incubator-cassandra-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Jonathan Ellis <jbel...@gmail.com>
Subject Re: Persistently increasing read latency
Date Fri, 04 Dec 2009 20:09:38 GMT
On Fri, Dec 4, 2009 at 1:31 PM, Freeman, Tim <tim.freeman@hp.com> wrote:
>>Fundamentally there's only so much I/O you can do at a time.  If you
>>don't have enough, you need to upgrade to servers with better i/o
>>(i.e. not EC2: http://pl.atyp.us/wordpress/?p=2240&cpage=1) and/or
>>more ram to cache the reads against.
>
> I agree that any given configuration will support a limited amount of I/O.
>
> For the first few hours of my load test, I have enough I/O.  The problem is that Cassandra
is spending too much I/O on reads and writes and too little on compactions to function well
in the long term.

If you don't have enough room for both, it doesn't matter how you prioritize.

Mime
View raw message