hadoop-common-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Joydeep Sen Sarma (JIRA)" <j...@apache.org>
Subject [jira] Commented: (HADOOP-3155) reducers stuck at shuffling
Date Thu, 09 Oct 2008 06:54:44 GMT

    [ https://issues.apache.org/jira/browse/HADOOP-3155?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12638203#action_12638203
] 

Joydeep Sen Sarma commented on HADOOP-3155:
-------------------------------------------

i don't know why the ipc layer ignores interruptedexceptions. but the practical matter is
that it does - and my naiive suspicion is that changing that would be non trivial. also -
since the ipc layer always times out anyway - interrupts are not required to break out of
RPC calls.

as i mentioned - it's no longer a race condition. the assumption that the thread.interrupt()
works to kill the mapeventsfetcher is inherently wrong. my speculation is that both the threads
run forever - which is why new jobs/tasks also hit the same problem when they run on this
TT (i am assuming this since we had many many jobs that hit the same problem - and they started
hours apart).

we need a shutdown flag in addition to the interrupt and need to check that flag in the eventsfetcher
loop. otherwise thread.join will hang. (also - if u look at general documentation on the web
about using interrupts in java - everyone advises using a flag in addition as general practice).

i would be curious if there are other parts of the hadoop code base that suffer from the same
assumptions (about thread.interrupt being caught and thrown).

