How do I clear stuck/stale Resque workers?

Question

As you can see from the attached image, I\'ve got a couple of workers that seem to be stuck. Those processes shouldn\'t take longer than a couple of seconds.

Answer 1

You probably have the resque gem installed, so you can open the console and get current workers

Resque.workers

It returns a list of workers

#=> [#<Worker infusion.local:40194-0:JAVA_DYNAMIC_QUEUES,index_migrator,converter,extractor>]

pick the worker and prune_dead_workers, for example the first one

Resque.workers.first.prune_dead_workers

Answer 2

In your console:

queue_name = "process_numbers"
Resque.redis.del "queue:#{queue_name}"

Otherwise you can try to fake them as being done to remove them, with:

Resque::Worker.working.each {|w| w.done_working}

EDIT

A lot of people have been upvoting this answer and I feel that it's important that people try hagope's solution which unregisters workers off a queue, whereas the above code deletes queues. If you're happy to fake them, then cool.

Answer 3

I had stuck/stale resque workers here too, or should I say 'jobs', because the worker is actually still there and running fine, it's the forked process that is stuck.

I chose the brutal solution of killing the forked process "Processing" since more than 5min, via a bash script, then the worker just spawn the next in queue, and everything keeps on going

have a look at my script here: https://gist.github.com/jobwat/5712437

Answer 4

I just did:

% rails c production
irb(main):001:0>Resque.workers

Got the list of workers.

irb(main):002:0>Resque.remove_worker(Resque.workers[n].id)

... where n is the zero based index of the unwanted worker.

Answer 5

I've cleared them out from redis-cli directly. Luckily redistogo.com allows access from environments outside heroku. Get dead worker ID from the list. Mine was

55ba6f3b-9287-4f81-987a-4e8ae7f51210:2

Run this command in redis directly.

del "resque:worker:55ba6f3b-9287-4f81-987a-4e8ae7f51210:2:*"

You can monitor redis db to see what it's doing behind the scenes.

redis xxx.redistogo.com> MONITOR
OK
1380274567.540613 "MONITOR"
1380274568.345198 "incrby" "resque:stat:processed" "1"
1380274568.346898 "incrby" "resque:stat:processed:c65c8e2b-555a-4a57-aaa6-477b27d6452d:2:*" "1"
1380274568.346920 "del" "resque:worker:c65c8e2b-555a-4a57-aaa6-477b27d6452d:2:*"
1380274568.348803 "smembers" "resque:queues"

Second last line deletes the worker.

Answer 6

Started working on https://github.com/shaiguitar/resque_stuck_queue/ recently. It's not a solution to how to fix stuck workers but it addresses the issue of resque hanging/being stuck, so I figured it could be helpful for people on this thread. From README:

"If resque doesn't run jobs within a certain timeframe, it will trigger a pre-defined handler of your choice. You can use this to send an email, pager duty, add more resque workers, restart resque, send you a txt...whatever suits you."

Been used in production and works pretty well for me thus far.