maxuprc

[Georgina Swan]

Can anyone suggest a sensible value for maxuprc for a webserver? The nproc value on the system is 276, I've read that the maximum maxuprc value should be nproc-4, but what would be a sensible value. It is currently set at 75 and we frequently run out of processes.

[Sridhar Bhaskarla]

Georgina,

It makes sense to keep maxuprc equal to nproc-4 on the systems that have web servers running. Sensibility depends on the usage of the system. Certainly web servers spawn more processes as a single user (www). So, make it equal to the same formula. Also keep a track of your nproc size by doing a sar -v 5 10 at regular intervals.

-Sri

[Michael Tully]

Hi,

You can safely increase 'maxuprc' to 1024. In saying that you will need to also increase 'nproc' to at least 1028. Have a read of this document.

http://www.docs.hp.com/hpux/onlinedocs/os/KCparams.OverviewAll.html

-Michael

[Roger Baptiste]

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It basically depends on the
usage of the system. If this
is strictly a WEBSERVER without any other active users, then you use the minus four formula.
The current values of 276 and 75 is less for a websever.

Boost nproc to 1024 and
maxuprc to somewhere close to it (between 1000 and 1020).
IF you have a very busy server, then you can increase
it further too, depending on the usage at a later time.

HTH
raj

[harry d brown jr]

Because its a webserver, I want to point out this important white paper:

http://people.hp.se/stevesk/bastion.html

Secondly, it's always important to know what OS (10.20, 11.00/32, 11.00/64, 11i) you are running, what web server products you are using, are your applications threaded, and the expected number of users at the peak period. Because this also will determine what your kernel parameters need to be set at.

live free or die
harry

[Bill Hassell]

This will require some research. maxuprc is the maximum number of processes allowed to run by a single user. So there is no particular relationship between nproc or maxuprc. For a web server, you must count every process run by the web server user (typically www).

Now this may be tricky: a web page is served by an httpd process, which may start a cgi script which in turn starts another process. So for a specific web page request, 3 or more processes may be needed for each request. Multiply that times the number of independent web pages that may be served at the same time and maxuprc can grow rapidly.

So the formula is something like:

maxuprc = number-of-independent-page-requests * maximum-number-of-subprocesses

[Sanjay_6]

Hi Georgina,

Take a look at the threads below for more info on maxuprc,

http://www.docs.hp.com/hpux/onlinedocs/os/KCparam.MaxUprc.html

this is also dependent on nproc, check this link on nproc,

http://www.docs.hp.com/hpux/onlinedocs/os/KCparam.Nproc.html

And here is a link from ITRC on the performance tuning for a WEb-server,

http://us-support.external.hp.com/cki/bin/doc.pl/sid=400174a00d1946bd3c/screen=ckiDisplayDocument?docId=200000056144591

http://us-support.external.hp.com/cki/bin/doc.pl/sid=400174a00d1946bd3c/screen=ckiDisplayDocument?docId=200000051850892

Hope this helps.

Regds