Different service integration bus topologies can be used depending
on your requirements.
A topology consisting of just one messaging engine is adequate for some
applications. However, there are advantages in deploying more than one messaging
engine, and linking them together:
- Spreading messaging workload across multiple servers.
- Placing message processing close to the applications that are using it,
so as to reduce network traffic. For example, if the sending and receiving
applications are running in the same server process it would be inefficient
to route all the messages that flow between them through a messaging engine
running in a remote server.
- Improving availability in the face of system or link failure. This includes
removing a single point of failure, and allowing store and forward between
two servers should this be required.
- Providing improved scalability
- Accommodating firewalls or other network restrictions that limit the ability
of network hosts to all connect to a single messaging engine.
A topology can also contain links to WebSphere MQ networks. This allows
applications connected to a WebSphere MQ queue manager to send messages to
an application attached to a service integration bus, and vice versa.