Rails ActiveRecord/Postgres single query timeout?

Question

I have a logging query (a simple INSERT ) that happens on every single request.

For this request only (the one that happens on every page load), I want to set the limit to 500ms in case the database is locked/slow/down it won't affect the site, where the site hangs while it waits to connect/write.

Is there a way I can specify a timeout somehow on a per-query basis that I can abort the LoggedRequest.create! if it's taking too long?

I don't want to set it in my config because I have many other queries that shouldn't have timeouts that low.

I'm using Postgres 11.7

I also don't know how I feel about setting a timeout for the entire session because I don't want that connection to be shared from the pool with other queries that can't have that timeout.

Answer 1

Rails 6 introduces event based triggers for notifications, logging etc that comes in very handy, provided you are using/can afford to migrate to Rails 6. Here'a useful post that demonstrates creating event based triggers for notifications/logging: https://pramodbshinde.wordpress.com/2020/03/20/custom-events-tracking-with-activesupportnotifications-and-audited/

If, for some reason, you cannot use Rails 6, perhaps this article might help you find some answers: https://evilmartians.com/chronicles/the-silence-of-the-ruby-exceptions-a-rails-postgresql-database-transaction-thriller

If I were you, I could also contemplate using AJAX with a fire-and-forget API request to server for logging/whatever that is not critical to normal functioning of the application.