1 / 25

Background

State and Events for Web Services: A comparison of Five WS-Resource Framework and WS-Notification Implementations. Marty Humphrey, Glenn Wasson, JarekGawor, Joe Bester, Sam Lang, Ian Foster, Stephen Pickles, Mark McKeown, Keith Jackson, Joshua Boverhof, Matt Rodriguez, Sam Meder.

evonne
Download Presentation

Background

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. State and Events for Web Services: A comparison of Five WS-Resource Framework and WS-Notification Implementations Marty Humphrey, Glenn Wasson, JarekGawor, Joe Bester, Sam Lang, Ian Foster, Stephen Pickles, Mark McKeown, Keith Jackson, Joshua Boverhof, Matt Rodriguez, Sam Meder. Presented by Jonatan Alava

  2. Background • What are web services? • What is WSRF? • What is WSN? • And what do they have to do with Grids?

  3. Web Services • Designed to support interoperable machine-to-machine interaction over a network. • Uses a previously described interface (WSDL). • Communicates using messages via HTTP enclosed in a SOAP envelope. • Allows intercommunication amongst different platform and/or programming languages. • OASIS and the W3C responsible for the standardization of web services. • WS-I established to improve interoperability.

  4. WSRF • Stands for Web Services Resource Framework • Improves on the concept of Web Services by creating a separate view for the resource state. • Simplifies WSDL and reduces message size and complexity (XML gets heavy and complicated fast)

  5. WSRF Specification • WSRF Resource Properties. • WSRF Resource Lifetime. • WSRF Base Faults. • WSRF Service Group.

  6. WSN • Define a set of specifications that standardize the way Web services interact. • Foundations for Event Driven Architectures built using Web services. • "Publish/Subscribe for Web services".

  7. WSN Specification • WS-BaseNotification • WS-Topics • WS-BrokeredNotification

  8. GT1 Grid GT2 OGSI Started far apart in apps & tech Have been converging WSRF WSDL 2, WSDM WSDL, WS-* Web HTTP Web Services and Grids - OGSA • OGSI problems solved by WSRF

  9. OGSA and WSRF • Open Grid Services Architecture • The Physiology of the Grid by Ian Foster, Carl Kesselman, Jeffrey M. Nick and Steven Tuecke • Service Orientation and Virtualization.

  10. Implementations Compared • GT4-Java (Argonne) • GT4-C (Argonne) • pyGridWare(Lawrence Berkeley Labs) • WSRF::Lite(University of Manchester) • WSRF.NET (University of Virginia)

  11. Comparison Parameters • Transport and SOAP processing. • Security Issues. • WS Dispatch and Container. • Persistence. • Finding/Discovering WS. • Lifetime Management. • Programming and Tooling. • WS-Notification.

  12. Canonical Architecture

  13. Key Features

  14. Notable fact • Reuse of existing tools: • GT4-Java: Apache Axis, Tomcat • GT4-C: libxml2 • pyGridWare: Zolera(ZSI), Twisted • WSRF::Lite: SOAP::Lite • WSRF.NET: IIS, ASP.NET, WSE

  15. Similarities in Resource Persistence • By default GT4-Java, GT4-C, pyGridWare and WSRF::Lite use in-memory store. • Only WSRF.NET uses database store by default. • All of them offer customization possibilities for the persistence store.

  16. Differences in Resource Indexing and Retrieval • GT4-Java and pyGridWare provide ResourceHome interface. • WSRF.NET uses db queries to find resources based on resource name or resource state. • GT4-C and WSRF::Lite provide own interface and default implementations.

  17. Differences in Lifetime Management • GT4-Java and pyGridWare use containers timers to periodically purge resources • GT4-C uses GT4-C common lib timing functions • WSRF::Lite varies by resource store • WSRF.NET uses a windows service to periodically perform database deletion queries

  18. WSN Issues • Not all WSN specs implemented by all. • WSRF.NET only implementation that includes complete WSN features. • GT4-Java and pyGridWare implement WS-BaseNotification and WS-Topics. • GT4-C implements client-side notification only. • WSRF::Lite currently does not support WSN.

  19. Performance Test • Systems implemented a Counter Service. • Single Resource Property: “counter_val” • GetRPtest → get counter’s value. • SetRPtest → set counter’s value. • Create test → create new counter resource. • Destroy test → destroy resource. • Notify test → send state change notifications to subscribed clients.

  20. Test Scenarios • 6 test scenarios • Client and Service on same machine or on separate machines with: • No security. • Transport security. • Message security.

  21. Performance Evaluation (NO SECURITY) No Security

  22. Performance Evaluation (TRANSPORT SECURITY) Transport Level Security

  23. Interoperability • Many issues in interoperability. • At the time the paper was published the implementation were using different versions on WSRF. • Non trivial problem for the future due to problems outside the scope of WSRF.

  24. In Closing • Paper offers a very brief look at WSRF implementations in the context of OGSA. • Not a real comparison of advantages and disadvantages.

  25. References • Wikipedia. www.wikipedia.com • WS-Resource Framework:Globus Alliance Perspectives a presentation by Ian Foster found at www.globus.org • Web Services Resource Framework (WSRF) – Primer from OASIS found at docs.oasis-open.org/wsrf/wsrf-primer-1.2-primer-cd-01.pdf • W3C at www.w3c.org • Web Service Notification (WSN) – Specification from OASIS found at docs.oasis-open.org/wsn/wsn-ws_base_notification-1.3-spec-pr-02.pdf • State and Events for Web Services:A Comparison of Five WS-Resource Framework and WS-Notification Implementations a presentation by Glenn Wasson from the 14th IEEE International Symposium on High Performance Distributed Computing (HPDC-14) found at www.caip.rutgers.edu/hpdc2005/presentations/session1-gwasson.pdf

More Related