Affinity Conditions

When a Broker is assigning tasks to Engines, one of the methods used to make optimal matches is affinity, or the degree to which an Engine has initialization data and updates from a particular Service. If there are a number of possible matches at a point in the scheduling decision, the Broker assigns tasks to the match with the highest affinity score. Affinity is a number that is calculated between an Engine and a Service Session. By default, the affinity number is based on the amount of state the Engine has for the session, whether it has loaded its Grid libraries, and whether it is on a Home Broker.

It is possible to use Affinity Condition to add affinity, typically based on Engine properties. This Condition is similar to a Discriminator Condition, except when it is satisfied, it adds a defined number to the affinity score.

If you plan to use affinity, aside from Affinity Conditions, you also need to tune how and how much the scheduler uses affinity. For more information see the TIBCO GridServer® Administration.