Re: [mod-security-users] Performance using ModSecurity with Apache 1.3.x

[Ivan R. <iv...@we...>]

K. C. Li wrote:
>
>>  Is that something that happened to you once, or is it something that
>>  happens every time you turn ModSecurity on? Also, which version of
> 
> We switched it on twice. The first time the high CPU usage occurred a few
> hours into the running. The second time the high CPU usage occurred about
> a day later. But when it occurs, Apache would effectively hang until
> restarted.
>
> ...
>
> The Apache server is quite busy so would probably produce a large amount
> of strace or debugging information. I'll have a read and see what are
> practical to do. Thanks.

  In my experience symptoms like the ones you reported occur
  when the web server experiences very high load (with or without
  ModSecurity). Since running ModSecurity requires additional resources
  it may be that it's what tipped the system over the edge so to speak.

-- 
Ivan Ristic
Apache Security (O'Reilly) - http://www.apachesecurity.net
Open source web application firewall - http://www.modsecurity.org