.DISABLED_MEMORY_LIMIT));
}
LOG.info(new StringBuilder().append("Scheduler configured with ").append(
"(memSizeForMapSlotOnJT, memSizeForReduceSlotOnJT,").append(
" limitMaxMemForMapTasks, limitMaxMemForReduceTasks) (").append(
memSizeForMapSlotOnJT).append(", ").append(memSizeForReduceSlotOnJT)
.append(", ").append(limitMaxMemForMapTasks).append(", ").append(
limitMaxMemForReduceTasks).append(")"));
}
private boolean perTaskMemoryConfigurationSetOnJT() {
if (limitMaxMemForMapTasks == JobConf.DISABLED_MEMORY_LIMIT
|| limitMaxMemForReduceTasks == JobConf.DISABLED_MEMORY_LIMIT
|| memSizeForMapSlotOnJT == JobConf.DISABLED_MEMORY_LIMIT
|| memSizeForReduceSlotOnJT == JobConf.DISABLED_MEMORY_LIMIT) {
return false;
}
return true;
}
/**
* Check the job if it has invalid requirements and throw and IOException if does have.
*
* @param job
* @throws IOException
*/
private void checkMemoryRequirements(JobInProgress job)
throws IOException {
if (!perTaskMemoryConfigurationSetOnJT()) {
LOG.debug("Per-Task memory configuration is not set on JT. "
+ "Not checking the job for invalid memory requirements.");
return;
}
boolean invalidJob = false;
String msg = "";
long maxMemForMapTask = job.getMemoryForMapTask();
long maxMemForReduceTask = job.getMemoryForReduceTask();
if (maxMemForMapTask == JobConf.DISABLED_MEMORY_LIMIT
|| maxMemForReduceTask == JobConf.DISABLED_MEMORY_LIMIT) {
invalidJob = true;
msg = "Invalid job requirements.";
}
if (maxMemForMapTask > limitMaxMemForMapTasks
|| maxMemForReduceTask > limitMaxMemForReduceTasks) {
invalidJob = true;
msg = "Exceeds the cluster's max-memory-limit.";
}
if (invalidJob) {
StringBuilder jobStr =
new StringBuilder().append(job.getJobID().toString()).append("(")
.append(maxMemForMapTask).append(" memForMapTasks ").append(
maxMemForReduceTask).append(" memForReduceTasks): ");
LOG.warn(jobStr.toString() + msg);
throw new IOException(jobStr.toString() + msg);
}
}
@Override
public void refreshQueueAcls() throws IOException{
LOG.info("Refreshing queue acls. requested by : " +
UserGroupInformation.getCurrentUGI().getUserName());
this.queueManager.refreshAcls(new Configuration(this.conf));
}
synchronized String getReasonsForBlacklisting(String host) {
FaultInfo fi = faultyTrackers.getFaultInfo(host, false);
if (fi == null) {
return "";
}
return fi.getTrackerFaultReport();
}
/** Test Methods */
synchronized Set<ReasonForBlackListing> getReasonForBlackList(String host) {
FaultInfo fi = faultyTrackers.getFaultInfo(host, false);
if (fi == null) {
return new HashSet<ReasonForBlackListing>();
}
return fi.getReasonforblacklisting();
}
public synchronized void retireCompletedJobs() {
synchronized (jobs) {
RETIRE_COMPLETED_JOBS = true;
}
}
/**
* @return the pluggable object for obtaining job resource information
*/
public ResourceReporter getResourceReporter() {
return resourceReporter;
}
/**
* Update totalMapTaskCapacity and totalReduceTaskCapacity to resolve the
* number of slots changed in a tasktracker. The change could be from
* TaskScheduler or TaskTrackerStatus
*
* @param status The status of the tasktracker
*/
private void updateTotalTaskCapacity(TaskTrackerStatus status) {
int mapSlots = taskScheduler.getMaxSlots(status, TaskType.MAP);
String trackerName = status.getTrackerName();
Integer oldMapSlots = trackerNameToMapSlots.get(trackerName);
if (oldMapSlots == null) {
oldMapSlots = 0;
}
int delta = mapSlots - oldMapSlots;
if (delta != 0) {
totalMapTaskCapacity += delta;
trackerNameToMapSlots.put(trackerName, mapSlots);
LOG.info("Changing map slot count due to " + trackerName + " from " +
oldMapSlots + " to " + mapSlots + ", totalMap = " + totalMapTaskCapacity);
}
int reduceSlots = taskScheduler.getMaxSlots(status, TaskType.REDUCE);
Integer oldReduceSlots = trackerNameToReduceSlots.get(trackerName);
if (oldReduceSlots == null) {
oldReduceSlots = 0;
}
delta = reduceSlots - oldReduceSlots;
if (delta != 0) {
totalReduceTaskCapacity += delta;
trackerNameToReduceSlots.put(trackerName, reduceSlots);
LOG.info("Changing reduce slot count due to " + trackerName + " from " +
oldReduceSlots + " to " + reduceSlots +
", totalReduce = " + totalReduceTaskCapacity);
}
}
/**
* Update totalMapTaskCapacity and totalReduceTaskCapacity for removing
* a tasktracker
*
* @param status The status of the tasktracker
*/
private void removeTaskTrackerCapacity(TaskTrackerStatus status) {
Integer mapSlots = trackerNameToMapSlots.remove(status.getTrackerName());
if (mapSlots == null) {
mapSlots = 0;
}
totalMapTaskCapacity -= mapSlots;
Integer reduceSlots = trackerNameToReduceSlots.remove(status.getTrackerName());
if (reduceSlots == null) {
reduceSlots = 0;
}
totalReduceTaskCapacity -= reduceSlots;
LOG.info("Removing " + mapSlots + " map slots, " + reduceSlots +
" reduce slots due to " + status.getTrackerName() +
", totalMap = " + totalMapTaskCapacity + ", totalReduce = " + totalReduceTaskCapacity);
}
public TaskErrorCollector getTaskErrorCollector() {
return taskErrorCollector;
}
}