/**
* 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
* <p/>
* http://www.apache.org/licenses/LICENSE-2.0
* <p/>
* 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.gridmix;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.IOUtils;
import org.apache.hadoop.mapred.ClusterStatus;
import org.apache.hadoop.mapred.gridmix.Statistics.ClusterStats;
import org.apache.hadoop.mapred.gridmix.Statistics.JobStats;
import org.apache.hadoop.security.UserGroupInformation;
import org.apache.hadoop.tools.rumen.JobStory;
import org.apache.hadoop.tools.rumen.JobStoryProducer;
import java.io.IOException;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.locks.Condition;
public class StressJobFactory extends JobFactory<Statistics.ClusterStats> {
public static final Log LOG = LogFactory.getLog(StressJobFactory.class);
private final LoadStatus loadStatus = new LoadStatus();
private final Condition condUnderloaded = this.lock.newCondition();
/**
* The minimum ratio between pending+running map tasks (aka. incomplete map
* tasks) and cluster map slot capacity for us to consider the cluster is
* overloaded. For running maps, we only count them partially. Namely, a 40%
* completed map is counted as 0.6 map tasks in our calculation.
*/
static final float OVERLOAD_MAPTASK_MAPSLOT_RATIO = 2.0f;
/**
* The minimum ratio between pending+running reduce tasks (aka. incomplete
* reduce tasks) and cluster reduce slot capacity for us to consider the
* cluster is overloaded. For running reduces, we only count them partially.
* Namely, a 40% completed reduce is counted as 0.6 reduce tasks in our
* calculation.
*/
static final float OVERLOAD_REDUCETASK_REDUCESLOT_RATIO = 2.5f;
/**
* The maximum share of the cluster's mapslot capacity that can be counted
* toward a job's incomplete map tasks in overload calculation.
*/
static final float MAX_MAPSLOT_SHARE_PER_JOB=0.1f;
/**
* The maximum share of the cluster's reduceslot capacity that can be counted
* toward a job's incomplete reduce tasks in overload calculation.
*/
static final float MAX_REDUCESLOT_SHARE_PER_JOB=0.1f;
/**
* Creating a new instance does not start the thread.
*
* @param submitter Component to which deserialized jobs are passed
* @param jobProducer Stream of job traces with which to construct a
* {@link org.apache.hadoop.tools.rumen.ZombieJobProducer}
* @param scratch Directory into which to write output from simulated jobs
* @param conf Config passed to all jobs to be submitted
* @param startFlag Latch released from main to start pipeline
* @throws java.io.IOException
*/
public StressJobFactory(
JobSubmitter submitter, JobStoryProducer jobProducer, Path scratch,
Configuration conf, CountDownLatch startFlag, UserResolver resolver)
throws IOException {
super(
submitter, jobProducer, scratch, conf, startFlag, resolver);
}
public Thread createReaderThread() {
return new StressReaderThread("StressJobFactory");
}
/*
* Worker thread responsible for reading descriptions, assigning sequence
* numbers, and normalizing time.
*/
private class StressReaderThread extends Thread {
public StressReaderThread(String name) {
super(name);
}
/**
* STRESS: Submits the job in STRESS mode.
* while(JT is overloaded) {
* wait();
* }
* If not overloaded , get number of slots available.
* Keep submitting the jobs till ,total jobs is sufficient to
* load the JT.
* That is submit (Sigma(no of maps/Job)) > (2 * no of slots available)
*/
public void run() {
try {
startFlag.await();
if (Thread.currentThread().isInterrupted()) {
return;
}
LOG.info("START STRESS @ " + System.currentTimeMillis());
while (!Thread.currentThread().isInterrupted()) {
lock.lock();
try {
while (loadStatus.overloaded()) {
//Wait while JT is overloaded.
try {
condUnderloaded.await();
} catch (InterruptedException ie) {
return;
}
}
while (!loadStatus.overloaded()) {
try {
final JobStory job = getNextJobFiltered();
if (null == job) {
return;
}
submitter.add(
jobCreator.createGridmixJob(
conf, 0L, job, scratch, userResolver.getTargetUgi(
UserGroupInformation.createRemoteUser(
job.getUser())), sequence.getAndIncrement()));
// TODO: We need to take care of scenario when one map/reduce
// takes more than 1 slot.
loadStatus.mapSlotsBackfill -=
calcEffectiveIncompleteMapTasks(
loadStatus.mapSlotCapacity, job.getNumberMaps(), 0.0f);
loadStatus.reduceSlotsBackfill -=
calcEffectiveIncompleteReduceTasks(
loadStatus.reduceSlotCapacity, job.getNumberReduces(),
0.0f);
--loadStatus.numJobsBackfill;
} catch (IOException e) {
LOG.error("Error while submitting the job ", e);
error = e;
return;
}
}
} finally {
lock.unlock();
}
}
} catch (InterruptedException e) {
return;
} finally {
IOUtils.cleanup(null, jobProducer);
}
}
}
/**
* STRESS Once you get the notification from StatsCollector.Collect the
* clustermetrics. Update current loadStatus with new load status of JT.
