Ranking of Web Services Eyhab Al-Masri

Outline Discovery of Web Services 1 Ranking of Web Services 2 Approaches 3 Conclusion 4 Q & A 5

Eyhab Al-Masri Web Service Properties  Self-Describing  Service interaction must be well defined through an interface Well Documented Human Readable  Self-Discoverable  Simple mechanism to publish info  Easy way to find services  Efficient way to interact with Web services

Eyhab Al-Masri Current Web Service Architecture Service Provider Service Registry Service Consumer Publish Find Interact Implements the service and makes it available over the Internet Central directory for publishing and finding services Consumer of a service

Eyhab Al-Masri UDDI Business Registry (UBR)  UDDI:  Universal Description, Discovery, and Integration  Central location for publishing, managing, and discovering Web services  A focal point where all businesses of all sizes can meet in an open, global framework  As the number of Web services increase, the success of businesses will depend on service discovery

Eyhab Al-Masri UDDI Business Registry (UBR)  UBR APIs should be able to:  Effective search functionality  Enable clients to choose between two implementations of Web service based on quality of service metrics  Provide multiple search techniques (i.e. search by name, by category, contextual information, etc…)  Provide a mechanism for outputting desired Web services

Eyhab Al-Masri UDDI Business Registry (UBR) UBR v 3.0 Current Status Centralized or decentralizedDecentralized Can Associate Web services specific measurements? No Standard mechanism Abstract LevelVery Abstract Search techniquesVery basic Any guarantee to quality of published information No. Registration is voluntary Range-based searchingNo Support for versioningNo Caching?No Validate, govern, and secure Web services? No

Eyhab Al-Masri UDDI Business Registry (UBR) Clients will be unable to distinguish Web services from one another UBR limitations Depending on keyword matching (which is very limited), clients will be flooded with results Clients will take longer to find relevant Web services Service providers may not have enough visibility

Eyhab Al-Masri UDDI Business Registry (UBR) Limited UBR Features Discovering Web services will be less productive Discovery results become inaccurate Finding relevant Web services will be very time consuming Locating information will be a challenging task Business collaboration will not be cost effective Discovering Web services becomes unreliable “… UBR got passed around like a bad cold and it ended up hooking up with the wrong people…” Miko Matsumura, Vice President Infravio Inc & Chair OASIS SOA Blueprints Technical Committee From “Who Killed UBR” 2006 – SearchWebSevices.com

Eyhab Al-Masri What is a possible solution?  One apparent solution is to think of a way to “differentiate” between Web services  How ?  Ranking Ranking is an important part of many information retrieval systems Discovery of Web services involves the collection and retrieval of information, therefore, a ranking mechanism becomes extremely significant

Eyhab Al-Masri Ranking of Web Services As Web services proliferate: I.UDDI Business Registries will be filled with millions of published Web services

Eyhab Al-Masri Ranking of Web Services II.Decentralizing UBRs will add to the already existing problem of finding relevant Web services UDDI.org: UDDI Products and Components

Eyhab Al-Masri Ranking of Web Services III.Without a ranking mechanism, it will become very common that search queries will return thousands if not millions of results, a common dilemma faced with regular Web searches. Google.com’s search for “Web” keyword

Eyhab Al-Masri Ranking of Web Services IV.The nature of how service registries operate makes the querying technique different from the ones used on the Web and other traditional information retrieval systems UDDI.org (Service Discovery - - Section 2.1)

Eyhab Al-Masri Approaches  QoS-based:  Measure QoS for Web services  Allow Clients to search for Web services by specifying QoS parameters (i.e. search for all Web services that have the keyword ‘weather’ in Guelph with 99% reliability”)  Liu, Y., Ngu, A.H., Zeng, L., QoS computation and policing in dynamic web service selection, Proceedings of the 13th international World Wide Web conference on Alternate track papers & posters, May 19-21, 2004, New York, NY, USA.  Zeng, L., Benatallah, B., Dumas, M., Kalagnanam, K., and Sheng, Q.Z., Quality Driven Web Services Composition Proc. 12th Int'l Conf. World Wide Web (WWW), May 2003.

Eyhab Al-Masri Approaches  Caverlee, J., Liu, L., and, Rocco, D., Discovering and ranking web services with BASIL: a personalized approach with biased focus, Proceedings of the 2nd international conference on Service oriented computing, November 15-19, 2004, New York, NY, USA  Uses two distinct techniques:  Categorization  Personalized relevance  Ranks highly relevant data services and measures the relevance between services using a series of biased probing methods.  E. Rahm and P. A. Bernstein. A survey on approaches to automatic schema matching. VLDB Journal, 10(4),  tries to collected information about the semantics of the schemas, and provide analysis based on them. Analysis includes: linguistic analysis, structural analysis, domain knowledge  Lu, H., Semantic Web Services Discovery and Ranking, Web Intelligence, 2005  Semantic discovery and ranking of Web services through a sequence of types in its inputs and output variables and using a partial matching technique

Eyhab Al-Masri Conclusion 1 As the number of Web services increase, the success of businesses will depend on service discovery. 2 It is a crucial to provide effective means to distinguish between Web services particularly if they share similar functionalities. 3 Providing a ranking mechanism for Web services is inevitable and can significantly enhance the discovery process by outputting desired services within top results.

Q & A