You are viewing a plain text version of this content. The canonical link for it is here.
Posted to mapreduce-dev@hadoop.apache.org by "Harsh J Chouraria (JIRA)" <ji...@apache.org> on 2010/12/29 20:39:56 UTC
[jira] Created: (MAPREDUCE-2236) No task may execute due to an
Integer overflow possibility
No task may execute due to an Integer overflow possibility
----------------------------------------------------------
Key: MAPREDUCE-2236
URL: https://issues.apache.org/jira/browse/MAPREDUCE-2236
Project: Hadoop Map/Reduce
Issue Type: Bug
Affects Versions: 0.20.2
Environment: Linux, Hadoop 0.20.2
Reporter: Harsh J Chouraria
Assignee: Harsh J Chouraria
Priority: Critical
Fix For: 0.23.0
If the attempts is configured to use Integer.MAX_VALUE, an overflow occurs inside TaskInProgress, and thereby no task is attempted by the cluster and the map tasks stay in pending state forever.
For example, here's a job driver that causes this:
{code}
import java.io.IOException;
import org.apache.hadoop.fs.FSDataOutputStream;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.mapred.FileInputFormat;
import org.apache.hadoop.mapred.JobClient;
import org.apache.hadoop.mapred.JobConf;
import org.apache.hadoop.mapred.TextInputFormat;
import org.apache.hadoop.mapred.lib.IdentityMapper;
import org.apache.hadoop.mapred.lib.NullOutputFormat;
@SuppressWarnings("deprecation")
public class IntegerOverflow {
/**
* @param args
* @throws IOException
*/
@SuppressWarnings("deprecation")
public static void main(String[] args) throws IOException {
JobConf conf = new JobConf();
Path inputPath = new Path("ignore");
FileSystem fs = FileSystem.get(conf);
if (!fs.exists(inputPath)) {
FSDataOutputStream out = fs.create(inputPath);
out.writeChars("Test");
out.close();
}
conf.setInputFormat(TextInputFormat.class);
conf.setOutputFormat(NullOutputFormat.class);
FileInputFormat.addInputPath(conf, inputPath);
conf.setMapperClass(IdentityMapper.class);
conf.setNumMapTasks(1);
// Problem inducing line follows.
conf.setMaxMapAttempts(Integer.MAX_VALUE);
// No reducer in this test, although setMaxReduceAttempts leads to the same problem.
conf.setNumReduceTasks(0);
JobClient.runJob(conf);
}
}
{code}
The above code will not let any map task run. Additionally, a log would be created inside JobTracker logs with the following information that clearly shows the overflow:
{code}
2010-12-30 00:59:07,836 WARN org.apache.hadoop.mapred.TaskInProgress: Exceeded limit of -2147483648 (plus 0 killed) attempts for the tip 'task_201012300058_0001_m_000000'
{code}
The issue lies inside the TaskInProgress class (/o/a/h/mapred/TaskInProgress.java), at line 1018 (trunk), part of the getTaskToRun(String taskTracker) method.
{code}
public Task getTaskToRun(String taskTracker) throws IOException {
// Create the 'taskid'; do not count the 'killed' tasks against the job!
TaskAttemptID taskid = null;
/* ============ THIS LINE v ====================================== */
if (nextTaskId < (MAX_TASK_EXECS + maxTaskAttempts + numKilledTasks)) {
/* ============ THIS LINE ^====================================== */
// Make sure that the attempts are unqiue across restarts
int attemptId = job.getNumRestarts() * NUM_ATTEMPTS_PER_RESTART + nextTaskId;
taskid = new TaskAttemptID( id, attemptId);
++nextTaskId;
} else {
LOG.warn("Exceeded limit of " + (MAX_TASK_EXECS + maxTaskAttempts) +
" (plus " + numKilledTasks + " killed)" +
" attempts for the tip '" + getTIPId() + "'");
return null;
}
{code}
Since all three variables being added are integer in type, one of them being Integer.MAX_VALUE makes the condition fail with an overflow, thereby logging and returning a null as the result is negative.
One solution would be to make one of these variables into a long, so the addition does not overflow?
--
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.
[jira] [Resolved] (MAPREDUCE-2236) No task may execute due to an
Integer overflow possibility
Posted by "Harsh J (Resolved) (JIRA)" <ji...@apache.org>.
[ https://issues.apache.org/jira/browse/MAPREDUCE-2236?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Harsh J resolved MAPREDUCE-2236.
