The Load Balancer dispatches tasks to achieve optimal performance and scalability. When you run a workflow, the Load Balancer dispatches the Session, Command, and predefined Event-Wait tasks within the workflow. The Load Balancer matches task requirements with resource availability to identify the best node to run a task. It dispatches the task to a PowerCenter Integration Service process running on the node. It may dispatch tasks to a single node or across nodes.
The Load Balancer dispatches tasks in the order it receives them. When the Load Balancer needs to dispatch more Session and Command tasks than the PowerCenter Integration Service can run, it places the tasks it cannot run in a queue. When nodes become available, the Load Balancer dispatches tasks from the queue in the order determined by the workflow service level.
The following concepts describe Load Balancer functionality:
Dispatch process. The Load Balancer performs several steps to dispatch tasks.
Resources. The Load Balancer can use PowerCenter resources to determine if it can dispatch a task to a node.
Resource provision thresholds. The Load Balancer uses resource provision thresholds to determine whether it can start additional tasks on a node.
Dispatch mode. The dispatch mode determines how the Load Balancer selects nodes for dispatch.
Service levels. When multiple tasks are waiting in the dispatch queue, the Load Balancer uses service levels to determine the order in which to dispatch tasks from the queue.