The JMS pub-sub model supports durable subscribers. A durable subscriber's subscription remains valid until explicitly removed by the client program; thus, a durable subscriber survives both client connection failures and server restarts.

A durable subscriber provides a means of guaranteeing document delivery. If the subscribing application is not running at the time a message is sent, or there is a disconnection between the JMS application and the JMS provider (or, in a Java EE application, between the MDB's container connection and the JMS provider), the messages that would have been received are held by the JMS provider in non-volatile storage. When the application reconnects, the messages are redelivered from the provider.

A durable subscriber is implemented as a guaranteed Broker client that subscribes to the corresponding document type. To create durable subscribers, you must specify a JMS connection.

JMS allows you to create durable subscribers on different connections with identical names. To accommodate this name scoping rule, the client IDs of the guaranteed Broker clients for the durable subscribers concatenate the connection client ID property and the durable subscriber names (supplied by the JMS client program). Thus, the durable subscriber names are identical in JMS but are associated with unique identifiers within Broker.