ruby - Upgrade to Rails 5 - Deadlock happening for Sidekiq Workers -

i upgraded rails version 4.2.5.2 5.0.0. current sidekiq version 4.2.10

i have 2 models participation has many engagements.

for each engagement, have different instances of sidekiq worker running in parallel. , trying update same parent participation.

participation = @engagement.participation participation.update_attributes(         likes_count: engagement_metrics_for_participation.likes,         comments_count: engagement_metrics_for_participation.comments,         shares_count: engagement_metrics_for_participation.shares,         total_engagement: engagement_metrics_for_participation.total_engagement,         total_impression: engagement_metrics_for_participation.total_impression       ) 

now workers getting deadlock , running forever. tried http://api.rubyonrails.org/classes/activerecord/locking/pessimistic.html

and updated code

participation = @engagement.participation participation.with_lock    participation.likes_count = engagement_metrics_for_participation.likes   participation.comments_count = engagement_metrics_for_participation.comments   participation.shares_count = engagement_metrics_for_participation.shares   participation.total_engagement =   engagement_metrics_for_participation.total_engagement   participation.total_impression = engagement_metrics_for_participation.total_impression   participation.save end 

but still facing same issue. need solve issue.

first of should consider upgrading rails 5.0.2(latest when posting answer), since 5.0.0 not called stable , lot of bug fixes came after release.

secondly, since model code has not been shared can tell there in model thats causing updation fail, maybe validation errors, callback errors, etc.

a workaround suggest is, if don't care callbacks or validations particular method use update_columns instead of update_attributes skip model validations , wont trigger callbacks.