GGF14, Chicago, IL June 2005 Experiences with WS-Transfer and WS-Eventing for Grids Marty Humphrey Glenn Wasson Computer Science Department University of Virginia GGF14 OGSA-MWS BOF June 28, 2005
GGF14, Chicago, IL June 2005 Some Goals of OGSA Leverage Web services tooling and run-time infrastructure Minimize the amount of “stuff” that our community has to provide and/or maintain Promote interoperability and composability
GGF14, Chicago, IL June 2005 WSRF.NET M. Humphrey, G. Wasson, K. Jackson, J. Boverhof, M. Rodriguez, J. Gawor, S. Lang, I. Foster, S. Meder, S. Pickles, and M. McKeown. State and Events for Web Services: A Comparison of Five WS-Resource Framework and WS-Notification Implementations. 14th IEEE International Symposium on High Performance Distributed Computing (HPDC-14), Research Triangle Park, NC, July 2005.State and Events for Web Services: A Comparison of Five WS-Resource Framework and WS-Notification Implementations
GGF14, Chicago, IL June 2005 Comparing WSRF to WS-Transfer et. al. Goal: Objective, scientific exploration and comparison of WSRF to WS-Transfer, WS- Eventing, et. al. M. Humphrey, G. Wasson, Y. Kiryakov, S-M. Park, D. Del Vecchio, N. Beekwilder, and J. Gray. Alternative Software Stacks for OGSA-based Grids. Proceedings of Supercomputing 2005, Seattle, WA, Nov 12-18, Alternative Software Stacks for OGSA-based Grids.
GGF14, Chicago, IL June 2005 Methodology Implement both stacks on.NET Comparing the specs Comparing the implementation of the specs Comparing the performance of the implementation of the specs
GGF14, Chicago, IL June 2005 Results: Comparing the Specs Lack of “create” in WSRF is problematic Lack of input/output schema in WS-Transfer is problematic WS-Transfer is less complex (implications?) WSRF: single “type” of resource; WS-Transfer is agnostic WS-Notification is more complex than WS- Eventing But much of WS-Notification is optional
GGF14, Chicago, IL June 2005 Results: Implementing the Specifications Both are resource-oriented, so not surprising that both are back-ended with an XML database (Xindice) WS-Transfer was easier to implement than WSRF Neither define a Programming model Not many implementations of WS-Notification are going to implement all of it
GGF14, Chicago, IL June 2005 Results: Micro-experiments
GGF14, Chicago, IL June 2005 WSRF.NET Grid-in-a-Box Client Reservation Service What resources are available for my application? Available Exec/Data Services Does this user have an account in this VO? Resource Allocation Service Create new reservation under client’s DN Data Service Create new data resource Stage-in data Start application Claim reservation by lengthening resource’s lifetime Reserve resources Exec Service Async. notification when done Proc Spawn Win Service WS-Resources are directories WS-Resources are processes WS-Resources are reservations Account Service WS-Resources are accounts WS-Resources are allocatable resources Data input/output Launch job Authorization based on DN, all messages X509 signed a 10b 9 11
GGF14, Chicago, IL June 2005 WSRF.NET Grid-in-a-Box GUI
GGF14, Chicago, IL June 2005 Results: Macro-Experiments
GGF14, Chicago, IL June 2005 Summary of Results Is one spec/implementation faster? No. Is one spec/implementation easier to program clients/services? No – both are complicated by resource vs. representation issue. Programming model is (arguably) orthogonal. Can WS-Transfer imply mapping too much to CRUD? Yes.
GGF14, Chicago, IL June 2005 Summary of Results If one is "more full-featured" than another, are the extra features useful? Jury is still out on the additional functionality of WSRF (brokered notification, service groups, lifetime management, resource property queries) How easy is it to switch from one stack to the other? Switching from WS-Transfer/WS-Eventing to WSRF/WS- Notification is likely easier.
GGF14, Chicago, IL June 2005 WSRF WST Translation via Server-Side Translation Filter WSRF Client (any platform) WSRF WS-T Web Service (.Net based) Web Service WS-T Translator Filter WSRF request WSRF response Works similarly for a WS-T client and a WSRF service.
GGF14, Chicago, IL June translate() WSRF request message WSRF WST Translation via Translation Service 2. WS-T equivalent 3. WS-T request TranslationService (.Net based) WSRF Client (any platform) WSRF WS-T Web Service (any platform) WS-T 4. WS-T response 5. translate() WS-T response message 6. WSRF equivalent
GGF14, Chicago, IL June 2005 Summary We have concrete experience that Grid services can be built via WS-Transfer et. al. Services comparable to WSRF-based services, in behavior and performance Microsoft et. al. has enumerated plans to build on WS-Transfer et. al. “these specs should be in a standards body within 1 year” OGSA needs the plumbing to be “just there” Is it time for an OGSA Profile based on WS-Transfer et. al.?