[CentOS] Finding memory usage

Fri Jul 27 18:29:17 UTC 2018
Bowie Bailey <Bowie_Bailey at BUC.com>

On 7/27/2018 12:58 PM, mark wrote:
> Bowie Bailey wrote:
>> On 7/27/2018 11:50 AM, Warren Young wrote:
>>> On Jul 27, 2018, at 9:10 AM, Bowie Bailey <Bowie_Bailey at BUC.com> wrote:
>>>> I have a CentOS 7 server that is running out of memory
>>> How do you know that?  Give a specific symptom.
>> This was brought to my attention because one program was killed by the
>> kernel to free memory and another program failed because it was unable to
>> allocate enough memory.
> <snip>
> Um, wait a minute - are you saying the oom-killer was invoked? My reaction
> to that is to define the system, at that point, to be in an undefined
> state, because you don't know what some threads that were killed are.

Probably true, but the system has been rebooted since then and the
oom-killer has not been activated since then.  When I first noticed the
problem, I also found that my swap partition had been deactivated, which
is why the oom-killer got involved in the first place instead of just
having swap usage slow the system to a crawl.

I think I have identified the program that is causing the problem
(memory usage went back to normal when the process ended), but I'm still
not sure how it ended up using 10x the memory that top reported for it.