Sidekiq + Sidetiq recurrence every 2 hours?

Question

I can't exactly find how to set my recurrence rule to initiate the job every 2 hours. Currently I have my job to run at 3am every day (I think) using something like this in my Sidekiq worker class:

recurrence do
  daily.hour_of_day(3)
end

What's the best way of making this run every 2 hours or every hour? This uses the icecube gem underneath the hood, I believe.

Answer 1

Have you tried hourly(2)?

recurrence do
  hourly(2)
  # if you want to specify the exactly minute or minutes
  # `minute_of_hour(30, ...)`
  # hourly(2).minute_of_hour(30)
end

It is in the icecube's README, but I haven't tried it yet.

You could also do something like that:

recurrence do
  # set recurrence to [0, 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22]
  daily.hour_of_day(*(0..23).to_a.select { |hour_of_day| hour_of_day.even? })
end

But IMHO hourly(2) is the better choice.

Another option without Sidetiq is to add self.perform_in(2.hours) before ending the perform method.

def perform
   # ...
   self.class.perform_in(2.hours)
end

UPDATE:

https://github.com/tobiassvn/sidetiq/wiki/Known-Issues

Unfortunately, using ice_cube's interval methods is terribly slow on start-up (it tends to eat up 100% CPU for quite a while) and on every recurrence run. This is due to it calculating every possible occurrence since the schedule's start time.

So, it is better to use the more explicit way:

recurrence { hourly.minute_of_hour(0, 15, 30, 45) }

Answer 2

hourly(2) is bad idea even with Ruby 2.0.0 and above ?

The Sidetiq wiki says -

"Potential memory have been reported when Sidetiq is running under Ruby 1.9.3 . However, under Ruby 2.0.0+ this is not an issue."

Sorry if I misunderstood anything here, but we do use hourly as recurrence but with Ruby 2.0.0 and above, did not notice this issue on local or server. But ill check it thoroughly. Any more details aledalgrande and Pablo would help.