Memory Usage

Hi, I am using Persistent Task Queue for the background worker class. When the backgroundrb server is started it consumes as much as a Rails instance consumes. Consider it consumes 300MB memory at the beginning, but gradually it goes upto 600MB. I am not getting why this worker class is consuming this huge memory. The thread pool size is 5. In the same worker class i am making a call for the add_periodic_timer twice for the two different methods.

Can anyone figure out what might be causing it?