How do you adjust the maximum number of concurrent connections for apache to accept? What is a good amount to be safe?

Thanks-

there is a 'maxclients' option in the config file, but by default it can't go over 256
if you want a higher value, you need to edit httpd.h and change the hard limit

On Apache 2 you can set the MaxClients (maximum number of server processes allowed to start).

Also you should consider having a generous MaxSpareThreads/MaxSpareServers. i.e. the maximum number of handlers waiting idly for a new connection to come in.

IIRC the limit on Apache1.3 was 255 connections (unless you recompiled apahce). I'm not sure on Apache 2. Try it and see.

cPanel automatically adjust it to 260, no more. You can set it higher, and see what happens.

Keep MaxSpareServers to the possible minimum, 8 or 10, the same of max requests per child.

Well, I think that every server has its own individuality and requires special, even unique treatment. One have to be a good psycho-analyst to cope with those characters.:-)