copied this to viewtopic.php?f=3&t=5638&p=32530#p32530
so it'd be a single thread...
I am thinking I am running into high loads due to apache spawning way too many children, that being said - what's the deal with rewrite rules in .htaccess?
mod_rewrite rules don't have anything to do with ASL (so there is no conflict). Poorly written rewrite rules can kill your system, they can cause loops, wasted cycles, etc. rewrite rules can be VERY cpu intensive.
If you disabled modsecurity and that helped your load, that sounds like you may:
1) be running low on memory -
2) if load without mod_security is already at 1+, then your CPU is overworked already. Whats the hardware on your system? It sounds like you may already be saturating your system.
3) If the system is virtualized, you actual CPU utilization may be limited (and in such a way that you cant see it) - this can have horrifying effects on performance
4) if you have modsec enabled before you installed ASL, you may have a very inefficient configuration - were you running modsec before you installed ASL?
5) Did you enable any RBL or URI modsec rules? These require a fast local DNS server, if you don't have that your load will suffer accordingly
6) recompiled modsecurity module - some products, like cpanel, may replace the optimized modsec module ASL installs with a non-optimized module. Are you using cpanel or a third parties modsec module?
7) are you using a compiled apache, or an optimized apache provided by your OS vendor? If the former, us your OS vendors apache build. Source builds are hard to get optimized correctly.
1 - definitely running low on memory
2 - runs a bit above 1 w/out mod_sec - you are right about that - system is over loaded...
3 - not virtualized - is a root server @ 1and1 here the specs:
dedicated single core root server @ 1and1 w/CentOS 5 with 1 gig ram, Parallels Plesk Panel 10.3.1 (64-bit)
CPU AuthenticAMD, AMD Athlon(tm) 64 Processor 3500+
Version Parallels Plesk Panel v10.3.1_build1013110726.09 os_CentOS 5
5 - dunno - will look at that...
6 - no mod_security before ASL
7 - it's using the apache that came with plesk 10.3.1: 2.2.3-53.el5.centos