Service integration bus configuration for the Web messaging service

The Web messaging service makes use of the service integration bus provided as part of WebSphere® Application Server V6.0.x and later to provide the underlying publish and subscribe capability required to support Bayeaux clients. To determine how Bayeaux publishers and subscribers interact with the service integration bus, it is necessary to provide some configuration parameters when deploying an application that provides Bayeaux capability.

The Bayeaux subscription channel concept is equivalent to a topic in the service integration bus such that it enables classification of events into related groups, for example /sports/football or /weather. In the service integration bus, topics exist within a topic space destination to which producers and consumers attach. Topics in one topic space are completely independent of topics, even potentially with the same name, that exist in a different topic space. Part of the configuration of the Feature Pack for Web 2.0 end of name->thus gives the application developer the ability to specify which service integration bus topic space is used by Bayeaux applications.

Additionally, events (messages) published to a service integration bus topic space have a reliability applied to them that determines how the messages are treated inside the bus. This includes the conditions under which the messages can be discarded by the messaging infrastructure. In some scenarios, it is acceptable for messages to be discarded if the server becomes resource constrained, possibly due to a high workload, while in others it is preferable to retain messages even at the risk of overloading the server.

When configuring advanced scenarios that include concepts such as workload management or security it is also necessary to consider the implications of those requirements on the service integration bus. Each of these concepts is described in further detail below.

The following option are available for configuring the way that Bayeaux applications interact with the service integration bus.

  busName

    A service integration bus is required for Web messaging operations. Clients can only connect to a single service integration bus through a single incoming URI. Connecting to multiple buses is only possible by creating a separate Web messaging configuration definition and specifying a different bus name, but the client will have to connect through separate URIs and use multiple connections. When using an Ajax client it is only feasible to make one Bayeux connection to a single server on a single Web page. Different pages can specifiy different URIs and connect to different buses.

Name: busName
Required or Optional: Required
Data type: String
Supported values: The name of any service integration bus
Default value: No default
Description:

The service integration bus that incoming Web messaging clients use for publish or subscribe operations.

  destination

    In the majority of scenarios a Bayeaux application needs to consume or produce messages from a single service integration bus topic space. The destination property enables the application developer to specify which topic space is used for all interactions with the service integration bus.

Name: destination
Required or Optional: Optional
Data type: String
Supported values: The name of any service integration bus topic space
Default value: Default.Topic.Space
Description:

This is the topic space on the service integration bus that the application consumes from or produce to.

The destination specified can be a real topic space, or alternatively it can be an alias (see