How do you differentiate background and worker processes? I’m currently running VMs for background processes processing pub sub topics. Is that not something that could go on cloud run?
When an instance isn't handling a request it either gets killed almost immediately, or if even if you have min idle instances configured, its CPU get's throttled to nothing. So you can't have goroutines or some such doing anything outside of the request context. It's my team's one gripe with Cloud Run. It'd be great to have an option for long-lived instances.
Like I said, even if the instance is "alive", if it's not currently handling a request it's CPU is throttled to nothing so you can't trust any background process will finish its work.
You can use an HTTP push subscription to an IAM protected Cloud Run service.