SQLite Busy Exceptions not being treated as cache misses

[Th3-M4jor]

We're experimenting with using SolidCache backed by SQLite in production and found that SolidCache::Store::Failsafe does not include SQLite::Busy exceptions as a possible transient error that would be treated is if it were a cache miss.

Since this is something that could still theoretically occur with sharding and a reasonable busy timeout on SQLite configured, should this be added to the list of possible transient ActiveRecord errors?

[djmb]

Oh interesting. I would expect the SQlite::BusyExceptions to be wrapped up as ActiveRecord::StatementTimeout, which we do rescue - see here.

Sounds like this is not working though - do you know why?

[Th3-M4jor]

I'm actually seeing it be wrapped as a ActiveRecord::StatementInvalid when it happens.

I added the below code to a Rails initializer and it seems to solve the issue for us:

module PatchSolidCacheFailSafe
  private

  def failsafe(method, returning: nil)
    super
  rescue ActiveRecord::StatementInvalid => e
    raise e unless e.cause.is_a?(SQLite3::BusyException)

    Rails.logger.warn("Caught SQLite3::BusyException in SolidCache::Store::FailSafe. Treating as cache miss.")

    returning
  end
end

SolidCache::Store::Failsafe.prepend(PatchSolidCacheFailSafe)

Note: This is with Rails 7.2.2.1

[Th3-M4jor]

Dug a little further and it seems that it's because 7-2-stable does not wrap SQLite3::BusyException as an ActiveRecord::StatementTimeout so the catch all in the abstract adapter will convert it to a StatementInvalid