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MAPREDUCE-7278. Speculative execution behavior is observed even when mapreduce.map.speculative and mapreduce.reduce.speculative are false 

Contributed by Tarun Parimi.
This commit is contained in:
Wilfred Spiegelenburg 2020-05-28 13:23:01 +10:00
parent 4c5cd751e3
commit 10db97df1c
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GPG Key ID: 7BB711D7AC5E7F29
2 changed files with 124 additions and 8 deletions
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11
hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-app/src/main/java/org/apache/hadoop/mapreduce/v2/app/job/impl/TaskImpl.java
View File

@ -36,6 +36,7 @@ import org.apache.hadoop.fs.Path;
import org.apache.hadoop.mapred.JobConf;
import org.apache.hadoop.mapreduce.Counters;
import org.apache.hadoop.mapreduce.MRConfig;
import org.apache.hadoop.mapreduce.MRJobConfig;
import org.apache.hadoop.mapreduce.OutputCommitter;
import org.apache.hadoop.mapreduce.TypeConverter;
import org.apache.hadoop.mapreduce.jobhistory.JobHistoryEvent;
@ -142,6 +143,7 @@ public abstract class TaskImpl implements Task, EventHandler<TaskEvent> {
private boolean historyTaskStartGenerated = false;
// Launch time reported in history events.
private long launchTime;
private boolean speculationEnabled = false;
private static final SingleArcTransition<TaskImpl, TaskEvent>
ATTEMPT_KILLED_TRANSITION = new AttemptKilledTransition();
@ -325,6 +327,9 @@ public abstract class TaskImpl implements Task, EventHandler<TaskEvent> {
this.appContext = appContext;
this.encryptedShuffle = conf.getBoolean(MRConfig.SHUFFLE_SSL_ENABLED_KEY,
MRConfig.SHUFFLE_SSL_ENABLED_DEFAULT);
this.speculationEnabled = taskType.equals(TaskType.MAP) ?
conf.getBoolean(MRJobConfig.MAP_SPECULATIVE, false) :
conf.getBoolean(MRJobConfig.REDUCE_SPECULATIVE, false);
// This "this leak" is okay because the retained pointer is in an
// instance variable.
@ -1079,6 +1084,7 @@ public abstract class TaskImpl implements Task, EventHandler<TaskEvent> {
if (task.successfulAttempt == null) {
boolean shouldAddNewAttempt = true;
if (task.inProgressAttempts.size() > 0) {
if(task.speculationEnabled) {
// if not all of the inProgressAttempts are hanging for resource
for (TaskAttemptId attemptId : task.inProgressAttempts) {
if (((TaskAttemptImpl) task.getAttempt(attemptId))
@ -1087,6 +1093,11 @@ public abstract class TaskImpl implements Task, EventHandler<TaskEvent> {
break;
}
}
} else {
// No need to add new attempt if there are in progress attempts
// when speculation is false
shouldAddNewAttempt = false;
}
}
if (shouldAddNewAttempt) {
task.addAndScheduleAttempt(Avataar.VIRGIN);

107
hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-jobclient/src/test/java/org/apache/hadoop/mapreduce/v2/TestSpeculativeExecution.java
View File

