[Catalyst] Re: memory usage of mod_perl process

[Perrin Harkins]

On 2/8/07, Jeffrey Ng <jeffreyn at gmail.com> wrote:
> when i run this "free" test, should i run it on the live server, or on a
> test server with single process apache mode?

I wouldn't mess with things on your live server, but you want to run
in normal mode, not single-process.

> here's the result on a live server:
>
>              total       used       free     shared    buffers     cached
> Mem:       4150972    2654016    1496956          0      27548    1313344
> -/+ buffers/cache:    1313124    2837848
> Swap:      8385912       6920    8378992
[...]
> Our CPU load is extremely high. But the actual RAM usage is not high at all.
> we are using only 260 gig out of 400 gig.

Not even that much.  You're using about 1.3 GB and the rest of that
2.6 is just being used to cache files.  You should be able to run a
lot more apache processes on this machine, or maybe give some RAM to
whatever else needs it on there, like a database.

> From our top results, does it look
> like the memory usage of our processes is the bottleneck?

No, you have tons of free RAM.  It sounds like something else is
slowing you down.  You have a lot of CPU being used on there (about
60%) which might mean you need to profile your code for CPU
bottlenecks.  You may also be waiting on database queries, which you
can find out with Devel::DProf or the DBI profiler.

- Perrin