Check_MK now supports recurring scheduled downtimes (or simply recurring downtimes). Let's assume that you have a couple of servers that are rebooted once a week always at the same time. You surely do not want any notifications about that, you also do not want to have these hosts displayed as "problems" in the problem views.
Up to now the only useful tool in such situations was the notification period. But that way you can just suppress notifications - not the problem display. Also setting up notification periods requires configuration permissions (WATO).
The new recurring downtimes create normal scheduled downtimes for you on a regular base. This is a direct enhancement of the downtimes that already exist. They now have a new field where you can specify an interval in which the downtime should be repeated. Everything is then handled by the monitoring core (CMC) and no external cron job is involved. This has a few advantages:
The easiest way is to just use the same commands as for creating one-time downtimes. The command box now has a new option Repeat this downtime on a regular base every ____. You can choose between hourly, daily and weekly. If you e.g. create a downtime for 12:34 on Monday and select weekly then this downtime will be repeated on every Monday from now on. Changes in the daylight saving time are compensated, so the time of day (12:34) will be valid in and out of DST.
Such downtimes behave exactly like one-time downtimes - with the single difference that they are not being deleted when they end but shifted to the next interval instead.
U2:Using rule sets
There is a second way to create recurring downtimes: two new WATO rule sets called Recurring downtimes for hosts and Recurring downtimes for services. Using these you can base the downtimes on WATO folders and host tags. While this could also by done by selecting host and services via the GUI and applying commands - it still has one advantage: You can specify downtimes for objects that still do not exist. If you create a recurring downtime for all servers with the tag Windows then also Windows hosts that will be added at a later time will automatically get that recurring downtime.
Recurring downtimes that have been created via a rule can not be deleted by the operator via a command, of course. All downtime views have a new column Origin that shows you wether a downtime exists due to a command or due to configuration.