/**
* 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.File;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.OutputStream;
import java.io.RandomAccessFile;
import java.lang.ref.WeakReference;
import java.net.InetSocketAddress;
import java.net.URI;
import java.net.URISyntaxException;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
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.Queue;
import java.util.Random;
import java.util.Set;
import java.util.TreeMap;
import java.util.Vector;
import java.util.WeakHashMap;
import java.util.concurrent.BlockingQueue;
import java.util.concurrent.Callable;
import java.util.concurrent.FutureTask;
import java.util.concurrent.LinkedBlockingQueue;
import java.util.concurrent.ThreadPoolExecutor;
import java.util.concurrent.TimeUnit;
import java.util.regex.Pattern;
import javax.management.ObjectName;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.conf.ReconfigurableBase;
import org.apache.hadoop.conf.ReconfigurationException;
import org.apache.hadoop.conf.ReconfigurationServlet;
import org.apache.hadoop.filecache.DistributedCache;
import org.apache.hadoop.fs.DF;
import org.apache.hadoop.fs.FSDataInputStream;
import org.apache.hadoop.fs.FileStatus;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.FileUtil;
import org.apache.hadoop.fs.LocalDirAllocator;
import org.apache.hadoop.fs.LocalFileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.http.HttpServer;
import org.apache.hadoop.http.NettyMapOutputHttpServer;
import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.io.Writable;
import org.apache.hadoop.ipc.ProtocolSignature;
import org.apache.hadoop.ipc.RPC;
import org.apache.hadoop.ipc.RemoteException;
import org.apache.hadoop.ipc.Server;
import org.apache.hadoop.mapred.CleanupQueue.PathDeletionContext;
import org.apache.hadoop.mapred.TaskController.TaskControllerPathDeletionContext;
import org.apache.hadoop.mapred.TaskLog.LogFileDetail;
import org.apache.hadoop.mapred.TaskLog.LogName;
import org.apache.hadoop.mapred.TaskTrackerStatus.TaskTrackerHealthStatus;
import org.apache.hadoop.mapred.pipes.Submitter;
import org.apache.hadoop.mapreduce.TaskType;
import org.apache.hadoop.metrics.MetricsContext;
import org.apache.hadoop.metrics.MetricsException;
import org.apache.hadoop.metrics.MetricsRecord;
import org.apache.hadoop.metrics.MetricsUtil;
import org.apache.hadoop.metrics.Updater;
import org.apache.hadoop.metrics.util.MBeanUtil;
import org.apache.hadoop.net.DNS;
import org.apache.hadoop.net.NetUtils;
import org.apache.hadoop.security.SecurityUtil;
import org.apache.hadoop.security.authorize.ConfiguredPolicy;
import org.apache.hadoop.security.authorize.PolicyProvider;
import org.apache.hadoop.security.authorize.ServiceAuthorizationManager;
import org.apache.hadoop.util.DiskChecker;
import org.apache.hadoop.util.DiskChecker.DiskErrorException;
import org.apache.hadoop.util.MRAsyncDiskService;
import org.apache.hadoop.util.ProcfsBasedProcessTree;
import org.apache.hadoop.util.PulseChecker;
import org.apache.hadoop.util.PulseCheckable;
import org.apache.hadoop.util.ReflectionUtils;
import org.apache.hadoop.util.ResourceCalculatorPlugin;
import org.apache.hadoop.util.RunJar;
import org.apache.hadoop.util.Shell.ShellCommandExecutor;
import org.apache.hadoop.util.StringUtils;
import org.apache.hadoop.util.VersionInfo;
import org.jboss.netty.channel.ChannelPipeline;
import org.jboss.netty.channel.ChannelPipelineFactory;
import org.jboss.netty.channel.Channels;
import org.jboss.netty.handler.codec.http.HttpChunkAggregator;
import org.jboss.netty.handler.codec.http.HttpRequestDecoder;
import org.jboss.netty.handler.codec.http.HttpResponseEncoder;
import org.jboss.netty.handler.stream.ChunkedWriteHandler;
/*******************************************************
* TaskTracker is a process that starts and tracks MR Tasks
* in a networked environment. It contacts the JobTracker
* for Task assignments and reporting results.
*
*******************************************************/
public class TaskTracker extends ReconfigurableBase
implements MRConstants, TaskUmbilicalProtocol, Runnable, PulseCheckable {
/**
* @deprecated
*/
@Deprecated
static final String MAPRED_TASKTRACKER_VMEM_RESERVED_PROPERTY =
"mapred.tasktracker.vmem.reserved";
/**
* @deprecated
*/
@Deprecated
static final String MAPRED_TASKTRACKER_PMEM_RESERVED_PROPERTY =
"mapred.tasktracker.pmem.reserved";
static final String MAP_USERLOG_RETAIN_SIZE =
"mapreduce.cluster.map.userlog.retain-size";
static final String REDUCE_USERLOG_RETAIN_SIZE =
"mapreduce.cluster.reduce.userlog.retain-size";
static final String CHECK_TASKTRACKER_BUILD_VERSION =
"mapreduce.tasktracker.build.version.check";
static final long LOCALIZE_TASK_TIMEOUT = 10 * 60 * 1000L;
static final long WAIT_FOR_DONE = 3 * 1000;
// Port for jetty http server, not netty http server
protected int httpPort;
static enum State {NORMAL, STALE, INTERRUPTED, DENIED}
static{
Configuration.addDefaultResource("mapred-default.xml");
Configuration.addDefaultResource("mapred-site.xml");
}
public static final Log LOG =
LogFactory.getLog(TaskTracker.class);
public static final String MR_CLIENTTRACE_FORMAT =
"src: %s" + // src IP
", dest: %s" + // dst IP
", bytes: %s" + // byte count
", op: %s" + // operation
", cliID: %s" + // task id
", duration: %s"; // duration
public static final Log ClientTraceLog =
LogFactory.getLog(TaskTracker.class.getName() + ".clienttrace");
volatile boolean running = true;
volatile long lastHeartbeat = 0;
private LocalDirAllocator localDirAllocator = null;
String taskTrackerName;
String localHostname;
InetSocketAddress jobTrackAddr;
InetSocketAddress taskReportAddress;
Server taskReportServer = null;
InterTrackerProtocol jobClient;
// last heartbeat response recieved
short heartbeatResponseId = -1;
static final String TASK_CLEANUP_SUFFIX = ".cleanup";
/*
* This is the last 'status' report sent by this tracker to the JobTracker.
*
* If the rpc call succeeds, this 'status' is cleared-out by this tracker;
* indicating that a 'fresh' status report be generated; in the event the
* rpc calls fails for whatever reason, the previous status report is sent
* again.
*/
TaskTrackerStatus status = null;
// The system-directory on HDFS where job files are stored
Path systemDirectory = null;
// The filesystem where job files are stored
FileSystem systemFS = null;
private HttpServer server;
/**
* If netty will be used for map outputs, then this is the first port
* it tries to bind to. If binding fails, it will retry with increasing
* port numbers.
*/
public static String NETTY_MAPOUTPUT_HTTP_PORT =
"mapred.task.tracker.netty.http.port";
public static String NETTY_MAPOUTPUT_USE = "mapred.task.tracker.netty.use";
private NettyMapOutputHttpServer nettyMapOutputServer = null;
/** If this port is -1, it is not being used */
protected int nettyMapOutputHttpPort = -1;
volatile boolean shuttingDown = false;
Map<TaskAttemptID, TaskInProgress> tasks = new HashMap<TaskAttemptID, TaskInProgress>();
/**
* Map from taskId -> TaskInProgress.
*/
protected Map<TaskAttemptID, TaskInProgress> runningTasks = null;
Map<JobID, RunningJob> runningJobs = null;
volatile int mapTotal = 0;
volatile int reduceTotal = 0;
boolean justStarted = true;
boolean justInited = true;
/** Keeps track of the last N milliseconds to refill a map slot */
private final Queue<Integer> mapSlotRefillMsecsQueue =
new LinkedList<Integer>();
/** Keeps track of the last N milliseconds to refill a reduce slot */
private final Queue<Integer> reduceSlotRefillMsecsQueue =
new LinkedList<Integer>();
/** Maximum length of the map or reduce refill queues */
private int maxRefillQueueSize;
/** Configuration key for max refill queue size */
public static final String MAX_REFILL_QUEUE_SIZE =
"mapred.maxRefillQueueSize";
/** Default max refill size of 50 */
public static final int DEFAULT_MAX_REFILL_QUEUE_SIZE = 50;
// Mark reduce tasks that are shuffling to rollback their events index
//dir -> DF
Map<String, DF> localDirsDf = new HashMap<String, DF>();
long minSpaceStart = 0;
//must have this much space free to start new tasks
boolean acceptNewTasks = true;
long minSpaceKill = 0;
//if we run under this limit, kill one task
//and make sure we never receive any new jobs
//until all the old tasks have been cleaned up.
//this is if a machine is so full it's only good
//for serving map output to the other nodes
static Random r = new Random();
private static final String SUBDIR = "taskTracker";
private static final String CACHEDIR = "archive";
private static final String JOBCACHE = "jobcache";
private static final String OUTPUT = "output";
protected JobConf originalConf;
protected JobConf fConf;
/** Max map slots used for scheduling */
private int maxMapSlots;
/** Max reduce slots used for scheduling */
private int maxReduceSlots;
/** Actual max map slots that can be used for metrics */
private int actualMaxMapSlots;
/** Actual max reduce slots that can be used for metrics */
private int actualMaxReduceSlots;
private int failures;
private FileSystem localFs;
// Performance-related config knob to send an out-of-band heartbeat
// on task completion
static final String TT_OUTOFBAND_HEARBEAT =
"mapreduce.tasktracker.outofband.heartbeat";
private volatile boolean oobHeartbeatOnTaskCompletion;
static final String TT_FAST_FETCH = "mapred.tasktracker.events.fastfetch";
private volatile boolean fastFetch = false;
public static final String TT_PROFILE_ALL_TASKS = "mapred.tasktracker.profile.alltasks";
private volatile boolean profileAllTasks = false;
// Track number of completed tasks to send an out-of-band heartbeat
protected IntWritable finishedCount = new IntWritable(0);
private MapEventsFetcherThread mapEventsFetcher;
// A store of map task completion events. The mapping is a TCE to a weak
// reference of the same TCE. Given a TCE, this enables fetching of a stored
// equivalent TCE while allowing the GC to remove non-referenced instances.
// It's useful for saving memory when there are multiple TT in the same JVM
// that fetch task completion events for the same job, e.g. simulation.
// This is the same idea as using String.intern() to reduce overall memory
// usage.
private static WeakHashMap<TaskCompletionEvent,
WeakReference<TaskCompletionEvent>>
taskCompletionEventsStore =
new WeakHashMap<TaskCompletionEvent, WeakReference<TaskCompletionEvent>>();
// Vars to control the task completion event store. See above.
public static final String MAPRED_TASKTRACKER_TCE_STORE_PROPERTY =
"mapred.tasktracker.task.completion.event.store";
private boolean useTaskCompletionEventsStore = false;
int workerThreads;
CleanupQueue directoryCleanupThread;
volatile JvmManager jvmManager;
private long previousCounterUpdate = 0;
private TaskMemoryManagerThread taskMemoryManager;
private boolean taskMemoryManagerEnabled = true;
private long totalVirtualMemoryOnTT = JobConf.DISABLED_MEMORY_LIMIT;
private long totalPhysicalMemoryOnTT = JobConf.DISABLED_MEMORY_LIMIT;
private long mapSlotMemorySizeOnTT = JobConf.DISABLED_MEMORY_LIMIT;
private long reduceSlotSizeMemoryOnTT = JobConf.DISABLED_MEMORY_LIMIT;
private long totalMemoryAllottedForTasks = JobConf.DISABLED_MEMORY_LIMIT;
private TaskLogsMonitor taskLogsMonitor;
public static final String MAPRED_TASKTRACKER_MEMORY_CALCULATOR_PLUGIN_PROPERTY =
"mapred.tasktracker.memory_calculator_plugin";
protected ResourceCalculatorPlugin resourceCalculatorPlugin = null;
/**
* the minimum interval between jobtracker polls
*/
private volatile int heartbeatInterval = HEARTBEAT_INTERVAL_MIN;
/**
* Number of maptask completion events locations to poll for at one time
*/
private int probe_sample_size = 500;
private IndexCache indexCache;
private MRAsyncDiskService asyncDiskService;
private ObjectName versionBeanName;
/**
* Handle to the specific instance of the {@link TaskController} class
*/
private TaskController taskController;
/**
* Handle to the specific instance of the {@link NodeHealthCheckerService}
*/
private NodeHealthCheckerService healthChecker;
/*
* A list of commitTaskActions for whom commit response has been received
*/
protected List<TaskAttemptID> commitResponses =
Collections.synchronizedList(new ArrayList<TaskAttemptID>());
protected ShuffleServerMetrics shuffleServerMetrics;
/** This class contains the methods that should be used for metrics-reporting
* the specific metrics for shuffle. The TaskTracker is actually a server for
* the shuffle and hence the name ShuffleServerMetrics.
*/
public class ShuffleServerMetrics implements Updater {
private MetricsRecord shuffleMetricsRecord = null;
private int serverHandlerBusy = 0;
private long outputBytes = 0;
private int failedOutputs = 0;
private int successOutputs = 0;
private int httpQueueLen = 0;
private ThreadPoolExecutor nettyWorkerThreadPool = null;
ShuffleServerMetrics(JobConf conf) {
MetricsContext context = MetricsUtil.getContext("mapred");
shuffleMetricsRecord =
MetricsUtil.createRecord(context, "shuffleOutput");
this.shuffleMetricsRecord.setTag("sessionId", conf.getSessionId());
context.registerUpdater(this);
}
synchronized void serverHandlerBusy() {
++serverHandlerBusy;
}
synchronized void serverHandlerFree() {
--serverHandlerBusy;
}
public synchronized void outputBytes(long bytes) {
outputBytes += bytes;
}
synchronized void failedOutput() {
++failedOutputs;
}
synchronized void successOutput() {
++successOutputs;
}
synchronized void setHttpQueueLen(int queueLen) {
this.httpQueueLen = queueLen;
}
synchronized void setNettyWorkerThreadPool(ThreadPoolExecutor workerThreadPool) {
this.nettyWorkerThreadPool = workerThreadPool;
}
public void doUpdates(MetricsContext unused) {
synchronized (this) {
if (workerThreads != 0) {
shuffleMetricsRecord.setMetric("shuffle_handler_busy_percent",
100*((float)serverHandlerBusy/workerThreads));
} else {
shuffleMetricsRecord.setMetric("shuffle_handler_busy_percent", 0);
}
shuffleMetricsRecord.setMetric("shuffle_queue_len", httpQueueLen);
shuffleMetricsRecord.incrMetric("shuffle_output_bytes",
outputBytes);
shuffleMetricsRecord.incrMetric("shuffle_failed_outputs",
failedOutputs);
shuffleMetricsRecord.incrMetric("shuffle_success_outputs",
successOutputs);
// Netty map output metrics
if (nettyWorkerThreadPool != null) {
shuffleMetricsRecord.setMetric("netty_mapoutput_activecount",
nettyWorkerThreadPool.getActiveCount());
shuffleMetricsRecord.setMetric("netty_mapoutput_poolsize",
nettyWorkerThreadPool.getPoolSize());
shuffleMetricsRecord.setMetric("netty_mapoutput_maximumpoolsize",
nettyWorkerThreadPool.getMaximumPoolSize());
shuffleMetricsRecord.setMetric("netty_mapoutput_largestpoolsize",
nettyWorkerThreadPool.getLargestPoolSize());
shuffleMetricsRecord.setMetric("netty_mapoutput_taskcount",
nettyWorkerThreadPool.getTaskCount());
}
outputBytes = 0;
failedOutputs = 0;
successOutputs = 0;
}
shuffleMetricsRecord.update();
}
}
private TaskTrackerInstrumentation myInstrumentation = null;
public TaskTrackerInstrumentation getTaskTrackerInstrumentation() {
return myInstrumentation;
}
/**
* A list of tips that should be cleaned up.
*/
protected BlockingQueue<TaskTrackerAction> tasksToCleanup =
new LinkedBlockingQueue<TaskTrackerAction>();
/**
* Variables related to running a simulated tasktracker where map/reduce tasks
* finish without doing any actual work. Saves CPU and memory as no JVM is
* launched.
*/
// Whether the task tracker is running in the simulation mode
private boolean simulatedTaskMode = false;
// A thread that simulates the running of map/reduce tasks
protected SimulatedTaskRunner simulatedTaskRunner = null;
// Conf var name for whether TT should run in simulation mode
protected static String TT_SIMULATED_TASKS =
"mapred.tasktracker.simulated.tasks";
// Conf var name for how long the simulated task should take to finish in ms
// Applies to both maps and reduces.
protected static String TT_SIMULATED_TASK_RUNNING_TIME =
"mapred.tasktracker.simulated.tasks.running.time";
/**
* Purge old user logs, and clean up half of the logs if the number of logs
* exceed the limit.
*/
private Thread logCleanupThread =
new Thread(new LogCleanupThread(TaskLog.getUserLogDir()), "logCleanup");
class LogCleanupThread implements Runnable {
File logDir;
public LogCleanupThread(File logDir) {
this.logDir = logDir;
}
public void run() {
long logCleanupIntervalTime = fConf.getLong("mapred.userlog.cleanup.interval", 300000);
int logsRetainHours = fConf.getInt("mapred.userlog.retain.hours", 24);
int logsNumberLimit = fConf.getInt("mapred.userlog.files.limit", 20000);
while(true) {
try{
TaskLog.cleanup(logDir, logsRetainHours, logsNumberLimit);
Thread.sleep(logCleanupIntervalTime);
} catch (Throwable except) {
LOG.warn("Error in cleanup thread ", except);
}
}
}
}
/**
* A daemon-thread that pulls tips off the list of things to cleanup.
