Using the service coroner tool for diagnosing stale references in the OSGi platform

ABSTRACT

The OSGi Service Platform is becoming the de facto middleware for the deployment of dynamic modular Java-based applications. It gives the possibility to install, to activate, to update and to uninstall application modules without needing to restart the host Java Virtual Machine. However, modules run on the memory space, and it is not possible to ensure that objects from unavailable (e.g. uninstalled) modules will no longer be referenced, since it depends on developers to correctly provide code that will handle the corresponding OSGi events which inform the departure of a module. Such errors, resulted from the mishandling of the dynamic arrival and departure of modules, are a hard to detect problem described in the OSGi specification as Stale References. It may lead to inconsistencies in application's behavior, state and memory. So far there were no tools addressing the diagnostics of this issue. In this demo we present the live utilization of our experimental tool, Service Coroner, which helps OSGi application developers and administrators in the diagnosis of stale references. Our presentation focus on the diagnosis of actual OSGi based applications that present the occurrence of stale references upon dynamic updates of modules.

REFERENCES

• 1: OSGi Alliance. http://www.osgi.org
• 2: O. Gruber , B. J. Hargrave , J. McAffer , P. Rapicault , T. Watson, The Eclipse 3.0 platform: adopting OSGi technology, IBM Systems Journal, v.44 n.2, p.289-299, January 2005
• 3: Mikael Desertot , Didier Donsez , Philippe Lalanda, A Dynamic Service-Oriented Implementation for Java EE Servers, Proceedings of the IEEE International Conference on Services Computing, p.159-166, September 18-22, 2006 [doi>10.1109/SCC.2006.4]
• 4: K. Gama and D. Donsez. A Practical Approach for Finding Stale References in a Dynamic Service Platform. In 11th International Symposium on Component Based Software Engineering (CBSE 2008). Springer LNCS volume 5282, 2008.
• 5: K. Gama and D. Donsez. Service Coroner: A Diagnostic Tool for Finding OSGi Stale References. In Proceedings of the 34th EUROMICRO Conference on Software Engineering and Advanced Applications (SEAA). IEEE, 2008.
• 6: G. Kiczales, J. Lamping, A. Mendhekar, C. Maeda, C. V. Lopes, J. M. Loingtier, J. Irwin: Aspect-Oriented Programming. In: M. Akşit, S. Matsuoka (eds.) ECOOP 1997. LNCS, vol. 1241. Springer, Heidelberg (1997)
• 7: The AspectJ Project. http://www.eclipse.org/aspectj
• 8: Apache Felix. http://felix.apache.org
• 9: Equinox Framework. http://www.eclipse.org/equinox/framework
• 10: Knopflerfish OSGi. http://www.knopflerfish.org
• 11: JOnAS Open Source Java EE Application Server, http://jonas.objectweb.org
• 12: SIP Communicator, http://www.sip-communicator.org
• 13: Newton Framework, http://newton.codecauldron.org
• 14: Zebin Chen , Stephen Fickas, Do No Harm: Model Checking eHome Applications, Proceedings of the 29th International Conference on Software Engineering Workshops, p.194, May 20-26, 2007 [doi>10.1109/ICSEW.2007.88]

INDEX TERMS

Primary Classification:
  D. Software
  D.2 SOFTWARE ENGINEERING
      D.2.5 Testing and Debugging
          Subjects: Diagnostics

General Terms:
Experimentation, Verification

Keywords:
OSGi, aspect oriented programming, services platform, stale references