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Posted to user@cassandra.apache.org by Brian Jeltema <br...@digitalenvoy.net> on 2013/02/07 19:01:46 UTC
are CFs consistent after a repair
I'm confused about consistency. I have a 6-node group (RF=3) and I have a table that
was known to be inconsistent across replicas (a Hadoop app was sensitive to this).
So a did a 'nodetool -pr repair' on every node in the cluster. After the repairs were
complete, the Hadoop app still indicated inconsistencies. Is this to be expected?
Brian
Re: are CFs consistent after a repair
Posted by Brian Jeltema <br...@digitalenvoy.net>.
I'm afraid I can't investigate further; enough time has elapsed that it appears the inconsistencies
have worked their way out of the cluster.
On Feb 7, 2013, at 9:25 PM, aaron morton wrote:
>> 'nodetool -pr repair'
> Assuming nodetool repair -pr
>
> If there is no write activity all reads (at any CL level) will return the same value after a successful repair.
>
> If there is write activity there is always a possibility of inconsistencies, and so only access where R + W >N (e.g. QUORUM + QUROUM ) will be consistent.
>
> Can you drill down into the consistency problem?
>
> Cheers
>
> -----------------
> Aaron Morton
> Freelance Cassandra Developer
> New Zealand
>
> @aaronmorton
> http://www.thelastpickle.com
>
> On 8/02/2013, at 7:01 AM, Brian Jeltema <br...@digitalenvoy.net> wrote:
>
>> I'm confused about consistency. I have a 6-node group (RF=3) and I have a table that
>> was known to be inconsistent across replicas (a Hadoop app was sensitive to this).
>>
>> So a did a 'nodetool -pr repair' on every node in the cluster. After the repairs were
>> complete, the Hadoop app still indicated inconsistencies. Is this to be expected?
>>
>> Brian
>
Re: are CFs consistent after a repair
Posted by aaron morton <aa...@thelastpickle.com>.
> 'nodetool -pr repair'
Assuming nodetool repair -pr
If there is no write activity all reads (at any CL level) will return the same value after a successful repair.
If there is write activity there is always a possibility of inconsistencies, and so only access where R + W >N (e.g. QUORUM + QUROUM ) will be consistent.
Can you drill down into the consistency problem?
Cheers
-----------------
Aaron Morton
Freelance Cassandra Developer
New Zealand
@aaronmorton
http://www.thelastpickle.com
On 8/02/2013, at 7:01 AM, Brian Jeltema <br...@digitalenvoy.net> wrote:
> I'm confused about consistency. I have a 6-node group (RF=3) and I have a table that
> was known to be inconsistent across replicas (a Hadoop app was sensitive to this).
>
> So a did a 'nodetool -pr repair' on every node in the cluster. After the repairs were
> complete, the Hadoop app still indicated inconsistencies. Is this to be expected?
>
> Brian