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From Peter Schuller <peter.schul...@infidyne.com>
Subject Re: what causes MESSAGE-DESERIALIZER-POOL to spike
Date Mon, 26 Jul 2010 20:31:11 GMT
> Hpw does one set/get the read-concurrency? Also which read-concurrency, for
> which pool? According to the threads tab in jconsole read-concurrency could
> be among different pools. There are row-read-stag threads, lots of write
> threads, row mutation stage etc.

Short version: Ignoremy concurrency speculation as it doesn't apply.

Long version:

I meant the ConcurrentReads settings in
storage-conf.xml/cassandra.yaml (depending on version), but I was
speculating.

Having a look now, I presume it's not set to 1 because a minimum of 2
seems to be required (DatabaseDescriptor.java). And since you ask
where I suspect it's at its default value of 8 anyway.

Also, looking at StageManager it appears this is applied to
ROW-READ-STAGE so is indeed unrelated to MESSAGE-DESERIALIZER-POOL.

MESSAGE-DESERIALIZER-POOL seems to be unrelated to disk I/O
alltogether and seems to be used by MessagingService.java. So - please
ignore my read concurrency speculation as it doesn't apply.

-- 
/ Peter Schuller

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