*/
private Thread taskCleanupThread =
new Thread(new Runnable() {
public void run() {
while (true) {
try {
TaskTrackerAction action = tasksToCleanup.take();
if (action instanceof KillJobAction) {
purgeJob((KillJobAction) action);
} else if (action instanceof KillTaskAction) {
TaskInProgress tip;
KillTaskAction killAction = (KillTaskAction) action;
synchronized (TaskTracker.this) {
tip = tasks.get(killAction.getTaskID());
}
LOG.info("Received KillTaskAction for task: " +
killAction.getTaskID());
purgeTask(tip, false);
} else {
LOG.error("Non-delete action given to cleanup thread: "
+ action);
}
} catch (Throwable except) {
LOG.warn(StringUtils.stringifyException(except));
}
}
}
}, "taskCleanup");
TaskController getTaskController() {
return taskController;
}
private RunningJob addTaskToJob(JobID jobId,
TaskInProgress tip) throws IOException {
synchronized (runningJobs) {
RunningJob rJob = null;
if (!runningJobs.containsKey(jobId)) {
rJob = createRunningJob(jobId, tip);
rJob.localized = false;
rJob.tasks = new HashSet<TaskInProgress>();
runningJobs.put(jobId, rJob);
} else {
rJob = runningJobs.get(jobId);
}
synchronized (rJob) {
rJob.tasks.add(tip);
}
runningJobs.notify(); //notify the fetcher thread
return rJob;
}
}
protected RunningJob createRunningJob(JobID jobId, TaskInProgress tip)
throws IOException {
return new RunningJob(jobId, this.jobClient, null);
}
private void removeTaskFromJob(JobID jobId, TaskInProgress tip) {
synchronized (runningJobs) {
RunningJob rjob = runningJobs.get(jobId);
if (rjob == null) {
LOG.warn("Task " + tip.getTask().getTaskID() +
" being deleted from unknown job " + jobId);
} else {
synchronized (rjob) {
rjob.tasks.remove(tip);
}
}
}
}
protected synchronized void removeRunningTask(TaskAttemptID attemptID) {
runningTasks.remove(attemptID);
}
protected List<TaskAttemptID> getRunningTasksForJob(JobID jobId) {
List<TaskAttemptID> running = new ArrayList<TaskAttemptID>();
synchronized (this) {
for (TaskAttemptID attemptId: runningTasks.keySet()) {
if (jobId.equals(attemptId.getJobID())) {
running.add(attemptId);
}
}
}
return running;
}
public IndexRecord getIndexInformation(String mapId, int reduce,
Path fileName) throws IOException {
return indexCache.getIndexInformation(mapId, reduce, fileName);
}
TaskLogsMonitor getTaskLogsMonitor() {
return this.taskLogsMonitor;
}
void setTaskLogsMonitor(TaskLogsMonitor t) {
this.taskLogsMonitor = t;
}
static String getCacheSubdir() {
return TaskTracker.SUBDIR + Path.SEPARATOR + TaskTracker.CACHEDIR;
}
static String getJobCacheSubdir() {
return TaskTracker.SUBDIR + Path.SEPARATOR + TaskTracker.JOBCACHE;
}
static String getLocalJobDir(String jobid) {
return getJobCacheSubdir() + Path.SEPARATOR + jobid;
}
static String getLocalTaskDir(String jobid, String taskid) {
return getLocalTaskDir(jobid, taskid, false) ;
}
public static String getIntermediateOutputDir(String jobid, String taskid) {
return getLocalTaskDir(jobid, taskid)
+ Path.SEPARATOR + TaskTracker.OUTPUT ;
}
static String getLocalTaskDir(String jobid,
String taskid,
boolean isCleanupAttempt) {
String taskDir = getLocalJobDir(jobid) + Path.SEPARATOR + taskid;
if (isCleanupAttempt) {
taskDir = taskDir + TASK_CLEANUP_SUFFIX;
}
return taskDir;
}
String getPid(TaskAttemptID tid) {
TaskInProgress tip = tasks.get(tid);
if (tip != null) {
return jvmManager.getPid(tip.getTaskRunner());
}
return null;
}
public long getProtocolVersion(String protocol,
long clientVersion) throws IOException {
if (protocol.equals(TaskUmbilicalProtocol.class.getName())) {
return TaskUmbilicalProtocol.versionID;
} else {
throw new IOException("Unknown protocol for task tracker: " +
protocol);
}
}
public ProtocolSignature getProtocolSignature(String protocol,
long clientVersion, int clientMethodsHash) throws IOException {
return ProtocolSignature.getProtocolSignature(
this, protocol, clientVersion, clientMethodsHash);
}
/**
* Do the real constructor work here. It's in a separate method
* so we can call it again and "recycle" the object after calling
* close().
*/
protected synchronized void initialize(JobConf conf) throws IOException {
maxRefillQueueSize =
conf.getInt(MAX_REFILL_QUEUE_SIZE, DEFAULT_MAX_REFILL_QUEUE_SIZE);
if (maxRefillQueueSize <= 0) {
throw new RuntimeException("Illegal value for " +
MAX_REFILL_QUEUE_SIZE + " " + maxRefillQueueSize);
}
this.originalConf = conf;
// use configured nameserver & interface to get local hostname
this.fConf = new JobConf(conf);
localFs = FileSystem.getLocal(fConf);
if (fConf.get("slave.host.name") != null) {
this.localHostname = fConf.get("slave.host.name");
}
if (localHostname == null) {
this.localHostname =
DNS.getDefaultHost
(fConf.get("mapred.tasktracker.dns.interface","default"),
fConf.get("mapred.tasktracker.dns.nameserver","default"));
}
Class<? extends ResourceCalculatorPlugin> clazz =
fConf.getClass(MAPRED_TASKTRACKER_MEMORY_CALCULATOR_PLUGIN_PROPERTY,
null, ResourceCalculatorPlugin.class);
resourceCalculatorPlugin =
(ResourceCalculatorPlugin) ResourceCalculatorPlugin
.getResourceCalculatorPlugin(clazz, fConf);
LOG.info("Using ResourceCalculatorPlugin : " + resourceCalculatorPlugin);
int numCpuOnTT = resourceCalculatorPlugin.getNumProcessors();
maxMapSlots = getMaxSlots(fConf, numCpuOnTT, TaskType.MAP);
maxReduceSlots = getMaxSlots(fConf, numCpuOnTT, TaskType.REDUCE);
actualMaxMapSlots =
getMaxActualSlots(fConf, numCpuOnTT, TaskType.MAP);
actualMaxReduceSlots =
getMaxActualSlots(fConf, numCpuOnTT, TaskType.REDUCE);
LOG.info("Num cpus = " + numCpuOnTT +
", max map slots = " + maxMapSlots +
", max reduce slots = " + maxReduceSlots +
", actual max map slots = " + actualMaxMapSlots +
", actual max reduce slots = " + actualMaxReduceSlots);
// Check local disk, start async disk service, and clean up all
// local directories.
checkLocalDirs(this.fConf.getLocalDirs());
asyncDiskService = new MRAsyncDiskService(FileSystem.getLocal(fConf),
fConf.getLocalDirs(), fConf);
asyncDiskService.cleanupAllVolumes();
DistributedCache.purgeCache(fConf, asyncDiskService);
versionBeanName = VersionInfo.registerJMX("TaskTracker");
// Clear out state tables
this.tasks.clear();
this.runningTasks = new LinkedHashMap<TaskAttemptID, TaskInProgress>();
this.runningJobs = new TreeMap<JobID, RunningJob>();
this.mapTotal = 0;
this.reduceTotal = 0;
this.acceptNewTasks = true;
this.status = null;
this.minSpaceStart = this.fConf.getLong("mapred.local.dir.minspacestart", 0L);
this.minSpaceKill = this.fConf.getLong("mapred.local.dir.minspacekill", 0L);
//tweak the probe sample size (make it a function of numCopiers)
probe_sample_size = this.fConf.getInt("mapred.tasktracker.events.batchsize", 500);
// Set up TaskTracker instrumentation
this.myInstrumentation = createInstrumentation(this, fConf);
// bind address
String address =
NetUtils.getServerAddress(fConf,
"mapred.task.tracker.report.bindAddress",
"mapred.task.tracker.report.port",
"mapred.task.tracker.report.address");
InetSocketAddress socAddr = NetUtils.createSocketAddr(address);
String bindAddress = socAddr.getHostName();
int tmpPort = socAddr.getPort();
this.jvmManager = new JvmManager(this);
// Set service-level authorization security policy
if (this.fConf.getBoolean(
ServiceAuthorizationManager.SERVICE_AUTHORIZATION_CONFIG, false)) {
PolicyProvider policyProvider =
(PolicyProvider)(ReflectionUtils.newInstance(
this.fConf.getClass(PolicyProvider.POLICY_PROVIDER_CONFIG,
MapReducePolicyProvider.class, PolicyProvider.class),
this.fConf));
SecurityUtil.setPolicy(new ConfiguredPolicy(this.fConf, policyProvider));
}
// RPC initialization
int max = actualMaxMapSlots > actualMaxReduceSlots ?
actualMaxMapSlots : actualMaxReduceSlots;
//set the num handlers to max*2 since canCommit may wait for the duration
//of a heartbeat RPC
int numHandlers = 2 * max;
LOG.info("Starting RPC server with " + numHandlers + " handlers");
this.taskReportServer =
RPC.getServer(this, bindAddress, tmpPort, numHandlers, false, this.fConf);
this.taskReportServer.start();
// get the assigned address
this.taskReportAddress = taskReportServer.getListenerAddress();
this.fConf.set("mapred.task.tracker.report.address",
taskReportAddress.getHostName() + ":" + taskReportAddress.getPort());
LOG.info("TaskTracker up at: " + this.taskReportAddress);
this.taskTrackerName = "tracker_" + localHostname + ":" + taskReportAddress;
LOG.info("Starting tracker " + taskTrackerName);
this.justInited = true;
this.running = true;
initializeMemoryManagement();
setTaskLogsMonitor(new TaskLogsMonitor(getMapUserLogRetainSize(),
getReduceUserLogRetainSize()));
getTaskLogsMonitor().start();
this.indexCache = new IndexCache(this.fConf);
pulseChecker = PulseChecker.create(this, "TaskTracker");
heartbeatMonitor = new HeartbeatMonitor(this.fConf);
mapLauncher =
new TaskLauncher(TaskType.MAP, maxMapSlots, actualMaxMapSlots);
reduceLauncher =
new TaskLauncher(TaskType.REDUCE, maxReduceSlots, actualMaxReduceSlots);
mapLauncher.start();
reduceLauncher.start();
Class<? extends TaskController> taskControllerClass
= fConf.getClass("mapred.task.tracker.task-controller",
DefaultTaskController.class,
TaskController.class);
taskController = (TaskController)ReflectionUtils.newInstance(
taskControllerClass, fConf);
//setup and create jobcache directory with appropriate permissions
taskController.setup();
//Start up node health checker service.
if (shouldStartHealthMonitor(this.fConf)) {
startHealthMonitor(this.fConf);
}
oobHeartbeatOnTaskCompletion =
fConf.getBoolean(TT_OUTOFBAND_HEARBEAT, false);
fastFetch = fConf.getBoolean(TT_FAST_FETCH, false);
// Setup the launcher if in simulation mode
simulatedTaskMode = fConf.getBoolean(TT_SIMULATED_TASKS, false);
LOG.info("simulatedTaskMode = " + simulatedTaskMode);
long simulatedTaskRunningTime =
fConf.getLong(TT_SIMULATED_TASK_RUNNING_TIME, 20000);
if (simulatedTaskMode) {
simulatedTaskRunner =
new SimulatedTaskRunner(simulatedTaskRunningTime, this);
simulatedTaskRunner.start();
}
// Setup task completion event store
useTaskCompletionEventsStore = fConf.getBoolean(
MAPRED_TASKTRACKER_TCE_STORE_PROPERTY, false);
profileAllTasks = fConf.getBoolean(TT_PROFILE_ALL_TASKS, false);
}
protected String getLocalHostname() {
return localHostname;
}
protected TaskUmbilicalProtocol getUmbilical(
TaskInProgress tip ) throws IOException {
return this;
}
protected void cleanupUmbilical(TaskUmbilicalProtocol t) {
return;
}
public boolean getProfileAllTasks() {
return profileAllTasks;
}
protected void initializeMapEventFetcher() {
// start the thread that will fetch map task completion events
this.mapEventsFetcher = new MapEventsFetcherThread();
mapEventsFetcher.setDaemon(true);
mapEventsFetcher.setName(
"Map-events fetcher for all reduce tasks on " + taskTrackerName);
mapEventsFetcher.start();
}
public static Class<?>[] getInstrumentationClasses(Configuration conf) {
return conf.getClasses("mapred.tasktracker.instrumentation",
TaskTrackerMetricsInst.class);
}
public static void setInstrumentationClass(
Configuration conf, Class<? extends TaskTrackerInstrumentation> t) {
conf.setClass("mapred.tasktracker.instrumentation",
t, TaskTrackerInstrumentation.class);
}
public static TaskTrackerInstrumentation createInstrumentation(
TaskTracker tt, Configuration conf) {
try {
Class<?>[] instrumentationClasses = getInstrumentationClasses(conf);
if (instrumentationClasses.length == 0) {
LOG.error("Empty string given for mapred.tasktracker.instrumentation" +
" property -- will use default instrumentation class instead");
return new TaskTrackerMetricsInst(tt);
} else if (instrumentationClasses.length == 1) {
// Just one instrumentation class given; create it directly
Class<?> cls = instrumentationClasses[0];
java.lang.reflect.Constructor<?> c =
cls.getConstructor(new Class[] {TaskTracker.class} );
return (TaskTrackerInstrumentation) c.newInstance(tt);
} else {
// Multiple instrumentation classes given; use a composite object
List<TaskTrackerInstrumentation> instrumentations =
new ArrayList<TaskTrackerInstrumentation>();
for (Class<?> cls: instrumentationClasses) {
java.lang.reflect.Constructor<?> c =
cls.getConstructor(new Class[] {TaskTracker.class} );
TaskTrackerInstrumentation inst =
(TaskTrackerInstrumentation) c.newInstance(tt);
instrumentations.add(inst);
}
return new CompositeTaskTrackerInstrumentation(tt, instrumentations);
}
} catch(Exception e) {
// Reflection can throw lots of exceptions -- handle them all by
// falling back on the default.
LOG.error("Failed to initialize TaskTracker metrics", e);
return new TaskTrackerMetricsInst(tt);
}
}
/**
* Removes all contents of temporary storage. Called upon
* startup, to remove any leftovers from previous run.
*
* Use MRAsyncDiskService.moveAndDeleteAllVolumes instead.
* @see org.apache.hadoop.util.MRAsyncDiskService#cleanupAllVolumes()
*/
@Deprecated
public void cleanupStorage() throws IOException {
this.fConf.deleteLocalFiles();
}
// Object on wait which MapEventsFetcherThread is going to wait.
private Object waitingOn = new Object();
private class MapEventsFetcherThread extends Thread {
public List <FetchStatus> reducesInShuffle() {
List <FetchStatus> fList = new ArrayList<FetchStatus>();
for (Map.Entry <JobID, RunningJob> item : runningJobs.entrySet()) {
RunningJob rjob = item.getValue();
JobID jobId = item.getKey();
FetchStatus f;
synchronized (rjob) {
f = rjob.getFetchStatus();
for (TaskInProgress tip : rjob.tasks) {
Task task = tip.getTask();
if (!task.isMapTask()) {
if (((ReduceTask)task).getPhase() ==
TaskStatus.Phase.SHUFFLE) {
if (rjob.getFetchStatus() == null) {
//this is a new job; we start fetching its map events
f = new FetchStatus(
jobId, ((ReduceTask)task).getNumMaps(), rjob);
rjob.setFetchStatus(f);
}
f = rjob.getFetchStatus();
fList.add(f);
break; //no need to check any more tasks belonging to this
}
}
}
}
}
//at this point, we have information about for which of
//the running jobs do we need to query the jobtracker for map
//outputs (actually map events).
return fList;
}
@Override
public void run() {
LOG.info("Starting thread: " + this.getName());
while (running) {
try {
List <FetchStatus> fList = null;
synchronized (runningJobs) {
while (((fList = reducesInShuffle()).size()) == 0) {
try {
runningJobs.wait();
} catch (InterruptedException e) {
LOG.info("Shutting down: " + this.getName());
return;
}
}
}
// now fetch all the map task events for all the reduce tasks
// possibly belonging to different jobs
boolean fetchAgain = false; //flag signifying whether we want to fetch
//immediately again.
for (FetchStatus f : fList) {
long currentTime = System.currentTimeMillis();
try {
//the method below will return true when we have not
//fetched all available events yet
if (f.fetchMapCompletionEvents(currentTime)) {
fetchAgain = true;
}
} catch (Exception e) {
LOG.warn(
"Ignoring exception that fetch for map completion" +
" events threw for " + f.jobId + " threw: ", e);
}
if (!running) {
break;
}
}
synchronized (waitingOn) {
try {
if (!fetchAgain) {
waitingOn.wait(heartbeatInterval);
}
} catch (InterruptedException ie) {
LOG.info("Shutting down: " + this.getName());
return;
}
}
} catch (Exception e) {
LOG.info("Ignoring exception ", e);
}
}
}
}
public class FetchStatus {
/** The next event ID that we will start querying the JobTracker from*/
public IntWritable fromEventId;
/** This is the cache of map events for a given job */
private List<TaskCompletionEvent> allMapEvents;
/** What jobid this fetchstatus object is for*/
private JobID jobId;
private long lastFetchTime;
private boolean fetchAgain;
private RunningJob rJob;
public FetchStatus(JobID jobId, int numMaps, RunningJob rJob) {
this.fromEventId = new IntWritable(0);
this.jobId = jobId;
this.allMapEvents = new ArrayList<TaskCompletionEvent>(numMaps);
this.rJob = rJob;
}
/**
* Reset the events obtained so far.
