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MapReduce >> mail # user >> Why LineRecordWriter.write(..) is synchronized


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Sathwik B P 2013-08-08, 06:53
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Azuryy Yu 2013-08-08, 07:06
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Azuryy Yu 2013-08-08, 10:12
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Re: Why LineRecordWriter.write(..) is synchronized
While we don't fork by default, we do provide a MultithreadedMapper
implementation that would require such synchronization. But if you are
asking is it necessary, then perhaps the answer is no.
On Aug 8, 2013 3:43 PM, "Azuryy Yu" <[EMAIL PROTECTED]> wrote:

> its not hadoop forked threads, we may create a line record writer, then
> call this writer concurrently.
> On Aug 8, 2013 4:00 PM, "Sathwik B P" <[EMAIL PROTECTED]> wrote:
>
>> Hi,
>> Thanks for your reply.
>> May I know where does hadoop fork multiple threads to use a single
>> RecordWriter.
>>
>> regards,
>> sathwik
>>
>> On Thu, Aug 8, 2013 at 7:06 AM, Azuryy Yu <[EMAIL PROTECTED]> wrote:
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>>> because we may use multi-threads to write a single file.
>>> On Aug 8, 2013 2:54 PM, "Sathwik B P" <[EMAIL PROTECTED]> wrote:
>>>
>>>> Hi,
>>>>
>>>> LineRecordWriter.write(..) is synchronized. I did not find any other
>>>> RecordWriter implementations define the write as synchronized.
>>>> Any specific reason for this.
>>>>
>>>> regards,
>>>> sathwik
>>>>
>>>
>>
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Niels Basjes 2013-08-08, 11:00
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Jay Vyas 2013-08-08, 11:53
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Sathwik B P 2013-08-08, 12:21
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Niels Basjes 2013-08-08, 13:37
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Azuryy Yu 2013-08-08, 14:22
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Harsh J 2013-08-11, 12:59
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Niels Basjes 2013-08-11, 16:02
NEW: Monitor These Apps!
elasticsearch, apache solr, apache hbase, hadoop, redis, casssandra, amazon cloudwatch, mysql, memcached, apache kafka, apache zookeeper, apache storm, ubuntu, centOS, red hat, debian, puppet labs, java, senseiDB