IBM Corp. and several other vendors on Tuesday unveiled three specifications intended to converge Web services and grid computing.
Introduced at the GlobusWorld 2004 conference were WS-Notification, a Web services specification for triggering events in IT infrastructure; WS-Resource Lifetime, enabling a user to specify the period during which a resource definition is valid; and WS-Resource Properties, which defines how data associated with a stateful resource can be queried and changed using Web services technologies. All are part of a greater WS-Resource Framework (WSRF).
WSRF designs statefulness into Web services, said Daniel Sabbah, vice-president of software development and strategy at IBM. “That’s a pretty radical notion for those who have been around Web services for a while,” Sabbah said.
WSRF fills out the Web services stack to be consistent with the Open Grid Services Infrastructure, Sabbah said.
While WS-Notification is part of WSRF, IBM is referring to them separately because of the level of vendor involvement in the two proposals. Other vendors participating in the proposals are Hewlett-Packard, Sonic Software, Tibco, Akamai and The Globus Alliance.
WS-Notification and WSRF provide a standards-based infrastructure for business applications, grid resources, and systems management, according to IBM. The effort will provide a publish and subscribe messaging model and the ability to model “stateful” resources using Web services. Stateful resources are elements that can be modeled using physical entities such as servers to logical constructs such as business agreements.
Access to stateful resources enables customers to realize business efficiencies including time procurement with multiple suppliers, systems outage detection and recovery, and grid-based workload balancing, according to IBM.
“I view what’s been announced today as a culmination of months and months of effort” between the Web services and grid communities, said Charles Catlett, chairman of the Global Grid Forum.
An analyst noted similarities between WSRF and the recent WS-Eventing proposal.
“On the face of it, one would think that WS-Notifications competes with the WS-Eventing spec, and you’d be right — on the face of it, it does,” said Ronald Schmelzer, senior analyst at ZapThink, in an e-mail. “These two specs will probably not be used together in [a] specific implementation. WS-Eventing, recently announced by Microsoft, BEA, Tibco, and others, also seeks to address standards-based, pub/sub messaging and provides a dictionary for defining the events themselves.”
“It was conspicuous that IBM was absent from that announcement, and now we know why: IBM was working on (its) own spec, WS-Notification,” Schmelzer said.
Specifications to be added to WSRF later this year are WS-Base Faults, providing a way of surfacing faults in the execution of resources and Web services; WS-Renewable References, providing life cycle management for resource identifiers; and Service Groups, for clustering of services in the WSRF.
WSRF is to be submitted to a standards organization such as OASIS in approximately three to six months, following implementations and interoperability tests, Sabbah said.