Decentralised dynamic code management for OSGi

ABSTRACT

Originally designed for the management of network-attached devices OSGi builds a de-facto standard to modularise all kinds of complex Java applications. It enables deployment and updating of components, which are called bundles, by supporting automatic resolution of inter-component dependencies. Despite these benefits the OSGi specification omits dedicated support for discovery, selection and loading of locally unavailable bundles. However, this is a key requirement for large distributed applications especially in dynamic and heterogeneous environments. Current solutions are server-based and provide a central bundle repository thereby representing a single point of failure. Furthermore, these approaches lack support for automatic bundle selection based on non-functional properties such as resource demand or performance.

We introduce the D²CM infrastructure accounting these issues and enabling automatic discovery, selection and loading of bundles in a distributed system on basis of the peer-to-peer platform JXTA. By providing extended bundle descriptions, non-functional properties can be automatically evaluated for bundle selection and dependency resolution.

REFERENCES

• 1: Osgi Alliance, Osgi Service Platform, Release 3, IOS Press, Inc., 2003
• 2: Holger Schmidt , Franz J. Hauck, SAMProc: middleware for self-adaptive mobile processes in heterogeneous ubiquitous environments, Proceedings of the 4th on Middleware doctoral symposium, p.1-6, November 26-30, 2007, Newport Beach, California [doi>10.1145/1377934.1377935]
• 3: Li Gong, JXTA: A Network Programming Environment, IEEE Internet Computing, v.5 n.3, p.88-95, May 2001 [doi>10.1109/4236.935182]
• 4: JXTA Project. JXTA v2.0 protocols specification. Technical report, Sun Microsystems, 2001.
• 5: R. Kapitza, H. Schmidt, U. Bartlang, and F. J. Hauck. A Generic Infrastructure for Decentralised Dynamic Loading of Platform-Specific Code. In DAIS '07, 2007.
• 6: Inc. Sun Microsystems. Java Web Start overview. White paper, Sun Microsystems Inc., 2005.
• 7: R. Kapitza and F. J. Hauck. DLS: a CORBA service for dynamic loading of code. In OTM '03, 2003.
• 8: S. Paal, R. Kammüller, and B. Freisleben. Dynamic software deployment with distributed application repositories. In KiVS '05. Springer, 2005.
• 9: Stefan Paal , Reiner Kammuller , Bernd Freisleben, Self-Managing Application Composition for Cross-Platform Operating Environments, Proceedings of the International Conference on Autonomic and Autonomous Systems, p.37, July 19-21, 2006 [doi>10.1109/ICAS.2006.51]
• 10: S. Frenot and Y. Royon. Component deployment using a peer-to-peer overlay. In Component Deployment, volume 3798 of LNCS, 2005.
• 11: R. Kapitza, U. Bartlang, H. Schmidt, and F. J. Hauck. Dynamic Integration of Peer-to-Peer Services into a CORBA-Compliant Middleware. In OTM '06 Workshops, volume 4277 of LNCS, pages 28--29, 2006.
• 12: D. Parker and D. Cleary. A P2P approach to classloading in Java. In AP2PC '03, 2003.
• 13: J. S. Rellermeyer, G. Alonso, and T. Roscoe. R-OSGi: Distributed Applications Through Software Modularization. In Middleware '07, volume 4834 of LNCS. Springer, 2007.
• 14: Apache Software Foundation. Apache Felix. http://felix.apache.org/, 2008.
• 15: Eclipse Foundation. Equinox. http://www.eclipse.org/equinox/, 2008.

INDEX TERMS

Primary Classification:
  D. Software
  D.2 SOFTWARE ENGINEERING
        D.2.11 Software Architectures
            Subjects: Domain-specific architectures

Additional Classification:
  C. Computer Systems Organization
  C.2 COMPUTER-COMMUNICATION NETWORKS
      C.2.4 Distributed Systems
          Subjects: Distributed applications

General Terms:
Design

Keywords:
OSGi, automatic code selection, dependency resolution, dynamic loading of code, non-functional properties