Configure uniform distributed topics

A distributed topic is a single unit of JMS topics that are accessible as a single, logical topic to a client (for example, a distributed topic has its own JNDI name). The members of the unit are usually distributed across multiple servers within a cluster, with each topic member belonging to a separate JMS server.

By configuring uniform distributed topics, you no longer need to create or designate the topic members. Instead, WebLogic Server uniformly creates the necessary members on the JMS servers to which a JMS module is targeted. This ensures the consistent configuration of all distributed destination parameters, particularly in regards to weighting, security, persistence, paging, and quotas across a cluster.

The legacy weighted distributed topic feature is still available for users who prefer to manually fine-tune topic members to carry extra message load or have extra capacity. However, BEA strongly recommends configuring uniform distributed topics to avoid possible administrative and application problems due to a weighted distributed topic not being deployed consistently across a cluster. For more information, see Create weighted distributed topics.

To configure a uniform distributed topic:

If necessary, configure a JMS system module for the uniform distributed topic. See Configure JMS system modules.
Before creating a uniform distributed topic resource in a module, you can optionally create other quota and destination key resources in the module that can be referenced from within the distributed topic:
- Quotas are used to control the allotment of system resources available to members of a uniform distributed topic. See Configure quotas for destinations.
- Destination keys allow you to define the sort order of messages that arrive on a members of a uniform distributed topic. See Configure destination keys.
Create uniform distributed topics
After creating a uniform distributed topic, you can define a number of optional properties:
1. Uniform distributed topics - configure general parameters
  Configuring optional General properties includes selecting a destination key for sorting messages as they arrive on members of the distributed topic, or modifying the load balancing policy.
2. Uniform distributed topics - configure advanced parameters
  Configuring optional Advanced properties includes specifying unit-of-order parameters and attaching the credentials of message senders.
3. Uniform distributed topics - configure thresholds and quota
  Define upper and lower byte and/or message thresholds for the members of a uniform distributed topic, select a pre-configured quota specifying the maximum number of bytes or messages that the distributed topic members are allowed to store, or specify a maximum size allowed for messages on the distributed topic members.
4. Uniform distributed topics - configure delivery overrides
  Define message delivery override values, such as message priority and time-to-deliver values, that can override those specified by a message producer.
5. Uniform distributed topics - configure message logging
  Enable the logging of message life cycle information into a JMS message log file. The content of the message log always includes message ID and correlation ID, but you can also configure information like message type and user properties.
6. Uniform distributed topics - configure delivery failure parameters
  Define default message delivery failure values, such as defining a message redelivery limit, selecting a message expiration policy, and specifying an error destination for expired messages.
7. Uniform distributed topics - configure multicast parameters
  Define multicast parameters that enable the delivery of messages to a select group of hosts that subsequently forward the messages to subscribers.
If you skipped the targeting step when you created a uniform distributed topic, or want to modify the current targeting parameters, you can do so at anytime. See Uniform distributed topics - configure targets.
Optionally, add or remove security roles and policies to a uniform distributed topic. See Uniform distributed topics - create security roles and Uniform distributed topics - configure security policies.
In the event that you need to troubleshoot a uniform distributed topic, you can temporarily pause all message production, insertion (in-flight messages), and consumption operations on all the members of a distributed topic. See Uniform distributed topics - pause message operations on server restart.