Topic: mod_fcgi is NOT a replacement for mod_fastcgi

[Ra]

After perusing the site here, I noticed some confusion about fcgid and fastcgi. As a long time user (10 years) of mod_fastcgi on both Windows and Linux, often running hundreds of virtual host fastcgi servers behind one instance of Apache 2, I know that FCGID cannot always replace mod_fastcgi.

Two misconceptions about fcgid continue to be put forth.

The following two statements are FALSE:

(1) mod_fcgid and mod_fastcgi "do the same thing" [False]
(2) mod_fastcgi has not been developed in some time, therefore mod_fcgid is somehow "better." [False]

FIRST:
mod_fcgid and mod_fastcgi don't "do the same thing." They both support the published "FastCGI" protocol, but how they control their FastCGI servers differs considerably. mod_fcgid quickly eliminates FastCGI servers and starts new ones. This is a problem and actually goes against the original intent of the FastCGI protocol. The FastCGI protocol was designed to allow long-running FastCGI server processes to quickly process requests without the overhead of starting a new process for every request (as in the original CGI protocol). Our apps are similar to PHP in that they can take multiple simultaneously requests from apache and internally spawn multiple threads to handle the requests. This scenario is not possible for us with mod_fcgid because of the great number of processes created/destroyed. (I'm not talking about anything involving mod_php.)

This bug report discussion is a good description of the problem and differences between the modules mod_fcgid and mod_fastcgi:
http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=504132#25

SECOND:
True, the level of development activity is quite low on the mod_fastcgi project. FastCGI is a small lightweight protocol and the implementation doesn't require much maintenance. The two latest bug fixes I know of include the mod_fastcgi "deflate" problem and the mod_fastcgi problem "does not retry select() after an interrupted system call (linux only)." To my knowledge both of these have been fixed. In other words, mod_FastCGI is a stable project, therefore, not much development is required.

So if you're running mod_fcgid and having performance problems, you might want to check and see if mod_fcgid is starting/stopping too many of your FastCGI servers.

I would also like to encourage the maintenance of a mod_fastcgi build for the apachelounge.com version of Apache 2 because mod_fastcgi is required for true high-volume/high-performance websites.

I've depended on mod_fastcgi for years and I've tried and found that mod_fcgid cannot and will not work for me in it's current implementation.

I would like to try the apachelounge images, but until I build or obtain mod_fastcgi for it, we'll be sticking with the apache.org images.

Thanks for reading,
Ra Lemley

[Smitty]

Ra,

Thanks for the detailed explanation on the differences between the two.

It would be great if AL could host the mod_fastcgi as well. I'd love to test it vs. mod_fcgid.

[Kanashii]

[jimski]