[CentOS] Memory leak - how to investigate

Mon Feb 3 19:59:19 UTC 2014
m.roth at 5-cent.us <m.roth at 5-cent.us>

Kwan Lowe wrote:
> On Mon, Feb 3, 2014 at 8:43 AM, Jussi Hirvi <listmember at greenspot.fi>
> wrote:
>
>> My web & name server runs out of memory from time to time, to the point
>> where it's completely unresponsive to anything. At that point reset is
>> the only alternative. (Or, as this is a virtual guest, I just say "virsh
>> destroy").
>>
>> But why this happens - I would like to know.
>
> Sever things could be occurring. The first thing I notice is that you have
> many httpd processes running. This can be useful if you have many
> simultaneous hits. If you don't, you can tune the number of processes down

We've got a number of websites on one of our production servers, and they
get hit moderately (it's not Amazon... but they are US gov't scientific
research sites), and I think we've got 25 threads running, total, to
server *all* of them.
<snip>
>>  From "top" (situation now):
>> Mem:   1361564k total,  1264324k used,    97240k free,     8428k buffers
>> Swap:  3014648k total,    64852k used,  2949796k free,   358676k cached
>>
> That doesn't look like a lot of memory.. Possible to add another .5G or
> so?

Ah! I missed that. Is it actually the case that your server doesn't even
have 2G of RAM? That's a *real* problem. If you're not running it on a
five year old desktop, you need to add - I'd say you shouldn't be running
with under 4GB of real memory.

        mark "got 8G on my home ssytem, and 6G on my workstation at work"