This is a wrapper for cron jobs which implements common housekeeping tasks.
- Jitter
- Overlap protection
- Timeout
- Failure suppression
- Priority
If enabled cronwrap will delay for a random amount of time up to a specified maximum before starting the job. This is useful for jobs that run on many machines but access a centralized service. The random number generator is seeded with the hostname of the machine so that the job runs at a consistent time on each machine.
cronwrap --jitter 5m <job>
If enabled cronwrap will not start multiple simultaneous copies of job. For example, you have a job that runs once an hour and usually completes in a minute. However, there's a chance it will get stuck and take more than an hour or even hang forever. You might not want cron to start another copy of the job while the previous job is still running.
cronwrap --overlap <job>
If enabled cronwrap will terminate the process if it runs longer than the specified timeout. A SIGTERM will be sent to the job followed by a SIGKILL after 5 seconds.
cronwrap --timeout 1h <job>
Set process priority similar to the Unix utility nice
cronwrap --nice 19 <job>
If enabled cronwrap will suppress non-zero exit values and output unless the job exceeds the specified number of consecutive failures. This is useful for jobs that might fail occasionally due to extenuating circumstances but for which the occasional failure is acceptable as long as it the job starts running successfully again soon.
cronwrap --suppress 3 <job>
Tarballs available from the tags page.
I now have a version of cronwrap with the same functionality written in Go at https://github.com/jheiss/gocronwrap