I have seen jobs that have successfully completed, but do not emit either of succeeded or failed. The problem seems more likely on jobs that finish quickly. It also may be influenced by the concurrency setting.

I would expect that any job that has had job.save() successfully resolve will eventually emit either succeeded or failed. However, we can create and save jobs which never emit either of those job-level events. We have observed this in Docker containers running under Docker for Mac and under Docker on Ubuntu on Digital Ocean droplets.

Here's a repo that builds images that reliably demonstrate the problem, although not deterministically.

https://github.com/hughsw/stress-beequeue#run-the-bee-queue-client

This underlying issue may be the same as reported here #78