19 Introduction to Coherence Topics
This chapter includes the following sections:
- Topics Overview
The Topics API enables the building of data pipelines between loosely coupled producers and consumers.
Parent topic: Using Topics
Topics Overview
One or more publishers publish a stream of values to a topic. One to many subscribers consume the stream of values to a topic. The topic values are spread evenly across all Oracle Coherence data servers, enabling high throughput processing in a distributed and fault tolerant manner. Each direct subscriber to a topic receives all values published to the topic.
Figure 19-1 Topic Values
In publish and subscribe messaging, messages are only delivered to active subscribers of the topic. Subscriber groups add queue processing capabilities to topics. Once a subscriber group is created on a topic, all values sent to the topic are accumulated for the subscriber group. One or more subscribers can subscribe to a subscriber group. For the stream of values accumulated by a subscriber group, each value is only delivered to one of its subscriber group members, thus enabling distributed, parallel processing of these values.
Note:
For examples of basic topic operations, see Performing Basic Topic Publish and Subscribe Operations.Figure 19-2 Topic Values in a Subscriber Group
Parent topic: Introduction to Coherence Topics