*/
public void reset() {
// Note that the sync is first on fromEventId and then on allMapEvents
synchronized (fromEventId) {
synchronized (allMapEvents) {
fromEventId.set(0); // set the new index for TCE
allMapEvents.clear();
}
}
}
public TaskCompletionEvent[] getMapEvents(int fromId, int max) {
TaskCompletionEvent[] mapEvents =
TaskCompletionEvent.EMPTY_ARRAY;
boolean notifyFetcher = false;
synchronized (allMapEvents) {
if (allMapEvents.size() > fromId) {
int actualMax = Math.min(max, (allMapEvents.size() - fromId));
List <TaskCompletionEvent> eventSublist =
allMapEvents.subList(fromId, actualMax + fromId);
mapEvents = eventSublist.toArray(mapEvents);
} else {
// Notify Fetcher thread.
notifyFetcher = true;
// Go to the jobtracker right away
fetchAgain = TaskTracker.this.fastFetch;
}
}
if (notifyFetcher) {
synchronized (waitingOn) {
waitingOn.notify();
}
}
return mapEvents;
}
public boolean fetchMapCompletionEvents(long currTime) throws IOException {
if (!fetchAgain && (currTime - lastFetchTime) < heartbeatInterval) {
return false;
}
int currFromEventId = 0;
synchronized (fromEventId) {
currFromEventId = fromEventId.get();
List <TaskCompletionEvent> recentMapEvents =
queryJobTracker(fromEventId, jobId, rJob.getJobClient());
synchronized (allMapEvents) {
allMapEvents.addAll(recentMapEvents);
}
lastFetchTime = currTime;
if (fromEventId.get() - currFromEventId >= probe_sample_size) {
//return true when we have fetched the full payload, indicating
//that we should fetch again immediately (there might be more to
//fetch
fetchAgain = true;
return true;
}
}
fetchAgain = false;
return false;
}
}
private static LocalDirAllocator lDirAlloc =
new LocalDirAllocator("mapred.local.dir");
// intialize the job directory
private JobConf localizeJob(TaskInProgress tip) throws IOException {
Path localJarFile = null;
Task t = tip.getTask();
JobID jobId = t.getJobID();
Path jobFile = new Path(t.getJobFile());
// Get sizes of JobFile and JarFile
// sizes are -1 if they are not present.
FileStatus status = null;
long jobFileSize = -1;
try {
status = systemFS.getFileStatus(jobFile);
jobFileSize = status.getLen();
} catch(FileNotFoundException fe) {
jobFileSize = -1;
}
Path localJobFile = lDirAlloc.getLocalPathForWrite(
getLocalJobDir(jobId.toString())
+ Path.SEPARATOR + "job.xml",
jobFileSize, fConf);
RunningJob rjob = addTaskToJob(jobId, tip);
synchronized (rjob.localizationLock) {
if (rjob.localized == false) {
// Actually start the job localization IO.
FileSystem localFs = FileSystem.getLocal(fConf);
// this will happen on a partial execution of localizeJob.
// Sometimes the job.xml gets copied but copying job.jar
// might throw out an exception
// we should clean up and then try again
Path jobDir = localJobFile.getParent();
if (localFs.exists(jobDir)){
LOG.warn("Deleting pre-existing jobDir: " + jobDir
+ " when localizeJob for tip " + tip);
localFs.delete(jobDir, true);
boolean b = localFs.mkdirs(jobDir);
if (!b)
throw new IOException("Not able to create job directory "
+ jobDir.toString());
}
systemFS.copyToLocalFile(jobFile, localJobFile);
JobConf localJobConf = new JobConf(localJobFile);
// create the 'work' directory
// job-specific shared directory for use as scratch space
Path workDir = lDirAlloc.getLocalPathForWrite(
(getLocalJobDir(jobId.toString())
+ Path.SEPARATOR + "work"), fConf);
if (!localFs.mkdirs(workDir)) {
throw new IOException("Mkdirs failed to create "
+ workDir.toString());
}
System.setProperty("job.local.dir", workDir.toString());
localJobConf.set("job.local.dir", workDir.toString());
// copy Jar file to the local FS and unjar it.
String jarFile = localJobConf.getJar();
long jarFileSize = -1;
boolean changeLocalJobConf = jarFile != null;
if (changeLocalJobConf) {
boolean shared =
localJobConf.getBoolean("mapred.cache.shared.enabled", false);
// If sharing is turned on, we already have the jarFileSize, so we
// don't have to make another RPC call to NameNode
Path jarFilePath = new Path(jarFile);
if (shared) {
try {
jarFileSize =
Long.parseLong(DistributedCache.
getSharedArchiveLength(localJobConf)[0]);
} catch (NullPointerException npe) {
jarFileSize = -1;
}
} else {
try {
status = systemFS.getFileStatus(jarFilePath);
jarFileSize = status.getLen();
} catch(FileNotFoundException fe) {
jarFileSize = -1;
}
}
// Here we check for and we check five times the size of jarFileSize
// to accommodate for unjarring the jar file in work directory
localJarFile = new Path(lDirAlloc.getLocalPathForWrite(
getLocalJobDir(jobId.toString())
+ Path.SEPARATOR + "jars",
5 * jarFileSize, fConf), "job.jar");
if (!localFs.mkdirs(localJarFile.getParent())) {
throw new IOException("Mkdirs failed to create jars directory ");
}
if (!shared) {
// we copy the job jar to the local disk and unjar it
// for the shared case - this is done inside TaskRunner
systemFS.copyToLocalFile(jarFilePath, localJarFile);
RunJar.unJar(new File(localJarFile.toString()),
new File(localJarFile.getParent().toString()));
}
localJobConf.setJar(localJarFile.toString());
}
reconfigureLocalJobConf(localJobConf, localJobFile, tip, changeLocalJobConf);
synchronized (rjob) {
rjob.keepJobFiles = ((localJobConf.getKeepTaskFilesPattern() != null) ||
localJobConf.getKeepFailedTaskFiles());
rjob.jobConf = localJobConf;
taskController.initializeJob(jobId);
rjob.localized = true;
}
}
}
return new JobConf(rjob.jobConf);
}
protected void reconfigureLocalJobConf(
JobConf localJobConf, Path localJobFile, TaskInProgress tip, boolean changed)
throws IOException {
if (!changed) {
return;
}
OutputStream out = localFs.create(localJobFile);
try {
localJobConf.writeXml(out);
} finally {
out.close();
}
}
public synchronized void shutdown() throws IOException {
shuttingDown = true;
close();
}
/**
* Close down the TaskTracker and all its components. We must also shutdown
* any running tasks or threads, and cleanup disk space. A new TaskTracker
* within the same process space might be restarted, so everything must be
* clean.
*/
public synchronized void close() throws IOException {
//
// Kill running tasks. Do this in a 2nd vector, called 'tasksToClose',
// because calling jobHasFinished() may result in an edit to 'tasks'.
//
TreeMap<TaskAttemptID, TaskInProgress> tasksToClose =
new TreeMap<TaskAttemptID, TaskInProgress>();
tasksToClose.putAll(tasks);
for (TaskInProgress tip : tasksToClose.values()) {
tip.jobHasFinished(false);
}
this.running = false;
if (pulseChecker != null) {
pulseChecker.shutdown();
}
if (versionBeanName != null) {
MBeanUtil.unregisterMBean(versionBeanName);
}
// Clear local storage
if (asyncDiskService != null) {
// Clear local storage
asyncDiskService.cleanupAllVolumes();
// Shutdown all async deletion threads with up to 10 seconds of delay
asyncDiskService.shutdown();
try {
if (!asyncDiskService.awaitTermination(10000)) {
asyncDiskService.shutdownNow();
asyncDiskService = null;
}
} catch (InterruptedException e) {
asyncDiskService.shutdownNow();
asyncDiskService = null;
}
}
// Shutdown the fetcher thread
if (this.mapEventsFetcher != null) {
this.mapEventsFetcher.interrupt();
}
// Stop the launchers
this.mapLauncher.interrupt();
this.reduceLauncher.interrupt();
if (this.heartbeatMonitor != null) {
this.heartbeatMonitor.interrupt();
}
// Stop memory manager thread
if (this.taskMemoryManager != null) {
this.taskMemoryManager.shutdown();
}
// All tasks are killed. So, they are removed from TaskLog monitoring also.
// Interrupt the monitor.
getTaskLogsMonitor().interrupt();
jvmManager.stop();
// shutdown RPC connections
RPC.stopProxy(jobClient);
// wait for the fetcher thread to exit
for (boolean done = false; !done; ) {
try {
if (this.mapEventsFetcher != null) {
this.mapEventsFetcher.join();
}
done = true;
} catch (InterruptedException e) {
}
}
if (taskReportServer != null) {
taskReportServer.stop();
taskReportServer = null;
}
if (healthChecker != null) {
//stop node health checker service
healthChecker.stop();
healthChecker = null;
}
if (this.server != null) {
try {
LOG.info("Shutting down StatusHttpServer");
this.server.stop();
LOG.info("Shutting down Netty MapOutput Server");
if (this.nettyMapOutputServer != null) {
this.nettyMapOutputServer.stop();
}
} catch (Exception e) {
LOG.warn("Exception shutting down TaskTracker", e);
}
}
}
/**
* Start with the local machine name, and the default JobTracker
*/
public TaskTracker(JobConf conf) throws IOException {
// Default is to use netty over jetty
boolean useNetty = conf.getBoolean(NETTY_MAPOUTPUT_USE, true);
this.shuffleServerMetrics = new ShuffleServerMetrics(conf);
if (useNetty) {
initNettyMapOutputHttpServer(conf);
}
initHttpServer(conf, useNetty);
LOG.info("Http port " + httpPort +
", netty map output http port " + nettyMapOutputHttpPort +
", use netty = " + useNetty);
initJobClient(conf);
initialize(conf);
initializeMapEventFetcher();
}
protected void initJobClient(JobConf conf) throws IOException {
this.jobTrackAddr = JobTracker.getAddress(conf);
this.jobClient = (InterTrackerProtocol)
RPC.waitForProxy(InterTrackerProtocol.class,
InterTrackerProtocol.versionID,
jobTrackAddr,conf);
}
protected void initNettyMapOutputHttpServer(JobConf conf) throws IOException {
int nettyHttpPort = conf.getInt(NETTY_MAPOUTPUT_HTTP_PORT, 0);
NettyMapOutputAttributes attributes = new NettyMapOutputAttributes(
conf, this, FileSystem.getLocal(conf),
new LocalDirAllocator("mapred.local.dir"), shuffleServerMetrics);
nettyMapOutputServer = new NettyMapOutputHttpServer(nettyHttpPort);
nettyMapOutputServer.init(conf);
shuffleServerMetrics.setNettyWorkerThreadPool(
nettyMapOutputServer.getWorkerThreadPool());
HttpMapOutputPipelineFactory pipelineFactory =
new HttpMapOutputPipelineFactory(attributes, nettyHttpPort);
this.nettyMapOutputHttpPort = nettyMapOutputServer.start(pipelineFactory);
}
protected void initHttpServer(JobConf conf,
boolean useNettyMapOutputs) throws IOException {
String infoAddr =
NetUtils.getServerAddress(conf,
"tasktracker.http.bindAddress",
"tasktracker.http.port",
"mapred.task.tracker.http.address");
InetSocketAddress infoSocAddr = NetUtils.createSocketAddr(infoAddr);
String httpBindAddress = infoSocAddr.getHostName();
int httpPort = infoSocAddr.getPort();
server = new HttpServer("task", httpBindAddress, httpPort,
httpPort == 0, conf);
workerThreads = conf.getInt("tasktracker.http.threads", 40);
server.setThreads(1, workerThreads);
// let the jsp pages get to the task tracker, config, and other relevant
// objects
FileSystem local = FileSystem.getLocal(conf);
this.localDirAllocator = new LocalDirAllocator("mapred.local.dir");
server.setAttribute("task.tracker", this);
server.setAttribute("local.file.system", local);
server.setAttribute("conf", conf);
server.setAttribute("log", LOG);
server.setAttribute("localDirAllocator", localDirAllocator);
server.setAttribute("shuffleServerMetrics", shuffleServerMetrics);
server.setAttribute(ReconfigurationServlet.
CONF_SERVLET_RECONFIGURABLE_PREFIX + "/ttconfchange",
TaskTracker.this);
server.setAttribute("nettyMapOutputHttpPort", nettyMapOutputHttpPort);
server.addInternalServlet("reconfiguration", "/ttconfchange",
ReconfigurationServlet.class);
server.addInternalServlet(
"mapOutput", "/mapOutput", MapOutputServlet.class);
server.addInternalServlet("taskLog", "/tasklog", TaskLogServlet.class);
server.start();
this.httpPort = server.getPort();
checkJettyPort();
}
/**
* Blank constructor. Only usable by tests.
*/
TaskTracker() {
server = null;
}
/**
* Configuration setter method for use by tests.
*/
void setConf(JobConf conf) {
fConf = conf;
}
public boolean isJettyLowOnThreads() {
return server.isLowOnThreads();
}
public int getJettyQueueSize() {
return server.getQueueSize();
}
public int getJettyThreads() {
return server.getThreads();
}
protected void checkJettyPort() throws IOException {
//See HADOOP-4744
int port = server.getPort();
if (port < 0) {
shuttingDown = true;
throw new IOException("Jetty problem. Jetty didn't bind to a " +
"valid port");
}
}
// This method is stubbed for testing only
public void startLogCleanupThread() throws IOException {
logCleanupThread.setDaemon(true);
logCleanupThread.start();
}
protected void startCleanupThreads() throws IOException {
taskCleanupThread.setDaemon(true);
taskCleanupThread.start();
logCleanupThread.setDaemon(true);
logCleanupThread.start();
directoryCleanupThread = new CleanupQueue();
}
/**
* The connection to the JobTracker, used by the TaskRunner
* for locating remote files.
*/
public InterTrackerProtocol getJobClient() {
return jobClient;
}
/** Return the port at which the tasktracker bound to */
public synchronized InetSocketAddress getTaskTrackerReportAddress() {
return taskReportAddress;
}
/**
* Given a TaskCompletionEvent, it checks the store and returns an equivalent
* copy that can be used instead. If not in the store, it adds it to the store
* and returns the same supplied TaskCompletionEvent. If the caller uses the
* stored copy, we have an opportunity to save memory.
* @param t the TaskCompletionEvent to check in the store. If not in the store
* add it
* @return the equivalent TaskCompletionEvent to use instead. May be the same
* as the one passed in.
*/
private static TaskCompletionEvent getTceFromStore(TaskCompletionEvent t) {
// Use the store so that we can save memory in simulations where there
// are multiple task trackers in memory
synchronized(taskCompletionEventsStore) {
WeakReference<TaskCompletionEvent> e =
taskCompletionEventsStore.get(t);
// If it's not in the store, then put it in
if (e == null) {
taskCompletionEventsStore.put(t,
new WeakReference<TaskCompletionEvent>(t));
return t;
}
// It might be in the map, but the actual item might have been GC'ed
// just after we got it from the map
TaskCompletionEvent tceFromStore = e.get();
if (tceFromStore == null) {
taskCompletionEventsStore.put(t,
new WeakReference<TaskCompletionEvent>(t));
return t;
}
return tceFromStore;
}
}
/** Queries the job tracker for a set of outputs ready to be copied
* @param fromEventId the first event ID we want to start from, this is
* modified by the call to this method
* @param jobClient the job tracker
* @return a set of locations to copy outputs from
* @throws IOException
*/
private List<TaskCompletionEvent> queryJobTracker(IntWritable fromEventId,
JobID jobId,
InterTrackerProtocol jobClient)
throws IOException {
if (jobClient == null) {
List<TaskCompletionEvent> empty = Collections.emptyList();
return empty;
}
TaskCompletionEvent t[] = jobClient.getTaskCompletionEvents(
jobId,
fromEventId.get(),
probe_sample_size);
//we are interested in map task completion events only. So store
//only those
List <TaskCompletionEvent> recentMapEvents =
new ArrayList<TaskCompletionEvent>();
for (int i = 0; i < t.length; i++) {
if (t[i].isMap) {
if (useTaskCompletionEventsStore) {
// Try to get it from a store so that we don't have duplicate instances
// in memory in the same JVM. This could happen if there are multiple TT's
// and different reduce tasks from the same job are running in each TT.
recentMapEvents.add(getTceFromStore(t[i]));
} else {
recentMapEvents.add(t[i]);
}
}
}
fromEventId.set(fromEventId.get() + t.length);
return recentMapEvents;
}
private class HeartbeatMonitor extends Thread {
public static final long DEFAULT_HEARTBEAT_GAP = 30 * 60 * 1000; // 30 min.
final private long maxHeartbeatGap;
public HeartbeatMonitor(Configuration conf) {
maxHeartbeatGap =
conf.getLong("mapred.tasktraker.maxheartbeatgap", DEFAULT_HEARTBEAT_GAP);
}
@Override
public void run() {
LOG.info("Starting HeartbeatMonitor");
boolean forceExit = false;
long gap = 0;
while (running && !shuttingDown) {
long now = System.currentTimeMillis();
gap = now - lastHeartbeat;
if (gap > maxHeartbeatGap) {
forceExit = true;
break;
}
try {
Thread.sleep(1000);
} catch (InterruptedException e) {
}
}
if (forceExit) {
LOG.fatal("No heartbeat for " + gap + " msec, TaskTracker has to die");
ReflectionUtils.logThreadInfo(LOG, "No heartbeat", 1);
System.exit(-1);
} else {
LOG.info("Stopping HeartbeatMonitor, running=" + running +
", shuttingDown=" + shuttingDown);
}
}
}
/**
* Main service loop. Will stay in this loop forever.
