State cycle of a resource group

Figure 1 shows the state transitions that occur when System Automation for Multiplatforms successfully starts and stops a resource group.
Figure 1. State cycle of a resource group
State cycle of a resource group

At the beginning of the cycle ( 1 ), the resource group's DesiredState is Offline, its ObservedState is Offline, and the members of the resource group are unbound, which results in a BindingState of Unbound.

If the NominalState of the resource group is changed to Online ( 2 ), the DesiredState of the resource group also changes to Online. The BindingState is still Unbound ( 3 ).

In the binding step ( 4 ), the binder tries to find a placement for all members of the resource group that satisfies all dependencies defined in the automation policy. If the binding step is successful, the BindingState of the resource group changes to Bound ( 5 ), otherwise the BindingState of the resource group will end up in state Sacrificed and the resources will not be started.

When all resource group members are bound, System Automation knows on which node to start them. The logic deck sends out start orders for the members of the resource group ( 6 ) and ensures that all dependencies defined in the automation policy are fulfilled. While the resources are starting, the ObservedState of the resource group changes to Pending Online ( 7 ).

When all resources are Online, the ObservedState of the resource group changes to Online ( 8 ).

When the NominalState of the resource group is changed to Offline ( 9 ), the DesiredState of the resource group changes to Offline ( 10 ). This will trigger System Automation to stop all members of the resource group. The logic deck sends out stop orders for the resources ( 11 ) and ensures that all dependencies defined in the automation policy are fulfilled. While the resources are stopping, the ObservedState changes to Pending Offline ( 12 ). When all resources are Offline, the ObservedState of the resource group changes to Offline ( 13 ).

In the unbinding step ( 14 ), the node placement of the resource group members is deleted from the internal tables and the BindingState of the resource group changes to Unbound ( 1 ).