Thank you, actually the mmap uses my memory. But is there a way to limit the memory usage of mmap? Because the memory usage of Cassandra goes incredible high (~7Gb on a 8Gb machine).


2010/6/16 Jonathan Ellis <>
you're just seeing address space used by mmap, not actually
allocated-by-the-jvm memory.

On Wed, Jun 16, 2010 at 7:02 AM, György Dózsa <> wrote:
> Hi,
> I have a Cassandra cluster and I set java Xmx to 2G in in
> every node, but the memory usage of cassandra daemon is 3 or 4 times of that
> (so 6-8 Gb).
> Have you got any idea to decrease the memory usage of cassandra?
> There are 4 nodes in the cluster and the system has approx 1000 reads and
> writes per sec.
> Every node has debian.
> --
> Thx,
> Gyuri

Jonathan Ellis
Project Chair, Apache Cassandra
co-founder of Riptano, the source for professional Cassandra support