In Salt versions greater than 0.12.0, the scheduling system allows incremental
executions on minions or the master. The schedule system exposes the execution 
of any execution function on minions or any runner on the master.

Scheduling is enabled via the ``schedule`` option on either the master or minion 
config files, or via a minion's pillar data.

.. note::

    The scheduler executes different functions on the master and minions. When
    running on the master the functions reference runner functions, when
    running on the minion the functions specify execution functions.

Specify ``maxrunning`` to ensure that there are no more than N copies of
a particular routine running.  Use this for jobs that may be long-running
and could step on each other or otherwise double execute.  The default for 
``maxrunning`` is 1.

States are executed on the minion, as all states are. You can pass positional
arguments and provide a yaml dict of named arguments.

.. code-block:: yaml

    schedule:
      job1:
        function: state.sls
        seconds: 3600
        args:
          - httpd
        kwargs:
          test: True

This will schedule the command: state.sls httpd test=True every 3600 seconds
(every hour)
 
.. code-block:: yaml

    schedule:
      job1:
        function: state.sls
        seconds: 3600
        args:
          - httpd
        kwargs:
          test: True
        splay: 15

This will schedule the command: state.sls httpd test=True every 3600 seconds
(every hour) splaying the time between 0 and 15 seconds

.. code-block:: yaml

    schedule:
      job1:
        function: state.sls
        seconds: 3600
        args:
          - httpd
        kwargs:
          test: True
        splay:
          start: 10
          end: 15

This will schedule the command: state.sls httpd test=True every 3600 seconds
(every hour) splaying the time between 10 and 15 seconds

.. versionadded:: Helium

Frequency of jobs can also be specified using date strings supported by
the python dateutil library.

.. code-block:: yaml

    schedule:
      job1:
        function: state.sls
        args:
          - httpd
        kwargs:
          test: True
        when: 5:00pm

This will schedule the command: state.sls httpd test=True at 5:00pm minion
localtime.

.. code-block:: yaml

    schedule:
      job1:
        function: state.sls
        args:
          - httpd
        kwargs:
          test: True
        when:
            - Monday 5:00pm
            - Tuesday 3:00pm
            - Wednesday 5:00pm
            - Thursday 3:00pm
            - Friday 5:00pm

This will schedule the command: state.sls httpd test=True at 5pm on Monday, Wednesday
and Friday, and 3pm on Tuesday and Thursday.

.. code-block:: yaml

    schedule:
      job1:
        function: state.sls
        seconds: 3600
        args:
          - httpd
        kwargs:
          test: True
        range:
            start: 8:00am
            end: 5:00pm

This will schedule the command: state.sls httpd test=True every 3600 seconds
(every hour) between the hours of 8am and 5pm.  The range parameter must be a
dictionary with the date strings using the dateutil format.

.. versionadded:: Helium

The scheduler also supports ensuring that there are no more than N copies of
a particular routine running.  Use this for jobs that may be long-running
and could step on each other or pile up in case of infrastructure outage.

The default for maxrunning is 1.

.. code-block:: yaml

    schedule:
      long_running_job:
          function: big_file_transfer
          jid_include: True

States
======

.. code-block:: yaml

    schedule:
      log-loadavg:
        function: cmd.run
        seconds: 3660
        args:
          - 'logger -t salt < /proc/loadavg'
        kwargs:
          stateful: False
          shell: True

Highstates
==========

To set up a highstate to run on a minion every 60 minutes set this in the
minion config or pillar:

.. code-block:: yaml

    schedule:
      highstate:
        function: state.highstate
        minutes: 60

Time intervals can be specified as seconds, minutes, hours, or days. 

Runners
=======

Runner executions can also be specified on the master within the master 
configuration file:

.. code-block:: yaml

    schedule:
      overstate:
        function: state.over
        seconds: 35
        minutes: 30
        hours: 3

The above configuration will execute the state.over runner every 3 hours,
30 minutes and 35 seconds, or every 12,635 seconds.

Scheduler With Returner
=======================

The scheduler is also useful for tasks like gathering monitoring data about
a minion, this schedule option will gather status data and send it to a MySQL
returner database:

.. code-block:: yaml

    schedule:
      uptime:
        function: status.uptime
        seconds: 60
        returner: mysql
      meminfo:
        function: status.meminfo
        minutes: 5
        returner: mysql
      
Since specifying the returner repeatedly can be tiresome, the
``schedule_returner`` option is available to specify one or a list of global
returners to be used by the minions when scheduling.