Question: We use Apache 2.2 to host SVN repository on a Windows 2003 machine.

Works fine except that over a couple of weeks the `httpd` process inflates and starts consuming something like 1.5 gigabytes of virtual memory. All operations with the repository become very slow.

What to tweak to prevent `httpd` from cosuming so many resources?

Answer: 
APR can [slowly leak memory](http://old.nabble.com/apr-pools---memory-leaks-td19766375.html) because of the way APR pools fragment available RAM over time. If you can configure the max requests per child limit in Apache lower so the tasks will restart sooner that should mitigate the problem to an extent. The [MaxMemFree](http://httpd.apache.org/docs/current/mod/mpm_common.html#maxmemfree) directive may also be helpful, but be warned that the mailing list post suggests it doesn't work as advertised.
I use VisualSVN Server, which is a packaged Apache+SVN system and it doesn't use anywhere near this amount of RAM. I've got 12Mb virtual use right now.

However - when committing you will see the memory use rise, when the files have been committed it should drop right down again.

I'd check the access use - make sure there's no extra processes running wild in there. use ProcessExplorer from sysinternals site to see what's happening inside it. Basically, high memory use for SVN+Apache is not a normal problem.