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From Sam Overton <sover...@acunu.com>
Subject Re: how to know if nodetool cleanup is safe?
Date Tue, 23 Aug 2011 15:56:38 GMT
On 21 August 2011 12:34, Yan Chunlu <springrider@gmail.com> wrote:

> since "nodetool cleanup" could remove hinted handoff,  will it cause the
> data loss?


Hi Yan,

Hints are not guaranteed to be delivered and "nodetool cleanup" is one of
the reasons for that. This will only cause data-loss if you are writing at
CL.ANY where a hint counts as a write. If you are writing at CL.ONE or above
then at least one replica must receive the data for the write to succeed, so
losing hints will not cause data-loss.

If a hint is not delivered then the replica to which it was intended will
become consistent after a read-repair, or after manual anti-entropy repair.

Sam

-- 
Sam Overton
Acunu | http://www.acunu.com | @acunu

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