--------------------------------
Resolution: Not A Problem
>From above comments, apparently not a problem on 0.23+. We may reopen this if it is.
> No task may execute due to an Integer overflow possibility
> ----------------------------------------------------------
>
> Key: MAPREDUCE-2236
> URL: https://issues.apache.org/jira/browse/MAPREDUCE-2236
> Project: Hadoop Map/Reduce
> Issue Type: Bug
> Affects Versions: 0.20.2
> Environment: Linux, Hadoop 0.20.2
> Reporter: Harsh J
> Assignee: Harsh J
> Priority: Critical
> Fix For: 0.24.0
>
> Attachments: MAPREDUCE-2236.r1.diff, MAPREDUCE-2236.r1.diff, MAPREDUCE-2236.r2.diff
>
>
> If the attempts is configured to use Integer.MAX_VALUE, an overflow occurs inside TaskInProgress, and thereby no task is attempted by the cluster and the map tasks stay in pending state forever.
> For example, here's a job driver that causes this:
> {code}
> import java.io.IOException;
> import org.apache.hadoop.fs.FSDataOutputStream;
> import org.apache.hadoop.fs.FileSystem;
> import org.apache.hadoop.fs.Path;
> import org.apache.hadoop.mapred.FileInputFormat;
> import org.apache.hadoop.mapred.JobClient;
> import org.apache.hadoop.mapred.JobConf;
> import org.apache.hadoop.mapred.TextInputFormat;
> import org.apache.hadoop.mapred.lib.IdentityMapper;
> import org.apache.hadoop.mapred.lib.NullOutputFormat;
> @SuppressWarnings("deprecation")
> public class IntegerOverflow {
> /**
> * @param args
> * @throws IOException
> */
> @SuppressWarnings("deprecation")
> public static void main(String[] args) throws IOException {
> JobConf conf = new JobConf();
>
> Path inputPath = new Path("ignore");
> FileSystem fs = FileSystem.get(conf);
> if (!fs.exists(inputPath)) {
> FSDataOutputStream out = fs.create(inputPath);
> out.writeChars("Test");
> out.close();
> }
>
> conf.setInputFormat(TextInputFormat.class);
> conf.setOutputFormat(NullOutputFormat.class);
> FileInputFormat.addInputPath(conf, inputPath);
>
> conf.setMapperClass(IdentityMapper.class);
> conf.setNumMapTasks(1);
> // Problem inducing line follows.
> conf.setMaxMapAttempts(Integer.MAX_VALUE);
>
> // No reducer in this test, although setMaxReduceAttempts leads to the same problem.
> conf.setNumReduceTasks(0);
>
> JobClient.runJob(conf);
> }
> }
> {code}
> The above code will not let any map task run. Additionally, a log would be created inside JobTracker logs with the following information that clearly shows the overflow:
> {code}
> 2010-12-30 00:59:07,836 WARN org.apache.hadoop.mapred.TaskInProgress: Exceeded limit of -2147483648 (plus 0 killed) attempts for the tip 'task_201012300058_0001_m_000000'
> {code}
> The issue lies inside the TaskInProgress class (/o/a/h/mapred/TaskInProgress.java), at line 1018 (trunk), part of the getTaskToRun(String taskTracker) method.
> {code}
> public Task getTaskToRun(String taskTracker) throws IOException {
> // Create the 'taskid'; do not count the 'killed' tasks against the job!
> TaskAttemptID taskid = null;
> /* ============ THIS LINE v ====================================== */
> if (nextTaskId < (MAX_TASK_EXECS + maxTaskAttempts + numKilledTasks)) {
> /* ============ THIS LINE ^====================================== */
> // Make sure that the attempts are unqiue across restarts
> int attemptId = job.getNumRestarts() * NUM_ATTEMPTS_PER_RESTART + nextTaskId;
> taskid = new TaskAttemptID( id, attemptId);
> ++nextTaskId;
> } else {
> LOG.warn("Exceeded limit of " + (MAX_TASK_EXECS + maxTaskAttempts) +
> " (plus " + numKilledTasks + " killed)" +
> " attempts for the tip '" + getTIPId() + "'");
> return null;
> }
> {code}
> Since all three variables being added are integer in type, one of them being Integer.MAX_VALUE makes the condition fail with an overflow, thereby logging and returning a null as the result is negative.
> One solution would be to make one of these variables into a long, so the addition does not overflow?
--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators: https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa
For more information on JIRA, see: http://www.atlassian.com/software/jira