Oban Periodic (CRON) Job multi node question

Questions / Help
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1

Hey,

I have been using quantum for cron kind of jobs in a project, and when 2 instances of this project were running the jobs were running 2 which is not surprising. I know this could be solved(highlander etc.) but I have been eyeing with Oban for a while.

This is a quote from their readme:

Periodic (CRON) Jobs — Automatically enqueue jobs on a cron-like schedule. Duplicate jobs are never enqueued, no matter how many nodes you’re running.

Does this mean that if I have 2 instances of the same project running while connected to 1 database I would not see these jobs duplicated anymore without doing any additional work(other than setting up Oban and migrating the jobs)?

Thank you

2

Yes. That’s exactly what it means :slightly_smiling_face:

2 Likes
3

Hi,

What are the criteria for duplicates in case of the Oban.Plugins.Cron? Would the following crontab entries be handled as duplicates or two distinct jobs?

{"0 * * * *", MyApp.HourlyWorker, args: %{custom: "arg"}},

{"0 * * * *", MyApp.HourlyWorker, args: %{custom: "some other value"}},

My use case would be to change my worker’s arguments with a new release.

Thank you in advance.

4

That’s a perfectly fine change. Those would be different jobs because the args are different.

No unique checks would apply anyhow, because it’s inserting those jobs an hour apart and the default unique period is only for 59 seconds.