Resource Type: schedule

NOTE: This page was generated from the Puppet source code on 2024-10-18 10:08:53 -0700

schedule

Description

Define schedules for Puppet. Resources can be limited to a schedule by using the schedule metaparameter.

Important: When a scheduled resource is skipped because the current time is outside of its schedule, Puppet still runs any resources that are dependent on it.

Schedules can only be used to stop a resource from being applied. They cannot cause a resource to be applied when it otherwise wouldn't be, and they cannot accurately specify a time when a resource should run.

Every time Puppet applies its configuration, it will apply the set of resources whose schedule does not eliminate them from running right then, but there is currently no system in place to guarantee that a given resource runs at a given time. If you specify a very restrictive schedule and Puppet happens to run at a time within that schedule, then the resources will get applied; otherwise, that work may never get done.

Thus, it is advisable to use wider scheduling (for example, over a couple of hours) combined with periods and repetitions. For instance, if you wanted to restrict certain resources to only running once, between the hours of two and 4 AM, then you would use this schedule:

schedule { 'maint':
  range  => '2 - 4',
  period => daily,
  repeat => 1,
}

With this schedule, the first time that Puppet runs between 2 and 4 AM, all resources with this schedule will get applied, but they won't get applied again between 2 and 4 because they will have already run once that day, and they won't get applied outside that schedule because they will be outside the scheduled range.

Puppet automatically creates a schedule for each of the valid periods with the same name as that period (such as hourly and daily). Additionally, a schedule named puppet is created and used as the default, with the following attributes:

schedule { 'puppet':
  period => hourly,
  repeat => 2,
}

This will cause resources to be applied every 30 minutes by default.

The statettl setting on the agent affects the ability of a schedule to determine if a resource has already been checked. If the statettl is set lower than the span of the associated schedule resource, then a resource could be checked & applied multiple times in the schedule as the information about when the resource was last checked will have expired from the cache.

Attributes 

schedule { 'resource title':
  name        => # (namevar) The name of the schedule.  This name is used...
  period      => # The period of repetition for resources on this...
  periodmatch => # Whether periods should be matched by a numeric...
  range       => # The earliest and latest that a resource can be...
  repeat      => # How often a given resource may be applied in...
  weekday     => # The days of the week in which the schedule...
  # ...plus any applicable metaparameters.
}

name

(Namevar: If omitted, this attribute's value defaults to the resource's title.)

The name of the schedule. This name is used when assigning the schedule to a resource with the schedule metaparameter:

schedule { 'everyday':
  period => daily,
  range  => '2 - 4',
}

exec { '/usr/bin/apt-get update':
  schedule => 'everyday',
}

(↑ Back to schedule attributes)

period

The period of repetition for resources on this schedule. The default is for resources to get applied every time Puppet runs.

Note that the period defines how often a given resource will get applied but not when; if you would like to restrict the hours that a given resource can be applied (for instance, only at night during a maintenance window), then use the range attribute.

If the provided periods are not sufficient, you can provide a value to the repeat attribute, which will cause Puppet to schedule the affected resources evenly in the period the specified number of times. Take this schedule:

schedule { 'veryoften':
  period => hourly,
  repeat => 6,
}

This can cause Puppet to apply that resource up to every 10 minutes.

At the moment, Puppet cannot guarantee that level of repetition; that is, the resource can applied up to every 10 minutes, but internal factors might prevent it from actually running that often (for instance, if a Puppet run is still in progress when the next run is scheduled to start, that next run will be suppressed).

See the periodmatch attribute for tuning whether to match times by their distance apart or by their specific value.

Tip: You can use period => never, to prevent a resource from being applied in the given range. This is useful if you need to create a blackout window to perform sensitive operations without interruption.

Allowed values:

  • hourly

  • daily

  • weekly

  • monthly

  • never

(↑ Back to schedule attributes)

periodmatch

Whether periods should be matched by a numeric value (for instance, whether two times are in the same hour) or by their chronological distance apart (whether two times are 60 minutes apart).

Default: distance

Allowed values:

  • number

  • distance

(↑ Back to schedule attributes)

range

The earliest and latest that a resource can be applied. This is always a hyphen-separated range within a 24 hour period, and hours must be specified in numbers between 0 and 23, inclusive. Minutes and seconds can optionally be provided, using the normal colon as a separator. For instance:

schedule { 'maintenance':
  range => '1:30 - 4:30',
}

This is mostly useful for restricting certain resources to being applied in maintenance windows or during off-peak hours. Multiple ranges can be applied in array context. As a convenience when specifying ranges, you can cross midnight (for example, range => "22:00 - 04:00").

(↑ Back to schedule attributes)

weekday

The days of the week in which the schedule should be valid. You may specify the full day name 'Tuesday', the three character abbreviation 'Tue', or a number (as a string or as an integer) corresponding to the day of the week where 0 is Sunday, 1 is Monday, and so on. Multiple days can be specified as an array. If not specified, the day of the week will not be considered in the schedule.

If you are also using a range match that spans across midnight then this parameter will match the day that it was at the start of the range, not necessarily the day that it is when it matches. For example, consider this schedule:

schedule { 'maintenance_window':
  range   => '22:00 - 04:00',
  weekday => 'Saturday',
}

This will match at 11 PM on Saturday and 2 AM on Sunday, but not at 2 AM on Saturday.

(↑ Back to schedule attributes)