Connecting to the Broker

As shown in Figure 1–6 both application clients and administration clients can connect to the broker. The JMS specification does not dictate that providers implement any specific wire protocols. Message Queue services, used by application clients and administration clients to connect to the broker, are currently layered on top of TCP, TLS, HTTP, or HTTPS protocols. (Services layered on top of HTTP allow messages to pass through firewalls.)

• Services that provide JMS support and allow clients to connect to the broker (jms, ssljms, http, or https) have a service type of NORMAL and are layered on top of TCP, TLS, HTTP, or HTTPS protocols.

• Services that allow administrators to connect to the broker ( admin, ssladmin) have a service type of ADMIN and are layered on top of TCP or TLS protocols.

By default, when you start the broker, jms and admin services are up and running. Additionally, you can configure a broker to run any or all of these connection services. Each service supports specific authentication and authorization (access control) features and each service is multi-threaded, supporting multiple connections.

Should a connection fail, the Message Queue service can automatically retry connecting the client to the same broker or to a different broker if this feature is enabled. For more information, see the description of the automatic reconnect feature in Appendix B, Message Queue Features

Clients can configure connection runtime support when they create the connection factory from which they obtain their connections. Options allow you to specify which brokers to connect to, how to handle reconnection, message flow control, and so on. For additional information about how connections can be configured, see Connection Factories and Connections.