sql-queue-workers

sql-queue-workers

Two worker clients over one SQLite file, each serving its own queue, the way an app deploys separate worker processes per queue on the SQL driver. Everything that coordinates them is a row in the database: a queue paused from one client holds the other, and a failed run is listed, retried from its failed step and forgotten from whichever client the operator happens to use.

cd examples
go run ./sql-queue-workers

email while mail is paused: queued
email after resume: succeeded, on queue mail
failed: build-report at step render on queue default
after retry: gather ran 1 time(s), render 2
after delete: not found
mail worker drained: true

The SQLite file lives in a temporary directory removed at exit.

The code

• send-email runs on the mail queue, build-report on the default one. The mail client is built with sqlstore.WithQueues(workflow.QueueConfig{Name: "mail", Workers: 1}), the reports client with the default queue only, so each claims only its own queue's steps.
• Pause(workflow.PauseQueue("mail")) on the reports client holds the email on the mail client; Resume releases it.
• Runs filters failed runs by label, Retry re-runs the failed run from render (the gather step keeps its output and does not run again), and Delete forgets it.
• Drain stops the mail client gracefully; Done closes once it has stopped.

main_test.go runs the same program and checks every line it prints. The guide docs/drivers/sqlstore.md copies its code from the regions marked snippet:.