> > I like the idea of Apache::SizeLimit, to no longer worry about
> > setting MaxRequestsPerChild. That just seems smart, and might
> > get maximum usage out of each Apache child.
> >
> > What I would like to see though is instead of killing the
> > child based on VmRSS on Linux, which seems to be the apparent
> > size of the process in virtual memory RAM, I would like to
> > kill it based on the amount of unshared RAM, which is ultimately
> > what we care about.
>
> It exists for a long time: Apache::GTopLimit. Of course if you have GTop.
> And it's in the guide including all the calculations of the real memory
> used (used by Apache::VMonitor)
So, forgive me for not "getting it," but is there a way to do this without
endless retries and experimentation? It seems to me that blocking on a
per-child size usage is silly (even tho I'm shure it's what is available at
the programming level).
I mean,
I have a machine w/ 512MB of ram.
unload the webserver, see that I have, say, 450MB free.
So I would like to tell apache that it is allowed to use at most 425MB.
It's not out there as far as I can find.
So far all I've been able to find is:
Run your service for awhile.
Do some math and guesswork about size/totals/available.
Run it again.
Recheck your math.
Use (per-process limiting module).
Pray that your processes never grow because of rarely used
functionality/peak usage/larger than usual queries ...
because then all of your hard work before goes RIGHT out the window, and I'm
talking about a 10-15 MB difference between JUST FINE and DEATH SPIRAL,
because we've now just crossed that horrible, horrible threshold of (say it
quietly now) swapping! <shudder>
Have I jumped to the wrong conclusion? Is there a module (or usage) I've
missed? Somehow I doubt I'm the only one who sees the problem in these
terms... has anybody seen the SOLUTION in these terms??
L8r,
Rob
