The Java Message Service (JMS) API provides messaging capabilities to Java applications. In addition to exchanging messages among QAnywhere client applications, you can exchange messages with external messaging systems that support a JMS interface. You do this using a specially configured client known as a connector. In a QAnywhere deployment, the external messaging system is set up to act like a QAnywhere client. It has its own address and configuration.

For more information about the architecture of this approach, see Scenario for messaging with external messaging systems.

When running MobiLink with QAnywhere messaging in a server farm environment, only the QAnywhere connectors in the primary server start. If the primary server fails, the QAnywhere connectors are automatically started in the new primary server so that message ordering is preserved while exchanging data in the external messaging system, such as JMS. For more information, see Running the MobiLink server in a server farm.