*/
private State offerService() throws Exception {
while (running && !shuttingDown) {
try {
long now = System.currentTimeMillis();
long waitTime = heartbeatInterval - (now - lastHeartbeat);
if (waitTime > 0) {
// sleeps for the wait time or
// until there are empty slots to schedule tasks
synchronized (finishedCount) {
if (finishedCount.get() == 0) {
finishedCount.wait(waitTime);
}
finishedCount.set(0);
}
}
// If the TaskTracker is just starting up:
// 1. Verify the buildVersion
// 2. Get the system directory & filesystem
if(justInited) {
String jobTrackerBV = jobClient.getBuildVersion();
if(doCheckBuildVersion() &&
!VersionInfo.getBuildVersion().equals(jobTrackerBV)) {
String msg = "Shutting down. Incompatible buildVersion." +
"\nJobTracker's: " + jobTrackerBV +
"\nTaskTracker's: "+ VersionInfo.getBuildVersion();
LOG.error(msg);
try {
jobClient.reportTaskTrackerError(taskTrackerName, null, msg);
} catch(Exception e ) {
LOG.info("Problem reporting to jobtracker: " + e);
}
return State.DENIED;
}
String dir = jobClient.getSystemDir();
if (dir == null) {
throw new IOException("Failed to get system directory");
}
systemDirectory = new Path(dir);
systemFS = systemDirectory.getFileSystem(fConf);
}
boolean sendCounters = false;
if (now > (previousCounterUpdate + COUNTER_UPDATE_INTERVAL)) {
sendCounters = true;
previousCounterUpdate = now;
}
status = updateTaskTrackerStatus(
sendCounters, status, runningTasks.values(), jobTrackAddr);
// Send heartbeat only when there is at least one task in progress
HeartbeatResponse heartbeatResponse = transmitHeartBeat(
jobClient, heartbeatResponseId, status);
// The heartbeat got through successfully!
// Force a rebuild of 'status' on the next iteration
status = null;
heartbeatResponseId = heartbeatResponse.getResponseId();
final boolean firstHeartbeat = (lastHeartbeat == 0);
// Note the time when the heartbeat returned, use this to decide when to send the
// next heartbeat
lastHeartbeat = System.currentTimeMillis();
// Start the heartbeat monitor after the first heartbeat.
if (firstHeartbeat) {
heartbeatMonitor.start();
}
TaskTrackerAction[] actions = heartbeatResponse.getActions();
if(LOG.isDebugEnabled()) {
LOG.debug("Got heartbeatResponse from JobTracker with responseId: " +
heartbeatResponse.getResponseId() + " and " +
((actions != null) ? actions.length : 0) + " actions");
}
if (reinitTaskTracker(actions)) {
return State.STALE;
}
// resetting heartbeat interval from the response.
heartbeatInterval = heartbeatResponse.getHeartbeatInterval();
justStarted = false;
justInited = false;
if (actions != null){
for(TaskTrackerAction action: actions) {
if (action instanceof LaunchTaskAction) {
addToTaskQueue((LaunchTaskAction)action);
} else if (action instanceof CommitTaskAction) {
CommitTaskAction commitAction = (CommitTaskAction)action;
if (!commitResponses.contains(commitAction.getTaskID())) {
LOG.info("Received commit task action for " +
commitAction.getTaskID());
commitResponses.add(commitAction.getTaskID());
}
} else {
tasksToCleanup.put(action);
}
}
}
markUnresponsiveTasks();
killOverflowingTasks();
//we've cleaned up, resume normal operation
if (!acceptNewTasks && isIdle()) {
acceptNewTasks=true;
}
//The check below may not be required every iteration but we are
//erring on the side of caution here. We have seen many cases where
//the call to jetty's getLocalPort() returns different values at
//different times. Being a real paranoid here.
checkJettyPort();
} catch (InterruptedException ie) {
LOG.info("Interrupted. Closing down.");
return State.INTERRUPTED;
} catch (DiskErrorException de) {
String msg = "Exiting task tracker for disk error:\n" +
StringUtils.stringifyException(de);
LOG.error(msg);
synchronized (this) {
jobClient.reportTaskTrackerError(taskTrackerName,
"DiskErrorException", msg);
}
return State.STALE;
} catch (RemoteException re) {
String reClass = re.getClassName();
if (DisallowedTaskTrackerException.class.getName().equals(reClass)) {
LOG.info("Tasktracker disallowed by JobTracker.");
return State.DENIED;
}
} catch (Exception except) {
LOG.error("Caught exception: ", except);
}
}
return State.NORMAL;
}
/**
* Build and transmit the heart beat to the JobTracker
* @param jobClient The jobTracker RPC handle
* @param heartbeatResponseId Last heartbeat response received
* @param status TaskTrackerStatus to transmit
* @return false if the tracker was unknown
* @throws IOException
*/
protected HeartbeatResponse transmitHeartBeat(
InterTrackerProtocol jobClient, short heartbeatResponseId,
TaskTrackerStatus status) throws IOException {
//
// Check if we should ask for a new Task
//
boolean askForNewTask;
long localMinSpaceStart;
synchronized (this) {
askForNewTask =
((status.countOccupiedMapSlots() < maxMapSlots ||
status.countOccupiedReduceSlots() < maxReduceSlots) &&
acceptNewTasks);
localMinSpaceStart = minSpaceStart;
}
if (askForNewTask) {
checkLocalDirs(fConf.getLocalDirs());
askForNewTask = enoughFreeSpace(localMinSpaceStart);
gatherResourceStatus(status);
}
//add node health information
TaskTrackerHealthStatus healthStatus = status.getHealthStatus();
synchronized (this) {
if (healthChecker != null) {
healthChecker.setHealthStatus(healthStatus);
} else {
healthStatus.setNodeHealthy(true);
healthStatus.setLastReported(0L);
healthStatus.setHealthReport("");
}
}
//
// Xmit the heartbeat
//
HeartbeatResponse heartbeatResponse = jobClient.heartbeat(status,
justStarted,
justInited,
askForNewTask,
heartbeatResponseId);
synchronized (this) {
for (TaskStatus taskStatus : status.getTaskReports()) {
if (taskStatus.getRunState() != TaskStatus.State.RUNNING &&
taskStatus.getRunState() != TaskStatus.State.UNASSIGNED &&
taskStatus.getRunState() != TaskStatus.State.COMMIT_PENDING &&
!taskStatus.inTaskCleanupPhase()) {
if (taskStatus.getIsMap()) {
mapTotal--;
} else {
reduceTotal--;
}
try {
myInstrumentation.completeTask(taskStatus.getTaskID());
} catch (MetricsException me) {
LOG.warn("Caught: " + StringUtils.stringifyException(me));
}
removeRunningTask(taskStatus.getTaskID());
}
}
// Clear transient status information which should only
// be sent once to the JobTracker
for (TaskInProgress tip: runningTasks.values()) {
tip.getStatus().clearStatus();
}
}
return heartbeatResponse;
}
protected TaskTrackerStatus updateTaskTrackerStatus(
boolean sendCounters, TaskTrackerStatus oldStatus,
Collection<TaskInProgress> tips, InetSocketAddress jobTrackerAddr) {
//
// Check if the last heartbeat got through...
// if so then build the heartbeat information for the JobTracker;
// else resend the previous status information.
//
if (oldStatus == null) {
synchronized (this) {
return new TaskTrackerStatus(taskTrackerName, localHostname,
httpPort,
cloneAndResetRunningTaskStatuses(
tips, sendCounters),
failures,
maxMapSlots,
maxReduceSlots);
}
}
LOG.info("Resending 'status' to '" + jobTrackAddr.getHostName() +
"' with reponseId '" + heartbeatResponseId);
return oldStatus;
}
public Boolean isAlive() {
long timeSinceHearbeat = System.currentTimeMillis() - lastHeartbeat;
long expire = fConf.getLong("mapred.tasktracker.expiry.interval", 10 * 60 * 1000);
if (timeSinceHearbeat > expire) {
return false;
}
return true;
}
private void gatherResourceStatus(TaskTrackerStatus status)
throws IOException {
long freeDiskSpace = getDiskSpace(true);
long totVmem = getTotalVirtualMemoryOnTT();
long totPmem = getTotalPhysicalMemoryOnTT();
long availableVmem = resourceCalculatorPlugin.getAvailableVirtualMemorySize();
long availablePmem = resourceCalculatorPlugin.getAvailablePhysicalMemorySize();
long cumuCpuTime = resourceCalculatorPlugin.getCumulativeCpuTime();
long cpuFreq = resourceCalculatorPlugin.getCpuFrequency();
int numCpu = resourceCalculatorPlugin.getNumProcessors();
float cpuUsage = resourceCalculatorPlugin.getCpuUsage();
status.getResourceStatus().setAvailableSpace(freeDiskSpace);
status.getResourceStatus().setTotalVirtualMemory(totVmem);
status.getResourceStatus().setTotalPhysicalMemory(totPmem);
status.getResourceStatus().setAvailableVirtualMemory(availableVmem);
status.getResourceStatus().setAvailablePhysicalMemory(availablePmem);
status.getResourceStatus().setMapSlotMemorySizeOnTT(
mapSlotMemorySizeOnTT);
status.getResourceStatus().setReduceSlotMemorySizeOnTT(
reduceSlotSizeMemoryOnTT);
status.getResourceStatus().setCumulativeCpuTime(cumuCpuTime);
status.getResourceStatus().setCpuFrequency(cpuFreq);
status.getResourceStatus().setNumProcessors(numCpu);
status.getResourceStatus().setCpuUsage(cpuUsage);
}
protected boolean doCheckBuildVersion() {
return fConf.getBoolean(CHECK_TASKTRACKER_BUILD_VERSION, true);
}
long getMapUserLogRetainSize() {
return fConf.getLong(MAP_USERLOG_RETAIN_SIZE, -1);
}
void setMapUserLogRetainSize(long retainSize) {
fConf.setLong(MAP_USERLOG_RETAIN_SIZE, retainSize);
}
long getReduceUserLogRetainSize() {
return fConf.getLong(REDUCE_USERLOG_RETAIN_SIZE, -1);
}
void setReduceUserLogRetainSize(long retainSize) {
fConf.setLong(REDUCE_USERLOG_RETAIN_SIZE, retainSize);
}
/**
* Returns the MRAsyncDiskService object for async deletions.
*/
public MRAsyncDiskService getAsyncDiskService() {
return asyncDiskService;
}
/**
* Return the total virtual memory available on this TaskTracker.
* @return total size of virtual memory.
*/
long getTotalVirtualMemoryOnTT() {
return totalVirtualMemoryOnTT;
}
/**
* Return the total physical memory available on this TaskTracker.
* @return total size of physical memory.
*/
long getTotalPhysicalMemoryOnTT() {
return totalPhysicalMemoryOnTT;
}
long getTotalMemoryAllottedForTasksOnTT() {
return totalMemoryAllottedForTasks;
}
/**
* Check if the jobtracker directed a 'reset' of the tasktracker.
*
* @param actions the directives of the jobtracker for the tasktracker.
* @return <code>true</code> if tasktracker is to be reset,
* <code>false</code> otherwise.
*/
private boolean reinitTaskTracker(TaskTrackerAction[] actions) {
if (actions != null) {
for (TaskTrackerAction action : actions) {
if (action.getActionId() ==
TaskTrackerAction.ActionType.REINIT_TRACKER) {
LOG.info("Recieved RenitTrackerAction from JobTracker");
return true;
}
}
}
return false;
}
/**
* Kill any tasks that have not reported progress in the last X seconds.
*/
protected synchronized void markUnresponsiveTasks() throws IOException {
long now = System.currentTimeMillis();
for (TaskInProgress tip: runningTasks.values()) {
if (tip.getRunState() == TaskStatus.State.RUNNING ||
tip.getRunState() == TaskStatus.State.COMMIT_PENDING ||
tip.isCleaningup()) {
// Check the per-job timeout interval for tasks;
// an interval of '0' implies it is never timed-out
long jobTaskTimeout = tip.getTaskTimeout();
if (jobTaskTimeout == 0) {
continue;
}
// Check if the task has not reported progress for a
// time-period greater than the configured time-out
long timeSinceLastReport = now - tip.getLastProgressReport();
if (timeSinceLastReport > jobTaskTimeout && !tip.wasKilled) {
String msg =
"Task " + tip.getTask().getTaskID() + " failed to report status for "
+ (timeSinceLastReport / 1000) + " seconds. Killing!";
LOG.info(tip.getTask().getTaskID() + ": " + msg);
ReflectionUtils.logThreadInfo(LOG, "lost task", 30);
tip.reportDiagnosticInfo(msg);
myInstrumentation.timedoutTask(tip.getTask().getTaskID());
purgeTask(tip, true);
}
}
}
}
private static PathDeletionContext[] buildPathDeletionContexts(FileSystem fs,
Path[] paths) {
int i = 0;
PathDeletionContext[] contexts = new PathDeletionContext[paths.length];
for (Path p : paths) {
contexts[i++] = new PathDeletionContext(fs, p.toUri().getPath());
}
return contexts;
}
static PathDeletionContext[] buildTaskControllerPathDeletionContexts(
FileSystem fs, Path[] paths, Task task, boolean isWorkDir,
TaskController taskController)
throws IOException {
int i = 0;
PathDeletionContext[] contexts =
new TaskControllerPathDeletionContext[paths.length];
for (Path p : paths) {
contexts[i++] = new TaskControllerPathDeletionContext(fs, p, task,
isWorkDir, taskController);
}
return contexts;
}
/**
* The task tracker is done with this job, so we need to clean up.
* @param action The action with the job
* @throws IOException
*/
protected synchronized void purgeJob(KillJobAction action) throws IOException {
JobID jobId = action.getJobID();
LOG.info("Received 'KillJobAction' for job: " + jobId);
RunningJob rjob = null;
synchronized (runningJobs) {
rjob = runningJobs.get(jobId);
}
if (rjob == null) {
if (LOG.isDebugEnabled()) {
// We cleanup the job on all tasktrackers in the cluster
// so there is a good chance it never ran a single task from it
LOG.debug("Unknown job " + jobId + " being deleted.");
}
} else {
synchronized (rjob) {
// Add this tips of this job to queue of tasks to be purged
for (TaskInProgress tip : rjob.tasks) {
tip.jobHasFinished(false);
Task t = tip.getTask();
if (t.isMapTask()) {
indexCache.removeMap(tip.getTask().getTaskID().toString());
}
}
// Delete the job directory for this
// task if the job is done/failed
if (!rjob.keepJobFiles){
PathDeletionContext[] contexts = buildPathDeletionContexts(localFs,
getLocalFiles(fConf, getLocalJobDir(rjob.getJobID().toString())));
directoryCleanupThread.addToQueue(contexts);
}
// Remove this job
rjob.tasks.clear();
}
}
synchronized(runningJobs) {
runningJobs.remove(jobId);
}
}
/**
* Remove the tip and update all relevant state.
*
* @param tip {@link TaskInProgress} to be removed.
* @param wasFailure did the task fail or was it killed?
*/
private void purgeTask(TaskInProgress tip, boolean wasFailure)
throws IOException {
if (tip != null) {
LOG.info("About to purge task: " + tip.getTask().getTaskID());
// Remove the task from running jobs,
// removing the job if it's the last task
removeTaskFromJob(tip.getTask().getJobID(), tip);
tip.jobHasFinished(wasFailure);
if (tip.getTask().isMapTask()) {
indexCache.removeMap(tip.getTask().getTaskID().toString());
}
}
}
/** Check if we're dangerously low on disk space
* If so, kill jobs to free up space and make sure
* we don't accept any new tasks
* Try killing the reduce jobs first, since I believe they
* use up most space
* Then pick the one with least progress
*/
protected void killOverflowingTasks() throws IOException {
long localMinSpaceKill;
synchronized(this){
localMinSpaceKill = minSpaceKill;
}
if (!enoughFreeSpace(localMinSpaceKill)) {
acceptNewTasks=false;
//we give up! do not accept new tasks until
//all the ones running have finished and they're all cleared up
synchronized (this) {
TaskInProgress killMe = findTaskToKill(null);
if (killMe!=null) {
String msg = "Tasktracker running out of space." +
" Killing task.";
LOG.info(killMe.getTask().getTaskID() + ": " + msg);
killMe.reportDiagnosticInfo(msg);
purgeTask(killMe, false);
}
}
}
}
/**
* Pick a task to kill to free up memory/disk-space
* @param tasksToExclude tasks that are to be excluded while trying to find a
* task to kill. If null, all runningTasks will be searched.
* @return the task to kill or null, if one wasn't found
*/
synchronized TaskInProgress findTaskToKill(List<TaskAttemptID> tasksToExclude) {
TaskInProgress killMe = null;
for (Iterator it = runningTasks.values().iterator(); it.hasNext();) {
TaskInProgress tip = (TaskInProgress) it.next();
if (tasksToExclude != null
&& tasksToExclude.contains(tip.getTask().getTaskID())) {
// exclude this task
continue;
}
if ((tip.getRunState() == TaskStatus.State.RUNNING ||
tip.getRunState() == TaskStatus.State.COMMIT_PENDING) &&
!tip.wasKilled) {
if (killMe == null) {
killMe = tip;
} else if (!tip.getTask().isMapTask()) {
//reduce task, give priority
if (killMe.getTask().isMapTask() ||
(tip.getTask().getProgress().get() <
killMe.getTask().getProgress().get())) {
killMe = tip;
}
} else if (killMe.getTask().isMapTask() &&
tip.getTask().getProgress().get() <
killMe.getTask().getProgress().get()) {
//map task, only add if the progress is lower
killMe = tip;
}
}
}
return killMe;
}
/**
* Check if any of the local directories has enough
* free space (more than minSpace)
*
* If not, do not try to get a new task assigned
* @return
* @throws IOException
*/
private boolean enoughFreeSpace(long minSpace) throws IOException {
if (minSpace == 0) {
return true;
}
return minSpace < getDiskSpace(true);
}
/**
* Obtain the maximum disk space (free or total) in bytes for each volume
* @param free If true returns free space, else returns capacity
* @return disk space in bytes
* @throws IOException
*/
long getDiskSpace(boolean free) throws IOException {
long biggestSeenSoFar = 0;
String[] localDirs = fConf.getLocalDirs();
for (int i = 0; i < localDirs.length; i++) {
DF df = null;
if (localDirsDf.containsKey(localDirs[i])) {
df = localDirsDf.get(localDirs[i]);
} else {
df = new DF(new File(localDirs[i]), fConf);
localDirsDf.put(localDirs[i], df);
}
long onThisVol = free ? df.getAvailable() : df.getCapacity();
if (onThisVol > biggestSeenSoFar) {
biggestSeenSoFar = onThisVol;
}
}
//Should ultimately hold back the space we expect running tasks to use but
//that estimate isn't currently being passed down to the TaskTrackers
return biggestSeenSoFar;
}
/**
* Try to get the size of output for this task.
