cassandra-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Huy Le <>
Subject Re: Out of control memory consumption
Date Thu, 10 Feb 2011 16:34:02 GMT
We use Cassandra version 0.6.11. Our cache size is very small.  11 out of 12
servers have used heap size less than 500MB of 3GB allocated. Just one
server that had memory usage run out of control.

The issue is isolated.  It turn out that one CF has a row with compacted row
size of 50MB.  And this row happens to be very active row that get updated
every few seconds.   By deleting this row, heap memory usage is consistently
low across servers on the cluster.

It came to my surprise how expensive it is to have this row of 50MB
compacted size being updated every few seconds.  Does anyone have any
insight as to why the row mentioned is so expensive to have?



On Wed, Feb 9, 2011 at 2:34 PM, Robert Coli <> wrote:

> On Wed, Feb 9, 2011 at 11:04 AM, Huy Le <> wrote:
> > Memory usage grows overtime.
> It is relatively typical for caches to exert memory pressure over time
> as they fill. What are your cache settings, for how many
> columnfamilies, and with what sized memtables? What version of
> Cassandra?
> =Rob

Huy Le
Spring Partners, Inc.

View raw message