Re: Runaway CPU and memory on high load

To make your like as easy as possible, I would do this:
fresh untar Apache,
"apply" mod_backhand to that source tree using ./precompile.

Add -g to the CFLAGS and ./configure apache adding mode_backhand 
_statically_.
make install
cd src

And: gdb httpd <pid>

You should have a full symbol set at that point.  It would be good to 
have full symbols in apache as well so that we can account for a 
ping-pong infinite recursion between mod_backhand and an Apache 
internal call -- should there be one.

On Thursday, Jun 5, 2003, at 19:20 US/Eastern, Brian McCashin wrote:
> I've never gdb'ed an apache module. Do I have to only compile symbols 
> into the backhand module or apache as well
> to get a usable backtrace.
>
> On Tuesday, June 3, 2003, at 08:36 AM, Theo Schlossnagle wrote:
>
>> Would it be possible to combile backhand into apache on that machine 
>> and attach GDB to one of the run-away processes.  I've heard of that 
>> problem before.  It appears to be some sort of infinite recursion (as 
>> I don't see how infinite loops would occur in the code).  If you can 
>> gdb it, break it and give me a full backtrace I will try to get to 
>> the bottom of the problem.
>>
>> On Tuesday, May 27, 2003, at 17:37 US/Eastern, Brian McCashin wrote:
>>
>>> I've been running  backhand 1.2.2 and apache 1.3.27/php 4.3.0 
>>> RH7.1(2.4.2-2)  tenuously
>>> for 2 weeks now. (It was a backup plan for a failed Aeropoint.)
>>> My moderator handles ~600 hits per second at the daily peak
>>> to four backend servers all (except 1) Dual 800 Xeons.
>>>
>>> The problem is that after a short time 1 or 2 apache processes start 
>>> growing
>>> and sucking up CPU. If got a cron'ed job to kill processes if they 
>>> exceed
>>> 15Meg in VM but without this the moderator would soon run out of 
>>> memory.
>>> Config follows.
>>> Also I don't use byBusychildren because one of the backend never 
>>> show servers
>>> in use and gets all new traffic.
>>>
>>> I'm renicing the moderator and the moderator has keepalives off 
>>> whereas the rest are on.
>>> Any ideas??
>>>
>>> <IfModule mod_backhand.c>
>>>   UnixSocketDir /usr/local/apache/backhand
>>>   MulticastStats 10.0.0.200 10.0.0.255:4445
>>>   AcceptStats 10.0.0.0/24
>>>   BackhandModeratorPIDFile /usr/local/apache/backhand/moderator.pid
>>> BackhandConnectionPools off
>>>   <Location "/backhand">
>>>     SetHandler backhand-handler
>>>   </Location>
>>> </IfModule>
>>>
>>> <Directory "/usr/local/apache/htdocs">
>>>      Backhand removeSelf
>>>      Backhand byAge
>>>      Backhand bySession
>>> </Directory>
>>>
>>>
>>>
>>>
>>>
>>> _______________________________________________
>>> backhand-users mailing list
>>> [email protected]
>>> http://lists.backhand.org/mailman/listinfo/backhand-users
>>>
>> -- Theo Schlossnagle
>> Principal Consultant
>> OmniTI Computer Consulting, Inc. -- http://www.omniti.com/
>> Phone:  +1 410 872 4910 x201     Fax:  +1 410 872 4911
>> 1024D/82844984/95FD 30F1 489E 4613 F22E  491A 7E88 364C 8284 4984
>> 2047R/33131B65/71 F7 95 64 49 76 5D BA  3D 90 B9 9F BE 27 24 E7
>>
>
>
-- 
Theo Schlossnagle
Principal Consultant
OmniTI Computer Consulting, Inc. -- http://www.omniti.com/
Phone:  +1 410 872 4910 x201     Fax:  +1 410 872 4911
1024D/82844984/95FD 30F1 489E 4613 F22E  491A 7E88 364C 8284 4984
2047R/33131B65/71 F7 95 64 49 76 5D BA  3D 90 B9 9F BE 27 24 E7