Subsystems is an OSGi Alliance specification that standardizes the development and deployment of bundle collections. The specification was motivated by the need for bundle collections exhibited by many existing products & projects, including: Apache Karaf, Apache Aries, Eclipse Virgo, WebSphere Application Server, etc.
Three different types of collections are defined in the specification: feature, composite & application, each having different rules covering sharing of packages and services, and each being designed with different use cases in mind. Subsystems was first introduced in OSGi Enterprise R5 and since then work has continued on further enhancements. This talk will introduce the Subsystems specification, describe some practical use cases, provide demonstrations based on the Apache Aries Reference Implementation, and finally talk a bit about what's coming in the next version.
Graham Charters is a Senior Technical Staff Member in the IBM WebSphere Application Server development organization. He is responsible for the OSGi Applications feature of the Application Server and a committer and PMC member of the Apache Aries OSGi programming model project. He is also the IBM technical lead in the OSGi Alliance Enterprise Expert Group.