Constraints on task execution, e.g. a execution group, allowed/disallowed nodes, etc. EXPERIMENTAL.

Item Summary
Name	Type	Multiplicity	Description
group	property string	[0,1]	A group this task is a part of.
groupTaskLimit	property int	[0,1]	Number of tasks within the group that can be executed at once (clusterwide).
secondaryGroup	container TaskExecutionGroupConstraintType	[0,-1]	TODO
retryAfter	property duration	[0,1]	In what time to retry after clusterwide execution constraints are not met.

Items
- group
  
  Flags: RAM,runtime
  
  Multiplicity: [0,1]
  
  A group this task is a part of. In the future, task execution groups will probably have more complex parameters. But for now, their only parameter is the (clusterwide) member tasks limit. They are also referenced from NodeType when specifying execution limitations for them.
- groupTaskLimit
  
  Flags: RAM,runtime
  
  Multiplicity: [0,1]
  
  Number of tasks within the group that can be executed at once (clusterwide). Default is "unlimited". This parameter will be moved into separate task group object in a later version of midPoint.
- secondaryGroup
  
  Flags: RAM,runtime
  
  Multiplicity: [0,-1]
  
  TODO
- retryAfter
  
  Flags: RAM,runtime
  
  Multiplicity: [0,1]
  
  In what time to retry after clusterwide execution constraints are not met. The default is 1 minute.