The FioranoMQ Dispatcher is the solution to the problem of load balancing the incoming client connections between a group of servers. The Dispatcher server is connected to multiple servers belonging to a "cluster". The dispatcher services this "cluster". FioranoMQ Dispatcher maintains a persistent connection with each FioranoMQ server in a cluster. This persistent connection is used to pass information from the server to the dispatcher, enabling the dispatcher to maintain real-time in-memory statistics about the precise load in terms of the number of connections on each server. The dispatcher uses this information to determine the least loaded server in the cluster and routes the new incoming client requests to it.
The dispatcher is a normal FioranoMQ Server with an additional dispatcher component. Once the dispatcher functionality is turned ON in the server, it automatically routes connection requests to the least loaded server.. That is the sole difference between a plain vanilla server and a dispatcher enabled server. An advantage of using Fiorano Dispatcher is that no changes are required in the client application to use the Dispatcher since the client application is transparent to internal re-routing taking place inside the dispatcher.
However, as mentioned before, a dispatcher server is perfectly capable of handling connection client requests as well as any MQ server. Even if none of the servers in the dispatcher's cluster are alive, the client's connection request would still be served by the dispatcher server itself.
To make use of the dispatcher functionality, the user can either use the preconfigured Dispatcher enabled FioranoMQ profile named FioranoMQ_Dispatcher or enable Dispatcher in a profile by following the steps given in the next section.
For information about configuring profiles through a text based file, see FioranoMQ Getting Started.
Following topics are covered in this chapter:
- 10.1 How to Configure Dispatcher
- 10.2 Adding Servers to Dispatcher Cluster
- 10.3 Configuring Client Applications to Use Dispatcher
- 10.4 Using Preferred-Server Configuration