incubator-cassandra-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Dan Retzlaff <dretzl...@gmail.com>
Subject Re: 0.6.5 OOM during high read load
Date Mon, 21 Mar 2011 15:07:58 GMT
Beautiful, thanks.

On Sun, Mar 20, 2011 at 4:36 PM, Jonathan Ellis <jbellis@gmail.com> wrote:

> 0.7.1+ uses zero-copy reads in mmap'd mode so having 80k references to
> the same column is essentially just the reference overhead.
>
> On Fri, Mar 18, 2011 at 7:11 PM, Dan Retzlaff <dretzlaff@gmail.com> wrote:
> > Dear experts, :)
> > Our application triggered an OOM error in Cassandra 0.6.5 by reading the
> > same 1.7MB column repeatedly (~80k reads). I analyzed the heap dump, and
> it
> > looks like the column value was queued 5400 times in an
> > OutboundTcpConnection destined for the Cassandra instance that received
> the
> > client request. Unfortunately, this intra-node connection goes across a
> > 100Mb data center interconnect, so it was only a matter of time before
> the
> > heap was exhausted.
> > Is there something I can do (other than change the application behavior)
> to
> > avoid this failure mode? I'm not the first to run into this, am I?
> > Thanks,
> > Dan
>
>
>
> --
> Jonathan Ellis
> Project Chair, Apache Cassandra
> co-founder of DataStax, the source for professional Cassandra support
> http://www.datastax.com
>

Mime
View raw message