Ask HN : Suggestions for Writing Background jobs

I need to implement a few background jobs, that run continuously in the background and do a lot of http calls to some API's to gather some data and store it in mysql. I would like your suggestions and comments on what will be the best way, architecture, language to use so that the system is scalable.

I will need it to be threaded so that i can pull data simultaneously.

What language should I use.

1) Ruby 2) Scala 3) Java 5) PHP

I know Ruby PHP and Java well.

Thanks