Lot of Apache idle workers after an attack

[Olivier Bonvalet <olivier.bonvalet@xxxxxxxxxx>]

Hello,

I have a problem : after a small attack (DDoS), the AMD64 Apache2 nodes 
have a lots of idle workers :
  "29 requests currently being processed, 541 idle workers"

Some precisions :
- it's a LVS-TUN setup, with 6 nodes (3 i386 and 3 amd64)
- other apache2 servers which are not behind LVS haven't got this problem
- i386 servers behind LVS haven't this problem
- the number of idle workers don't decrease after some hours
- MinSpareServers is 30, and MaxSpareServers is 50
- a graceful correct the problem, but since this attacks are frequents 
since 24 hours, I'm searching to way to "correct" this
- the website on this cluster works fine, so it's not a "big problem"
- I use Apache 2.0.54, on Debian Sarge

Have you got any idea ?


I try this :
- switch to the backup LVS. Nothing change.
- reduce the "tcp_fin_timeout" to 3 seconds. It has decreased the number 
of "TIME_WAIT" connections, but Apache 2 don't change
Thanks in advance,
Olivier