Brokers

A broker is a set of execution processes that hosts one or more message flows to route, transform, and enrich inflight messages.

Applications send messages to the broker using WebSphere MQ queues and connections. The broker routes each message using the rules defined in message flows and message sets, and transforms the data into the structure required by the receiving application.

The broker uses sender and receiver channels to communicate with the Configuration Manager and other brokers in the broker domain.

You install the broker component on the platforms described in Operating system requirements. You create the broker using command line instructions on the machine where the component is installed. You can install and create one or more brokers, on one or more machines.

The broker depends on a broker database to hold broker information. This includes control data for resources defined to the broker, for example deployed message flows. You need to define a database and authorize access for specific users before you create the broker because creating the broker creates tables within the database. The database is also known as the broker's local persistent store.

The broker connects to the database using an ODBC connection.

When you create a broker, you must give it a name that is unique within the broker domain. Broker names are case-sensitive on all supported platforms, except Windows platforms. You must use the same name when you create a reference to the broker in the broker domain topology in the workbench. The reference to the broker is a representation of the physical broker in the configuration repository.

When you have created the broker reference, you deploy the changes to your broker domain. Deployment starts communications between the broker and the Configuration Manager. The broker receives configuration information from the Configuration Manager, and stores it in the configuration repository. Deployment also initializes the broker to make it ready to execute message flows.

Resources associated with a broker

When you create a broker, the following resources are also defined and created:
  • A set of database tables for storing the information used by the broker to process messages at run time.

    You can use one of a number of database products to create the database tables, depending on which platform the product is installed. See Supported databases for more information.

    You must create a DB2 database if you are using WebSphere Event Broker for z/OS.

  • A WebSphere MQ queue manager, if one does not already exist.
  • A set of fixed-name queues that are defined to the WebSphere MQ queue manager.
Related tasks
Creating a broker