* Returns -1 if it can't be found.
* @return
*/
long tryToGetOutputSize(TaskAttemptID taskId, JobConf conf) {
try{
TaskInProgress tip;
synchronized(this) {
tip = tasks.get(taskId);
}
if(tip == null)
return -1;
if (!tip.getTask().isMapTask() ||
tip.getRunState() != TaskStatus.State.SUCCEEDED) {
return -1;
}
MapOutputFile mapOutputFile = new MapOutputFile();
mapOutputFile.setJobId(taskId.getJobID());
mapOutputFile.setConf(conf);
// In simulation mode, maps/reduces complete instantly and don't produce
// any output
if (this.simulatedTaskMode) {
return 0;
}
Path tmp_output = null;
try {
tmp_output = mapOutputFile.getOutputFile(taskId);
} catch (DiskErrorException dex) {
if (LOG.isDebugEnabled()) {
LOG.debug("Error getting map output of a task " + taskId, dex);
}
}
if(tmp_output == null)
return 0;
FileSystem localFS = FileSystem.getLocal(conf);
FileStatus stat = localFS.getFileStatus(tmp_output);
if(stat == null)
return 0;
else
return stat.getLen();
} catch(IOException e) {
LOG.info(e);
return -1;
}
}
private PulseChecker pulseChecker;
private HeartbeatMonitor heartbeatMonitor;
private TaskLauncher mapLauncher;
private TaskLauncher reduceLauncher;
public JvmManager getJvmManagerInstance() {
return jvmManager;
}
protected void addToTaskQueue(LaunchTaskAction action) {
if (action.getTask().isMapTask()) {
mapLauncher.addToTaskQueue(action);
} else {
reduceLauncher.addToTaskQueue(action);
}
}
/**
* Simple helper class for the list of tasks to launch
*/
private class TaskLaunchData {
/** Time when this task in progress requested */
final long startedMsecs = System.currentTimeMillis();
/** Actual task in progress */
final TaskInProgress taskInProgress;
TaskLaunchData(TaskInProgress taskInProgress) {
this.taskInProgress = taskInProgress;
}
}
protected class TaskLauncher extends Thread {
private IntWritable numFreeSlots;
/** Maximum slots used for scheduling */
private final int maxSlots;
/** The real number of maximum slots */
private final int actualMaxSlots;
/** Tasks to launch in order of insert time */
private final List<TaskLaunchData> tasksToLaunch;
/** Used to determine which metrics to append to (map or reduce) */
private final TaskType taskType;
/** Keep track of the last free times for all the slots */
private final LinkedList<Long> lastFreeMsecsQueue;
/**
* Constructor.
*
* @param taskType Type of the task (i.e. Map, Reduce)
* @param numSlots Number of slots available for scheduling
* @param actualNumSlots Actual number of slots on this TaskTracker
* (metrics)
*/
public TaskLauncher(TaskType taskType, int numSlots, int actualNumSlots) {
this.maxSlots = numSlots;
this.actualMaxSlots = actualNumSlots;
this.numFreeSlots = new IntWritable(numSlots);
this.tasksToLaunch = new LinkedList<TaskLaunchData>();
setDaemon(true);
setName("TaskLauncher for " + taskType + " tasks");
this.taskType = taskType;
// Initialize the last free times for all the slots based on the actual
// number of slots
lastFreeMsecsQueue = new LinkedList<Long>();
long currentTime = System.currentTimeMillis();
for (int i = 0; i < actualNumSlots; ++i) {
lastFreeMsecsQueue.add(currentTime);
}
}
public void addToTaskQueue(LaunchTaskAction action) {
synchronized (tasksToLaunch) {
TaskInProgress tip = registerTask(action, this);
tasksToLaunch.add(new TaskLaunchData(tip));
tasksToLaunch.notifyAll();
}
}
public void cleanTaskQueue() {
tasksToLaunch.clear();
}
/**
* Get the number of used slots for metrics
*
* @return Number of used slots for this TaskLauncher
*/
public int getNumUsedSlots() {
synchronized (numFreeSlots) {
return maxSlots - numFreeSlots.get();
}
}
public void addFreeSlots(int numSlots) {
synchronized (numFreeSlots) {
numFreeSlots.set(numFreeSlots.get() + numSlots);
assert (numFreeSlots.get() <= maxSlots);
LOG.info("addFreeSlot : " + taskType + " current free slots : " +
numFreeSlots.get() + ", queue size : " + lastFreeMsecsQueue.size() +
", max queue size : " + maxSlots);
// Create the initial timestamps for starting a slot refill
// for these newly free slots
long currentTime = System.currentTimeMillis();
for (int i = 0; i < numSlots; ++i) {
lastFreeMsecsQueue.add(currentTime);
}
// Due to a possible violations of using more than the actual slots,
// we only allow the queue to grow to its maximum actual size
if (lastFreeMsecsQueue.size() > actualMaxSlots) {
LOG.warn("addFreeSlots: " + taskType + " lastFreeMsecsQueue is " +
" too large (overscheduled) with " + lastFreeMsecsQueue.size() +
" instead of " + actualMaxSlots + " slots.");
while (lastFreeMsecsQueue.size() > actualMaxSlots) {
lastFreeMsecsQueue.removeLast();
}
}
numFreeSlots.notifyAll();
}
}
/**
* Add the update refill msecs to the metrics. This method needs to be
* synchronized with numFreeSlots and is currently only called in run()
* under synchronization of numFreeSlots.
*
* @param usedSlots Number of slots refilled
*/
private void updateRefillMsecs(int usedSlots) {
long currentTime = System.currentTimeMillis();
for (int i = 0; i < usedSlots; ++i) {
// There should also be at least usedSlots entries in
// lastFreeMsecsQueue, but Corona can violate this
// principle by scheduling tasks before another task resource is
// confirmed to have been released.
if (lastFreeMsecsQueue.isEmpty()) {
LOG.warn("updateRefillMsecs: Only obtained refill times for " + i +
" out of " + usedSlots + " slots.");
break;
}
int refillMsecs = (int) (currentTime - lastFreeMsecsQueue.remove());
if (taskType == TaskType.MAP) {
addAveMapSlotRefillMsecs(refillMsecs);
} else if (taskType == TaskType.REDUCE) {
addAveReduceSlotRefillMsecs(refillMsecs);
} else {
throw new RuntimeException("updateRefillMsecs doesn't " +
"suppport task type " + taskType);
}
}
}
public void run() {
while (running) {
try {
TaskInProgress tip;
TaskLaunchData taskLaunchData;
Task task;
synchronized (tasksToLaunch) {
while (tasksToLaunch.isEmpty()) {
tasksToLaunch.wait();
}
taskLaunchData = tasksToLaunch.remove(0);
//get the TIP
tip = taskLaunchData.taskInProgress;
task = tip.getTask();
LOG.info("Trying to launch : " + tip.getTask().getTaskID() +
" which needs " + task.getNumSlotsRequired() + " slots");
}
//wait for free slots to run
synchronized (numFreeSlots) {
while (numFreeSlots.get() < task.getNumSlotsRequired()) {
LOG.info("TaskLauncher : Waiting for " + task.getNumSlotsRequired() +
" to launch " + task.getTaskID() + ", currently we have " +
numFreeSlots.get() + " free slots");
numFreeSlots.wait();
}
LOG.info("In TaskLauncher, current free slots : " + numFreeSlots.get()+
" and trying to launch " + tip.getTask().getTaskID() +
" which needs " + task.getNumSlotsRequired() + " slots");
numFreeSlots.set(numFreeSlots.get() - task.getNumSlotsRequired());
assert (numFreeSlots.get() >= 0);
// Add the refill times for the used slots
updateRefillMsecs(task.getNumSlotsRequired());
}
synchronized (tip) {
//to make sure that there is no kill task action for this
if (tip.getRunState() != TaskStatus.State.UNASSIGNED &&
tip.getRunState() != TaskStatus.State.FAILED_UNCLEAN &&
tip.getRunState() != TaskStatus.State.KILLED_UNCLEAN) {
//got killed externally while still in the launcher queue
addFreeSlots(task.getNumSlotsRequired());
continue;
}
tip.slotTaken = true;
}
// Got a free slot. If it's in simulation mode, add it to the queue
// so that it will be automatically marked as finished after some
// time. Otherwise, start the task.
if (simulatedTaskMode) {
// Also mark the task as running. If it's not marked as running,
// the JT may declare it as a failed launch while waiting to start
// The task status is transmitted via heartbeat. See
// "Error launching task" in JT. We allow KILLED_UNCLEAN tasks
/// as that's the state of killed tasks.
if (tip.taskStatus.getRunState() == TaskStatus.State.UNASSIGNED) {
LOG.info("For running as simulation, changing run state for " +
tip.getTask().getTaskID() + " from UNASSIGNED to RUNNING");
tip.taskStatus.setRunState(TaskStatus.State.RUNNING);
} else if (tip.taskStatus.getRunState() ==
TaskStatus.State.KILLED_UNCLEAN) {
// We can't change the run state to running as it will prevent
// tasks from getting killed.
LOG.info("For simulation, leaving run state same for " +
tip.getTask().getTaskID() + " as KILLED_UNCLEAN");
} else {
throw new RuntimeException("Task " + tip.getTask().getTaskID() +
" is not in the UNASSIGNED/KILLED_UNCLEAN state. Instead " +
"it's in " + tip.taskStatus
);
}
// Set the start time so we get cleaner looking tables in UI
tip.taskStatus.setStartTime(System.currentTimeMillis());
// This must be called here as localizeJob() is not called during
// simulation. Without this call, the TT won't fetch map task
// completion events for the job, and the reducers won't know when
// they can start
addTaskToJob(tip.getTask().getJobID(), tip);
// Map tasks and cleanup tasks can be queued up to finish ASAP.
// However, reduce tasks should wait until all the mappers have
// finished. launchTask() should handle this.
simulatedTaskRunner.launchTask(tip);
} else {
startNewTask(tip);
}
// Add metrics on how long it took to launch the task after added
myInstrumentation.addTaskLaunchMsecs(
System.currentTimeMillis() - taskLaunchData.startedMsecs);
} catch (InterruptedException e) {
if (!running)
return; // ALL DONE
LOG.warn ("Unexpected InterruptedException");
} catch (Throwable th) {
LOG.error("TaskLauncher error " +
StringUtils.stringifyException(th));
}
}
}
}
private TaskInProgress registerTask(LaunchTaskAction action,
TaskLauncher launcher) {
Task t = action.getTask();
LOG.info("LaunchTaskAction (registerTask): " + t.getTaskID() +
" task's state:" + t.getState());
TaskInProgress tip = new TaskInProgress(
t, fConf, launcher, action.getExtensible());
synchronized (this) {
tasks.put(t.getTaskID(), tip);
runningTasks.put(t.getTaskID(), tip);
boolean isMap = t.isMapTask();
if (isMap) {
mapTotal++;
} else {
reduceTotal++;
}
}
return tip;
}
/**
* Start a new task.
* All exceptions are handled locally, so that we don't mess up the
* task tracker.
*/
private void startNewTask(TaskInProgress tip) {
try {
boolean launched = localizeAndLaunchTask(tip);
if (!launched) {
// Free the slot.
tip.kill(true);
tip.cleanup(true);
}
} catch (Throwable e) {
String msg = ("Error initializing " + tip.getTask().getTaskID() +
":\n" + StringUtils.stringifyException(e));
LOG.error(msg, e);
tip.reportDiagnosticInfo(msg);
try {
tip.kill(true);
tip.cleanup(true);
} catch (IOException ie2) {
LOG.info("Error cleaning up " + tip.getTask().getTaskID() + ":\n" +
StringUtils.stringifyException(ie2));
}
// Careful!
// This might not be an 'Exception' - don't handle 'Error' here!
if (e instanceof Error) {
throw ((Error) e);
}
}
}
/**
* Localize and launch the task.
* If it takes too long, try cancel the thread that does localization.
* If the thread cannot be terminated, kill the JVM.
* The TaskTracker will die.
*
* We have seen localizeTask hangs TaskTracker. In this case we lose the
* node. This method will kill tasktracker and so it can be restarted later.
*/
private boolean localizeAndLaunchTask(final TaskInProgress tip)
throws IOException {
FutureTask<Boolean> task = new FutureTask<Boolean>(
new Callable<Boolean>() {
public Boolean call() throws IOException {
JobConf localConf = localizeJob(tip);
boolean launched = false;
synchronized (tip) {
tip.setJobConf(localConf);
launched = tip.launchTask();
}
return launched;
}
});
String threadName = "Localizing " + tip.getTask().toString();
Thread thread = new Thread(task);
thread.setName(threadName);
thread.setDaemon(true);
thread.start();
boolean launched = false;
try {
launched = task.get(LOCALIZE_TASK_TIMEOUT, TimeUnit.MILLISECONDS);
} catch (Exception e) {
task.cancel(true);
try {
LOG.info("Wait the localizeTask thread to finish");
thread.join(LOCALIZE_TASK_TIMEOUT);
} catch (InterruptedException ie) {
}
if (thread.isAlive()) {
LOG.error("Stacktrace of " + threadName + "\n" +
StringUtils.stackTraceOfThread(thread));
LOG.fatal("Cannot kill the localizeTask thread." + threadName +
" TaskTracker has to die!!");
System.exit(-1);
}
throw new IOException("TaskTracker got stuck for localized Task:" +
tip.getTask().getTaskID(), e);
}
return launched;
}
void addToMemoryManager(TaskAttemptID attemptId, boolean isMap,
JobConf conf) {
if (isTaskMemoryManagerEnabled()) {
taskMemoryManager.addTask(attemptId,
isMap ? conf
.getMemoryForMapTask() * 1024 * 1024L : conf
.getMemoryForReduceTask() * 1024 * 1024L);
}
}
void removeFromMemoryManager(TaskAttemptID attemptId) {
// Remove the entry from taskMemoryManagerThread's data structures.
if (isTaskMemoryManagerEnabled()) {
taskMemoryManager.removeTask(attemptId);
}
}
/**
* Notify the tasktracker to send an out-of-band heartbeat.
*/
private void notifyTTAboutTaskCompletion() {
if (oobHeartbeatOnTaskCompletion) {
synchronized (finishedCount) {
int value = finishedCount.get();
finishedCount.set(value+1);
finishedCount.notifyAll();
}
}
}
/**
* The server retry loop.
* This while-loop attempts to connect to the JobTracker.
*/
public void run() {
try {
startCleanupThreads();
try {
// This while-loop attempts reconnects if we get network errors
while (running && !shuttingDown) {
try {
State osState = offerService();
if (osState == State.STALE || osState == State.DENIED) {
// Shutdown TaskTracker instead of reinitialize.
// TaskTracker should be restarted by external tools.
LOG.error("offerService returns " + osState + ". Shutdown. ");
break;
}
} catch (Exception ex) {
if (!shuttingDown) {
LOG.info("Lost connection to JobTracker [" +
jobTrackAddr + "]. Retrying...", ex);
try {
Thread.sleep(5000);
} catch (InterruptedException ie) {
}
}
}
}
} finally {
shutdown();
}
} catch (IOException iex) {
LOG.error("Got fatal exception while initializing TaskTracker", iex);
return;
}
}
///////////////////////////////////////////////////////
// TaskInProgress maintains all the info for a Task that
// lives at this TaskTracker. It maintains the Task object,
// its TaskStatus, and the TaskRunner.
///////////////////////////////////////////////////////
class TaskInProgress {
Task task;
long lastProgressReport;
StringBuffer diagnosticInfo = new StringBuffer();
private TaskRunner runner;
volatile boolean done = false;
volatile boolean wasKilled = false;
private JobConf defaultJobConf;
private JobConf localJobConf;
private boolean keepFailedTaskFiles;
private boolean alwaysKeepTaskFiles;
private TaskStatus taskStatus;
private long taskTimeout;
private String debugCommand;
private volatile boolean slotTaken = false;
private TaskLauncher launcher;
private Writable extensible = null;
public Writable getExtensible() {
return extensible;
}
public TaskInProgress(Task task, JobConf conf,
TaskLauncher launcher, Writable extensible) {
this.task = task;
this.launcher = launcher;
this.lastProgressReport = System.currentTimeMillis();
this.defaultJobConf = conf;
this.extensible = extensible;
localJobConf = null;
taskStatus = TaskStatus.createTaskStatus(task.isMapTask(), task.getTaskID(),
0.0f,
task.getNumSlotsRequired(),
task.getState(),
diagnosticInfo.toString(),
"initializing",
getName(),
task.isTaskCleanupTask() ?
