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Re: memory detection and performance on forking new processes



> On Sat, Oct 21, 2000 at 06:03:43PM +0200, henning_(_dot_)_brauer_(_at_)_bsmail_(_dot_)_de wrote:
> > Hi all,
> >
> > i've set up a new server a few days ago. it's a not even small
webserver,
> > apache statically compiled. There are typically 50 to 100
httpd-processes

> Statically compiled apache probably will not give visible perfomance
> improvments, but eat more memory. Compiling apache statically will make
> sense only if you actively use DSO modules. Increase MinSpareServers to
> improve perfomance.

i tried both versions before, the statically compiled apache is
dramatically faster. give ouself a chance on www.chat4free.de/forum/ - php4
with mysql-database on the discussed box.

> > running (total 90 to 150 processes on the machine) and apache serves
the
> > pages (even the dynamic ones) really really really fast.
> > I notices that forking new processes takes a long time, for example
when
> > starting an editor (jed in my case), for about 5 seconds happens
nothing

> It's normal. The system spend 5 second not forking, it is read a program
> from the disk. Your problem is loaded and relatively slow IDE disk.

This is historic, the problem has gone ;-))
It was the nfs-problem, moving the mrtg (which caused the trouble) to
another obsd-box and everything is great.
the disk is IDE, but not slow...

> > and then it fires up very fast. And there are some nfs-problems
> > (client-machine on linux complains about "can't get slot" what seems to
be
> > related to the nfs-server-responsetime).
> > I've looked in "top" and have seen it only reports 75Megs of Memory -
but
> > the machine has 128MB as seen in dmesg below - is think dmesg (and
sysctl)
> > are right, but i'm not sure. I've seen linux on athlon-machines only
seeing

> Your system correctly detect memory. top don't display total memory
> size.

thx, i had a too fast look - on linux there is the real memory on the left
top ;-))

> > 64 of the 128 or more megs of ram, there i needed to set the mem=XXXm
> > boot-parameter.
> > Anonther question is about the parameter "maxusers" in
> > kernel-configuration. I found no docs about it (yes, I've read man
config),
> > only that (at least in freebsd) maxfiles is calculated from that value.
Is
> > there anywhere a document like "optimize openbsd for large servers" ors
> > something like that? which parameters to modify? shouldn't i set
maxfiles,
> > maxprocs, ip-queuelenght and such parameters to higher values?

> $ grep  MAXUSERS /sys/conf/param.c
>  * Compiled with -DHZ=xx -DTIMEZONE=x -DDST=x -DMAXUSERS=xx
> #define NPROC (20 + 16 * MAXUSERS)
> int     maxfiles = 3 * (NPROC + MAXUSERS) + 80;
> int     nclist = 60 + 12 * MAXUSERS;
> $

> see man 8 sysctl

read it before, of course...
nevertheless, the info above is very valuable. Setting maxusers to s/t abou
64-128 will be a good idea, nor?

> You may wish to increase BUFCACHEPERCENT, see faq11, man 4 options.

thx


>    Grigoriy.

Greetings from Germany_(_at_)_night

Henning


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