Well, that’s how exq with redis works. It uses backup queues to manage in-progress jobs. When exq performs a job, it takes the job request off the queue and places it into a “backup” queue with a node identifier that will process the job. If the job completes successfully it will remove it from the “backup” queue. If the node crashes for some reason it will remain in the “backup” queue. On start-up of the node, it will move any entries in the “backup” queue and move it back to the main queue, where it will be processed again. The issue is, that when we deploy we have a new instance running, but with the same node id. So it assumes that there has been a crash, removes it from the “backup” queue so the job is performed again, while the older node is still running the job which completes successfully. So, we end up processing job twice. And above I’ve described how we go about that. I think I am pretty happy with the solution we came up. Just wanted to see if that’s an idiomatic way to solve this.
