Automation Engine Priority
The AE priority influences the processing of tasks. It can be used for clients and tasks, although with very different impacts.
The UC_CLIENT_SETTINGS variable contains entries for both priority types in which the administrator can specify default values:
|
AE priority |
Setting |
|---|---|
|
Client priority |
Key: CLIENT_PRIORITY Priority of the client |
|
Task priority |
Key: TASK_PRIORITY Default priority for all the objects of a client You can also specify a priority in the Attributes Pages of Executable Objects of an object. The priority specified here applies to that particular object only. It overrules the entry made in TASK_PRIORITY. |
Client Priority
An Automation Engine system consists of the system client 0000 and up to 9999 user-defined clients.
The Automation Engine processes all messages sent by those clients, with the client priority determining the order in which they are processed. Clients of a higher priority are always given priority to clients of a lower priority, regardless of the order in which the messages were originally sent. The First-In-First-Out principle applies when there are two clients with the same priority. The message arriving first is processed first.
- Highest priority: 200
- Lowest priority: 255
- Default value: 200
Task Priority
Task priority is not the same as client priority!
The priority specified for tasks influences the starting order of tasks that are in a waiting condition. The task with the highest priority is started first. However, it does not influence the further processing of these tasks.
- Highest priority: 1
- Lowest priority: 255
- Default value: 200
The default value "0" has been preset in the Attributes page of objects. Hence, the priority specified in the UC_CLIENT_SETTINGS variable (key: TASK_PRIORITY) applies.
For tasks of the same priority, the "First in/first out" principle applies.