Sem mais atualizações, agora estou com 30. Eu suspeito que eles estão falhando por timeout, exceto que minha conta de teste recebeu o resumo semanal (atrasado), e presumo que isso esteja relacionado. Não tenho certeza de onde procurar nos logs para saber se algum deles está realmente desistindo.
Eles parecem falhar na maioria das vezes, mas ocasionalmente funcionam, o que definitivamente cheira a uma condição de corrida em algum lugar.
Meus backtraces parecem os mesmos que @RBoy e @md-misko viram, mas aqui está o backtrace completo, não apenas o truncado do botão "Copiar":
activerecord-7.0.3/lib/active_record/validations.rb:80:in `raise_validation_error'
activerecord-7.0.3/lib/active_record/validations.rb:53:in `save!'
activerecord-7.0.3/lib/active_record/transactions.rb:302:in `block in save!'
activerecord-7.0.3/lib/active_record/transactions.rb:354:in `block in with_transaction_returning_status'
activerecord-7.0.3/lib/active_record/connection_adapters/abstract/database_statements.rb:314:in `transaction'
activerecord-7.0.3/lib/active_record/transactions.rb:350:in `with_transaction_returning_status'
activerecord-7.0.3/lib/active_record/transactions.rb:302:in `save!'
activerecord-7.0.3/lib/active_record/suppressor.rb:54:in `save!'
activerecord-7.0.3/lib/active_record/persistence.rb:55:in `create!'
activerecord-7.0.3/lib/active_record/relation.rb:869:in `_create!'
activerecord-7.0.3/lib/active_record/relation.rb:115:in `block in create!'
activerecord-7.0.3/lib/active_record/relation.rb:880:in `_scoping'
activerecord-7.0.3/lib/active_record/relation.rb:428:in `scoping'
activerecord-7.0.3/lib/active_record/relation.rb:115:in `create!'
activerecord-7.0.3/lib/active_record/relation.rb:219:in `block in create_or_find_by!'
activerecord-7.0.3/lib/active_record/connection_adapters/abstract/transaction.rb:319:in `block in within_new_transaction'
activesupport-7.0.3/lib/active_support/concurrency/load_interlock_aware_monitor.rb:25:in `handle_interrupt'
activesupport-7.0.3/lib/active_support/concurrency/load_interlock_aware_monitor.rb:25:in `block in synchronize'
activesupport-7.0.3/lib/active_support/concurrency/load_interlock_aware_monitor.rb:21:in `handle_interrupt'
activesupport-7.0.3/lib/active_support/concurrency/load_interlock_aware_monitor.rb:21:in `synchronize'
activerecord-7.0.3/lib/active_record/connection_adapters/abstract/transaction.rb:317:in `within_new_transaction'
activerecord-7.0.3/lib/active_record/connection_adapters/abstract/database_statements.rb:316:in `transaction'
activerecord-7.0.3/lib/active_record/transactions.rb:209:in `transaction'
activerecord-7.0.3/lib/active_record/relation/delegation.rb:67:in `block in transaction'
activerecord-7.0.3/lib/active_record/relation.rb:880:in `_scoping'
activerecord-7.0.3/lib/active_record/relation.rb:428:in `scoping'
activerecord-7.0.3/lib/active_record/relation/delegation.rb:67:in `transaction'
activerecord-7.0.3/lib/active_record/relation.rb:219:in `create_or_find_by!'
activerecord-7.0.3/lib/active_record/querying.rb:22:in `create_or_find_by!'
/var/www/discourse/lib/email/sender.rb:498:in `get_reply_key'
/var/www/discourse/lib/email/sender.rb:105:in `send'
/var/www/discourse/app/jobs/regular/user_email.rb:83:in `send_user_email'
/var/www/discourse/app/jobs/regular/user_email.rb:38:in `execute'
/var/www/discourse/app/jobs/base.rb:232:in `block (2 levels) in perform'
/var/www/discourse/lib/rails_multisite/connection_management.rb:80:in `with_connection'
/var/www/discourse/app/jobs/base.rb:221:in `block in perform'
/var/www/discourse/app/jobs/base.rb:217:in `each'
/var/www/discourse/app/jobs/base.rb:217:in `perform'
sidekiq-6.4.2/lib/sidekiq/processor.rb:196:in `execute_job'
sidekiq-6.4.2/lib/sidekiq/processor.rb:164:in `block (2 levels) in process'
sidekiq-6.4.2/lib/sidekiq/middleware/chain.rb:138:in `block in invoke'
/var/www/discourse/lib/sidekiq/pausable.rb:138:in `call'
sidekiq-6.4.2/lib/sidekiq/middleware/chain.rb:140:in `block in invoke'
sidekiq-6.4.2/lib/sidekiq/middleware/chain.rb:143:in `invoke'
sidekiq-6.4.2/lib/sidekiq/processor.rb:163:in `block in process'
sidekiq-6.4.2/lib/sidekiq/processor.rb:136:in `block (6 levels) in dispatch'
sidekiq-6.4.2/lib/sidekiq/job_retry.rb:114:in `local'
sidekiq-6.4.2/lib/sidekiq/processor.rb:135:in `block (5 levels) in dispatch'
sidekiq-6.4.2/lib/sidekiq.rb:40:in `block in <module:Sidekiq>'
sidekiq-6.4.2/lib/sidekiq/processor.rb:131:in `block (4 levels) in dispatch'
sidekiq-6.4.2/lib/sidekiq/processor.rb:257:in `stats'
sidekiq-6.4.2/lib/sidekiq/processor.rb:126:in `block (3 levels) in dispatch'
sidekiq-6.4.2/lib/sidekiq/job_logger.rb:13:in `call'
sidekiq-6.4.2/lib/sidekiq/processor.rb:125:in `block (2 levels) in dispatch'
sidekiq-6.4.2/lib/sidekiq/job_retry.rb:81:in `global'
sidekiq-6.4.2/lib/sidekiq/processor.rb:124:in `block in dispatch'
sidekiq-6.4.2/lib/sidekiq/job_logger.rb:39:in `prepare'
sidekiq-6.4.2/lib/sidekiq/processor.rb:123:in `dispatch'
sidekiq-6.4.2/lib/sidekiq/processor.rb:162:in `process'
sidekiq-6.4.2/lib/sidekiq/processor.rb:78:in `process_one'
sidekiq-6.4.2/lib/sidekiq/processor.rb:68:in `run'
sidekiq-6.4.2/lib/sidekiq/util.rb:56:in `watchdog'
sidekiq-6.4.2/lib/sidekiq/util.rb:65:in `block in safe_thread'
Há alguma outra informação que eu possa fornecer para ajudar a depurar isso?