Say the words "Web services," and the three things that will come to most developers minds are UDDI (Universal Description, Discovery and Integration), electronic business XML and SOAP. Not many people would include LDAP, yet the directory protocol might provide the key to building a solid Web services infrastructure.
LDAPs primary strengths—maturity, reliability, scalability and security—are still scarce in current Web services standards. These key attributes should make LDAP a major contributor in the near future, and several heavy hitters are working on doing just that.
On the standards front, Novell Inc. has issued the draft specification "LDAP Schema for UDDI," which aims to formalize the role of LDAP in Web services by extending LDAPs schema. (Go to www.eweek.com/links to see a copy of the draft.)
In particular, the draft defines schema elements to represent the following UDDI data types: BusinessEntity, BusinessService, BindingTemplate, tModel and Publisher Assertion.
On the product front, Sun Microsystems Inc.s new Sun ONE (Open Net Environment) Registry Server, which made its debut early this summer in the Sun ONE Developer Platform, allows IT managers to store UDDI repositories in an LDAP directory.
In addition to its evolving function in UDDI, LDAP will continue to play a central role in Web services security by acting as a central user identity store for large-scale Web services deployments.
Meanwhile, LDAP may move toward using a Web services-based interface as a directory synchronization technology (something Novell is already doing with its DirXML) and as an alternate query mechanism to the LDAP native query APIs.
LDAP will also play a role in efforts (principally at Microsoft, IBM and Systinet Corp.) to allow Web services servers to pass user credentials among themselves to create a chain of Web services.