The DDS Standard

The Data Distribution Service (DDS) for Real-time Systems standard, from the Object Management Group (OMG), defines an efficient, high-performance publish-subscribe system that offers a predictable way of meeting the data-distribution requirements of data-critical systems with minimal overhead. The standard can be found on the OMG web site at http://www.omg.org/technology/documents/formal/data_distribution.htm.

The DDS standard, in existence for almost two years, maps very naturally to the topologies and capabilities of switched fabrics. It's steadily maturing into a solid technical approach to managing data distribution across large-scale distributed networks.

The DDS standard has three main goals:

• To define a model for communication as pure data-centric exchanges, where applications publish (supply or stream) data, which is then available to remote applications that are interested in it.
• To provide a mechanism of specifying the available resources and providing policies that allow the middleware to align the resources to the most critical requirements. This gives system designers the ability to control Quality of Service (QoS) properties that affect predictability, overhead, and resource utilization.
• To permit systems to scale to hundreds or thousands of publishers and subscribers in a robust manner.