Intermittent CGI script errors. Need help to track down cause.

Hi,

I have an Apache web server running on a BSDI Unix box. Recently, I've started getting these intermittent errors associated with CGI programs.

The problem is most noticable in two separate CGI-based scripts, but they are affected simultaneously when the problem occurs: these are my UBB Bulletin Board and my CGI script for inserting banner ads onto my web pages.

When the problem occurs, anyone trying to post a message in the forum gets the 500 Server Error! page and all the web pages show the [an error occured while processing this directive] message where the banners are supposed to be. Interestingly, my web page header and footer are SSI (Server Side Include) files and they are unaffected when this problem is happening.

I used to have this problem a long time ago with just the banner ads, but I added more RAM to the server and changed the startup parameters for Apache to allow up to 600 child processes. That cleared things up back then. The recurrence of this problem started after my bsd core directory got damaged by a virus (actually a worm). The worm only damaged that directory and didn't touch any of my Apache files so I'm not sure if that had anything to do with it. Everything in the /bsd directory was restored from a backup.

I should mention that the server also has mod_perl running on it and this trips out on occasion. I just reboot the server when that happens and everything is okay with that.

The server isn't all that busy so I can't believe it's because the thing is getting overloaded. I'd like to run a TOP command when it's happening, but it usually only lasts for ten or fifteen seconds and then recitfies itself. But when it does happen, those ten or fifteen seconds seem like an eternity for folks trying to post on the forum.

I'm not a server expert by any stretch (mod_perl and the change to the Apache child processes were done for me by others), so any suggestions on where I might start looking for causes, or what sort of tests I could run, would be greatly appreciated.

--Douglas

It's relatively difficult to throw you a set of Directive values without getting more details about your Apache and other environments. So the best way to solve this kind of problem is to do some searching yourself. Start here -> http://httpd.apache.org/docs/misc/perf-tuning.html then go to google.com.

>> my web page header and footer are SSI (Server Side Include) files

Generally, it would save some load to your server without using SSI on every single page. Why not try mod_layout

>> I should mention that the server also has mod_perl running

mod_perl requires a little more complicated tuning in order to use it effectively. Start here -> http://perl.apache.org/tuning/
When mod_perl is installed or used frequently, you shouldn't set MaxRequestPerChild to be too high so the children can die off sooner rather than sucking your RAM for nothing.

freebsd,

As always, you are a seemingly endless source of extremely useful info. I've downloaded mod_layout and have started on the Apache tuning guide. I'll also see what I can do about lowering my MaxRequestsPerChild .

Thanks!