Perl - recursive looping and resource use

I'm developing a system where threads update a database table of URLs, post data, and match string text. I think it's impractical for each thread to open the socket and process its data before sending the waiting client its reply, so the idea is to use a persistent background process to check the table every half minute or so and serve the requests independent of the client's timeout.

Could anyone give me some information on the program structure I would use to make this possible with Perl or PHP?