This section contains the following topics:
UDDI stands for Universal Description, Discovery, and Integration. The UDDI Project is an industry initiative which aims to enable businesses to quickly, easily, and dynamically find and carry out transactions with one another.
A populated UDDI registry contains cataloged information about businesses; the services that they offer; and communication standards and interfaces they use to conduct transactions. A UDDI registry provides a standards-based foundation infrastructure for locating services, invoking services, and managing metadata about services (security, transport, or quality of service). The UDDI registry can store and provide these metadata using arbitrary categorizations. These categorizations are called taxonomies.
UDDI registries are used in an enterprise to share Web Services. Using UDDI registries helps companies organize and catalog Web Services for sharing and reuse in an enterprise or with trusted external partners. The UDDI version 3.0 specification is available at:
http://www.oasis-open.org/committees/uddi-spec/doc/tcspecs.htm#uddiv3. UDDI registries are based on this specification, which provides details on how to publish and locate information about Web Services using UDDI. The specification does not define run-time aspects of the services (it is only a directory of the services). UDDI provides a framework in which to classify your business, its services, and the technical details about the services you want to expose.
Publishing a service to a registry requires knowledge of the service type and the data structure representing that service in the registry. A registry entry has certain properties associated with it and these property types are defined when the registry is created. You can publish your service to a registry and make it available for other organizations to discover and use. Proxy services developed in ALSB can be published to a UDDI registry. ALSB can interact with any version 3.0-compliant UDDI registry. BEA provides the AquaLogic Service Registry.
Figure 7-1 illustrates the integration of ALSB with a UDDI registry.
The ALSB Web-based interface to AquaLogic Service Registry makes the registry accessible and easy to use. In working with UDDI, ALSB promotes the reuse of standards-based Web Services. In this way, ALSB registry entries can be searched for, discovered, and used by multiple domains. Web Services and UDDI are built on a set of standards, so reuse promotes the use of acceptable, tested Web Services and application development standards across the enterprise. The Web Services and interfaces can be catalogued by type, function, or classification so that they can be discovered and managed more easily.
UDDI is based upon several established industry standards, including HTTP, XML, XML Schema Definition (XSD), SOAP, and WSDL. The UDDI specification describes a registry of Web Services and its programmatic interfaces. UDDI itself is a set of Web Services. The UDDI specification defines services that support the description and discovery of:
A UDDI registry stores data and metadata about business services. A UDDI registry offers a standards-based mechanism to classify, catalog, and manage Web Services so that they can be discovered and consumed by other applications. UDDI offers several benefits to IT managers and developers at both design time and run time, including the following:
UDDI uses a specific data model to represent entities that define organizations and services. Figure 7-2 shows the relationships between different UDDI entities.
Table 7-1 provides a high-level overview of UDDI entities.
Represents functionality or resources provided by a business entity. A business service is described by a name, a description, and a set of categories that represent the function of the service. A business service in a UDDI registry does not necessarily represent a Web Service. The UDDI registry can register arbitrary services, for example EJB, CORBA, and such.
Represents the technical details of how to invoke a business service. A business service can contain one or more binding templates. Binding templates are described by access points representing service endpoints (the endpoint URI and protocol specification), tModel instance information, and categories to reference specific features of the binding template.
Represents a technical specification; typically a specifications pointer, or metadata about a specification document, describing how services must be represented in the UDDI registry. The description of a service includes a name, a description, an overview document (a reference to a document specifying the purpose of the
For more information on the UDDI data model and entities used in UDDI, seein BEA AquaLogic Service Registry 3.0 User’s Guide. See also in WebLogic Web Services: Advanced Programming.
The following are two sample business scenarios that highlight the benefit of using UDDI.
This scenario shows how you can use ALSB to import services from a registry and then publish ALSB proxy services back to the registry. See Figure 7-3.
ALSB imports business services from a UDDI registry. Proxy services are configured to communicate with the business services in the proxy service message flow. The proxy services can then be published back to the registry and made available for use by other domains.
This scenario shows cross-domain deployment using ALSB. In this scenario, an ALSB application in one domain requires access to an ALSB service in another domain at run time. See Figure 7-4.
An instance of ALSB is deployed in each of two domains. The ALSB proxy service (P1) is configured in domain (D1). The ALSB proxy service (P2) in domain (D2) requires access to proxy service (P1). As the domains cannot communicate directly with each other, P2 in D2 cannot use P1 in D1. The ALSB import and export feature does not support run-time discovery of services in different domains, but publishing the service to a UDDI registry allows the discovery and use of a service in any domain. Once P1 is made available in the UDDI registry it can be invoked at run time (for example, get a stock quote) and imported as a business service in another ALSB proxy service.
