Due to a ransomware attack, the wiki was reverted to a July 2022 version. . We apologize for the lack of a more recent valid backup.
Work in progress
OSGi provides a framework for individual software components to declare certain parameters to be configurable. This framework allows changing these parameters in-flight and tracks their values across system restart. However, this occurs only on the local container, which in ONOS's case is Apache Karaf. For this reason, ONOS provides a subsystem, which overlays the OSGi mechanism, but which manages the configurations in a distributed fashion across the entire ONOS cluster. This assures that all ONOS cluster instances are running using the same configuration and at the same time provides a convenient means to view the state of the configuration parameters.
This subsystem continues to use the OSGi mechanism to persistently track configurable parameters in the local instance context and to notify components when the parameters change, so the application components can continue to use the standard and well-understood OSGi configuration via ComponentContext. Furthermore, if components use the Apache Felix compile-time @Property annotation, ONOS build process generates a configuration catalog