You can connect buses in different ways depending on your
requirements. For example, you can link messaging engines to distribute
message workload, and to provide system availability if there is a
system failure.
A topology that consists of a single messaging engine might be
adequate for some applications. Deploying more than one messaging
engine, and linking them together, has advantages:
- Distributes the messaging workload across multiple servers.
- Positions message processing close to the applications that are
using it, and reduces network traffic. For example, if both sending
and receiving applications are running in the same server process,
it is inefficient to route all the messages that flow between the
two applications through a messaging engine running in a remote server.
- Improves availability in the event of system or link failure.
For example, your bus topology can remove a single point of failure,
and allow store and forward between two servers.
- Provides improved scalability.
- Accommodates firewalls, or other network restrictions that limit
the ability of network hosts to connect to a single messaging engine.
A bus topology can contain links to WebSphere® MQ networks. This allows messages
to flow between applications connected to a WebSphere MQ queue manager and applications
attached to a service integration bus.
The application servers or server clusters that
host a messaging engine in the service integration bus are called
bus members.