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From Josh Elser <josh.el...@gmail.com>
Subject Re: Data Replication
Date Thu, 13 Oct 2016 16:46:23 GMT
I'm not familiar with MongoDB. Perhaps someone else can confirm this for 
you.

Yamini Joshi wrote:
> So, can I say that if I have a table split across nodes (i.e. num
> tablets > 1) and HDFS replication in my system, it is sort of equivalent
> to a sharded and replicated mongo architecture?
>
> Best regards,
> Yamini Joshi
>
> On Thu, Oct 13, 2016 at 11:06 AM, Josh Elser <josh.elser@gmail.com
> <mailto:josh.elser@gmail.com>> wrote:
>
>     The Accumulo (Data Center) Replication feature is for having
>     multiple active Accumulo clusters all containing the same data.
>
>     HDFS provides replication as a means for durability of the data it
>     is storing. The files that Accumulo creates on one HDFS instance are
>     replicated by HDFS. This does not help if your entire cluster become
>     unavailable. That is what the data center replication Accumulo
>     feature solves.
>
>     While both can be called "replication", they serve very different
>     purposes.
>
>
>     Yamini Joshi wrote:
>
>         Hello
>
>         I was going through some Accumulo docs and found out about
>         replication.
>         To enable replication,one needs to make some config settings as
>         described in
>         https://github.com/apache/accumulo/blob/master/docs/src/main/asciidoc/chapters/replication.txt
>         <https://github.com/apache/accumulo/blob/master/docs/src/main/asciidoc/chapters/replication.txt>.
>         I cannot seem to grasp the difference between this replication
>         conf and
>         the replication on HDFS level. What exactly is the use case for
>         replication? Are the replicated instances visible to the clients?
>
>         Best regards,
>         Yamini Joshi
>
>

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