Dependable distributed OSGi environment

ABSTRACT

As the vision of Service Oriented Computing matures the need for well defined architectures and protocols is essential. The SOC paradigm has several requirements to work properly: service composition and cooperation in a loosely coupled fashion, ability to adapt autonomously to environmental and business changes, proper integration between services, modularity and service dynamics. The OSGi[13] platform embodies key aspects of the SOC paradigm by defining a modular and dynamic architecture. However there is still room for improvement, namely on the creation of architectures and mechanisms to improve the dependability of the platform by strengthening key properties such as availability, reliability, integrity, safety and maintainability.

In this paper we propose a OSGi based middleware layer that offers the strong modular and dynamic properties required in a SOC environment, while addressing dependability concerns. The starting point to achieve this is by instrumenting a OSGi implementation with means to monitor and manage it accordingly to business and environmental requirements. By relying on group communication facilities and some properties from the OSGi specification we are able to migrate OSGi environments among nodes, thus minimizing service outage in the presence of faults and addressing, at the same time, Service Level Agreement properties by migrating (or shutting down) services that are consuming more resources than agreed/expected.

REFERENCES

• 1: Anurag Acharya , M. Ranganathan , Joel H. Saltz, Sumatra: A Language for Resource-Aware Mobile Programs, Selected Presentations and Invited Papers Second International Workshop on Mobile Object Systems - Towards the Programmable Internet, p.111-130, July 08-09, 1996
• 2: Amazon. Amazon web services. http://aws.amazon.com/, 1996--2008.
• 3: N. Carvalho, J. Pereira, and L. Rodrigues. Towards a generic group communication service. In On the Move to Meaningful Internet Systems 2006: CoopIS, DOA, GADA, and ODBASE, pages 1485--1502. Springer Berlin / Heidelberg, 2006.
• 4: G. Czajkowski. Resource consumption management api. Technical report, Java Community Process (JSR'284), 2007.
• 5: M. Grogan. Scripting for the java platform. Technical report, Java Community Process (JSR'223), 2006.
• 6: M. Matos , A. Correia, Jr. , J. Pereira , R. Oliveira, Serpentine: adaptive middleware for complex heterogeneous distributed systems, Proceedings of the 2008 ACM symposium on Applied computing, March 16-20, 2008, Fortaleza, Ceara, Brazil [doi>10.1145/1363686.1364214]
• 7: Y. Royon, S. Frénot, and F. L. Mouel. Virtualization of service gateways in multi-provider environments. In Component-Based Software Engineering, pages 385--392. SpringerLink, 2006.
• 8: Takahiro Sakamoto , Tatsurou Sekiguchi , Akinori Yonezawa, Bytecode Transformation for Portable Thread Migration in Java, Proceedings of the Second International Symposium on Agent Systems and Applications and Fourth International Symposium on Mobile Agents, p.16-28, September 13-15, 2000
• 9: B. Steensgaard , E. Jul, Object and native code thread mobility among heterogeneous computers (includes sources), Proceedings of the fifteenth ACM symposium on Operating systems principles, p.68-77, December 03-06, 1995, Copper Mountain, Colorado, United States
• 10: The Apache Software Foundation. Apache felix. http://felix.apache.org/.
• 11: The Eclipse Foundation. Equinox. http://www.eclipse.org/equinox/.
• 12: The Knopflerfish Project. Knopflerfish. http://www.knopflerfish.org/.
• 13: The OSGi Alliance. Osgi service platform. http://osgi.org/osgi technology/download_specs.asp, Aug. 2005. Release 4.
• 14: Eddy Truyen , Bert Robben , Bart Vanhaute , Tim Coninx , Wouter Joosen , Pierre Verbaeten, Portable Support for Transparent Thread Migration in Java, Proceedings of the Second International Symposium on Agent Systems and Applications and Fourth International Symposium on Mobile Agents, p.29-43, September 13-15, 2000
• 15: I. Yamasaki. Monitoring and managing resource usage on osgi frameworks. In OSGi World Congress, 2005.

INDEX TERMS

Primary Classification:
  C. Computer Systems Organization
  C.2 COMPUTER-COMMUNICATION NETWORKS
      C.2.4 Distributed Systems

Additional Classification:
  D. Software
  D.2 SOFTWARE ENGINEERING
        D.2.11 Software Architectures

General Terms:
Design, Management

Keywords:
JAVA, OSGi, SOC, virtualization