The Orion Context Broker is an open source implementation of the publish/subscribe pattern. It offers a central tool for the provision of context and attribute information about entities that can be freely defined by the user. Context information about entities can be stored and retrieved selectively by means of the most varied of filters.
Publishers (context producers) supply data which is made available to subscribers (context consumers) as an update in a push or pull system and can be retrieved using a variety of methods.
The publishers and subscribers involved can be managed flexibly via the API provided. There is no direct communication between the publishers and the subscribers. In this way, the technological aspects of data exchange are abstracted and the two parties do not have to know each other.
External applications communicate with the Orion Context Broker exclusively via the OSM NGSI API protocol, which was developed specifically for this purpose. The development process of external applications is thus significantly simplified and accelerated.
The Context Broker always only saves the latest version of an attribute value. Previous values that have been updated or overwritten over time are not retained or stored in a history.