Max instances / overlapping executions

Thuan Nguyen

FastCron founder

You can allow from zero to 5 overlapping executions by adjusting the Max instances.

FastCron runs cronjobs at the scheduled times by default, regardless of ongoing executions. If a cronjob takes more time to run than its interval, it leads to overlapping executions.

Before, you could prevent cronjob executions from overlapping by enabling the Single instance feature.

Now, you can allow up to 5 overlapping executions by adjusting the Max instances: instances

The table below shows running executions when you allow up to 3 overlaps:

TimeRunning executionsEvents
41,2,34 is skipped
51,3,52 complete
63, 5, 61 is removed
73, 5, 67 is skipped
86, 83 and 5 complete
996 and 8 complete
  • When there are 3 running executions, new executions are skipped.
  • When one execution is complete, another execution starts running.
  • When you remove a running execution (visit the Running tab, delete a running execution), another execution starts running.

Please note that removing a running execution just deletes it from our database. The execution will continue to run until it’s complete or timed out.

API function cron_add and cron_edit update: single is deprecated, please use instances instead.

← Back to blog

Ready for better cronjobs?

See why 7,000+ website developers and their team use FastCron to run their cronjobs 12 million times a day.

Start 7-day free trial