The Zenaton scheduler allows us to create schedules to run tasks and workflows on a recurrent basis.
Normally we would immediately dispatch a workflow or a task but we can also create a schedule so that the workflow or task is automatically dispatched at defined occurrences.
This is useful for processes that you would normally run using cron jobs, for example:
- generate daily / weekly / monthly reports
- update cached data on a regular basis
- cleanup a database every week
- launch a website scraping workflow every night
The Zenaton scheduler provides a straightforward way to launch recurrent tasks and workflows by writing it into our code. The scheduler can provide an added level of dependability when combined with other Zenaton features such as automatic retry and alerting.
# Creating Schedules
# Managing Schedules
delete any created schedules on the Schedules tab on your dashboard.
When a schedule is paused, future instances of the task or workflow will not be dispatched until the schedule has been resumed.
When a schedule has been deleted, no new instances of the task or workflow will be dispatched and the schedule will disapear on your dashboard. If we want to schedule your task or workflow afterward, we would need to create a new schedule.
The scheduler will dispatch tasks or workflows even if the previous execution isn’t completed.
Automatic Retry And Scheduling
Automatic-retry can lead to overlaps, we should setup our retry policy according to the schedule occurence to avoid that.
# Cron Format
When scheduling, we need to pass a cron string. Zenaton uses the following cron format to schedule tasks and workflows:
* * * * * * | | | | | | | | | | | +-- Year range: 1970-2099 wildcards: , - * / | | | | +---- Day of the Week range: 0-6 or SUN-SAT wildcards: , - * L # | | | +------ Month of the Year range: 1-12 or JAN-DEC wildcards: , - * / | | +-------- Day of the Month range: 1-31 wildcards: , - * / L W | +---------- Hour range: 0-23 wildcards: , - * / +------------ Minute range: 0-59 wildcards: , - * / Supported alias are: - @minutely run once a minute - @hourly run once an hour - @daily run once a day - @midnight run once a day, same as @daily - @monthly run once a month - @weekly run once a week - @yearly run once a year - @annually run once a year, same as @yearly
All schedules use UTC time zone and the minimum precision for schedules is 1 minute.
View cron expression reference for more informations.
We can also use crontab guru to help you build your cron expressions.