Why does rails runner not reconnect to the database if it goes away?

Question

I'm running puma, sidekiq, and ruby-clock. ruby-clock is invoked with rails runner. If I do something like restart my database, puma and sidekiq will figure it out and reconnect. But ruby-clock does not. Why is this happening? Are puma and sidekiq somehow instantiating the database pool with a config which allows reconnection?

Answer 1

The answer is that rails runner does not run code within an executor or reloader. Doing so fixed the problem.

• https://github.com/jjb/ruby-clock/commit/cbe01a75260eb954a441d8d844c5c3ab1c5e8ac0
• https://guides.rubyonrails.org/threading_and_code_execution.html
• https://github.com/rails/rails/blob/main/railties/lib/rails/commands/runner/runner_command.rb