The simplest configuration is a bus consisting of a single server. Use this configuration if there is a low volume of message throughput and scalability is not essential.
In a single-server bus, there is one messaging engine. All destinations, such as queues and topic spaces, are assigned to this single messaging engine.
The single server set up has the advantage of simplicity. It aids performance as all messages and application connections are on the same messaging engine which minimizes path length. It also easy to manage as all messages and application connections are on the same messaging engine which minimizes the number of configuration and runtime objects to monitor.
However, having only a single-server configuration has the drawback of limiting scalability and high availability of applications and messaging.
The following figure shows possible connections between a messaging engine and an application: