I was experimenting with threads in Perl. And Apache/mod_perl seemed to be an overkill for such a simple request/response script - that's why I tried to implement it purely in Perl. Of course, the main problem is DB requests. Though, apache/mod_perl takes a tremendous amount of memory. Anyway, I kept on using apache/mod_perl and got rid of DB requests at all. I stopped using mysql to keep my data and switched to memcachedb (not memcache but memcachedb). Still have this problem with memory leaks when using threads in perl. Lucky me, I don't experiment with it anymore. Thank you!