When importing and exporting from different domains you should have network connectivity. A proxy service might reference schemas located in the repository of a different domain, in which case you need HTTP access to the domain to import it using the URL. In the absence of connectivity an error message is returned.
ALSB works with any UDDI registry that is compliant with the version 3.0 implementation of UDDI. AquaLogic Service Registry 2.1 is a V3.0-compliant UDDI registry and is certified to work with ALSB.
Using the ALSB Console or ALSB Plug-in for WorkSpace Studio, you can:
For detailed procedural information, see the following topics in Using the AquaLogic Service Bus Console:
The typical workflow for using a UDDI registry with ALSB is as follows:
|Note:||AquaLogic Service Registry is not provided with ALSB. In order to use AquaLogic Service Registry you have to buy a separate licence from BEA. For more information on the management of AquaLogic Service Registry, particularly configuring the registry and managing permissions, approval, and replication, see.|
You can configure a UDDI registry, make it available in ALSB, and then publish ALSB proxy services to it or import business services from the registry to be used in a proxy service. You must be in an active session in the ALSB Console to configure the registry. For detailed information, see:
When publishing services to AquaLogic Service Registry, you need a valid user name and password for authentication to gain access to the registry. The user name and password combination is implemented as a service account resource in ALSB. You must define service accounts before configuring proxy services. Seein Using the AquaLogic Service Bus Console.
You can set up registries with multiple user names and passwords allowing different users to have different permissions based on the associated service accounts. In BEA AquaLogic Service Registry, administrators manage user privileges and create views into the registry, specific to the needs of different users. In ALSB, user permissions govern access to the registries, their content, and available functionality.
You can use the ALSB Console or the ALSB Plug-in for WorkSpace Studio to publish proxy services to the AquaLogic Service Registry. To do this you must have a user account set up in AquaLogic Service Registry. You can publish any proxy service to a UDDI registry. The permitted service types and transports are listed in Table 7-2.
You can select the Business Entity under which a service is to be published. Business Entity Administration (including creation, removal, update, and deletion of entities) is done using the management console provided by the registry vendor (for example, the Business Service Console of AquaLogic Service Registry). The first time you publish to a registry you must load the
tModels to that registry. You do this when you configure the publishing details in the ALSB Console or ALSB Plug-in for WorkSpace Studio. For more information on how to publish to a UDDI registry, see in Using the AquaLogic Service Bus Console.
|Note:||An error can occur when you attempt to import a service from a UDDI registry if that service was originally published to the registry from an ALSB cluster in which any of the clustered servers uses the localhost address. Specifically, when the service being imported references a resource (WSDL or XSD) which references other resources (WSDL or XSD).|
|Note:||Ensure that before you publish services to a UDDI registry from a clustered domain, none of the servers in the cluster use localhost in the server addresses. Instead, use either the machine name or the IP address.|
You can now publish local proxy services to UDDI so you can associate them with ALSB generic proxy services. For example, you might have an any SOAP or any XML generic proxy service that dynamically routes to multiple local transport proxy services with concrete WSDLs. Alternatively, you might have a generic proxy service in Enterprise Service Bus (ESB) 1 that dynamically routes to a generic proxy service in ESB 2 where the business service is attached. From the UDDI registry, you can get the WSDL of the local proxy service and the URL of the any SOAP or any XML generic proxy service. Combining the WSDL and URL creates an effective WSDL for sending messages to the local proxy service through the generic proxy service.
When you create a proxy service you can configure it to be published automatically to a default UDDI registry. You must first set up a default registry. See Using the AquaLogic Service Bus Console.in
To enable the auto-publish feature for individual proxy services, you select the Publish To Registry check box on the Create a Proxy Service-General Configuration page. When you enable the Publish To Registry option, the proxy service is published to the default registry upon session activation. If the UDDI registry is unavailable, the publish action is retried. Any further changes to the proxy service resets the retry attempts. When a proxy service is republished to a UDDI registry, all taxonomies and categorizations, which are defined in UDDI for the proxy service, are preserved.
When you change the default registry, all the proxy services that have auto-publish enabled will be published to the new default registry. Synchronization then takes place with the current default registry. When a proxy service is not synchronized, the ALSB Console displays a unsynchronized icon.
|Note:||When you have a default registry and you import a
You can import services from a registry as ALSB business services. When importing a WSDL-based service, if multiple UDDI binding templates are encountered, ALSB creates a different business service for each binding template.
