Topic: mod_fastcgi process fails apparently randomly

[ted.byers]

About 4% of the time, my FastCGI script fails. 7 out of 175 requests to it within the space of about 3 minutes fail.

In my error logs, I see many failed FastCGI processes with error messages of either with "terminated with exit with status '3'" or with "terminated with exit with status '25'". I also see messages in my error logs related to dynamicMaxClassProcs being reached. But only some of these can be related to the failed requests. I see virtually nothing in either the output my client script gets or in the error logs as to why this happens or anything specific to my code.

How does one debug and correct this sort of problem so that it does not happen again? Where is there detailed documentation of how to deal with debugging FastCGI scripts in general (I am tempted, also, to start writing FastCGI scripts in C++ (as I have C++ development tools - and I just need to source a library that I can link my C++ to, as well as learn how to deploy such a binary, but that is another matter entirely).

I see the documentation of the configurable parameters for mod_fastcgi, but I have yet to find good documentation on what values to use for each of these, why, and what combination(s) of such values will provide the greatest reliability and performance.

I am pleased with what I have seen so far, with requests being handled in less than 2 seconds (I suspect it would be even faster if it did not have to access web services on the other side fo the planet), where the CGI script it replaced took over 20 seconds, but I wonder what will happen with multiple, high frequency, requests being made to it. Is there anyone who can provide guidance on that matter?

I guess, this is a plea for two things. 1) an explanation and solution for my immediate problem, related to having 100% of my requests to my FastCGI process being successful, instead of only 96%, and 2) a series of links to resources that I can use to become more independant on figuring out how best to debug FastCGI processes, and solve whatever problems I see arising.

Thanks

Ted

[James Blond]

You might increase the dynamicMaxClassProcs setting. See http://www.fastcgi.com/mod_fastcgi/docs/mod_fastcgi.html

I think you need to increase

-processes
-maxClassProcesses
-maxProcesses