UNIT 10
UDDI
It is a directory service where businesses can register and search for Web services.
- A UDDI registry service is a Web service that manages information about service providers, service implementations, and service metadata.
- Service providers can use UDDI to advertise the services they offer.
- Service consumers can use UDDI to discover services that suit their requirements and to obtain the service metadata needed to consume those services.
The Specifications define:
- SOAP APIs that applications use to query and to publish information to a UDDI registry
- XML Schema schemata of the registry data model and the SOAP message formats
- WSDL definitions of the SOAP APIs
- UDDI registry definitions (technical models - tModels) of various identifier and category systems that may be used to identify and categorize UDDI registrations
UDDI has two functions:
- A SOAP-based protocol defines how clients communicate with UDDI registries.
- It is a particular set of global replicated registries.
A business or a company can register three types of information into a UDDI registry. This information is contained in three elements of UDDI. The three elements are white pages, yellow pages and green pages.
Information | Operations | Detailed information (supported by lower-level API) |
White pages: Information such as the name, address, telephone number, and other contact information of a given business | Publish: How the provider of a Web service registers itself. | Business information: Contained in a BusinessEntity object, which in turn contains information about services, categories, contacts, URLs, and other things necessary to interact with a given business. |
Yellow pages: Information that categorizes businesses. This is based on existing (non-electronic) standards | Find: How an application finds a particular Web service. | Service information: Describes a group of Web services. These are contained in a BusinessService object |
Green pages: Technical information about the Web services provided by a given business. | Bind: How an application connects to, and interacts with, a Web service after it's been found | Binding information: The technical details necessary to invoke a Web service. This includes URLs, information about method names, argument types, and so on. The BindingTemplate object represents this data. Service Specification Detail: This is metadata about the various specifications implemented by a given Web service. These are called tModels in the UDDI specification |
It consists of three parts −
- UDDI Data Model- is an XML schema for describing businesses and web services.
- UDDI API Specification - For searching and publishing UDDI data.
- UDDI Cloud Services – Specification of API for searching and publishing UDDI data.
UDDI Cloud Services
These are operator sites that provide implementations of the UDDI specification and synchronize all data on a scheduled basis.
- The UDDI Business Registry (UBR), also known as the Public Cloud, is a conceptually single system built from multiple nodes having their data synchronized through replication.
- The data submitted to one root node will automatically be replicated across all the other root nodes. Currently, data replication occurs every 24 hours.
- UDDI cloud services are currently provided by Microsoft and IBM.
- It is also possible to set up private UDDI registries.
Applications
- Enables organizations to standardise the way businesses organize discover, reuse and manage web services across the company.
- Provides centralized control of how web services are managed once these web services are deployed.
- Powerful means of organizing and sharing web services.
- Strong mechanism for promoting reuse and preventing unnecessary invention.
- With dynamic binding an application queries UDDI registry to determine the current binding information for the services it needs.