To establish access to UDDI registries in ALSB you must have ALSB IntegrationAdmin or IntegrationDeployer privileges. Seein the AquaLogic Service Bus Security Guide. The registry entries are located on the System Administration > Import from UDDI page in the ALSB Console. When importing, you select from the list of available registries. To discover a service in a registry you must query a specific registry. Entries in registries are unique. The query is performed when you specify what registry you want to use for importing a service.
You can import the following business services types from a UDDI registry into ALSB:
For information on how to use the ALSB Console to import services from a UDDI registry, see:
When a service is updated, you must re-import the service from the registry to get the most recent version, unless you have selected the Enable Auto Import option to auto-synchronize imported services with the UDDI registry. Any service that is imported with this option selected will be kept in synchrony with the UDDI registry. See Auto-Synchronization of Services With UDDI. If there is any failure during auto-synchronization, it will be reported on the Auto-Import Status page where you can update it manually.
Services have documents associated with them and these documents can include a number of other documents (schemas, policies, and so on). On import, the UDDI registry points to the document location based on the inquiry URL of the service. When a document that includes or references other resources is located, all of the referenced information and each included item is added as a separate resource in ALSB.
Business Entity and pattern are the criteria used to search for a service in a registry. For example, you can enter
foo%, when searching for a service. Services published by ALSB have specific
tmodel keys identifying the services that you use when searching for the service in the registry.
The Business Entity is the highest level of organization in the registry, though you can use other search criteria, such as business, application type, and so on. If you require authentication, then you need a user name and password which you must get from your system administrator.
http://www.oasis-open.org/committees/uddi-spec/doc/tns.htm. The note on Using WSDL in a UDDI Registry is important.
tModels) of various identifier and category systems that may be used to identify and categorize UDDI registrations
You can use the auto-import feature to synchronize the business services, which are imported from the AquaLogic Service Registry, with the corresponding services in the registry. Seein Using the AquaLogic Service Bus Console.
|Note:||Auto-import is available only in the ALSB Console, not in the ALSB Plug-in for WorkSpace Studio.|
You can use the Auto Import Status page to do the following:
You can synchronize the services you have imported from the registry. If the services in the registry change, you can synchronize services in the ALSB Console with those in the registry. The following use case illustrates the process of synchronization. If the business service is not detached from the registry, ALSB automatically subscribes to any changes to the service in the registry. If the service changes, a unsynchronized icon appears in the Resource Browser and Project Explorer indicating that the service needs to be synchronized. In addition, the Auto Import Status page shows this service and provides options for synchronizing the service or detaching it from the registry. Under certain circumstances, synchronizing the service might result in semantic validation errors that show up on the View Conflicts page. You will have to fix these errors before activating the session.
When a service is synchronized, the service is updated only with fields that are obtained from UDDI. Other fields in the service definition will preserve their values if modified since last import.
Consider a scenario where you publish services from Domain1 to a registry (see Figure 7-5). You then import these services from the registry into a domain, Domain2. Then you make changes to the services in Domain1 and update them in the registry. You can update the services in Domain2 by synchronizing them with the registry using the auto-import feature.
Sometimes you do not want the service in the ALSB Console to be synchronized with the corresponding service in the registry. You can avoid synchronization by detaching the service from the registry. Seein Using the AquaLogic Service Bus Console.
You can keep the service definitions in ALSB automatically synchronized (both ways) with those in UDDI.
Services can be automatically published to a UDDI registry after they are created or changed within ALSB and business service definitions can be imported from UDDI and automatically updated when the original service is changed in UDDI. Alternatively, you can configure the ALSB Console or the ALSB Plug-in for WorkSpace Studio to prompt you for approval for synchronization when a service changes in the UDDI registry.
When configuring a registry, select the Enable Auto Import option to auto-synchronize imported services with the UDDI registry. Any service that is imported with this option enabled will be kept in synchrony with the UDDI registry automatically. If there is any failure during auto-synchronization, it is reported on the Auto-Import Status page where you can update it manually. Seein Using the AquaLogic Service Bus Console.
ALSB proxy service attributes must be mapped to the data model supported by the UDDI registry to allow a proxy service to be published as a UDDI business entity. The following table shows the service types, message types, and transports relevant to the UDDI registry mapping for an ALSB proxy service.
|Note:||Optional parts are listed in parentheses. Messaging services can have different content for requests and responses, or can have no response at all (one-way messages). E-mail, File, SFTP, and FTP should be one-way.|
Proxy services have attributes in common and also attributes that are specifically defined by the transport protocols used by the service and the type of service. Each proxy service can deliver messages of a certain type.
