Overview of using UM in Apama applications
In an Apama application, correlators and adapters can connect to UM realms or clusters. A correlator or adapter connected to a UM realm or cluster uses UM as a message bus for sending Apama events between Apama components. Connecting a correlator or adapter to UM is an alternative to
Specifying a connection between two correlators by executing the
engine_connect correlator utility. This is the main reason to use UM.
Defining connections between an adapter and particular correlators in the
<apama> element of an adapter configuration file. This is a secondary reason to use UM. You might find that having some adapters connected to UM is a good fit for your application.
Using UM can simplify an Apama application configuration. Instead of specifying many point-to-point connections you specify only the address (or addresses) of the UM realm or cluster. Apama components connected to the same UM realm can use UM channels to send and receive events. (UM channels are equivalent to JMS topics.) Connections to UM are automatically made as needed, giving extra flexibility in how the application is architected.
When an Apama application uses UM a correlator automatically connects to the required UM channels. There is no need to explicitly connect UM channels to individual correlators. A correlator automatically receives events on UM channels that monitors subscribe to and automatically sends events to UM channels.