How Component Load Balancing Works

Component Load Balancing (CLB) balances load by spreading activation of COM+ components across a cluster of component servers. The illustration shows an Application Center configuration running an online store application. The Web server cluster (left) runs the presentation tier of the application, a set of Active Server Pages that communicate with customers over the Web. Pages activate COM+ business logic components, which perform basic operations (e.g., enter a new order, retrieve all orders for a customer). Requests to create components go through the CLB service on each Web server, which creates the components remotely on a component server cluster (right).

In a typical operation, an Active Server Page issues a request for a COM+ component (1) to begin the order entry process. The CLB service activates the component on the most lightly loaded component server (2), using load data it has collected by periodically polling the component servers. The Active Server Page subsequently communicates directly with the component to request operations and retrieve responses (3).