Automation Engine Priority

The Automation Engine priority influences the processing order of tasks. There are two types of priority, Client and task, with different impacts. The UC_CLIENT_SETTINGS variable contains entries for both priority types in which the administrator can specify default values.

Client Priority

An Automation Engine system consists of Client 0 and up to 9999 user-defined Clients. The Automation Engine processes all messages that are sent by those Clients, with the Client priority determining the order in which they are processed. Clients with a higher priority are 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

Administrator users set the priority of the Client in the CLIENT_PRIORITY key, UC_CLIENT_SETTINGS system variable.

Task Priority

The priority that is 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.

Allowed values: 0 - 255
Highest priority: 1
Lowest priority: 255
0 = the value specified in the TASK_PRIORITY key of the UC_CLIENT_SETTINGS variable applies

If no default priority is specified, or if the variable is not available in the Client, the priority is 200.

When you define an object, you set its priority on its Attributes Page. By default it is set to 0, which means that the priority specified in the UC_CLIENT_SETTINGS variable (key: TASK_PRIORITY) applies. For tasks with the same priority, the First-In-First-Out principle applies.

Administrator users set the priority of the Client in the TASK_PRIORITY key, UC_CLIENT_SETTINGS system variable.