On Wed, Mar 01, 2006 at 10:08:19AM -0500, Eric Covener wrote: > > Hmmm... the docs explain both a "soft limit" and a "maximum limit", but > > doesn't describe the difference between the two. > > The soft/hard limits are a notion held in the underlying > ulimit/setrlimit facility. > > Unrpivileged users can manipulate their soft limit to control the > limits on how much CPU time, memory, or # of processes their programs > can use. The "hard" limit acts as a ceiling for what the OS will let > you adjust your soft limit to.
Also - an application can catch a signal when it reaches its soft limit (e.g. SIGXCPU when the soft limit for CPU time has been reached), but not when it reaches its hard limit. But these limits are per-child. Better, in my opinion, is to capture rusage information for each child, generate a log entry when each CGI terminates, and then use this to generate CGI stats showing (for example) the top 20 users of CPU time by CGI path or by virtual host. You can then penalise bad users appropriately. However Apache doesn't support this out-of-the-box as far as I know. I did it by modifying suexec to fork, run the child in a sub-process, and then capture this information when the child dies. Regards, Brian.