> reducers stuck at shuffling 
> ----------------------------
>
>                 Key: HADOOP-3155
>                 URL: https://issues.apache.org/jira/browse/HADOOP-3155
>             Project: Hadoop Core
>          Issue Type: Bug
>            Reporter: Runping Qi
>            Assignee: Amareshwari Sriramadasu
>             Fix For: 0.19.0
>
>         Attachments: events-job_200807311630_0007.txt, fetcherThread.patch, fetcherThread.patch,
hadoop-3155-logs.tar.gz, jobevents_1007.txt, patch-3155-debug-0.16.txt, patch-3155-debug-0.17.txt,
task_200807311630_0007_r_000006_0.syslog.gz
>
>
> This happened with hadoop-0.16.2:
> In relatively small job (a few hundreds of mappers and reducers), reducers were stuck
at shuffling.
> I saw the lines like the following repeated hundreds of thousands of times over a few
hours:
> 2008-04-02 17:17:44,640 INFO org.apache.hadoop.mapred.ReduceTask: task_200804021200_0337_r_000008_0
Need 2 map output(s)
> 2008-04-02 17:17:44,641 INFO org.apache.hadoop.mapred.ReduceTask: task_200804021200_0337_r_000008_0:
Got 0 new map-outputs & 0 obsolete map-outputs from tasktracker and 0 map-outputs from
previous failures
> 2008-04-02 17:17:44,641 INFO org.apache.hadoop.mapred.ReduceTask: task_200804021200_0337_r_000008_0
Got 0 known map output location(s); scheduling...
> 2008-04-02 17:17:44,641 INFO org.apache.hadoop.mapred.ReduceTask: task_200804021200_0337_r_000008_0
Scheduled 0 of 0 known outputs (0 slow hosts and 0 dup hosts)
> 2008-04-02 17:17:46,643 INFO org.apache.hadoop.mapred.ReduceTask: task_200804021200_0337_r_000008_0
Need 2 map output(s)
> 2008-04-02 17:17:46,643 INFO org.apache.hadoop.mapred.ReduceTask: task_200804021200_0337_r_000008_0:
Got 0 new map-outputs & 0 obsolete map-outputs from tasktracker and 0 map-outputs from
previous failures
> 2008-04-02 17:17:46,643 INFO org.apache.hadoop.mapred.ReduceTask: task_200804021200_0337_r_000008_0
Got 0 known map output location(s); scheduling...
> 2008-04-02 17:17:46,643 INFO org.apache.hadoop.mapred.ReduceTask: task_200804021200_0337_r_000008_0
Scheduled 0 of 0 known outputs (0 slow hosts and 0 dup hosts)
> 2008-04-02 17:17:48,645 INFO org.apache.hadoop.mapred.ReduceTask: task_200804021200_0337_r_000008_0
Need 2 map output(s)
> 2008-04-02 17:17:48,645 INFO org.apache.hadoop.mapred.ReduceTask: task_200804021200_0337_r_000008_0:
Got 0 new map-outputs & 0 obsolete map-outputs from tasktracker and 0 map-outputs from
previous failures
> 2008-04-02 17:17:48,645 INFO org.apache.hadoop.mapred.ReduceTask: task_200804021200_0337_r_000008_0
Got 0 known map output location(s); scheduling...
> 2008-04-02 17:17:48,645 INFO org.apache.hadoop.mapred.ReduceTask: task_200804021200_0337_r_000008_0
Scheduled 0 of 0 known outputs (0 slow hosts and 0 dup hosts)
> 2008-04-02 17:17:50,647 INFO org.apache.hadoop.mapred.ReduceTask: task_200804021200_0337_r_000008_0
Need 2 map output(s)
> 2008-04-02 17:17:50,647 INFO org.apache.hadoop.mapred.ReduceTask: task_200804021200_0337_r_000008_0:
Got 0 new map-outputs & 0 obsolete map-outputs from tasktracker and 0 map-outputs from
previous failures
> 2008-04-02 17:17:50,647 INFO org.apache.hadoop.mapred.ReduceTask: task_200804021200_0337_r_000008_0
Got 0 known map output location(s); scheduling...
> 2008-04-02 17:17:50,647 INFO org.apache.hadoop.mapred.ReduceTask: task_200804021200_0337_r_000008_0
Scheduled 0 of 0 known outputs (0 slow hosts and 0 dup hosts)
> 2008-04-02 17:17:52,649 INFO org.apache.hadoop.mapred.ReduceTask: task_200804021200_0337_r_000008_0
Need 2 map output(s)
> 2008-04-02 17:17:52,650 INFO org.apache.hadoop.mapred.ReduceTask: task_200804021200_0337_r_000008_0:
Got 0 new map-outputs & 0 obsolete map-outputs from tasktracker and 0 map-outputs from
previous failures
> 2008-04-02 17:17:52,650 INFO org.apache.hadoop.mapred.ReduceTask: task_200804021200_0337_r_000008_0
Got 0 known map output location(s); scheduling...
> 2008-04-02 17:17:52,650 INFO org.apache.hadoop.mapred.ReduceTask: task_200804021200_0337_r_000008_0
Scheduled 0 of 0 known outputs (0 slow hosts and 0 dup hosts)
> 2008-04-02 17:17:54,651 INFO org.apache.hadoop.mapred.ReduceTask: task_200804021200_0337_r_000008_0
Need 2 map output(s)
> 2008-04-02 17:17:54,652 INFO org.apache.hadoop.mapred.ReduceTask: task_200804021200_0337_r_000008_0:
Got 0 new map-outputs & 0 obsolete map-outputs from tasktracker and 0 map-outputs from
previous failures
> 2008-04-02 17:17:54,652 INFO org.apache.hadoop.mapred.ReduceTask: task_200804021200_0337_r_000008_0
Got 0 known map output location(s); scheduling...
