Mailing-List: contact user-help@cassandra.apache.org; run by ezmlm
Precedence: bulk
Reply-To: user@cassandra.apache.org
Received-SPF: neutral (athena.apache.org: local policy)
Sender: Kyusik Chung <kyusik@umamibud.com>
From: Kyusik Chung <kyusik@discovereads.com>
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: quoted-printable
Subject: Memory usage continually increases with reads
Date: Wed, 28 Apr 2010 12:12:43 -0700
Message-Id: <63B33033-EAE8-4605-A6E4-5B790B1B6CD3@discovereads.com>
To: user@cassandra.apache.org
Mime-Version: 1.0 (Apple Message framework v1078)

Hello.  I am using Cassandra 0.6.1 on ubuntu 8.04.  3 node cluster.

I notice that when I start making lots of read requests (serially), =
memory usage of jsvc keeps climbing until it uses up all memory on the =
server (happens for all 3 servers in the cluster).  At that point, the =
box starts swapping a little (but not too much) and performance is =
degraded.  Read performance does not drop off a cliff, but it does take =
a serious hit (maybe 50%).

I have tried setting Xmx to various different values, but it doesnt seem =
to limit the growth in memory usage.  I understand that I should expect =
to see jsvc use a bit more memory than what the jvm is configured to =
use, but it doesnt seem to be limited to just an overhead.  I have set =
Xmx all the way down to 128M (just to test) and still jsvc will use up =
2G of memory.

Are there other settings that I should be changing?

Note that when I test by simply running a lot of writes but no reads, =
jsvc seems to respect the Xmx value.

Thanks!

Kyusik Chung=