how can I tell Apache to start more than 2 instances of it? On Unix you can do it by changing the httpd.conf file. On Windows I heard that there has to be a registry setting. But which one?
After reading the Apache documentation it seems that Apache on Windows is multi-threaded, whereas Apache on UNIX is not.
This is why there are many httpd processes running on UNIX (one per request), but just two on Windows (the parent process delegates to its one and only child, which spawns a different thread for each concurrent request).
To set the number of concurrent requests you want the child process to handle (equivalent to the number of processes on UNIX), you need to set the following parameter:
If you are using Apache 2.0.x, however, you do have the option to choose an alternative MPM (Multi-processing-module), that allows you to spawn processes instead of threads (although the default is as above).
This has to be done via a preprocessor directive at compilation time.
Hope this helps!