It's quite possible that's the problem. I'll re-run the tests over night and
collect the run times according to the JobTracker.

If I want to test the patch in HADOOP-4780, should I pull down branch-0.19
and go from there? This is not a production environment, so I'm not worried
about data loss or other problems. But I could certainly wait if 0.19.2 or
0.20.0 are expected to be released soon, if that would make more sense.

-Sean

On Tue, Mar 3, 2009 at 10:14 PM, Amar Kamat <[email protected]> wrote:

> Runping Qi wrote:
>
>> Could it be the case that the latter jobs ran slower because the tasks
>> took
>> longer time to get initialized?
>> If so, you may hit
>> https://issues.apache.org/jira/browse/HADOOP-4780
>>
>> Runping
>>
>> On Tue, Mar 3, 2009 at 2:02 PM, Sean Laurent <[email protected]
>> >wrote:
>>
>>
>>
>>> Hrmmm. According to hadoop-defaults.xml,
>>> mapred.jobtracker.completeuserjobs.maximum defaults to 100. So I tried
>>> setting it to 1, but that had no effect. I still see each successive run
>>> taking longer than the previous run.
>>>
>>> 1) Restart M/R
>>> 2) Run #1: 142.12 (secs)
>>> 3) Run #2 181.96 (secs)
>>> 4) Run #3  221.95 (secs)
>>> 5) Run #4  281.96 (secs)
>>>
>>>
>> Yeah. May be its not the problem with the JobTracker. Can you check (via
> job history) what is the best and the worst task runtimes? You can analyze
> the jobs after they complete.
> Amar

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