Some basic questions about 'delayed_job'

Question

I'm trying delayed_job now, and have some questions.

From the http://github.com/collectiveidea/delayed_job page, I can see some information:

Workers can be running on any computer, as long as they have access to the database and their clock is in sync. Keep in mind that each worker will check the database at least every 5 seconds.

1. When I invoke rake jobs:work once, it will create ONE worker, right?

2. When a worker checks the database, it will read ALL new and failed tasks EACH TIME, and run them?

3. it says a worker will check the database every 5 seconds, can I make it 2 seconds?

4. When I create a worker(rake jobs:work), there are already 10 tasks in the database, and each will take 3s. How many processes will DelayedJob create? And how many seconds need in total?

Answer 1

1. yes
2. yes
3. Delayed::Worker.sleep_delay = 2
4. 1 worker will work on each task in turn, passing or failing it before going onto the next. 30 seconds total + however long 9 sleep delays are for the total time (45 sec. by default). I'm not sure how to answer your question on processes. 1 worker is created, which is a process. Zero or more other processes may be created, depending on what the job to run is.