@ -192,6 +192,46 @@ public class TestSpeculativeExecution {
}
}
public static class FailOnceMapper extends
Mapper<Object, Text, Text, IntWritable> {
public void map(Object key, Text value, Context context)
throws IOException, InterruptedException {
TaskAttemptID taid = context.getTaskAttemptID();
try{
Thread.sleep(2000);
} catch(InterruptedException ie) {
// Ignore
}
// Fail mapper only for first attempt
if (taid.getId() == 0) {
throw new RuntimeException("Failing this mapper");
}
context.write(value, new IntWritable(1));
}
}
public static class FailOnceReducer extends
Reducer<Text, IntWritable, Text, IntWritable> {
public void reduce(Text key, Iterable<IntWritable> values,
Context context) throws IOException, InterruptedException {
TaskAttemptID taid = context.getTaskAttemptID();
try{
Thread.sleep(2000);
} catch(InterruptedException ie) {
// Ignore
}
// Fail reduce only for first attempt
if (taid.getId() == 0) {
throw new RuntimeException("Failing this reducer");
}
context.write(key, new IntWritable(0));
}
}
@Test
public void testSpeculativeExecution() throws Exception {
if (!(new File(MiniMRYarnCluster.APPJAR)).exists()) {
@ -218,6 +258,30 @@ public class TestSpeculativeExecution {
Assert.assertEquals(0, counters.findCounter(JobCounter.NUM_FAILED_MAPS)
.getValue());
/*------------------------------------------------------------------
* Test that Map/Red does not speculate if MAP_SPECULATIVE and
* REDUCE_SPECULATIVE are both false. When map tasks fail once and time out,
* we shouldn't launch two simultaneous attempts. MAPREDUCE-7278
* -----------------------------------------------------------------
*/
job = runNonSpecFailOnceTest();
succeeded = job.waitForCompletion(true);
Assert.assertTrue(succeeded);
Assert.assertEquals(JobStatus.State.SUCCEEDED, job.getJobState());
counters = job.getCounters();
// We will have 4 total since 2 map tasks fail and relaunch attempt once
Assert.assertEquals(4,
counters.findCounter(JobCounter.TOTAL_LAUNCHED_MAPS).getValue());
Assert.assertEquals(4,
counters.findCounter(JobCounter.TOTAL_LAUNCHED_REDUCES).getValue());
// Ensure no maps or reduces killed due to accidental speculation
Assert.assertEquals(0,
counters.findCounter(JobCounter.NUM_KILLED_MAPS).getValue());
Assert.assertEquals(0,
counters.findCounter(JobCounter.NUM_KILLED_REDUCES).getValue());
/*----------------------------------------------------------------------
* Test that Mapper speculates if MAP_SPECULATIVE is true and
* REDUCE_SPECULATIVE is false.
@ -295,7 +359,48 @@ public class TestSpeculativeExecution {
// Delete output directory if it exists.
try {
localFs.delete(TEST_OUT_DIR,true);
localFs.delete(TEST_OUT_DIR, true);
} catch (IOException e) {
// ignore
}
// Creates the Job Configuration
job.addFileToClassPath(APP_JAR); // The AppMaster jar itself.
job.setMaxMapAttempts(2);
job.submit();
return job;
}
private Job runNonSpecFailOnceTest()
throws IOException, ClassNotFoundException, InterruptedException {
Path first = createTempFile("specexec_map_input1", "a\nz");
Path secnd = createTempFile("specexec_map_input2", "a\nz");
Configuration conf = mrCluster.getConfig();
conf.setBoolean(MRJobConfig.MAP_SPECULATIVE, false);
conf.setBoolean(MRJobConfig.REDUCE_SPECULATIVE, false);
// Prevent blacklisting since tasks fail once
conf.setBoolean(MRJobConfig.MR_AM_JOB_NODE_BLACKLISTING_ENABLE, false);
// Setting small task exit timeout values reproduces MAPREDUCE-7278
conf.setInt(MRJobConfig.TASK_EXIT_TIMEOUT, 20);
conf.setInt(MRJobConfig.TASK_EXIT_TIMEOUT_CHECK_INTERVAL_MS, 10);
Job job = Job.getInstance(conf);
job.setJarByClass(TestSpeculativeExecution.class);
job.setMapperClass(FailOnceMapper.class);
job.setReducerClass(FailOnceReducer.class);
job.setOutputKeyClass(Text.class);
job.setOutputValueClass(IntWritable.class);
job.setNumReduceTasks(2);
FileInputFormat.setInputPaths(job, first);
FileInputFormat.addInputPath(job, secnd);
FileOutputFormat.setOutputPath(job, TEST_OUT_DIR);
// Delete output directory if it exists.
try {
localFs.delete(TEST_OUT_DIR, true);
} catch (IOException e) {
// ignore
}