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From Harsh J <ha...@cloudera.com>
Subject Re: Replication and failure
Date Thu, 28 Jul 2011 07:17:23 GMT
Mohit,

I believe Tom's book (Hadoop: The Definitive Guide) covers this
precisely well. Perhaps others too.

Replication is a best-effort sort of thing. If 2 nodes are all that is
available, then two replicas are written and one is left to the
replica monitor service to replicate later as possible (leading to an
underreplicated write for the moment). The scenario (with default
configs) would only fail if you have 0 DataNodes 'available' to write
to.

Or are you asking about what happens when a DN fails during a write operation?

On Thu, Jul 28, 2011 at 5:08 AM, Mohit Anchlia <mohitanchlia@gmail.com> wrote:
> Just trying to understand what happens if there are 3 nodes with
> replication set to 3 and one node fails. Does it fail the writes too?
>
> If there is a link that I can look at will be great. I tried searching
> but didn't see any definitive answer.
>
> Thanks,
> Mohit
>



-- 
Harsh J

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