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HBase >> mail # user >> question about clienttrace logs in hdfs and shortcircuit read

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Re: question about clienttrace logs in hdfs and shortcircuit read
Thanks Viral.. Confusion came to me as the heading of the mails say abt SCR
metric and finally speaks abt hbase handled checksum metric which are 2
features..  Agree that hbase checksum works only with SCR as of now, this
might change later..  That is why I was just making it clear  .. NP :)

As I said pls check the DFS client side log(RS log) for BlockReaderLocal.
AFAIK there should not be HDFS_READ op log in DN side when the SCR is


On Fri, Jul 5, 2013 at 1:31 PM, Viral Bajaria <[EMAIL PROTECTED]>wrote:

> No worries, Anoop. Here is some clarification for this chain.
> It started initially to figure out how to check whether SCR is effective at
> the RS or not. I could not find the metric anywhere in ganglia/JMX and
> didn't find any RegionServer level metric either and so started looking at
> my DN logs. I saw a lot of "clienttrace" logs which are basically logs for
> HDFS_READ and HDFS_WRITE ops. I wanted to see if it's a valid assumption
> that SCR is working if I don't see any clienttrace logs for the RS that is
> hosted on the same box as the DN.
> Hopefully I clarified it.
> On Fri, Jul 5, 2013 at 12:55 AM, Anoop John <[EMAIL PROTECTED]> wrote:
> > Agree that right now the HBase handled checksum will work only with SCR.
> > But it might work without SCR also later (as support come from HDFS)..
>  So
> > I am not getting the direct relation btw the SCR metric and this one. Am
> I
> > missed some thing in the mail loop? Sorry just trying to be clear on this
> > :)
> >