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From Benjamin Black...@b3k.us>
Subject Re: 10 minute cassandra pause
Date Wed, 23 Jun 2010 22:30:22 GMT
Are you seeing any sort of log messages from Cassandra at all?

On Wed, Jun 23, 2010 at 2:26 PM, Sean Bridges <sean.bridges@gmail.com> wrote:
> We were running a load test against a single 0.6.2 cassandra node.  24
> hours into the test,  Cassandra appeared to be nearly frozen for 10
> minutes.  Our write rate went to almost 0, and we had a large number
> of write timeouts.  We weren't swapping or gc'ing at the time.
>
> It looks like the problems were caused by our memtables flushing after
> 24 hours (we have MemtableFlushAfterMinutes=1440).  Some of our column
> families are written to infrequently so that they don't hit the flush
> thresholds in MemtableOperationsInMillions and MemtableThroughputInMB.
>  After 24 hours we had ~3000 commit log files.
>
> Is this flushing causing Cassandra to become unresponsive?  I would
> have thought Cassandra could flush in the background without blocking
> new writes.
>
> Thanks,
>
> Sean
>

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