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HBase, mail # user - support checksums in HBase block


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Re: support checksums in HBase block
Stack 2012-09-15, 20:30
On Sat, Sep 15, 2012 at 10:31 AM, jlei liu <[EMAIL PROTECTED]> wrote:
> I use Hbase0.94.1 and  hadoop-0.20.2-cdh3u5.
>
> The Hbase0.94.1 write checksums in HBase block, so we don't need to read
> checksums from metadata file of block file. But I find the BlockSender
> still read checksums from metadata file of block file every time,

How are you figuring this?   That sounds like a regression.

In 0.94.x the default is that hbase.regionserver.checksum.verify is
true which should have hbase doing checksum verify on read rather than
hdfs.

>  so the
> Hbase0.94.1 can't decrease the iops, that is right? If that is right,
> should I set the  hbase.regionserver.checksum.verify property to false in
> order to  avoid the Hbase0.94.1 to verify th checksum?
>

It would be interesting flipping the switch.  If things went faster,
then for sure there is a regression.
St.Ack