I am hosting a public heavy CPU web service, and I would like to configure Apache2 to only allow 1 simultaneous connection per IP address to the location at hand, to prevent single clients from using too much resources.
Is there a neat apache2 solution to do this? I have looked into mod_bw but this does not seem to do the trick (the MaxConnections only applies for all users, not per IP). There also is a module called apache2-mod-limitipconn, but this one has no precompiled packages and I think is longer maintained as the website is dead. I would prefer something that I can include as a formal dependency in Ubuntu.
Best Answer
From my experience it's a little more complicated than just limiting "one connection per IP" I'm afraid (isn't it always :-)).
There were however other configurable parameters such as "MinSpareServers, MaxSpareServers and StartServers" (I'm not sure if these still exist but they were certainly in Apache 2.0).
Also apparently compressing the output can improve bandwidth needs and speed up response time by up to 75% with "mod_deflate" if that helps.
"mod_bandwidth" may offer some assistance rather than trying to limit a single connection and is probably the route I'd go down after looking at compression.
Or if you can write C then you could create a module yourself to count connections per IP.
The thing to watch to out for is what happens when an IP has been served a single connection. Let's just say that usually it's not a pretty sight ! You can drop to a "Server Busy" page or similar but I'd go down the route of optimising your Server so it's a good as it can be than frustrating visitors.