TaskStatus.Phase.CLEANUP :
task.isMapTask()? TaskStatus.Phase.MAP:
TaskStatus.Phase.SHUFFLE,
task.getCounters());
taskTimeout = (10 * 60 * 1000);
}
private void localizeTask(Task task) throws IOException{
Path localTaskDir =
lDirAlloc.getLocalPathForWrite(
TaskTracker.getLocalTaskDir(task.getJobID().toString(),
task.getTaskID().toString(), task.isTaskCleanupTask()),
defaultJobConf );
FileSystem localFs = FileSystem.getLocal(fConf);
if (!localFs.mkdirs(localTaskDir)) {
throw new IOException("Mkdirs failed to create "
+ localTaskDir.toString());
}
// create symlink for ../work if it already doesnt exist
String workDir = lDirAlloc.getLocalPathToRead(
TaskTracker.getLocalJobDir(task.getJobID().toString())
+ Path.SEPARATOR
+ "work", defaultJobConf).toString();
String link = localTaskDir.getParent().toString()
+ Path.SEPARATOR + "work";
File flink = new File(link);
if (!flink.exists())
FileUtil.symLink(workDir, link);
// create the working-directory of the task
Path cwd = lDirAlloc.getLocalPathForWrite(
getLocalTaskDir(task.getJobID().toString(),
task.getTaskID().toString(), task.isTaskCleanupTask())
+ Path.SEPARATOR + MRConstants.WORKDIR,
defaultJobConf);
if (!localFs.mkdirs(cwd)) {
throw new IOException("Mkdirs failed to create "
+ cwd.toString());
}
Path localTaskFile = new Path(localTaskDir, "job.xml");
task.setJobFile(localTaskFile.toString());
localJobConf.set("mapred.local.dir",
fConf.get("mapred.local.dir"));
if (fConf.get("slave.host.name") != null) {
localJobConf.set("slave.host.name",
fConf.get("slave.host.name"));
}
localJobConf.set("mapred.task.id", task.getTaskID().toString());
keepFailedTaskFiles = localJobConf.getKeepFailedTaskFiles();
task.localizeConfiguration(localJobConf);
Task.saveStaticResolutions(localJobConf);
if (task.isMapTask()) {
debugCommand = localJobConf.getMapDebugScript();
} else {
debugCommand = localJobConf.getReduceDebugScript();
}
String keepPattern = localJobConf.getKeepTaskFilesPattern();
if (keepPattern != null) {
alwaysKeepTaskFiles =
Pattern.matches(keepPattern, task.getTaskID().toString());
} else {
alwaysKeepTaskFiles = false;
}
if (debugCommand != null || localJobConf.getProfileEnabled() ||
alwaysKeepTaskFiles || keepFailedTaskFiles) {
//disable jvm reuse
localJobConf.setNumTasksToExecutePerJvm(1);
}
if (isTaskMemoryManagerEnabled()) {
localJobConf.setBoolean("task.memory.mgmt.enabled", true);
}
OutputStream out = localFs.create(localTaskFile);
try {
localJobConf.writeXml(out);
} finally {
out.close();
}
task.setConf(localJobConf);
}
/**
*/
public Task getTask() {
return task;
}
public TaskRunner getTaskRunner() {
return runner;
}
public synchronized void setJobConf(JobConf lconf){
this.localJobConf = lconf;
keepFailedTaskFiles = localJobConf.getKeepFailedTaskFiles();
taskTimeout = localJobConf.getLong("mapred.task.timeout",
10 * 60 * 1000);
}
public synchronized JobConf getJobConf() {
return localJobConf;
}
/**
*/
public synchronized TaskStatus getStatus() {
taskStatus.setDiagnosticInfo(diagnosticInfo.toString());
if (diagnosticInfo.length() > 0) {
diagnosticInfo = new StringBuffer();
}
return taskStatus;
}
/**
* Kick off the task execution
*/
public synchronized boolean launchTask() throws IOException {
if (this.taskStatus.getRunState() == TaskStatus.State.UNASSIGNED ||
this.taskStatus.getRunState() == TaskStatus.State.FAILED_UNCLEAN ||
this.taskStatus.getRunState() == TaskStatus.State.KILLED_UNCLEAN) {
localizeTask(task);
if (this.taskStatus.getRunState() == TaskStatus.State.UNASSIGNED) {
this.taskStatus.setRunState(TaskStatus.State.RUNNING);
}
this.runner = task.createRunner(TaskTracker.this, this);
this.runner.start();
this.taskStatus.setStartTime(System.currentTimeMillis());
return true;
} else {
LOG.info("Not launching task: " + task.getTaskID() +
" since it's state is " + this.taskStatus.getRunState());
return false;
}
}
boolean isCleaningup() {
return this.taskStatus.inTaskCleanupPhase();
}
/**
* The task is reporting its progress
*/
public synchronized void reportProgress(TaskStatus taskStatus)
{
LOG.info(task.getTaskID() + " " + taskStatus.getProgress() +
"% " + taskStatus.getStateString());
// task will report its state as
// COMMIT_PENDING when it is waiting for commit response and
// when it is committing.
// cleanup attempt will report its state as FAILED_UNCLEAN/KILLED_UNCLEAN
if (this.done ||
(this.taskStatus.getRunState() != TaskStatus.State.RUNNING &&
this.taskStatus.getRunState() != TaskStatus.State.COMMIT_PENDING &&
!isCleaningup()) ||
((this.taskStatus.getRunState() == TaskStatus.State.COMMIT_PENDING ||
this.taskStatus.getRunState() == TaskStatus.State.FAILED_UNCLEAN ||
this.taskStatus.getRunState() == TaskStatus.State.KILLED_UNCLEAN) &&
taskStatus.getRunState() == TaskStatus.State.RUNNING)) {
//make sure we ignore progress messages after a task has
//invoked TaskUmbilicalProtocol.done() or if the task has been
//KILLED/FAILED/FAILED_UNCLEAN/KILLED_UNCLEAN
//Also ignore progress update if the state change is from
//COMMIT_PENDING/FAILED_UNCLEAN/KILLED_UNCLEA to RUNNING
LOG.info(task.getTaskID() + " Ignoring status-update since " +
((this.done) ? "task is 'done'" :
("runState: " + this.taskStatus.getRunState()))
);
return;
}
this.taskStatus.statusUpdate(taskStatus);
this.lastProgressReport = System.currentTimeMillis();
}
/**
*/
public long getLastProgressReport() {
return lastProgressReport;
}
/**
*/
public TaskStatus.State getRunState() {
return taskStatus.getRunState();
}
/**
* The task's configured timeout.
*
* @return the task's configured timeout.
*/
public long getTaskTimeout() {
return taskTimeout;
}
/**
* The task has reported some diagnostic info about its status
*/
public synchronized void reportDiagnosticInfo(String info) {
this.diagnosticInfo.append(info);
}
public synchronized void reportNextRecordRange(SortedRanges.Range range) {
this.taskStatus.setNextRecordRange(range);
}
/**
* The task is reporting that it's done running
*/
public synchronized void reportDone() {
if (isCleaningup()) {
if (this.taskStatus.getRunState() == TaskStatus.State.FAILED_UNCLEAN) {
this.taskStatus.setRunState(TaskStatus.State.FAILED);
} else if (this.taskStatus.getRunState() ==
TaskStatus.State.KILLED_UNCLEAN) {
this.taskStatus.setRunState(TaskStatus.State.KILLED);
}
} else {
this.taskStatus.setRunState(TaskStatus.State.SUCCEEDED);
}
this.taskStatus.setProgress(1.0f);
this.taskStatus.setFinishTime(System.currentTimeMillis());
this.done = true;
// Runner may be null in the case when we are running a simulation and
// no runner was actually launched
if (!simulatedTaskMode) {
jvmManager.taskFinished(runner);
runner.signalDone();
}
LOG.info("Task " + task.getTaskID() + " is done.");
LOG.info("reported output size for " + task.getTaskID() + " was " + taskStatus.getOutputSize());
myInstrumentation.statusUpdate(task, taskStatus);
}
public boolean wasKilled() {
return wasKilled;
}
/**
* A task is reporting in as 'done'.
*
* We need to notify the tasktracker to send an out-of-band heartbeat.
* If isn't <code>commitPending</code>, we need to finalize the task
* and release the slot it's occupied.
*
* @param commitPending is the task-commit pending?
*/
void reportTaskFinished(boolean commitPending) {
if (!commitPending) {
taskFinished();
releaseSlot();
}
notifyTTAboutTaskCompletion();
}
/* State changes:
* RUNNING/COMMIT_PENDING -> FAILED_UNCLEAN/FAILED/KILLED_UNCLEAN/KILLED
* FAILED_UNCLEAN -> FAILED
* KILLED_UNCLEAN -> KILLED
*/
private void setTaskFailState(boolean wasFailure) {
// go FAILED_UNCLEAN -> FAILED and KILLED_UNCLEAN -> KILLED always
if (taskStatus.getRunState() == TaskStatus.State.FAILED_UNCLEAN) {
taskStatus.setRunState(TaskStatus.State.FAILED);
} else if (taskStatus.getRunState() ==
TaskStatus.State.KILLED_UNCLEAN) {
taskStatus.setRunState(TaskStatus.State.KILLED);
} else if (task.isMapOrReduce() &&
taskStatus.getPhase() != TaskStatus.Phase.CLEANUP) {
if (wasFailure) {
taskStatus.setRunState(TaskStatus.State.FAILED_UNCLEAN);
} else {
taskStatus.setRunState(TaskStatus.State.KILLED_UNCLEAN);
}
} else {
if (wasFailure) {
taskStatus.setRunState(TaskStatus.State.FAILED);
} else {
taskStatus.setRunState(TaskStatus.State.KILLED);
}
}
}
/**
* The task has actually finished running.
*/
public void taskFinished() {
long start = System.currentTimeMillis();
//
// Wait until task reports as done. If it hasn't reported in,
// wait for a second and try again.
//
while (!done && (System.currentTimeMillis() - start < WAIT_FOR_DONE)) {
try {
Thread.sleep(1000);
} catch (InterruptedException ie) {
}
}
//
// Change state to success or failure, depending on whether
// task was 'done' before terminating
//
boolean needCleanup = false;
synchronized (this) {
// Remove the task from MemoryManager, if the task SUCCEEDED or FAILED.
// KILLED tasks are removed in method kill(), because Kill
// would result in launching a cleanup attempt before
// TaskRunner returns; if remove happens here, it would remove
// wrong task from memory manager.
if (done || !wasKilled) {
removeFromMemoryManager(task.getTaskID());
}
if (!done) {
if (!wasKilled) {
failures += 1;
setTaskFailState(true);
// call the script here for the failed tasks.
if (debugCommand != null) {
String taskStdout ="";
String taskStderr ="";
String taskSyslog ="";
String jobConf = task.getJobFile();
try {
Map<LogName, LogFileDetail> allFilesDetails =
TaskLog.getAllLogsFileDetails(task.getTaskID(), false);
// get task's stdout file
taskStdout =
TaskLog.getRealTaskLogFilePath(
allFilesDetails.get(LogName.STDOUT).location,
LogName.STDOUT);
// get task's stderr file
taskStderr =
TaskLog.getRealTaskLogFilePath(
allFilesDetails.get(LogName.STDERR).location,
LogName.STDERR);
// get task's syslog file
taskSyslog =
TaskLog.getRealTaskLogFilePath(
allFilesDetails.get(LogName.SYSLOG).location,
LogName.SYSLOG);
} catch(IOException e){
LOG.warn("Exception finding task's stdout/err/syslog files");
}
File workDir = null;
try {
workDir = new File(lDirAlloc.getLocalPathToRead(
TaskTracker.getLocalTaskDir(
task.getJobID().toString(),
task.getTaskID().toString(),
task.isTaskCleanupTask())
+ Path.SEPARATOR + MRConstants.WORKDIR,
localJobConf). toString());
} catch (IOException e) {
LOG.warn("Working Directory of the task " + task.getTaskID() +
"doesnt exist. Caught exception " +
StringUtils.stringifyException(e));
}
// Build the command
File stdout = TaskLog.getRealTaskLogFileLocation(
task.getTaskID(), TaskLog.LogName.DEBUGOUT);
// add pipes program as argument if it exists.
String program ="";
String executable = Submitter.getExecutable(localJobConf);
if ( executable != null) {
try {
program = new URI(executable).getFragment();
} catch (URISyntaxException ur) {
LOG.warn("Problem in the URI fragment for pipes executable");
}
}
String [] debug = debugCommand.split(" ");
Vector<String> vargs = new Vector<String>();
for (String component : debug) {
vargs.add(component);
}
vargs.add(taskStdout);
vargs.add(taskStderr);
vargs.add(taskSyslog);
vargs.add(jobConf);
vargs.add(program);
try {
List<String> wrappedCommand = TaskLog.captureDebugOut
(vargs, stdout);
// run the script.
try {
runScript(wrappedCommand, workDir);
} catch (IOException ioe) {
LOG.warn("runScript failed with: " + StringUtils.
stringifyException(ioe));
}
} catch(IOException e) {
LOG.warn("Error in preparing wrapped debug command");
}
// add all lines of debug out to diagnostics
try {
int num = localJobConf.getInt("mapred.debug.out.lines", -1);
addDiagnostics(FileUtil.makeShellPath(stdout),num,"DEBUG OUT");
} catch(IOException ioe) {
LOG.warn("Exception in add diagnostics!");
}
// Debug-command is run. Do the post-debug-script-exit debug-logs
// processing. Truncate the logs.
getTaskLogsMonitor().addProcessForLogTruncation(
task.getTaskID(), Arrays.asList(task));
}
}
taskStatus.setProgress(0.0f);
}
this.taskStatus.setFinishTime(System.currentTimeMillis());
needCleanup = (taskStatus.getRunState() == TaskStatus.State.FAILED ||
taskStatus.getRunState() == TaskStatus.State.FAILED_UNCLEAN ||
taskStatus.getRunState() == TaskStatus.State.KILLED_UNCLEAN ||
taskStatus.getRunState() == TaskStatus.State.KILLED);
}
//
// If the task has failed, or if the task was killAndCleanup()'ed,
// we should clean up right away. We only wait to cleanup
// if the task succeeded, and its results might be useful
// later on to downstream job processing.
//
if (needCleanup) {
removeTaskFromJob(task.getJobID(), this);
}
try {
cleanup(needCleanup);
} catch (IOException ie) {
}
}
/**
* Runs the script given in args
* @param args script name followed by its argumnets
* @param dir current working directory.
* @throws IOException
*/
public void runScript(List<String> args, File dir) throws IOException {
ShellCommandExecutor shexec =
new ShellCommandExecutor(args.toArray(new String[0]), dir);
shexec.execute();
int exitCode = shexec.getExitCode();
if (exitCode != 0) {
throw new IOException("Task debug script exit with nonzero status of "
+ exitCode + ".");
}
}
/**
* Add last 'num' lines of the given file to the diagnostics.
* if num =-1, all the lines of file are added to the diagnostics.
* @param file The file from which to collect diagnostics.
* @param num The number of lines to be sent to diagnostics.
* @param tag The tag is printed before the diagnostics are printed.
*/
public void addDiagnostics(String file, int num, String tag) {
RandomAccessFile rafile = null;
try {
rafile = new RandomAccessFile(file,"r");
int no_lines =0;
String line = null;
StringBuffer tail = new StringBuffer();
tail.append("\n-------------------- "+tag+"---------------------\n");
String[] lines = null;
if (num >0) {
lines = new String[num];
}
while ((line = rafile.readLine()) != null) {
no_lines++;
if (num >0) {
if (no_lines <= num) {
lines[no_lines-1] = line;
}
else { // shift them up
for (int i=0; i<num-1; ++i) {
lines[i] = lines[i+1];
}
lines[num-1] = line;
}
}
else if (num == -1) {
tail.append(line);
tail.append("\n");
}
}
int n = no_lines > num ?num:no_lines;
if (num >0) {
for (int i=0;i<n;i++) {
tail.append(lines[i]);
tail.append("\n");
}
}
if(n!=0)
reportDiagnosticInfo(tail.toString());
} catch (FileNotFoundException fnfe){
LOG.warn("File "+file+ " not found");
} catch (IOException ioe){
LOG.warn("Error reading file "+file);
} finally {
try {
if (rafile != null) {
rafile.close();
}
} catch (IOException ioe) {
LOG.warn("Error closing file "+file);
}
}
}
/**
* We no longer need anything from this task, as the job has
* finished. If the task is still running, kill it and clean up.
*
* @param wasFailure did the task fail, as opposed to was it killed by
* the framework
*/
public void jobHasFinished(boolean wasFailure) throws IOException {
// Kill the task if it is still running
synchronized(this){
if (getRunState() == TaskStatus.State.RUNNING ||
getRunState() == TaskStatus.State.UNASSIGNED ||
getRunState() == TaskStatus.State.COMMIT_PENDING ||
isCleaningup()) {
kill(wasFailure);
}
}
// Cleanup on the finished task
cleanup(true);
}
/**
* Something went wrong and the task must be killed.
* @param wasFailure was it a failure (versus a kill request)?
*/
public synchronized void kill(boolean wasFailure) throws IOException {
if (taskStatus.getRunState() == TaskStatus.State.RUNNING ||
taskStatus.getRunState() == TaskStatus.State.COMMIT_PENDING ||
isCleaningup()) {
wasKilled = true;
if (wasFailure) {
failures += 1;
}
// runner could be null if task-cleanup attempt is not localized yet
if (runner != null) {
runner.kill();
}
// If the task is killed, then there is no need to finish that tip
// anymore.
if (TaskTracker.this.simulatedTaskMode) {
TaskTracker.this.simulatedTaskRunner.cancel(this);
}
setTaskFailState(wasFailure);
} else if (taskStatus.getRunState() == TaskStatus.State.UNASSIGNED) {
if (wasFailure) {
failures += 1;
taskStatus.setRunState(TaskStatus.State.FAILED);
} else {
taskStatus.setRunState(TaskStatus.State.KILLED);
}
}
taskStatus.setFinishTime(System.currentTimeMillis());
removeFromMemoryManager(task.getTaskID());
releaseSlot();
myInstrumentation.statusUpdate(task, taskStatus);
notifyTTAboutTaskCompletion();
}
private synchronized void releaseSlot() {
if (slotTaken) {
if (launcher != null) {
launcher.addFreeSlots(task.getNumSlotsRequired());
}
slotTaken = false;
}
}
/**
* The map output has been lost.
