Oban Periodic (CRON) Job multi node question

Yes. That’s exactly what it means

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.

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.

Thanks. Just to be sure I understand it correctly here’s the sequence I get out of this:

1. app starts with a single crontab entry with hourly worker args: %{custom: "arg"}
2. cron plugin adds a job instance with args: %{custom: "arg"} scheduled to run in an hour
3. app is shut down before the job ran
4. app starts with a single crontab entry but now with hourly worker args: %{custom: "some other value"}
5. cron plugin adds a job instance with args: %{custom: "some other value"} scheduled to run one hour from now
6. one hour after step 2 the first job (with args: %{custom: "arg"}) is executed, no new instance is added anymore
7. one hour after step 5 the second job (with args: %{custom: "some other value"}) is executed
8. cron plugin adds a job instance with args: %{custom: "some other value"} scheduled to run one hour from now

That’s not quite right.

Cron doesn’t schedule jobs to run later, it inserts them right at the time they’re supposed to run (at the top of the minute). Whichever args are set in your code when the plugin runs is what will be inserted.

Ah, makes sense. Thanks a lot for your time and this great project.