[users@httpd] Does this ps listing look correct when running Apache?

[John Hudak <jj...@gmail.com>]

Under ubuntu 8.04 I installed, configured, and am running Apache 2.2.8).

When I so a ps -lax, I see the following:

F   UID   PID  PPID PRI  NI    VSZ   RSS WCHAN  STAT TTY        TIME COMMAND
4     0  6242     1  20   0   6928  2612 -      Ss   tty1       0:00
/bin/login --
4  1000  6248  6242  20   0   5572  2992 -      S+   tty1       0:00 -bash
1     0  6285  6121  20   0   8084   876 -      S    ?          0:09
/usr/sbin/winbindd
1     0  6286  6121  20   0   8092  1296 -      S    ?          0:21
/usr/sbin/winbindd
5    10  8256     1  20   0   5352  1448 -      Ss   ?          0:00
/usr/sbin/faxq
1    10  8258     1  20   0   4688  1016 -      Ss   ?          0:00
/usr/sbin/hfaxd -i 4559
4    10  8266     1  20   0   5464  2412 -      S    ?          0:44
/usr/sbin/faxgetty ttyACM0
5     0 12714     1  20   0  23904  7080 -      Ss   ?          0:02
/usr/sbin/apache2 -k start
5    33 12716 12714  20   0  23904  4224 -      S    ?          0:00
/usr/sbin/apache2 -k start
5    33 12717 12714  20   0  23904  4232 -      S    ?          0:00
/usr/sbin/apache2 -k start
5    33 12731 12714  20   0  23904  4224 -      S    ?          0:00
/usr/sbin/apache2 -k start
5    33 12733 12714  20   0  23904  4224 -      S    ?          0:00
/usr/sbin/apache2 -k start
5    33 12734 12714  20   0  23904  4220 -      S    ?          0:00
/usr/sbin/apache2 -k start
5    33 12735 12714  20   0  23904  4224 -      S    ?          0:00
/usr/sbin/apache2 -k start
5    33 12737 12714  20   0  23904  4220 -      S    ?          0:00
/usr/sbin/apache2 -k start
5     0 12802     1  20   0   7600  2104 -      Ssl  ?          0:00
/usr/sbin/console-kit-daemon
5    33 13010 12714  20   0  23904  4224 -      S    ?          0:00
/usr/sbin/apache2 -k start
5    33 13069 12714  20   0  23904  4224 -      S    ?          0:00
/usr/sbin/apache2 -k start
5    33 13467 12714  20   0  23904  4200 -      S    ?          0:00
/usr/sbin/apache2 -k start
1  1000 14289     1  20   0   2384   612 -      Ss+  ttyS0      0:15
heyu_relay
---snip----

My question is: Why all the instantiations of apache2 -k start?  I expected
to see one.

Doing some investigation I discovered that I have  Apache built as
multi-process (pre-forked) so I am guessing that these are the suspended
processes?

If so, how many should there be? does this look right?

An ancillary question: the machine serves 4 name-based virtual sites, so
would it be better to have Apache built as multiprocess or mult-threaded?

The machine is a whopping 1.2 GHz, single core, with 1 GB of memory, and a
very large page size.

Thanks for the insight.

-John

Re: [users@httpd] Does this ps listing look correct when running Apache?

[Mark Montague <ma...@catseye.org>]

  On April 6, 2011 12:04 , John Hudak <jj...@gmail.com> wrote:
> Under ubuntu 8.04 I installed, configured, and am running Apache 2.2.8).
>
> 5    33 13467 12714  20   0  23904  4200 -      S    ?          0:00 
> /usr/sbin/apache2 -k start
>
> My question is: Why all the instantiations of apache2 -k start?  I 
> expected to see one.

Because you are using the preform MPM.  See the documentation at 
http://httpd.apache.org/docs/2.2/mod/prefork.html which says,

" A single control process is responsible for launching child processes 
which listen for connections and serve them when they arrive. Apache 
always tries to maintain several spare or idle server processes, which 
stand ready to serve incoming requests. In this way, clients do not need 
to wait for a new child processes to be forked before their requests can 
be served."


> Doing some investigation I discovered that I have  Apache built as 
> multi-process (pre-forked) so I am guessing that these are the 
> suspended processes?

They are not suspended, they are sleeping, waiting for incoming requests.


> If so, how many should there be? does this look right?

The number is controlled by the |StartServers 
<http://httpd.apache.org/docs/2.2/mod/mpm_common.html#startservers>|, 
|MinSpareServers 
<http://httpd.apache.org/docs/2.2/mod/prefork.html#minspareservers>|, 
and |MaxSpareServers 
<http://httpd.apache.org/docs/2.2/mod/prefork.html#maxspareservers>| 
directives in your Apache HTTP Server configuration file(s).  See the 
documentation at the URL above.


> An ancillary question: the machine serves 4 name-based virtual sites, 
> so would it be better to have Apache built as multiprocess or 
> mult-threaded?

It should not make a difference for most servers.  If you have a large 
number of requests, the worker MPM may be more resource-efficient.  
However, not all third-party modules are thread safe, and hence may not 
be usable with the worker MPM; I run the prefork MPM for this reason.


--
   Mark Montague
   mark@catseye.org