What happens to beanstalkd queue when system reboots?

I need to understand what happens to beanstalkd queue when system reboots, as I read that it is a in-memory queue, does it mean when we reboot our server the queue jobs yet to be processed just disappears on a reboot, or does beanstalkd persists these queues somewhere to continue from the point where it left before the reboot?

P.S. As I am not sure of this I am thinking of moving the queue to Amazon SQS.

via Chebli Mohamed