Important design decisions
Start communication via Topic
All communication via the Coordination layer starts via a Topic that is send to all. It is up to the individual subscribers to determine whether it is a message that concerns them, for example a Get message does only concern the pillars involved in a certain service level agreement.
Atomic operations
Operation must be as atomic and simple as possible. this serves to give simplicity, and to get as little overlap between different operations as possible.
Using Get as example
The Get operation can begin by asking pillars who will be the fastes, or it can start by actually sending a get message for a specific default pillar.
In the strict interpretation of single operations this will be seen as two operations
- GetTime
- Get
An the difference between the two get scenarios will be that teh first will both consist of a GetTime and a Get opertation, while the later will only consist of a Get.
In the below figure the two operations are illustrated, where message belonging to the same communication in an operation is placed edge to edge.
