httpd processes out of control - HELP

httpd processes out of control - HELP

Post by wing cho » Sun, 02 Sep 2001 05:31:23



Config: Sun E450 - 2 processors, 4GB RAM, Solaris 7,
WebSphere Application Server 3.0.2, IBM HTTP Server 1.3.6

When I do "apachectl start", and then "ps -ef |grep httpd", i get back
about 5 or 6 httpd processes. After some time, it goes up to around 35.

There are times when it goes as high as 50... Usually not a problem,
but today it went up to 159 and stayed there... web site became
extremely slow.... can't even load up the website's first page....
obviously, we got alot of phone calls :(

checked CPU utilization normal - around 5 - 10% sustained.

i checked "netstat -a" and did notice a lot of HTTP connections on
port 80. many were in ESTABLISHED state, and many more were in TIME_WAIT state.

don't know what caused this... hope somebody here can give some
insight.

i read in another article by Bill Stoddard that IBM HTTP Server
uses a process per concurrently connected client.

Question:

1) How many concurrent web connections can a server with the config
above support without extreme performance degradation??? i can't
believe a Sun E450 cannot handle 150+ concurrent web connections.

2) Where in httpd.conf can i limit the number of concurrent
connections that IBM HTTP Server will allow???

3) If 10 httpd processes are spawned off if there are 10 simultaneous
connections, if 5 of these connections disconnect, shouldn't 5 httpd
processes dissapear??? or they still stay there... what happens to
these httpd processes??? do they then cater to other web connections,
or they simply become orphaned????

Hope somebody can help. Thanks in advanced :)

 
 
 

httpd processes out of control - HELP

Post by Joshua Sliv » Sun, 02 Sep 2001 10:50:39



> 1) How many concurrent web connections can a server with the config
> above support without extreme performance degradation??? i can't
> believe a Sun E450 cannot handle 150+ concurrent web connections.

This depends on the amount of memory, the type of load, the
type of clients, and how you have the server configured (along
with a couple dozen other factors).  One place to look
to help you start thinking about the correct issues is:
http://httpd.apache.org/docs/misc/perf-tuning.html

Quote:> 2) Where in httpd.conf can i limit the number of concurrent
> connections that IBM HTTP Server will allow???

I don't know anything about the IBM HTTP Server.  Assuming
that it is a not-to-modified version of Apache, the number
of cuncurrent connections is controlled by the MaxClients
directive.

Quote:> 3) If 10 httpd processes are spawned off if there are 10 simultaneous
> connections, if 5 of these connections disconnect, shouldn't 5 httpd
> processes dissapear??? or they still stay there... what happens to
> these httpd processes??? do they then cater to other web connections,
> or they simply become orphaned????

This is discussed in the "process creation" section in the above
document.  The extra processes will not dissapear if they are
withing MaxSpareServers.  That way, the server does not need
to spawn new processes when more load comes in.

--
Joshua Slive

http://slive.ca/

 
 
 

httpd processes out of control - HELP

Post by Max Dittric » Mon, 03 Sep 2001 05:31:32


Ahoi,



Quote:> Config: Sun E450 - 2 processors, 4GB RAM, Solaris 7,
> WebSphere Application Server 3.0.2, IBM HTTP Server 1.3.6

You have any ideas in what particular features it differs from Apache ?

Quote:

> When I do "apachectl start", and then "ps -ef |grep httpd", i get back
> about 5 or 6 httpd processes. After some time, it goes up to around 35.

> There are times when it goes as high as 50... Usually not a problem,
> but today it went up to 159 and stayed there... web site became
> extremely slow.... can't even load up the website's first page....
> obviously, we got alot of phone calls :(

You might want to use "/usr/proc/bin/ptree" with a combination of
"ps -o stime" to see weither there are some server-processes blocked to
handle further requests by a spawned and not exiting cgi-process.

Quote:

> checked CPU utilization normal - around 5 - 10% sustained.

> i checked "netstat -a" and did notice a lot of HTTP connections on
> port 80. many were in ESTABLISHED state, and many more were in TIME_WAIT state.

To reduce the default Time waiting in TIME_WAIT see the wonderful
guide for tuning Solaris TCP/IP-Stack at
http://www.sean.de/Solaris/tune.html .

Quote:

> don't know what caused this... hope somebody here can give some
> insight.

> i read in another article by Bill Stoddard that IBM HTTP Server
> uses a process per concurrently connected client.

> Question:

> 1) How many concurrent web connections can a server with the config
> above support without extreme performance degradation??? i can't
> believe a Sun E450 cannot handle 150+ concurrent web connections.

> 2) Where in httpd.conf can i limit the number of concurrent
> connections that IBM HTTP Server will allow???

Lookup the httpd.conf for something called server-status, thos will
give some nice realtime-information.

Quote:

> 3) If 10 httpd processes are spawned off if there are 10 simultaneous
> connections, if 5 of these connections disconnect, shouldn't 5 httpd
> processes dissapear??? or they still stay there... what happens to
> these httpd processes??? do they then cater to other web connections,
> or they simply become orphaned????

> Hope somebody can help. Thanks in advanced :)

...max
 
 
 

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