*/
private synchronized void mapOutputLost(String failure
) throws IOException {
if (taskStatus.getRunState() == TaskStatus.State.COMMIT_PENDING ||
taskStatus.getRunState() == TaskStatus.State.SUCCEEDED) {
// change status to failure
LOG.info("Reporting output lost:"+task.getTaskID());
taskStatus.setRunState(TaskStatus.State.FAILED);
taskStatus.setProgress(0.0f);
reportDiagnosticInfo("Map output lost, rescheduling: " +
failure);
runningTasks.put(task.getTaskID(), this);
mapTotal++;
myInstrumentation.statusUpdate(task, taskStatus);
} else {
LOG.warn("Output already reported lost:"+task.getTaskID());
}
}
/**
* We no longer need anything from this task. Either the
* controlling job is all done and the files have been copied
* away, or the task failed and we don't need the remains.
* Any calls to cleanup should not lock the tip first.
* cleanup does the right thing- updates tasks in Tasktracker
* by locking tasktracker first and then locks the tip.
*
* if needCleanup is true, the whole task directory is cleaned up.
* otherwise the current working directory of the task
* i.e. <taskid>/work is cleaned up.
*/
void cleanup(boolean needCleanup) throws IOException {
TaskAttemptID taskId = task.getTaskID();
LOG.debug("Cleaning up " + taskId);
synchronized (TaskTracker.this) {
if (needCleanup) {
// see if tasks data structure is holding this tip.
// tasks could hold the tip for cleanup attempt, if cleanup attempt
// got launched before this method.
if (tasks.get(taskId) == this) {
tasks.remove(taskId);
}
}
synchronized (this){
if (alwaysKeepTaskFiles ||
(taskStatus.getRunState() == TaskStatus.State.FAILED &&
keepFailedTaskFiles)) {
return;
}
}
}
synchronized (this) {
try {
// localJobConf could be null if localization has not happened
// then no cleanup will be required.
if (localJobConf == null) {
return;
}
String taskDir = getLocalTaskDir(task.getJobID().toString(),
taskId.toString(), task.isTaskCleanupTask());
if (needCleanup) {
if (runner != null) {
//cleans up the output directory of the task (where map outputs
//and reduce inputs get stored)
runner.close();
}
//We don't delete the workdir
//since some other task (running in the same JVM)
//might be using the dir. The JVM running the tasks would clean
//the workdir per a task in the task process itself.
if (localJobConf.getNumTasksToExecutePerJvm() == 1) {
PathDeletionContext[] contexts =
buildTaskControllerPathDeletionContexts(localFs, getLocalDirs(),
task, false/* not workDir */, taskController);
directoryCleanupThread.addToQueue(contexts);
}
else {
PathDeletionContext[] contexts = buildPathDeletionContexts(
localFs, getLocalFiles(defaultJobConf, taskDir+"/job.xml"));
directoryCleanupThread.addToQueue(contexts);
}
} else {
if (localJobConf.getNumTasksToExecutePerJvm() == 1) {
PathDeletionContext[] contexts =
buildTaskControllerPathDeletionContexts(localFs, getLocalDirs(),
task, true /* workDir */,
taskController);
directoryCleanupThread.addToQueue(contexts);
}
}
} catch (Throwable ie) {
LOG.info("Error cleaning up task runner: " +
StringUtils.stringifyException(ie));
}
}
}
@Override
public boolean equals(Object obj) {
return (obj instanceof TaskInProgress) &&
task.getTaskID().equals
(((TaskInProgress) obj).getTask().getTaskID());
}
@Override
public int hashCode() {
return task.getTaskID().hashCode();
}
}
// ///////////////////////////////////////////////////////////////
// TaskUmbilicalProtocol
/////////////////////////////////////////////////////////////////
/**
* Called upon startup by the child process, to fetch Task data.
*/
public synchronized JvmTask getTask(JvmContext context)
throws IOException {
JVMId jvmId = context.jvmId;
LOG.debug("JVM with ID : " + jvmId + " asked for a task");
// save pid of task JVM sent by child
jvmManager.setPidToJvm(jvmId, context.pid);
if (!jvmManager.isJvmKnown(jvmId)) {
LOG.info("Killing unknown JVM " + jvmId);
return new JvmTask(null, true);
}
RunningJob rjob = runningJobs.get(jvmId.getJobId());
if (rjob == null) { //kill the JVM since the job is dead
LOG.info("Killing JVM " + jvmId + " since job " + jvmId.getJobId() +
" is dead");
jvmManager.killJvm(jvmId);
return new JvmTask(null, true);
}
TaskInProgress tip = jvmManager.getTaskForJvm(jvmId);
if (tip == null) {
return new JvmTask(null, false);
}
if (tasks.get(tip.getTask().getTaskID()) != null) { //is task still present
LOG.info("JVM with ID: " + jvmId + " given task: " +
tip.getTask().getTaskID());
return new JvmTask(tip.getTask(), false);
} else {
LOG.info("Killing JVM with ID: " + jvmId + " since scheduled task: " +
tip.getTask().getTaskID() + " is " + tip.taskStatus.getRunState());
return new JvmTask(null, true);
}
}
/**
* Called periodically to report Task progress, from 0.0 to 1.0.
*/
public synchronized boolean statusUpdate(TaskAttemptID taskid,
TaskStatus taskStatus)
throws IOException {
TaskInProgress tip = tasks.get(taskid);
if (tip != null) {
tip.reportProgress(taskStatus);
myInstrumentation.statusUpdate(tip.getTask(), taskStatus);
return true;
} else {
if (LOG.isDebugEnabled()) {
LOG.debug("Progress from unknown child task: "+taskid);
}
return false;
}
}
/**
* Called when the task dies before completion, and we want to report back
* diagnostic info
*/
public synchronized void reportDiagnosticInfo(TaskAttemptID taskid, String info) throws IOException {
TaskInProgress tip = tasks.get(taskid);
if (tip != null) {
tip.reportDiagnosticInfo(info);
} else {
LOG.warn("Error from unknown child task: "+taskid+". Ignored.");
}
}
public synchronized void reportNextRecordRange(TaskAttemptID taskid,
SortedRanges.Range range) throws IOException {
TaskInProgress tip = tasks.get(taskid);
if (tip != null) {
tip.reportNextRecordRange(range);
} else {
LOG.warn("reportNextRecordRange from unknown child task: "+taskid+". " +
"Ignored.");
}
}
/** Child checking to see if we're alive. Normally does nothing.*/
public synchronized boolean ping(TaskAttemptID taskid) throws IOException {
return tasks.get(taskid) != null;
}
/**
* Task is reporting that it is in commit_pending
* and it is waiting for the commit Response
*/
public synchronized void commitPending(TaskAttemptID taskid,
TaskStatus taskStatus)
throws IOException {
LOG.info("Task " + taskid + " is in commit-pending," +"" +
" task state:" +taskStatus.getRunState());
statusUpdate(taskid, taskStatus);
reportTaskFinished(taskid, true);
}
/**
* Child checking whether it can commit
*/
public synchronized boolean canCommit(TaskAttemptID taskid) {
return commitResponses.contains(taskid); //don't remove it now
}
/**
* The task is done.
*/
public synchronized void done(TaskAttemptID taskid)
throws IOException {
TaskInProgress tip = tasks.get(taskid);
commitResponses.remove(taskid);
if (tip != null) {
tip.reportDone();
} else {
LOG.warn("Unknown child task done: "+taskid+". Ignored.");
}
}
/**
* A reduce-task failed to shuffle the map-outputs. Kill the task.
*/
public synchronized void shuffleError(TaskAttemptID taskId, String message)
throws IOException {
LOG.fatal("Task: " + taskId + " - Killed due to Shuffle Failure: " + message);
TaskInProgress tip = runningTasks.get(taskId);
if (tip != null) {
tip.reportDiagnosticInfo("Shuffle Error: " + message);
purgeTask(tip, true);
}
}
/**
* A child task had a local filesystem error. Kill the task.
*/
public synchronized void fsError(TaskAttemptID taskId, String message)
throws IOException {
LOG.fatal("Task: " + taskId + " - Killed due to FSError: " + message);
TaskInProgress tip = runningTasks.get(taskId);
if (tip != null) {
tip.reportDiagnosticInfo("FSError: " + message);
purgeTask(tip, true);
}
}
/**
* A child task had a fatal error. Kill the task.
*/
public synchronized void fatalError(TaskAttemptID taskId, String msg)
throws IOException {
LOG.fatal("Task: " + taskId + " - Killed : " + msg);
TaskInProgress tip = runningTasks.get(taskId);
if (tip != null) {
tip.reportDiagnosticInfo("Error: " + msg);
purgeTask(tip, true);
}
}
public synchronized MapTaskCompletionEventsUpdate getMapCompletionEvents(
JobID jobId, int fromEventId, int maxLocs, TaskAttemptID id)
throws IOException {
TaskCompletionEvent[]mapEvents = TaskCompletionEvent.EMPTY_ARRAY;
RunningJob rjob;
synchronized (runningJobs) {
rjob = runningJobs.get(jobId);
if (rjob != null) {
synchronized (rjob) {
FetchStatus f = rjob.getFetchStatus();
if (f != null) {
mapEvents = f.getMapEvents(fromEventId, maxLocs);
}
}
}
}
return new MapTaskCompletionEventsUpdate(mapEvents, false);
}
/////////////////////////////////////////////////////
// Called by TaskTracker thread after task process ends
/////////////////////////////////////////////////////
/**
* The task is no longer running. It may not have completed successfully
*/
void reportTaskFinished(TaskAttemptID taskid, boolean commitPending) {
TaskInProgress tip;
synchronized (this) {
tip = tasks.get(taskid);
}
if (tip != null) {
tip.reportTaskFinished(commitPending);
} else {
LOG.warn("Unknown child task finished: "+taskid+". Ignored.");
}
}
/**
* A completed map task's output has been lost.
*/
public synchronized void mapOutputLost(TaskAttemptID taskid,
String errorMsg) throws IOException {
TaskInProgress tip = tasks.get(taskid);
if (tip != null) {
tip.mapOutputLost(errorMsg);
} else {
LOG.warn("Unknown child with bad map output: "+taskid+". Ignored.");
}
}
/**
* The datastructure for initializing a job
*/
static class RunningJob{
private JobID jobid;
private JobConf jobConf;
private volatile InterTrackerProtocol jobClient;
private Writable extensible;
// keep this for later use
volatile Set<TaskInProgress> tasks;
volatile boolean localized;
final Object localizationLock;
boolean keepJobFiles;
FetchStatus f;
RunningJob(JobID jobid, InterTrackerProtocol jobClient,
Writable extensible) {
this.jobid = jobid;
this.jobClient = jobClient;
this.extensible = extensible;
localized = false;
localizationLock = new Object();
tasks = new HashSet<TaskInProgress>();
keepJobFiles = false;
}
JobID getJobID() {
return jobid;
}
void setFetchStatus(FetchStatus f) {
this.f = f;
}
FetchStatus getFetchStatus() {
return f;
}
InterTrackerProtocol getJobClient() {
return jobClient;
}
void setJobClient(InterTrackerProtocol jobClient) {
this.jobClient = jobClient;
}
Writable getExtensible() {
return extensible;
}
}
/**
* Get the name for this task tracker.
* @return the string like "tracker_mymachine:50010"
*/
public String getName() {
return taskTrackerName;
}
private synchronized List<TaskStatus> cloneAndResetRunningTaskStatuses(
Collection<TaskInProgress> tips, boolean sendCounters) {
List<TaskStatus> result = new ArrayList<TaskStatus>(runningTasks.size());
for(TaskInProgress tip : tips) {
TaskStatus status = tip.getStatus();
status.setIncludeCounters(sendCounters);
status.setOutputSize(tryToGetOutputSize(status.getTaskID(), fConf));
// send counters for finished or failed tasks and commit pending tasks
if (status.getRunState() != TaskStatus.State.RUNNING) {
status.setIncludeCounters(true);
}
result.add((TaskStatus)status.clone());
status.clearStatus();
}
return result;
}
/**
* Get the list of tasks that will be reported back to the
* job tracker in the next heartbeat cycle.
* @return a copy of the list of TaskStatus objects
*/
synchronized List<TaskStatus> getRunningTaskStatuses() {
List<TaskStatus> result = new ArrayList<TaskStatus>(runningTasks.size());
for(TaskInProgress tip: runningTasks.values()) {
result.add(tip.getStatus());
}
return result;
}
/**
* Get the list of stored tasks on this task tracker.
* @return
*/
public synchronized List<TaskStatus> getNonRunningTasks() {
List<TaskStatus> result = new ArrayList<TaskStatus>(tasks.size());
for(Map.Entry<TaskAttemptID, TaskInProgress> task: tasks.entrySet()) {
if (!runningTasks.containsKey(task.getKey())) {
result.add(task.getValue().getStatus());
}
}
return result;
}
/**
* Get the list of tasks from running jobs on this task tracker.
* @return a copy of the list of TaskStatus objects
*/
synchronized List<TaskStatus> getTasksFromRunningJobs() {
List<TaskStatus> result = new ArrayList<TaskStatus>(tasks.size());
for (Map.Entry <JobID, RunningJob> item : runningJobs.entrySet()) {
RunningJob rjob = item.getValue();
synchronized (rjob) {
for (TaskInProgress tip : rjob.tasks) {
result.add(tip.getStatus());
}
}
}
return result;
}
/**
* Get the default job conf for this tracker.
*/
JobConf getJobConf() {
return fConf;
}
/**
* Check if the given local directories
* (and parent directories, if necessary) can be created.
* @param localDirs where the new TaskTracker should keep its local files.
* @throws DiskErrorException if all local directories are not writable
*/
private static void checkLocalDirs(String[] localDirs)
throws DiskErrorException {
boolean writable = false;
if (localDirs != null) {
for (int i = 0; i < localDirs.length; i++) {
try {
DiskChecker.checkDir(new File(localDirs[i]));
writable = true;
} catch(DiskErrorException e) {
LOG.warn("Task Tracker local " + e.getMessage());
}
}
}
if (!writable)
throw new DiskErrorException(
"all local directories are not writable");
}
/**
* Is this task tracker idle?
* @return has this task tracker finished and cleaned up all of its tasks?
*/
public synchronized boolean isIdle() {
return tasks.isEmpty() && tasksToCleanup.isEmpty();
}
/**
* Start the TaskTracker, point toward the indicated JobTracker
*/
public static void main(String argv[]) throws Exception {
StringUtils.startupShutdownMessage(TaskTracker.class, argv, LOG);
try {
if (argv.length == 0) {
JobConf conf = new JobConf();
ReflectionUtils.setContentionTracing
(conf.getBoolean("tasktracker.contention.tracking", false));
new TaskTracker(conf).run();
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);
// enable the server to track time spent waiting on locks
ReflectionUtils.setContentionTracing
(conf.getBoolean("tasktracker.contention.tracking", false));
new TaskTracker(conf).run();
return;
}
}
System.out.println("usage: TaskTracker [-instance <0|1>]");
System.exit(-1);
} catch (Throwable e) {
LOG.error("Can not start task tracker because "+
StringUtils.stringifyException(e));
System.exit(-1);
}
}
/**
* This class is used in TaskTracker's Jetty to serve the map outputs
* to other nodes.
*/
public static class MapOutputServlet extends HttpServlet {
private static final int MAX_BYTES_TO_READ = 64 * 1024;
@Override
public void doGet(HttpServletRequest request,
HttpServletResponse response
) throws ServletException, IOException {
String mapId = request.getParameter("map");
String reduceId = request.getParameter("reduce");
String jobId = request.getParameter("job");
if (jobId == null) {
throw new IOException("job parameter is required");
}
if (mapId == null || reduceId == null) {
throw new IOException("map and reduce parameters are required");
}
ServletContext context = getServletContext();
TaskTracker tracker =
(TaskTracker) context.getAttribute("task.tracker");
// When using netty, this servlet should use an HTTP redirect to get the
// sender to use the correct address and port for the netty server
if (tracker.nettyMapOutputHttpPort != -1) {
String redirectUrl = "http://" + request.getServerName() + ":" +
tracker.nettyMapOutputHttpPort + "/mapOutput?" +
request.getQueryString();
if (LOG.isDebugEnabled()) {
LOG.debug("Redirecting to " + redirectUrl + " from " +
request.getRequestURL() + "?" + request.getQueryString());
}
response.sendRedirect(redirectUrl);
return;
}
int reduce = Integer.parseInt(reduceId);
byte[] buffer = new byte[MAX_BYTES_TO_READ];
// true iff IOException was caused by attempt to access input
boolean isInputException = true;
OutputStream outStream = null;
FSDataInputStream mapOutputIn = null;
long totalRead = 0;
ShuffleServerMetrics shuffleMetrics =
(ShuffleServerMetrics) context.getAttribute("shuffleServerMetrics");
shuffleMetrics.setHttpQueueLen(tracker.getJettyQueueSize());
long startTime = 0;
try {
shuffleMetrics.serverHandlerBusy();
if(ClientTraceLog.isInfoEnabled())
startTime = System.nanoTime();
outStream = response.getOutputStream();
JobConf conf = (JobConf) context.getAttribute("conf");
LocalDirAllocator lDirAlloc =
(LocalDirAllocator)context.getAttribute("localDirAllocator");
FileSystem rfs = ((LocalFileSystem)
context.getAttribute("local.file.system")).getRaw();
// Index file
Path indexFileName = lDirAlloc.getLocalPathToRead(
TaskTracker.getIntermediateOutputDir(jobId, mapId)
+ "/file.out.index", conf);
// Map-output file
Path mapOutputFileName = lDirAlloc.getLocalPathToRead(
TaskTracker.getIntermediateOutputDir(jobId, mapId)
+ "/file.out", conf);
/**
* Read the index file to get the information about where
* the map-output for the given reducer is available.
