By default, the cron job allows concurrently running jobs but generally speaking, the behavior of your cron jobs will be more deterministic if you prevent them from running concurrently. Allowing concurrent cron jobs often requires locking mechanisms (to avoid race conditions) in addition to startup/cleanup handling.
Targeted resources by this rule (types of kind): CronJob
Enabled by default? False
Policy as code identifier: CRONJOB_MISSING_CONCURRENCYPOLICY_KEY
If a CronJob doesn't have concurrencyPolicy set or concurrencyPolicy is set to Allow
Set concurrencyPolicy to either Forbid or Replace