### Complete Description of Issue Sequel Version: 4.49.0
We've had a read replica (configured via the db `:servers` option) for a long time, but recently we added a second additional server (in total 3) and have started seeing a large increase in `ThreadError: deadlock;` issues. We're not entirely sure why - and digging into it now, but figured we'd post in here in case it was immediately clear to anyone else. It's possible connections to this newest database are slightly slower since it's not in the AWS network as is the rest of our infrastructure. The errors predominantly happen on queries to the replica or Citus, but sometimes also happen in large transactions on our primary node. ### Full Backtrace of Exception (if any) ``` ThreadError: deadlock; recursive locking - 14 non-project frames 1 File "/usr/local/bundle/gems/sequel-4.49.0/lib/sequel/connection_pool/threaded.rb" line 282 in synchronize 2 File "/usr/local/bundle/gems/sequel-4.49.0/lib/sequel/connection_pool/threaded.rb" line 282 in sync 3 File "/usr/local/bundle/gems/sequel-4.49.0/lib/sequel/extensions/connection_validator.rb" line 88 in disconnect_connection 4 File "/usr/local/bundle/gems/sequel-4.49.0/lib/sequel/connection_pool/sharded_threaded.rb" line 353 in remove 5 File "/usr/local/bundle/gems/sequel-4.49.0/lib/sequel/connection_pool/sharded_threaded.rb" line 336 in release 6 File "/usr/local/bundle/gems/sequel-4.49.0/lib/sequel/connection_pool/sharded_threaded.rb" line 138 in block in hold 7 File "/usr/local/bundle/gems/sequel-4.49.0/lib/sequel/connection_pool/threaded.rb" line 282 in block in sync 8 File "/usr/local/bundle/gems/sequel-4.49.0/lib/sequel/connection_pool/threaded.rb" line 282 in synchronize 9 File "/usr/local/bundle/gems/sequel-4.49.0/lib/sequel/connection_pool/threaded.rb" line 282 in sync 10 File "/usr/local/bundle/gems/sequel-4.49.0/lib/sequel/connection_pool/sharded_threaded.rb" line 138 in ensure in hold 11 File "/usr/local/bundle/gems/sequel-4.49.0/lib/sequel/connection_pool/sharded_threaded.rb" line 138 in hold 12 File "/usr/local/bundle/gems/sequel-4.49.0/lib/sequel/database/connecting.rb" line 301 in synchronize 13 File "/usr/local/bundle/gems/sequel-4.49.0/lib/sequel/adapters/postgres.rb" line 327 in execute 14 File "/usr/local/bundle/gems/sequel-4.49.0/lib/sequel/dataset/actions.rb" line 1135 in execute ``` Thanks for the great product Jeremy, we're big Sequel fans! -- You received this message because you are subscribed to the Google Groups "sequel-talk" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at https://groups.google.com/group/sequel-talk. For more options, visit https://groups.google.com/d/optout.
