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HBase, mail # user - confused info about region-regionserver locality


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Re: confused info about region-regionserver locality
Jean-Marc Spaggiari 2013-04-04, 15:25
Hi,

I think you're right and documentation need to be updated.

The 3rd replica is written on a random node in the same rack as the
2nd replica. I will double check. Can you please open a JIRA so this
is updated?

JM

2013/4/4 KIM JUN YOUNG <[EMAIL PROTECTED]>:
> Hi All.
>
> There is confused understanding about region-regionser locality.
>
> from the current document ,
>
> http://hbase.apache.org/book/regions.arch.html
> 9.7.3. Region-RegionServer Locality
> Over time, Region-RegionServer locality is achieved via HDFS block replication. The HDFS client does the following by default when choosing locations to write replicas:
>
> First replica is written to local node
> Second replica is written to another node in same rack
> Third replica is written to a node in another rack (if sufficient nodes)
>
>
> but, my understanding is different
> HDFS write blocks for replica
>
>         first, local node
>         second, another node in another rack
>         third, random another node in same rack
>
> need to be changed? or am I missing something?