*/
IndexRecord info =
tracker.indexCache.getIndexInformation(mapId, reduce,indexFileName);
//set the custom "from-map-task" http header to the map task from which
//the map output data is being transferred
response.setHeader(FROM_MAP_TASK, mapId);
//set the custom "Raw-Map-Output-Length" http header to
//the raw (decompressed) length
response.setHeader(RAW_MAP_OUTPUT_LENGTH,
Long.toString(info.rawLength));
//set the custom "Map-Output-Length" http header to
//the actual number of bytes being transferred
response.setHeader(MAP_OUTPUT_LENGTH,
Long.toString(info.partLength));
//set the custom "for-reduce-task" http header to the reduce task number
//for which this map output is being transferred
response.setHeader(FOR_REDUCE_TASK, Integer.toString(reduce));
//use the same buffersize as used for reading the data from disk
response.setBufferSize(MAX_BYTES_TO_READ);
/**
* Read the data from the sigle map-output file and
* send it to the reducer.
*/
//open the map-output file
mapOutputIn = rfs.open(mapOutputFileName);
//seek to the correct offset for the reduce
mapOutputIn.seek(info.startOffset);
long rem = info.partLength;
int len =
mapOutputIn.read(buffer, 0, (int)Math.min(rem, MAX_BYTES_TO_READ));
while (rem > 0 && len >= 0) {
rem -= len;
try {
shuffleMetrics.outputBytes(len);
outStream.write(buffer, 0, len);
outStream.flush();
} catch (IOException ie) {
isInputException = false;
throw ie;
}
totalRead += len;
len =
mapOutputIn.read(buffer, 0, (int)Math.min(rem, MAX_BYTES_TO_READ));
}
LOG.info("Sent out " + totalRead + " bytes for reduce: " + reduce +
" from map: " + mapId + " given " + info.partLength + "/" +
info.rawLength);
} catch (org.mortbay.jetty.EofException eof) {
// The Jetty EOFException is observed when the Reduce Task prematurely
// closes a connection to a jetty server. The RT might decide to do
// this when the expected map output size is less than its memory cache
// limit, but cannot fetch it now because it has already fetched
// several other map outputs to memory. In short, this is OK.
// See MAPREDUCE-5 for details.
LOG.info("EofException for map:" + mapId + " reduce:" + reduceId);
shuffleMetrics.failedOutput();
throw eof;
} catch (IOException ie) {
Log log = (Log) context.getAttribute("log");
String errorMsg = ("getMapOutput(" + mapId + "," + reduceId +
") failed");
log.error(errorMsg, ie);
if (isInputException) {
tracker.mapOutputLost(TaskAttemptID.forName(mapId), errorMsg);
}
response.sendError(HttpServletResponse.SC_GONE, errorMsg);
shuffleMetrics.failedOutput();
throw ie;
} finally {
if (null != mapOutputIn) {
mapOutputIn.close();
}
final long endTime = ClientTraceLog.isInfoEnabled() ? System.nanoTime() : 0;
shuffleMetrics.serverHandlerFree();
if (ClientTraceLog.isInfoEnabled()) {
ClientTraceLog.info(String.format(MR_CLIENTTRACE_FORMAT,
request.getLocalAddr() + ":" + request.getLocalPort(),
request.getRemoteAddr() + ":" + request.getRemotePort(),
totalRead, "MAPRED_SHUFFLE", mapId, endTime-startTime));
}
}
outStream.close();
shuffleMetrics.successOutput();
}
}
/**
* Pipeline for map output sending.
*/
class HttpMapOutputPipelineFactory implements ChannelPipelineFactory {
private final ShuffleHandler shuffleHandler;
public HttpMapOutputPipelineFactory(
NettyMapOutputAttributes attributes, int port) {
this.shuffleHandler = new ShuffleHandler(attributes, port);
}
@Override
public ChannelPipeline getPipeline() throws Exception {
return Channels.pipeline(
new HttpRequestDecoder(),
new HttpChunkAggregator(1 << 16),
new HttpResponseEncoder(),
new ChunkedWriteHandler(),
shuffleHandler);
}
}
// get the full paths of the directory in all the local disks.
Path[] getLocalFiles(JobConf conf, String subdir) throws IOException{
String[] localDirs = conf.getLocalDirs();
Path[] paths = new Path[localDirs.length];
FileSystem localFs = FileSystem.getLocal(conf);
for (int i = 0; i < localDirs.length; i++) {
paths[i] = new Path(localDirs[i], subdir);
paths[i] = paths[i].makeQualified(localFs);
}
return paths;
}
// get the paths in all the local disks.
Path[] getLocalDirs() throws IOException{
String[] localDirs = fConf.getLocalDirs();
Path[] paths = new Path[localDirs.length];
FileSystem localFs = FileSystem.getLocal(fConf);
for (int i = 0; i < localDirs.length; i++) {
paths[i] = new Path(localDirs[i]);
paths[i] = paths[i].makeQualified(localFs);
}
return paths;
}
FileSystem getLocalFileSystem(){
return localFs;
}
int getMaxCurrentMapTasks() {
return maxMapSlots;
}
int getMaxCurrentReduceTasks() {
return maxReduceSlots;
}
/**
* Metrics can use this to get the actual number of running maps
*
* @return Currently running maps
*/
int getRunningMaps() {
return mapLauncher.getNumUsedSlots();
}
/**
* Metrics can use this to get the actual number of running reduces
*
* @return Currently running reduces
*/
int getRunningReduces() {
return reduceLauncher.getNumUsedSlots();
}
/**
* Used for metrics only to get the actual max map tasks.
*
* @return Actual number of max map tasks.
*/
int getMaxActualMapTasks() {
return actualMaxMapSlots;
}
/**
* Used for metrics only to get the actual max reduce tasks.
*
* @return Actual number of max reduce tasks.
*/
int getMaxActualReduceTasks() {
return actualMaxReduceSlots;
}
/**
* Get the actual max number of tasks. This may be different than
* get(Max|Reduce)CurrentMapTasks() since that is the number used
* for scheduling. This allows the CoronaTaskTracker to return the
* real number of resources available.
*
* @param conf Configuration to look for slots
* @param numCpuOnTT Number of cpus on TaskTracker
* @param type Type of slot
* @return Actual number of map tasks, not what the TaskLauncher thinks.
*/
int getMaxActualSlots(JobConf conf, int numCpuOnTT, TaskType type) {
return getMaxSlots(conf, numCpuOnTT, type);
}
/**
* Get the average time in milliseconds to refill a free map slot. This
* average is calculated on a rotating buffer.
*
* @return Average time in milliseconds to refill a free map slot. Return -1
* if the value is not valid (hasn't actually refilled anything)
*/
int getAveMapSlotRefillMsecs() {
synchronized (mapSlotRefillMsecsQueue) {
if (mapSlotRefillMsecsQueue.isEmpty()) {
return -1;
}
int totalMapSlotRefillMsecs = 0;
for (int refillMsecs : mapSlotRefillMsecsQueue) {
totalMapSlotRefillMsecs += refillMsecs;
}
return totalMapSlotRefillMsecs / mapSlotRefillMsecsQueue.size();
}
}
/**
* Add this new refill time for the map slot refill queue. Delete
* the oldest value if the maximum size has been met.
*
* @param refillMsecs Time to refill a map slot
*/
void addAveMapSlotRefillMsecs(int refillMsecs) {
synchronized (mapSlotRefillMsecsQueue) {
mapSlotRefillMsecsQueue.add(refillMsecs);
if (mapSlotRefillMsecsQueue.size() >= maxRefillQueueSize) {
mapSlotRefillMsecsQueue.remove();
}
}
}
/**
* Get the average time in milliseconds to refill a free reduce slot. This
* average is calculated on a rotating buffer.
*
* @return Average time in milliseconds to refill a free reduce slot. Return -1
* if the value is not valid (hasn't actually refilled anything)
*/
int getAveReduceSlotRefillMsecs() {
synchronized (reduceSlotRefillMsecsQueue) {
if (reduceSlotRefillMsecsQueue.isEmpty()) {
return -1;
}
int totalReduceSlotRefillMsecs = 0;
for (int refillMsecs : reduceSlotRefillMsecsQueue) {
totalReduceSlotRefillMsecs += refillMsecs;
}
return totalReduceSlotRefillMsecs / reduceSlotRefillMsecsQueue.size();
}
}
/**
* Add this new refill time for the reduce slot refill queue. Delete
* the oldest value if the maximum size has been met.
*
* @param refillMsecs Time to refill a reduce slot
*/
void addAveReduceSlotRefillMsecs(int refillMsecs) {
synchronized (reduceSlotRefillMsecsQueue) {
reduceSlotRefillMsecsQueue.add(refillMsecs);
if (reduceSlotRefillMsecsQueue.size() >= maxRefillQueueSize) {
reduceSlotRefillMsecsQueue.remove();
}
}
}
/**
* Is the TaskMemoryManager Enabled on this system?
* @return true if enabled, false otherwise.
*/
public boolean isTaskMemoryManagerEnabled() {
return taskMemoryManagerEnabled;
}
public TaskMemoryManagerThread getTaskMemoryManager() {
return taskMemoryManager;
}
/**
* Normalize the negative values in configuration
*
* @param val
* @return normalized val
*/
private long normalizeMemoryConfigValue(long val) {
if (val < 0) {
val = JobConf.DISABLED_MEMORY_LIMIT;
}
return val;
}
/**
* Memory-related setup
*/
private void initializeMemoryManagement() {
//handling @deprecated
if (fConf.get(MAPRED_TASKTRACKER_VMEM_RESERVED_PROPERTY) != null) {
LOG.warn(
JobConf.deprecatedString(
MAPRED_TASKTRACKER_VMEM_RESERVED_PROPERTY));
}
//handling @deprecated
if (fConf.get(MAPRED_TASKTRACKER_PMEM_RESERVED_PROPERTY) != null) {
LOG.warn(
JobConf.deprecatedString(
MAPRED_TASKTRACKER_PMEM_RESERVED_PROPERTY));
}
//handling @deprecated
if (fConf.get(JobConf.MAPRED_TASK_DEFAULT_MAXVMEM_PROPERTY) != null) {
LOG.warn(
JobConf.deprecatedString(
JobConf.MAPRED_TASK_DEFAULT_MAXVMEM_PROPERTY));
}
//handling @deprecated
if (fConf.get(JobConf.UPPER_LIMIT_ON_TASK_VMEM_PROPERTY) != null) {
LOG.warn(
JobConf.deprecatedString(
JobConf.UPPER_LIMIT_ON_TASK_VMEM_PROPERTY));
}
totalVirtualMemoryOnTT = resourceCalculatorPlugin.getVirtualMemorySize();
totalPhysicalMemoryOnTT = resourceCalculatorPlugin.getPhysicalMemorySize();
mapSlotMemorySizeOnTT =
fConf.getLong(
JobTracker.MAPRED_CLUSTER_MAP_MEMORY_MB_PROPERTY,
JobConf.DISABLED_MEMORY_LIMIT);
reduceSlotSizeMemoryOnTT =
fConf.getLong(
JobTracker.MAPRED_CLUSTER_REDUCE_MEMORY_MB_PROPERTY,
JobConf.DISABLED_MEMORY_LIMIT);
totalMemoryAllottedForTasks =
maxMapSlots * mapSlotMemorySizeOnTT + maxReduceSlots
* reduceSlotSizeMemoryOnTT;
if (totalMemoryAllottedForTasks < 0) {
//adding check for the old keys which might be used by the administrator
//while configuration of the memory monitoring on TT
long memoryAllotedForSlot = fConf.normalizeMemoryConfigValue(
fConf.getLong(JobConf.MAPRED_TASK_DEFAULT_MAXVMEM_PROPERTY,
JobConf.DISABLED_MEMORY_LIMIT));
long limitVmPerTask = fConf.normalizeMemoryConfigValue(
fConf.getLong(JobConf.UPPER_LIMIT_ON_TASK_VMEM_PROPERTY,
JobConf.DISABLED_MEMORY_LIMIT));
if(memoryAllotedForSlot == JobConf.DISABLED_MEMORY_LIMIT) {
totalMemoryAllottedForTasks = JobConf.DISABLED_MEMORY_LIMIT;
} else {
if(memoryAllotedForSlot > limitVmPerTask) {
LOG.info("DefaultMaxVmPerTask is mis-configured. " +
"It shouldn't be greater than task limits");
totalMemoryAllottedForTasks = JobConf.DISABLED_MEMORY_LIMIT;
} else {
totalMemoryAllottedForTasks = (maxMapSlots +
maxReduceSlots) * (memoryAllotedForSlot/(1024 * 1024));
}
}
}
if (totalMemoryAllottedForTasks > totalPhysicalMemoryOnTT) {
LOG.info("totalMemoryAllottedForTasks > totalPhysicalMemoryOnTT."
+ " Thrashing might happen.");
} else if (totalMemoryAllottedForTasks > totalVirtualMemoryOnTT) {
LOG.info("totalMemoryAllottedForTasks > totalVirtualMemoryOnTT."
+ " Thrashing might happen.");
}
// start the taskMemoryManager thread only if enabled
setTaskMemoryManagerEnabledFlag();
if (isTaskMemoryManagerEnabled()) {
taskMemoryManager = new TaskMemoryManagerThread(this);
taskMemoryManager.setDaemon(true);
taskMemoryManager.start();
}
}
private void setTaskMemoryManagerEnabledFlag() {
if (!ProcfsBasedProcessTree.isAvailable()) {
LOG.info("ProcessTree implementation is missing on this system. "
+ "TaskMemoryManager is disabled.");
taskMemoryManagerEnabled = false;
return;
}
if (fConf.get(TaskMemoryManagerThread.TT_RESERVED_PHYSICAL_MEMORY_MB) == null
&& totalMemoryAllottedForTasks == JobConf.DISABLED_MEMORY_LIMIT) {
taskMemoryManagerEnabled = false;
LOG.warn("TaskTracker's totalMemoryAllottedForTasks is -1 and " +
"reserved physical memory is not configured. " +
"TaskMemoryManager is disabled.");
return;
}
taskMemoryManagerEnabled = true;
}
/**
* Clean-up the task that TaskMemoryMangerThread requests to do so.
* @param tid
* @param wasFailure mark the task as failed or killed. 'failed' if true,
* 'killed' otherwise
* @param diagnosticMsg
*/
synchronized void cleanUpOverMemoryTask(TaskAttemptID tid, boolean wasFailure,
String diagnosticMsg) {
TaskInProgress tip = runningTasks.get(tid);
if (tip != null) {
tip.reportDiagnosticInfo(diagnosticMsg);
try {
purgeTask(tip, wasFailure); // Marking it as failed/killed.
} catch (IOException ioe) {
LOG.warn("Couldn't purge the task of " + tid + ". Error : " + ioe);
}
}
}
/**
* Wrapper method used by TaskTracker to check if {@link NodeHealthCheckerService}
* can be started
* @param conf configuration used to check if service can be started
* @return true if service can be started
*/
private boolean shouldStartHealthMonitor(Configuration conf) {
return NodeHealthCheckerService.shouldRun(conf);
}
/**
* Wrapper method used to start {@link NodeHealthCheckerService} for
* Task Tracker
* @param conf Configuration used by the service.
*/
private void startHealthMonitor(Configuration conf) {
healthChecker = new NodeHealthCheckerService(conf);
healthChecker.start();
}
public List<FetchStatus> reducesInShuffle() {
if (mapEventsFetcher == null) {
List<FetchStatus> empty = Collections.emptyList();
return empty;
}
return mapEventsFetcher.reducesInShuffle();
}
/**
* Obtain username from TaskId
* @param taskId
* @return username
*/
public String getUserName(TaskAttemptID taskId) {
TaskInProgress tip = tasks.get(taskId);
if (tip != null) {
return tip.getJobConf().getUser();
}
return null;
}
/**
* Obtain the max number of task slots based on the configuration and CPU
*/
protected int getMaxSlots(JobConf conf, int numCpuOnTT, TaskType type) {
int maxSlots;
String cpuToSlots;
if (type == TaskType.MAP) {
maxSlots = conf.getInt("mapred.tasktracker.map.tasks.maximum", 2);
cpuToSlots = conf.get("mapred.tasktracker.cpus.to.maptasks");
} else {
maxSlots = conf.getInt("mapred.tasktracker.reduce.tasks.maximum", 2);
cpuToSlots = conf.get("mapred.tasktracker.cpus.to.reducetasks");
}
if (cpuToSlots != null) {
try {
// Format of the configuration is
// numCpu1:maxSlot1, numCpu2:maxSlot2, numCpu3:maxSlot3
for (String str : cpuToSlots.split(",")) {
String[] pair = str.split(":");
int numCpu = Integer.parseInt(pair[0].trim());
int max = Integer.parseInt(pair[1].trim());
if (numCpu == numCpuOnTT) {
maxSlots = max;
break;
}
}
} catch (Exception e) {
LOG.warn("Error parsing number of CPU to map slots configuration", e);
}
}
return maxSlots;
}
@Override
public Collection<String> getReconfigurableProperties() {
Set<String> properties = new HashSet<String>();
properties.add(TT_FAST_FETCH);
properties.add(TT_OUTOFBAND_HEARBEAT);
properties.add(TT_PROFILE_ALL_TASKS);
return properties;
}
@Override
protected void reconfigurePropertyImpl(String property, String newVal)
throws ReconfigurationException {
if (property.equals(TT_FAST_FETCH)) {
this.fastFetch = Boolean.valueOf(newVal);
} else if (property.equals(TT_OUTOFBAND_HEARBEAT)) {
this.oobHeartbeatOnTaskCompletion = Boolean.valueOf(newVal);
} else if (property.equals(TT_PROFILE_ALL_TASKS)) {
this.profileAllTasks = Boolean.valueOf(newVal);
}
}
}