*
* @param item
*/
@Override
public void update(Statistics.ClusterStats item) {
lock.lock();
try {
ClusterStatus clusterMetrics = item.getStatus();
try {
checkLoadAndGetSlotsToBackfill(item,clusterMetrics);
} catch (IOException e) {
LOG.error("Couldn't get the new Status",e);
}
if (!loadStatus.overloaded()) {
condUnderloaded.signalAll();
}
} finally {
lock.unlock();
}
}
static float calcEffectiveIncompleteMapTasks(int mapSlotCapacity,
int numMaps, float mapProgress) {
float maxEffIncompleteMapTasks = Math.max(1.0f, mapSlotCapacity
* MAX_MAPSLOT_SHARE_PER_JOB);
float mapProgressAdjusted = Math.max(Math.min(mapProgress, 1.0f), 0.0f);
return Math.min(maxEffIncompleteMapTasks, numMaps
* (1.0f - mapProgressAdjusted));
}
static float calcEffectiveIncompleteReduceTasks(int reduceSlotCapacity,
int numReduces, float reduceProgress) {
float maxEffIncompleteReduceTasks = Math.max(1.0f, reduceSlotCapacity
* MAX_REDUCESLOT_SHARE_PER_JOB);
float reduceProgressAdjusted = Math.max(Math.min(reduceProgress, 1.0f),
0.0f);
return Math.min(maxEffIncompleteReduceTasks, numReduces
* (1.0f - reduceProgressAdjusted));
}
/**
* We try to use some light-weight mechanism to determine cluster load.
*
* @param stats
* @param clusterStatus Cluster status
* @throws java.io.IOException
*/
private void checkLoadAndGetSlotsToBackfill(
ClusterStats stats, ClusterStatus clusterStatus) throws IOException {
loadStatus.mapSlotCapacity = clusterStatus.getMaxMapTasks();
loadStatus.reduceSlotCapacity = clusterStatus.getMaxReduceTasks();
loadStatus.numJobsBackfill = clusterStatus.getTaskTrackers()
- stats.getNumRunningJob();
if (loadStatus.numJobsBackfill <= 0) {
if (LOG.isDebugEnabled()) {
LOG.debug(System.currentTimeMillis() + " Overloaded is "
+ Boolean.TRUE.toString() + " NumJobsBackfill is "
+ loadStatus.numJobsBackfill);
}
return; // stop calculation because we know it is overloaded.
}
float incompleteMapTasks = 0; // include pending & running map tasks.
for (JobStats job : ClusterStats.getRunningJobStats()) {
float mapProgress = job.getJob().mapProgress();
int noOfMaps = job.getNoOfMaps();
incompleteMapTasks += calcEffectiveIncompleteMapTasks(clusterStatus
.getMaxMapTasks(), noOfMaps, mapProgress);
}
loadStatus.mapSlotsBackfill = (int) (OVERLOAD_MAPTASK_MAPSLOT_RATIO
* clusterStatus.getMaxMapTasks() - incompleteMapTasks);
if (loadStatus.mapSlotsBackfill <= 0) {
if (LOG.isDebugEnabled()) {
LOG.debug(System.currentTimeMillis() + " Overloaded is "
+ Boolean.TRUE.toString() + " MapSlotsBackfill is "
+ loadStatus.mapSlotsBackfill);
}
return; // stop calculation because we know it is overloaded.
}
float incompleteReduceTasks = 0; // include pending & running reduce tasks.
for (JobStats job : ClusterStats.getRunningJobStats()) {
int noOfReduces = job.getJob().getNumReduceTasks();
if (noOfReduces > 0) {
float reduceProgress = job.getJob().reduceProgress();
incompleteReduceTasks += calcEffectiveIncompleteReduceTasks(
clusterStatus.getMaxReduceTasks(), noOfReduces, reduceProgress);
}
}
loadStatus.reduceSlotsBackfill = (int) (OVERLOAD_REDUCETASK_REDUCESLOT_RATIO
* clusterStatus.getMaxReduceTasks() - incompleteReduceTasks);
if (loadStatus.reduceSlotsBackfill <= 0) {
if (LOG.isDebugEnabled()) {
LOG.debug(System.currentTimeMillis() + " Overloaded is "
+ Boolean.TRUE.toString() + " ReduceSlotsBackfill is "
+ loadStatus.reduceSlotsBackfill);
}
return; // stop calculation because we know it is overloaded.
}
if (LOG.isDebugEnabled()) {
LOG.debug(System.currentTimeMillis() + " Overloaded is "
+ Boolean.FALSE.toString() + "Current load Status is " + loadStatus);
}
}
static class LoadStatus {
int mapSlotsBackfill;
int mapSlotCapacity;
int reduceSlotsBackfill;
int reduceSlotCapacity;
int numJobsBackfill;
/**
* Construct the LoadStatus in an unknown state - assuming the cluster is
* overloaded by setting numSlotsBackfill=0.
*/
LoadStatus() {
mapSlotsBackfill = 0;
reduceSlotsBackfill = 0;
numJobsBackfill = 0;
mapSlotCapacity = -1;
reduceSlotCapacity = -1;
}
public boolean overloaded() {
return (mapSlotsBackfill <= 0) || (reduceSlotsBackfill <= 0)
|| (numJobsBackfill <= 0);
}
public String toString() {
return " Overloaded = " + overloaded()
+ ", MapSlotBackfill = " + mapSlotsBackfill
+ ", MapSlotCapacity = " + mapSlotCapacity
+ ", ReduceSlotBackfill = " + reduceSlotsBackfill
+ ", ReduceSlotCapacity = " + reduceSlotCapacity
+ ", NumJobsBackfill = " + numJobsBackfill
;
}
}
/**
* Start the reader thread, wait for latch if necessary.
*/
@Override
public void start() {
LOG.info(" Starting Stress submission ");
this.rThread.start();
}
}