Error "signal only works in main thread of the main interpreter" after a system failure

[tsunamilx]

Hi guys,

I am simulating a system failure: I setup a test server on AWS, ran a couple of tasks that take long time using RQ, then stop instance from AWS console, then restart it.

Now I get the error "signal only works in main thread of the main interpreter" and cannot get any queue information from RQ. I had to flush all from Redis in order to get RQ working again, but then I lost all queue information / task progression.

The error might not be directly from RQ, just want to know if there is any way to get rid of this error and get the queue data from RQ? Thanks.

The raw error:

ValueError: signal only works in main thread of the main interpreter
  File "rq/job.py", line 1428, in execute_failure_callback
    with death_penalty_class(self.failure_callback_timeout, JobTimeoutException, job_id=self.id):
  File "rq/timeouts.py", line 36, in __enter__
    self.setup_death_penalty()
  File "rq/timeouts.py", line 69, in setup_death_penalty
    signal.signal(signal.SIGALRM, self.handle_death_penalty)
  File "signal.py", line 56, in signal
    handler = _signal.signal(_enum_to_int(signalnum), _enum_to_int(handler))

[tsunamilx]

Edit: right after I posted this, the error is gone... now I can get the queue data, everything seems to be working. Can someone explain what's going on?