1. Web Services BOF This is a proposed new working group coming out of the Grid Computing Environments Research Group, as an outgrowth of their investigations of grid portals. Why Web Services ? Use of industry standards HTTP, HTTPS, XML, SOAP, WSDL, UDDI, … Support for many languages Compiled and scripted Self describing protocols easier management of versioning, evolution Support for authentication Strong Industry Support: Microsoft’s.NET initiative SUN’s ONE (Open Net Environment)

2. Web Browser XML to HTML servlet Web Service Application Web Service Grid Service Local Backend Services (batch, file, etc.) Web Server (Portal) Authenticated connections Remote Web Server Web Service Storage system Grid resources, e.g. Condor Batch system A three / four tier web services architecture

3. XML technologies Advantages Self describing data (contains meta data) Facilitates heterogenous systems Robust against evolution (no fragile versioning that distributed object systems encounter) New server generates additional tags which are ignored by old client New client detects absence of new tags & knows it is talking to an old server (and/or supplies defaults) Capable of defining all key concepts and operations for both client-server and client-portal communications Technologies XML – eXtensible Markup Language SOAP – Simple Object Access Protocol (~modern rpc system) WSDL – Web Services Description Language (~idl) UDDI – Universal Description, Discovery and Integration

4. Proposed New Working Group Activities 1) Investigate application of the latest web technologies to grid computing: XML, SOAP, WSDL, UDDI (Result: report) 2) Investigate options for authentication with web servers in the context of these technologies, including credential forwarding, proxy credential repositories, single sign-on (Result: report) 3) Set up a limited testbed of multiple sites and servers to demonstrate a small number of web services: batch system interface(s) data management interface(s) shared UDDI server (as if this were a "virtual organization“) and clients: web browser, human readable output (portal interactions) custom client with use of SOAP client libraries (Result: report, working demonstration code)