> 2008-04-02 17:17:54,652 INFO org.apache.hadoop.mapred.ReduceTask: task_200804021200_0337_r_000008_0
Scheduled 0 of 0 known outputs (0 slow hosts and 0 dup hosts)
> 2008-04-02 17:17:56,654 INFO org.apache.hadoop.mapred.ReduceTask: task_200804021200_0337_r_000008_0
Need 2 map output(s)
> 2008-04-02 17:17:56,654 INFO org.apache.hadoop.mapred.ReduceTask: task_200804021200_0337_r_000008_0:
Got 0 new map-outputs & 0 obsolete map-outputs from tasktracker and 0 map-outputs from
previous failures
> 2008-04-02 17:17:56,654 INFO org.apache.hadoop.mapred.ReduceTask: task_200804021200_0337_r_000008_0
Got 0 known map output location(s); scheduling...
> 2008-04-02 17:17:56,654 INFO org.apache.hadoop.mapred.ReduceTask: task_200804021200_0337_r_000008_0
Scheduled 0 of 0 known outputs (0 slow hosts and 0 dup hosts)
> 2008-04-02 17:17:58,656 INFO org.apache.hadoop.mapred.ReduceTask: task_200804021200_0337_r_000008_0
Need 2 map output(s)
> 2008-04-02 17:17:58,656 INFO org.apache.hadoop.mapred.ReduceTask: task_200804021200_0337_r_000008_0:
Got 0 new map-outputs & 0 obsolete map-outputs from tasktracker and 0 map-outputs from
previous failures
> 2008-04-02 17:17:58,656 INFO org.apache.hadoop.mapred.ReduceTask: task_200804021200_0337_r_000008_0
Got 0 known map output location(s); scheduling...
> 2008-04-02 17:17:58,656 INFO org.apache.hadoop.mapred.ReduceTask: task_200804021200_0337_r_000008_0
Scheduled 0 of 0 known outputs (0 slow hosts and 0 dup hosts)
> 2008-04-02 17:18:00,658 INFO org.apache.hadoop.mapred.ReduceTask: task_200804021200_0337_r_000008_0
Need 2 map output(s)
> 2008-04-02 17:18:00,658 INFO org.apache.hadoop.mapred.ReduceTask: task_200804021200_0337_r_000008_0:
Got 0 new map-outputs & 0 obsolete map-outputs from tasktracker and 0 map-outputs from
previous failures
> 2008-04-02 17:18:00,658 INFO org.apache.hadoop.mapred.ReduceTask: task_200804021200_0337_r_000008_0
Got 0 known map output location(s); scheduling...
> 2008-04-02 17:18:00,658 INFO org.apache.hadoop.mapred.ReduceTask: task_200804021200_0337_r_000008_0
Scheduled 0 of 0 known outputs (0 slow hosts and 0 dup hosts)
> 2008-04-02 17:18:02,660 INFO org.apache.hadoop.mapred.ReduceTask: task_200804021200_0337_r_000008_0
Need 2 map output(s)
> 2008-04-02 17:18:02,661 INFO org.apache.hadoop.mapred.ReduceTask: task_200804021200_0337_r_000008_0:
Got 0 new map-outputs & 0 obsolete map-outputs from tasktracker and 0 map-outputs from
previous failures
> 2008-04-02 17:18:02,661 INFO org.apache.hadoop.mapred.ReduceTask: task_200804021200_0337_r_000008_0
Got 0 known map output location(s); scheduling...
> 2008-04-02 17:18:02,661 INFO org.apache.hadoop.mapred.ReduceTask: task_200804021200_0337_r_000008_0
Scheduled 0 of 0 known outputs (0 slow hosts and 0 dup hosts)
> 2008-04-02 17:18:04,662 INFO org.apache.hadoop.mapred.ReduceTask: task_200804021200_0337_r_000008_0
Need 2 map output(s)
> 2008-04-02 17:18:04,663 INFO org.apache.hadoop.mapred.ReduceTask: task_200804021200_0337_r_000008_0:
Got 0 new map-outputs & 0 obsolete map-outputs from tasktracker and 0 map-outputs from
previous failures
> 2008-04-02 17:18:04,663 INFO org.apache.hadoop.mapred.ReduceTask: task_200804021200_0337_r_000008_0
Got 0 known map output location(s); scheduling...
> 2008-04-02 17:18:04,663 INFO org.apache.hadoop.mapred.ReduceTask: task_200804021200_0337_r_000008_0
Scheduled 0 of 0 known outputs (0 slow hosts and 0 dup hosts)
> 2008-04-02 17:18:06,664 INFO org.apache.hadoop.mapred.ReduceTask: task_200804021200_0337_r_000008_0
Need 2 map output(s)
> 2008-04-02 17:18:06,665 INFO org.apache.hadoop.mapred.ReduceTask: task_200804021200_0337_r_000008_0:
Got 0 new map-outputs & 0 obsolete map-outputs from tasktracker and 0 map-outputs from
previous failures
> 2008-04-02 17:18:06,665 INFO org.apache.hadoop.mapred.ReduceTask: task_200804021200_0337_r_000008_0
Got 0 known map output location(s); scheduling...
> 2008-04-02 17:18:06,665 INFO org.apache.hadoop.mapred.ReduceTask: task_200804021200_0337_r_000008_0
Scheduled 0 of 0 known outputs (0 slow hosts and 0 dup hosts)
> 2008-04-02 17:18:08,667 INFO org.apache.hadoop.mapred.ReduceTask: task_200804021200_0337_r_000008_0
Need 2 map output(s)
> 2008-04-02 17:18:08,667 INFO org.apache.hadoop.mapred.ReduceTask: task_200804021200_0337_r_000008_0:
Got 0 new map-outputs & 0 obsolete map-outputs from tasktracker and 0 map-outputs from
previous failures
> 2008-04-02 17:18:08,667 INFO org.apache.hadoop.mapred.ReduceTask: task_200804021200_0337_r_000008_0
Got 0 known map output location(s); scheduling...
