Memory usage of apache under Solaris

Memory usage of apache under Solaris

Post by u.. » Thu, 27 Feb 2003 07:02:21



I am experimenting apache 2.0.44 and openssl 0.9.7 as a Secure
(SSL)Reverse Proxy.

The OS is Solaris 2.6 (SPARC) and my Netra has 2 Go of memory.

Functionally, everything works without any issue.

Under heavy load (700 requests per second during 6 hours) I can see the
free memory rapidly decreasing (5 Mo per minute) down to 1,2 Go from
which it stops to decrease.
When I stop apache, the memory is not released.
I use the vmstat command.

I have tried different SSLsessioncache options but nothing has changed:
SSLsessioncache dbm:/path/to/datafile
SSLsessioncache none

I have reduced the MaxRequestsPerChild directive to 150 but there has
been no change.

I use prefork MPM.

What can I do to solve this issue?
Is it an apache or Solaris issue?

 
 
 

Memory usage of apache under Solaris

Post by Joachim Ri » Thu, 27 Feb 2003 20:38:54


Quote:> I am experimenting apache 2.0.44 and openssl 0.9.7 as a Secure
> (SSL)Reverse Proxy.

> The OS is Solaris 2.6 (SPARC) and my Netra has 2 Go of memory.

> Functionally, everything works without any issue.

> Under heavy load (700 requests per second during 6 hours) I can see the
> free memory rapidly decreasing (5 Mo per minute) down to 1,2 Go from
> which it stops to decrease.
> When I stop apache, the memory is not released.

i'd start looking for mem leaks in the solaris 6 libraries. or just
upgrade the os. is there any specific reason for using this fossil?

joachim

 
 
 

Memory usage of apache under Solaris

Post by Steve van der Bu » Thu, 27 Feb 2003 22:56:32



-reader11.wanadoo.fr>:

Quote:>I am experimenting apache 2.0.44 and openssl 0.9.7 as a Secure
>(SSL)Reverse Proxy.
>The OS is Solaris 2.6 (SPARC) and my Netra has 2 Go of memory.
>Under heavy load (700 requests per second during 6 hours) I can see
>the free memory rapidly decreasing (5 Mo per minute) down to 1,2 Go
>from which it stops to decrease.
>When I stop apache, the memory is not released.
>I use the vmstat command.
>Is it an apache or Solaris issue?

You are almost certainly seeing the Solaris filesystem cache using
memory.  Because unused memory is simply being wasted, SunOS caches
files (well, parts of files) in RAM.

This link should help explain what's going on:
   http://www.science.uva.nl/pub/solaris/solaris2/Q5.84.html

...Steve

--
Steve van der Burg
Technical Analyst, Information Services
London Health Sciences Centre
London, Ontario, Canada

 
 
 

1. Apache-1.3.14 higher than normal memory usage

We recently upgraded to apache-1.3.14 on a couple of servers.  These
servers have identical hardware, identical apache + php4 configurations,
and receive apporximately the same amount of traffic serving different
pages.  Despite this, one server will rise significantly in memory usage
after anywhere from 30min-5hrs while the other doesn't.

  For example, the server without this problem has top reporting
  PID USER     PRI  NI  SIZE  RSS SHARE STAT  LIB %CPU %MEM   TIME COMMAND
12793 httpd      0   0  9716 9072  3064 S       0  0.0  1.7   1:26 httpd

while top on the troubled server reports
32092 httpd      1   0 28560  27M  3568 S       0  0.0  5.5   0:05 httpd

Notice the SIZE, RSS, and %MEM.  

        We have tried simulating some standard page requests to see if a
script may somehow cause the memory increase but no luck yet.

Does anyone have any idea why the memory increases so much on this server?

                                --Brian Keffer--

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