httpd-users mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From P J <pauljfli...@gmail.com>
Subject Re: [users@httpd] Help troubleshooting performance issue, after "1000 total children" Apache no longer responds to HTTP requests. Not MaxClients issue?
Date Fri, 04 May 2012 19:20:32 GMT
On Fri, May 4, 2012 at 8:46 AM, Tom Evans <tevans.uk@googlemail.com> wrote:

> On Fri, May 4, 2012 at 4:18 PM, P J <pauljflists@gmail.com> wrote:
> > On Fri, May 4, 2012 at 5:28 AM, Jim Jagielski <jim@apache.org> wrote:
> >>
> >> The closer MinSpareServers/MaxSpareServers are, the more time
> >> Apache needs to spend killing and creating child processes
> >> to ensure it stays within that narrow limit
> >> On May 3, 2012, at 2:40 PM, P J wrote:
> >>
> >
> > Thanks. Yes, I understand that. I set them both to that number to try and
> > induce the issue we've been seeing.
> > If I set:
> >
> > MinSpareServers  1024
> > MaxSpareServers  2048
> >
> > 1000+ simultaneous connections is not uncommon this server.
> >
>
> This is unlikely to have a major effect on your issue, as I believe
> something strange is going on when you reach 1024 processes, but why
> do you have MinSpareServers so high?
>
> If you start 1024 children initially, and then 900 of them are busy,
> you are asking httpd to ensure there are at least 1924 children. It
> seems massive overkill to ensure that there are so many idle
> processes.
>
> If your high water mark is (say) 1536 clients, and you start 1024
> processes, then I would go with settings like this:
>
> MinSpareServers 128
> MaxSpareServers 1536
> StartServers 1024
> MaxClients 2048
> ServerLimit 2048
>
> So, you start with 1024 processes, increasing up to a maximum of 2048
> processes. If there are ever more than 1536 processes idle, kill some
> off.
>
> Cheers
>
> Tom
>
>
Thanks Tom, I agree. I don't normally have MinSpareServers at 1024, I was
just trying to see if I can force it to throw the:

"[debug] mpm_common.c(663): (70007)The timeout specified has expired:
connect to listener on [::]:80 error". error.

Which I can. The million $ questions is what is the magic 1024 limit I'm
hitting.

I'll hopefully try with a later version of Apache and let the list know if
that resolves it.

Thanks again.

--
PJ

Mime
View raw message