The primary relevant entities in UDDI are:
Figure 7-6 shows how WSDL-based services are mapped to UDDI business entities.
The technical note on Using WSDL in a UDDI registry, version 2.0.2, at
http://www.oasis-open.org/committees/uddi-spec/doc/tns.htm, is used as the basis for publishing WSDL-based proxy services to the UDDI registry. This document is also used as a reference point for publishing non-WSDL based services. The document and the base UDDI specification describe the canonical technical models (
tModels) used to describe UDDI entities. To publish ALSB proxy services as entities in the UDDI registry, you must provide additional canonical tModels to support some of the constructs specific to ALSB. Not all attributes of an ALSB proxy service are useful when searching for a service, for example, service type and transport details. These attributes do not categorize the service.
tmodels are configuration details of the service once it has been discovered. These configuration details are mapped to the business service binding template
tmodelinstanceDetails section. Other attributes specifically identify a service and can be used as the search criteria for the service. These attributes are mapped using keyed references to
tModels with values in the
categoryBag of the binding template.
An example of how ALSB maps to UDDI is shown in Figure 7-7.
ALSB high-level proxy service information maps to the business service as follows:
keyedReferenceGroupfor ALSB properties. An example of a key is
keyedReferencesin the service category. An example of a key is
keyedReferencein the ALSB
keyedReferenceGroup(Name = “
AquaLogicServiceBus”, Values = URL of the ALSB instance).
Listing 7-1 shows a mapping of high-level proxy service information to a business service.
keyName="Service Bus Instance"
|Note:||The key for the businessService created when a proxy service is published is a publisher assigned key name. It is derived from the ALSB domain name, the path of the proxy service, and the proxy service name. It takes the following form:|
|Note:||For example, AnonESBan, which is a domain in ALSB, contains a project named Proxy, which contains a folder named Accounting, which in turn contains a proxy service called PayoutProxy. When PayoutProxy is published to UDDI, its businessService is created with the following key:|
ALSB detailed proxy service information maps into the binding template as follows:
Listing 7-2 shows a detailed information mapping to the binding template.
<bindingTemplate bindingKey="uddi:" serviceKey="uddi:">
<property name="fileMask" value="*.*"/>
<property name="sortByArrival" value="false"/> </ALSBInstanceParms>
<property name="requestType" value="XML"/>
<property name="RequestSchema" value="http://domain.com:7001
<property name="responseType" value="None"/></ALSBInstanceParms>
Each of the transport types in the
uddi:uddi.org:transport: * group has a different set of detailed metadata. See Table 7-3. This metadata provides the configuration details of the transport for the proxy service. It is neither useful for characterizing the service nor useful in querying the service. However, after the service has been discovered, this data is needed to access the service. The metadata is represented by an XML string and is located in the
instanceParms field in
If you are mapping a proxy service that uses the HTTP transport, and as part of the HTTP configuration you need to describe some configuration details, including the required client authorization and the request and response character encoding. Listing 7-3 provides an example of what must appear in the bindingTemplate
<property name="client-auth" value="basic"/>
<property name="request-encoding" value="iso-8859-1"/>
<property name="response-encoding" value="utf-8"/>
<property name="Scheme" value="http"/>
|Note:||For each transport, the service endpoint is always stored in the bindingTemplate
client-auth property is present in the
instanceParms of the HTTP or HTTPS transport attributes whenever authentication is configured. The possible values for
custom-token. Whenever the value is
custom-token, two additional properties are present:
Because ALSB business service definitions do not support custom token authentication in this release, if you import a service from UDDI that has a value of custom-token for
client-auth, the service is imported as if it does not have any authentication configuration.
Table 7-4 is organized by transport type and lists the
instanceParms used by each of the transports.
1The accessPoint in the Binding Template for an E-mail transport uses the standard mailto URL format:
Table 7-5 provides a high-level description of each of the service types.
A simple marker protocol tModel in the bindingTemplate
The ALSB-UDDI mapping introduces a number of new canonical
tModels that are used to represent ALSB metadata and relationships. These
tModels must be registered in the UDDI registry to support this mapping. You can create these
tModels in AquaLogic Service Registry under the administrator ID.
Table 7-6 provides a summary of the new
Listing 7-4 is an example of the mapping for a Messaging Service, configured with JMS transport, the request being XML with a schema and the response being a text message.
<property name="is-queue" value="true"/>
<property name="Scheme" value="jms"/>
<property name="requestType" value="XML"/>
<property name="responseType" value="Text"/>
keyName="Service Bus Instance"