Process only one job of a given type at a time across containers

Is there a way to process only one job of a given type at a time across containers?

We have a number of job types that we want to process across a handful of containers. It is important that we process the jobs of each type in the order they were added to the queue, so we want only one job from a given job type to be processed at any given time across all the containers. However, we also want to be able to scale horizontally, so while container A is processing one job type, container B can process jobs of another type.

We can use the second parameter on `queue.process` to control concurrency within a container. Is there a way we can control concurrency across containers?

The issue names queue.process and asks about cross-container concurrency; start by reading that API and the queue's Redis-backed worker behavior. Done would require a documented or implemented way to serialize jobs by type across containers while allowing different types to run in parallel.

Written by the indexing model from the issue text.