This would be a Java VM option, not something Solr or other apps can know about.
Using this or procset seems like a great way to handle it.
On Wed, Sep 29, 2010 at 8:46 AM, Glen Newton <glen.new...@gmail.com> wrote:
> In a recent blog entry ("The MySQL “swap insanity” problem and the
> effects of the NUMA architecture"
> http://jcole.us/blog/archives/2010/09/28/mysql-swap-insanity-and-the-numa-architecture/),
> Jeremy Cole describes a particular but common problem with large memory
> installations of MySql on multi-core multi-cpu 64bit NUMA machines,
> where debilitating swapping of large amounts of memory occurs even
> when there is no (direct) indication of a need to swap.
>
> Without getting into the details (it involves how Linux assigns memory
> to the different nodes (each multi-core CPU is viewed as a
> 'node' in the Linux NUMA view)), the offered partial solution is to
> start MySql using the
> numactl[1] program, like:
> numactl --interleave all mysql
>
> I was wondering if any of the SOLR people have used this when starting
> up Apache
> (or whatever servlet engine you use for your SOLR) to reduce unnecessary swap.
>
> You probably want to be monitoring the NUMA memory hit statistics
> found here, with and without the numactl, while testing this:
> /sys/devices/system/node/node*/numastat
>
> --
>
> Note that numactl has a number of other interesting and useful
> features. One that I have used is the --cpubind which restricts the
> number of CPUs that an application can run on. There are times when
> this can improve performance, such as when you have 2 demanding
> applications running: by assigning one to half of the CPUs and the
> other to the other half of
> the CPUs, you _can_ have improved performance due to better locality, cache
> hits, etc. It takes some tuning and experimentation. YMWV
>
> -Glen
> http://zzzoot.blogspot.com/
>
> [1]http://linuxmanpages.com/man8/numactl.8.php
>
>
>
> --
>
> -
>
--
Lance Norskog
goks...@gmail.com
