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HDFS >> mail # user >> Re: Auto clean DistCache?


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Abdelrhman Shettia 2013-03-26, 19:53
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Vinod Kumar Vavilapalli 2013-03-26, 20:44
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Abdelrahman Shettia 2013-03-26, 23:12
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Jean-Marc Spaggiari 2013-03-27, 01:00
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Koji Noguchi 2013-03-27, 13:21
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Re: Auto clean DistCache?
Oh! good to know! It keep tracks even of month old entries??? There is no TTL?

I was not able to find the documentation for  local.cache.size or
mapreduce.tasktracker.cache.local.size  in 1.0.x branch. Do you know
where I can found that?

Thanks,

JM

2013/3/27 Koji Noguchi <[EMAIL PROTECTED]>:
>> Else, I will go for a customed script to delete all directories (and content) older than 2 or 3 days…
>>
> TaskTracker (or NodeManager in 2.*) keeps the list of dist cache entries in memory.
> So if external process (like your script) start deleting dist cache files, there would be inconsistency and you'll start seeing task initialization failures due to no file found error.
>
> Koji
>
>
> On Mar 26, 2013, at 9:00 PM, Jean-Marc Spaggiari wrote:
>
>> For the situation I faced I was really a disk space issue, not related
>> to the number of files. It was writing on a small partition.
>>
>> I will try with local.cache.size or
>> mapreduce.tasktracker.cache.local.size to see if I can keep the final
>> total size under 5GB... Else, I will go for a customed script to
>> delete all directories (and content) older than 2 or 3 days...
>>
>> Thanks,
>>
>> JM
>>
>> 2013/3/26 Abdelrahman Shettia <[EMAIL PROTECTED]>:
>>> Let me clarify , If there are lots of files or directories up to 32K (
>>> Depending on the user's # of files sys os config) in those distributed cache
>>> dirs, The OS will not be able to create any more files/dirs, Thus M-R jobs
>>> wont get initiated on those tasktracker machines. Hope this helps.
>>>
>>>
>>> Thanks
>>>
>>>
>>> On Tue, Mar 26, 2013 at 1:44 PM, Vinod Kumar Vavilapalli
>>> <[EMAIL PROTECTED]> wrote:
>>>>
>>>>
>>>> All the files are not opened at the same time ever, so you shouldn't see
>>>> any "# of open files exceeds error".
>>>>
>>>> Thanks,
>>>> +Vinod Kumar Vavilapalli
>>>> Hortonworks Inc.
>>>> http://hortonworks.com/
>>>>
>>>> On Mar 26, 2013, at 12:53 PM, Abdelrhman Shettia wrote:
>>>>
>>>> Hi JM ,
>>>>
>>>> Actually these dirs need to be purged by a script that keeps the last 2
>>>> days worth of files, Otherwise you may run into # of open files exceeds
>>>> error.
>>>>
>>>> Thanks
>>>>
>>>>
>>>> On Mar 25, 2013, at 5:16 PM, Jean-Marc Spaggiari <[EMAIL PROTECTED]>
>>>> wrote:
>>>>
>>>> Hi,
>>>>
>>>>
>>>> Each time my MR job is run, a directory is created on the TaskTracker
>>>>
>>>> under mapred/local/taskTracker/hadoop/distcache (based on my
>>>>
>>>> configuration).
>>>>
>>>>
>>>> I looked at the directory today, and it's hosting thousands of
>>>>
>>>> directories and more than 8GB of data there.
>>>>
>>>>
>>>> Is there a way to automatically delete this directory when the job is
>>>> done?
>>>>
>>>>
>>>> Thanks,
>>>>
>>>>
>>>> JM
>>>>
>>>>
>>>>
>>>
>
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Harsh J 2013-03-28, 06:33
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Jean-Marc Spaggiari 2013-03-28, 16:02
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Vinod Kumar Vavilapalli 2013-03-26, 20:43