Automation Engine Priority when Executing Objects

The Automation Engine priority influences the processing order of tasks. There are two types of priority, Client priority and task priority, with different impacts. The UC_CLIENT_SETTINGS - Various Client Settings variable contains entries for both priority types, in which the administrator can specify default values. In addition, the Queues in which you submit the objects for execution also have priorities.

Client Priority

An Automation Engine system consists of Client 0 (the administration Client) and up to 9999 user-defined (production) 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 parameters in the UC_CLIENT_SETTINGS variable.

More information:

• CLIENT Parameters
• UC_CLIENT_SETTINGS - Various Client Settings

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 TASK_PRIORITY parameter in the UC_CLIENT_SETTINGS variable applies. For tasks with the same priority, the First-In-First-Out principle applies.

Administrator users set the priority of the Client using the TASK_PRIORITY parameter in the UC_CLIENT_SETTINGS.

More information:

• Attributes Page
• TASK_PRIORITY
• UC_CLIENT_SETTINGS - Various Client Settings

QUEUE Priority

Queues are virtual spaces in which processes are submitted for execution. They determine the maximum number tasks that can run in parallel and their priorities. When you define objects, you assign them to Queue objects. These Queue objects also have a priority

• Default value: 200
• Allowed values: 0 to 255, where:
  • 0 = highest priority
  • 255 = lowest priority

Note: The priority that is defined in the Queue object is checked before the priority defined in the task. If two tasks have the same Queue priority, the priority that is specified in the task applies.