recurring schedule behavior in sms / sccm agents

background

while investigating long boot/logon cycles, i came to the realization that there really is no documented statement on how a sms agent behaves when set against a recurring schedule.  here’s a really brief summary of what i’ve discovered so far.

first of all, it turns out that regardless of the type of recurring situation, it’s always the same.  this means whether it’s inventory or software distribution the behavior is exactly alike.  i know there’s some confusion about this… but this is what i’m seeing.

basically when an agent does not miss its schedule, it runs as it should.  duh.  i don’t know why that took me so long to process, but i finally get it now!  really!  let me explain, if you still don’t follow.

 

inventory behavior

i have a computer named “myLaptop”.  myLaptop goes home in the evenings with me and stays off since i refuse to work outside of normal business hours.  because of this, when i log on the next morning, all kinds of things happen – whether i like it or not.  :|  squaring away our environmental details, here is what the schedule for myLaptop inventory times look like:

inventoryAction	lastReportDate	schedule
hardware	1/28/2009 11:32:51 AM	once/day
software	1/26/2009 4:33:52 PM	once/5 days
heartbeat	1/28/2009 4:42:46 PM	once/day

 

while myLaptop is turned off, it misses the scheduled execution for hardware inventory and heartbeat discovery.  i fire up the laptop at 1/28/2009 5:01:00 PM --because of this, the agent runs both hardware and discovery in tandem.  now if i reboot or restart the agent at any point until its next scheduled time, the agent will NOT run the inventories again. 

since software inventory is every 5 days, the laptop hasn’t missed its scheduled execution.  therefore, software inventory does not execute again.  if i had started the laptop at 1/31/2009, it would have run all 3 since every scheduled inventory would have been missed.

when inventory does fire off, all of the lastReportDate time frames will be reset to the current datetime value.  therefore, the machine will not run the inventory cycles again until the new scheduled times.

 

software distribution behavior

software distribution behaves exactly as i’ve detailed above.  it makes more sense though with software distribution since you control the mandatory execution timeframe.  also, it never changes the time frame.  if it misses an execution and has to run it, it doesn’t go reset the next scheduled time.  it runs again when you’ve scheduled it to go.

 

additional information

if you’re not familiar with the inventories i’ve mentioned below, they exist in the wmi class InventoryActionStatus.  This class resides in the namespace “root\ccm\invagt”.

from within wbemtest, you can view the details of the schedules by executing the following query:

select * from inventoryactionstatus

 

keep in mind that running the query in wmi returns all date fields in cim_datetime format.  if you want to see it in a better output, try this powershell command:

get-wmiobject -Namespace 'root\ccm\invagt' -Query 'select * from inventoryactionstatus' | ft -property InventoryActionID, @{label="ReportDate";expression={$_.ConvertToDateTime($_.LastReportDate)}}

 

you’ll get a list of inventory action ids.  you can find their translation here.

 

acknowledgement

thanks goes to mark mears.  :)