Bug #1842

spawn-fcgi.c - maximum child_count

Added by GeorgH over 11 years ago. Updated over 11 years ago.

Target version:


I wanted to take some performance tests under load with the number of fastcgi processes which i created via a script for spawn-fcgi. I found the maximum of 256 child processes when trying 300 childs. I think it's good to have some hardcoded limit, but this is far to low. I would suggest a count of 2048 or even 4096 as maximum.

--- spawn-fcgi.c        2008-12-10 14:30:04.178486414 +0100
+++    2008-12-10 14:31:04.405658960 +0100
@@ -52,8 +52,8 @@
                child_count = 5;

-       if (child_count > 256) {
-               child_count = 256;
+       if (child_count > 2048) {
+               child_count = 2048;


Updated by stbuehler over 11 years ago

  • Status changed from New to Invalid

This is obviously on purpose. If you don't like the limit, change it for yourself.

If we do set a limit, it should be sane one, and more than 256 child processes is insane.


Updated by GeorgH over 11 years ago

Why should 256 be a more sane limit then 257, 258, 1024 oder 2048?


Updated by Olaf-van-der-Spek over 11 years ago

GeorgH wrote:

Why should 256 be a more sane limit then 257, 258, 1024 oder 2048?

I think you should tell why it should be higher. ;)


Updated by GeorgH over 11 years ago

It should be higher to give the user (i.e. me) the freedom to test different settings in an environment under high load.

In the meantime, I did my performance tests with my own patches (which won't go into our production system with high probability), and it won't matter much to me, if this gets into any version. I also found out about the undocumented -F switch which will also allow to spawn multiple instances with 256 prozesses.

But I think it would be really great to document this limit somewhere else than in the sourcecode.

Thank you for your time and have nice holidays!

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