Support for Deployment of Multiple RQ Workers

[tyler-8]

It's possible, particularly now with plugins, to have a need for multiple rq-workers in the environment to process all the background tasks simultaneously. The default one-worker deployment could fall behind if multiple reports, scripts, and other tasks are queued at the same time. Plugins can introduce even more complex workflows that may take longer to run.

The good news is rq supports deploying multiple workers quite easily and without making any code changes to NetBox itself. The systemd method of doing so is documented in the official docs.

to start workers by invoking systemctl start rqworker@1.service, systemctl start rqworker@2.service from the terminal.

You can also reload all the workers by invoking systemctl reload rqworker@*.

I'm imagining a simple setting like netbox_rqworker_count = 1 as the default. Users could change it to 4, which would start & enable rqworker@1, rqworker@2, rqworker@3, rqworker@4.

[lae]

implemented in #161