Deadlocking in update_positions count query

[cmentch]

I have a larger database where I am using acts_as_list on various models. I have started seeing increased deadlocking on a specific count query. The stack dump revealed it was from the method "update_positions". This is being called from an after_update trigger on the model. Even if I am not updating the ordering column, this method is still firing off which seems unnecessary. Is there a need to trigger this even if the ordering column is not updated?

[brendon]

Hi @cmentch, Thanks for picking this up. I've committed a change to master that checks if the position has changed first before going through with the callback. It tests out well locally, and let's see if the CI passes. Can you have a go using master and see if you get the deadlocks still?

[brendon]

There was some trouble with Timecop. I think I've fixed it, so we'll see :)

[cmentch]

Thank you for the quick response. I have pointed this to master in my Gemfile. It looks like it is no longer performing the count query when the ordering column is not updated. Perfect! I won't be able to try this out in production yet. When do you formally publish a new version of the gem?

[brendon]

I'll just get @swanandp to take a quick look. @swanandp, I can't see any problems. The tests pass.

[brendon]

@cmentch, ping me back if we don't hear anything from @swanandp within a few days.

[swanandp]

@brendon 75ec5b9

Looks good. 👍

[brendon]

Roger. I'll release a new version @cmentch :)