> 2008-04-02 17:18:08,667 INFO org.apache.hadoop.mapred.ReduceTask: task_200804021200_0337_r_000008_0
Scheduled 0 of 0 known outputs (0 slow hosts and 0 dup hosts)
> 2008-04-02 17:18:10,669 INFO org.apache.hadoop.mapred.ReduceTask: task_200804021200_0337_r_000008_0
Need 2 map output(s)
> 2008-04-02 17:18:10,669 INFO org.apache.hadoop.mapred.ReduceTask: task_200804021200_0337_r_000008_0:
Got 0 new map-outputs & 0 obsolete map-outputs from tasktracker and 0 map-outputs from
previous failures
> 2008-04-02 17:18:10,669 INFO org.apache.hadoop.mapred.ReduceTask: task_200804021200_0337_r_000008_0
Got 0 known map output location(s); scheduling...
> 2008-04-02 17:18:10,669 INFO org.apache.hadoop.mapred.ReduceTask: task_200804021200_0337_r_000008_0
Scheduled 0 of 0 known outputs (0 slow hosts and 0 dup hosts)
> 2008-04-02 17:18:12,671 INFO org.apache.hadoop.mapred.ReduceTask: task_200804021200_0337_r_000008_0
Need 2 map output(s)
> 2008-04-02 17:18:12,671 INFO org.apache.hadoop.mapred.ReduceTask: task_200804021200_0337_r_000008_0:
Got 0 new map-outputs & 0 obsolete map-outputs from tasktracker and 0 map-outputs from
previous failures
> 2008-04-02 17:18:12,671 INFO org.apache.hadoop.mapred.ReduceTask: task_200804021200_0337_r_000008_0
Got 0 known map output location(s); scheduling...
> 2008-04-02 17:18:12,671 INFO org.apache.hadoop.mapred.ReduceTask: task_200804021200_0337_r_000008_0
Scheduled 0 of 0 known outputs (0 slow hosts and 0 dup hosts)
> 2008-04-02 17:18:14,673 INFO org.apache.hadoop.mapred.ReduceTask: task_200804021200_0337_r_000008_0
Need 2 map output(s)
> 2008-04-02 17:18:14,674 INFO org.apache.hadoop.mapred.ReduceTask: task_200804021200_0337_r_000008_0:
Got 0 new map-outputs & 0 obsolete map-outputs from tasktracker and 0 map-outputs from
previous failures
> 2008-04-02 17:18:14,674 INFO org.apache.hadoop.mapred.ReduceTask: task_200804021200_0337_r_000008_0
Got 0 known map output location(s); scheduling...
> 2008-04-02 17:18:14,674 INFO org.apache.hadoop.mapred.ReduceTask: task_200804021200_0337_r_000008_0
Scheduled 0 of 0 known outputs (0 slow hosts and 0 dup hosts)
> 2008-04-02 17:18:16,675 INFO org.apache.hadoop.mapred.ReduceTask: task_200804021200_0337_r_000008_0
Need 2 map output(s)
> 2008-04-02 17:18:16,676 INFO org.apache.hadoop.mapred.ReduceTask: task_200804021200_0337_r_000008_0:
Got 0 new map-outputs & 0 obsolete map-outputs from tasktracker and 0 map-outputs from
previous failures
> 2008-04-02 17:18:16,676 INFO org.apache.hadoop.mapred.ReduceTask: task_200804021200_0337_r_000008_0
Got 0 known map output location(s); scheduling...
> 2008-04-02 17:18:16,676 INFO org.apache.hadoop.mapred.ReduceTask: task_200804021200_0337_r_000008_0
Scheduled 0 of 0 known outputs (0 slow hosts and 0 dup hosts)
> 2008-04-02 17:18:18,678 INFO org.apache.hadoop.mapred.ReduceTask: task_200804021200_0337_r_000008_0
Need 2 map output(s)
> 2008-04-02 17:18:18,678 INFO org.apache.hadoop.mapred.ReduceTask: task_200804021200_0337_r_000008_0:
Got 0 new map-outputs & 0 obsolete map-outputs from tasktracker and 0 map-outputs from
previous failures
> 2008-04-02 17:18:18,678 INFO org.apache.hadoop.mapred.ReduceTask: task_200804021200_0337_r_000008_0
Got 0 known map output location(s); scheduling...
> 2008-04-02 17:18:18,678 INFO org.apache.hadoop.mapred.ReduceTask: task_200804021200_0337_r_000008_0
Scheduled 0 of 0 known outputs (0 slow hosts and 0 dup hosts)
> 2008-04-02 17:18:20,680 INFO org.apache.hadoop.mapred.ReduceTask: task_200804021200_0337_r_000008_0
Need 2 map output(s)
> 2008-04-02 17:18:20,680 INFO org.apache.hadoop.mapred.ReduceTask: task_200804021200_0337_r_000008_0:
Got 0 new map-outputs & 0 obsolete map-outputs from tasktracker and 0 map-outputs from
previous failures
> 2008-04-02 17:18:20,680 INFO org.apache.hadoop.mapred.ReduceTask: task_200804021200_0337_r_000008_0
Got 0 known map output location(s); scheduling...
> 2008-04-02 17:18:20,680 INFO org.apache.hadoop.mapred.ReduceTask: task_200804021200_0337_r_000008_0
Scheduled 0 of 0 known outputs (0 slow hosts and 0 dup hosts)
> 2008-04-02 17:18:22,682 INFO org.apache.hadoop.mapred.ReduceTask: task_200804021200_0337_r_000008_0
Need 2 map output(s)
> 2008-04-02 17:18:22,682 INFO org.apache.hadoop.mapred.ReduceTask: task_200804021200_0337_r_000008_0:
Got 0 new map-outputs & 0 obsolete map-outputs from tasktracker and 0 map-outputs from
previous failures
> 2008-04-02 17:18:22,682 INFO org.apache.hadoop.mapred.ReduceTask: task_200804021200_0337_r_000008_0
Got 0 known map output location(s); scheduling...

-- 
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.


Mime
View raw message