(For instance a common check in high frequency batch jobs is to prevent multiple scheduled batches from running concurrently when suddenly one batch takes much longer to process than expected and doesn't complete before cron has scheduled a next iteration. ) Where /15 specifies no matter whatever is Hour (H) run it at 15 every minutes. That approach, a check if the conditions are suitable at the start of the job before starting the actual work and exiting gracefully when not, can be, when done correctly, a very powerful solution that solves a whole range potential potential problems that CRON normally wouldn't be able to address. To run the job at a regular interval of 15 minutes you have to write it like below: /15 - Will run at every 15 minutes (may be at XX:01,XX:16,XX:31. Step values (like every five minutes) are accomplished by the / character: /5. You should then build additional logic into your job (or a shell script wrapper around the actual job) that checks if the conditions are right for the job to be run (and those condition can then be much more complex that just a check of the time) and when they are not, exit gracefully. Yes - you can specify the minuted value as 5, and leave the rest as wildcards: But wont that run every 5 minutes as opposed to 5 minutes after the hour Tim No. That is an intuitive solution that other admins can also easily read and understand.Īn other solution is to simply schedule your job to run much more frequently.

What you are currently doing, writing two different schedules that combined achieve a much more complex schedule than what native cron syntax would support is usually the best solution. Cron is at heart a very simple scheduler.

Cron job every 15 minutes