[ILUG] Re: OOM discussion...

[Donncha O Caoimh]

Nice idea. It would be great to have a small app sitting in the
background watching our for errant behaviour.
I'd like to see a flexible program that could be configured to handle
different types of applications..
ie. Apache starts eating too many resources for some reason (even if Max
children is set sensibly) then this program could change the number of
max children and signal apache to re-read httpd.conf, or something.
cgi programs that are stalled could be killed off if they start stalling
for some reason and chewing CPU cycles (I've done that.. works nicely :)

Of course, you have to balance all the above with the resulting load of
restarting a major software services..

Oohh.. I have my own OOM story. I tried the Unreal Tournament client
from sourceforge.net last week and read through some of the mails on
their list. A few complained about memory problems running it with a
Riva TNT. I tried the client a few times, and the first couple of times
it ran, but only displayed a screen 20 pixels high in the middle of the
screen. The last time it chewed RAM, even switching to a console I
couldn't reboot (ALT-CTRL-DEL) because there wasn't enough RAM to run
reboot! 

Donncha.

Paul Mc Auley wrote:
[snip]
> As it happens I think the problem should be solvable (soluble?) with a simple
> user-land program which allocates a small-ish block of memory and then
> monitors /proc/meminfo. When the memory drops below a certain threshold, it
> swapon(2)s a prebuilt swapfile and rings alarm bells, sends e-mails, frightens
> the cat etc. Alternatively, it could start gracefully shutting down certain
> applications, and killing others that are either in a kill list or not in an
> exempt list. Does anybody have any better ideas? Pointers to somewhere it has
> been done already? Horror stories?
>