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From aaron morton <>
Subject Re: Why my Cassandra is compacting like mad
Date Fri, 19 Oct 2012 02:07:30 GMT
Bryan , Manu

	Can you contribute your experience to this ticket
? If you have some steps to reproduce, or any information on schema changes you have made
that would be useful.

	The ticket is against 1.2.0b1 - so please include that you are running 1.1.5

Aaron Morton
Freelance Developer

On 19/10/2012, at 4:36 AM, Bryan <> wrote:

> I think I am seeing the same issue, but it doesn't seem to be related to the schema_columns.
I understand that repair is supposed to be intensive, but this is bringing the associated
 machine to its knees, to the point that logging on the machine takes a very, very long time
and requests are no longer served (load avg ~2000.0). Is this normal? Is this a symptom of
the machine not compacting enough during normal operation (minor compactions)? Thoughts?
> Cassandra 1.1.5, 12 node application cluster connected to a smaller analytics cluster
> The analytics cluster was repairing, but it seemed to swamp one of the nodes on 12-node
> Java 1.6_u5, CentOS
> 40 - 80 GB on each node (too much?)
> Main CF has 4 indexes
> standard configs, no multithreaded compaction, 16 mb compaction throughput
> Speaking of the throughput, reading the cassandra.yaml file made me think that the throughput
is not set correctly, but I'm not sure how to calculate the ideal value. Should I only consider
the actual data size inserted, or should I use a single-node load figure / uptime_seconds
as a guess (assuming constant load)?
> Thanks,
> Bryan
> Re:

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