Topic: two httpd processes starting up

[twelvenine]

i've just installed apache 2.4 on a winxp machine. it works, but when i start httpd, two httpd.exe processes start up according to the task manager. in my experience only one daemon is needed, in fact i can kill one of them and the server will still work. are there supposed to be two httpd processes or is something wrong?

[tdonovan]

I expect you mean Apache 2.2.4 - Apache 2.4 is probably still a few years in the future.

Yes, it is correct to have two httpd processes on Windows.

The first httpd process (...call it A...) checks the configuration, then starts the second httpd process (...call it B...).

B serves all the web requests.

After a few requests, B always shows greater memory use than A in Task Manager - so that's how you can tell them apart.

While Apache is running, A just monitors B.
If B dissappears (because of a failure), A starts a new B to continue serving requests.
The only other job for A is to shutdown B when you intentionally stop Apache.

The memory use shown in Task Manager for these two processes can be misleading because much of this memory is shared between the two processes.
For example: if your two httpd processes show 21mb and 13mb respectively, you might notice that your free memory only decreased by 24mb total when you started up Apache. This is because approx 10mb of this memory is common to both processes, so this scheme is not as inefficient as it looks in Task Manager.

-tom-

[twelvenine]

yeah, i meant 2.2.4. thanks

[Jorge]