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From Tom Brown <tombrow...@gmail.com>
Subject Re: Is there any way to partially process HDFS edits?
Date Wed, 25 Sep 2013 21:30:40 GMT
Unfortunately, I cannot give it that much RAM. The machine has 4GB total
(though could be expanded somewhat-- it's a VM).

Though if each edit is processed sequentially (in a streaming form), the
entire edits file will never be in RAM at once.

Is the edits file format well defined (could I break off 100MB chunks and
process them individually to achieve the same result as processing the
whole thing at once)?


On Wed, Sep 25, 2013 at 1:53 PM, Ravi Prakash <ravihoo@ymail.com> wrote:

> Tom! I would guess that just giving the NN JVM lots of memory (64Gb /
> 96Gb) should be the easiest way.
>   ------------------------------
>  *From:* Tom Brown <tombrown52@gmail.com>
> *To:* "user@hadoop.apache.org" <user@hadoop.apache.org>
> *Sent:* Wednesday, September 25, 2013 11:29 AM
> *Subject:* Is there any way to partially process HDFS edits?
> I have an edits file on my namenode that is 35GB. This is quite a bit
> larger than it should be (the secondary namenode wasn't running for some
> time, and HBASE-9648 caused a huge number of additional edits).
> The first time I tried to start the namenode, it chewed on the edits for
> about 4 hours and then ran out of memory. I have increased the memory
> available to the namenode (was 512MB, now 2GB), and started the process
> again.
> Is there any way that the edits file can be partially processed to avoid
> having to re-process the same edits over and over until I can allocate
> enough memory for it to be done in one shot?
> How long should it take (hours? days?) to process an edits file of that
> size?
> Any help is appreciated!
> --Tom

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