[ILUG] Hanging apache

[Niall O Broin]

I have a server which serves a number of domains. One of the domains  
can sometimes get very busy (to the extent of leading to a server  
load of 40+) so it was transferred to an IP of its own, with its own  
copy of apache running limited to a certain number of processes.

The problem is that sometimes, this apache hangs. Its processes are  
still there, but they won't serve any pages. Sending a HUP to the  
lead process doesn't help, and the only solution to the problem is to  
stop and restart the server.

There is no clue in neither the access nor error logs. The other  
server on the box, which is the same version of apache, never does this.

I realise that there's very little to go on here, but can anyone  
suggest what I can do next, or suggest any mechanisms by which apache  
processes can hang? I guess I need to strace a running process but of  
course, when this happens, I need to get the server going again  
quickly. The server version 1.3.33 which is of course ancient and  
indeed, the server will soon be retired, which will hopefully make  
the whole thing moot.

And another question, while I'm there - the new server will run  
apache 2.0 . Does it (or even 2.2) provide any mechanism for limiting  
the number of servers which are spawned for a given domain? It'd be  
useful to not have to run a separate server for that domain, and it'd  
be handy to not have to waste an IP address just for that one domain.




Niall