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From Robert Coli <rc...@eventbrite.com>
Subject Re: handling down node cassandra 2.0.15
Date Mon, 30 Nov 2015 20:26:32 GMT
On Wed, Nov 18, 2015 at 6:16 AM, Anuj Wadehra <anujw_2003@yahoo.co.in>
wrote:

> Suppose, gc grace seconds=10days, max hinted handoff period=3 hrs, 3 nodes
> are there A,B & C,RF =3 and my client is reading at CL ONE. C remains down
> for 5 hours and misses many updates including those which happened after
> max hinted handoff period of 3 hrs. Now I bring back node C with
> auto_bootstrap false and run repair. If client queries at CL ONE and
> fetches a row which got updated after max hinted handoff period, there is a
> very high possibility of client returning stale data  from node C . But as
> soon as node C has joined the ring, it will start participating in WRITEs.
>
> But if we follow the procedure you suggested, node C will come back, run
> repair but wont participate in reads till we join it to the cluster. During
> repair, if client queries at CL ONE and fetches a row which got updated
> after max hinted handoff period expired and was missed by node C, it will
> still get latest data from A and B. So, the integrity of data is not lost
> similar to the case when we auto_bootsrap with true. Additionally we save
> the unique data of node C. While repair is going on, node C will get all
> the Writes.
>

Yes, during this time, C is getting "extra" writes as it is repairing
itself vis a vis A and B, but it is not serving reads.

=Rob

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