Replace resque with solid queue

[ashwin47]

Replace Resque with Solid Queue as it is the recommended default for Rails.

I noticed an increase in memory usage after the switch. This is expected with Solid Queue's forking architecture. We can overcome this with async mode (rails/solid_queue#644), which runs everything as threads inside Puma instead, giving us lower memory usage than Resque.

Changes

• Replace resque + resque-pool gems with solid_queue
• Use async mode – runs workers as threads inside Puma instead of separate processes
• Add separate SQLite database for queue storage
• Remove workers process from Procfile (jobs run inside Puma)

We can wait until the async PR is merged before going ahead with this

cc @rosa

[rosa]

Hey @ashwin47, even if we switched Campfire to Solid Queue, I wouldn't set the async mode in any case. The fork mode is the recommended one and the default, as it's the only way you can use multiple CPUs. Running everything in the same process might use less memory, but it'll also be a significant downgrade in performance.

As for the migration from Resque to Solid Queue, I think this would be something to discuss with maintainers before even opening a PR 🤔

[ashwin47]

Thanks for the feedback @rosa! You're absolutely right about fork mode being the better default. I was too focused on keeping the memory under control because I have an instance running on a small VPS.

I've updated the PR to:

• Use fork mode as the default (via separate jobs process in Procfile)
• Switch to the official solid_queue gem instead of the async-mode fork
• Keep async mode as an opt-in option (SOLID_QUEUE_IN_PUMA=true) for
  memory-constrained environments

Regarding discussing with maintainers first — totally fair point. But i feel its time to switch to solid_queue as its the default.

Happy to close this if it's not something being considered, or continue iterating if there's interest.