Friday, February 22, 2013

From the Trenches 2 | Patching OSB and SOA Suite to PS5

In my previous blog I talked about a recent upgrade from Oracle Fusion Middleware 11g PS2 to 11g PS5. This blog continues with two post-installation steps that were required to complete the upgrade.

Patching Oracle B2B for ebMS-based services

In this particular project we implemented ebMS-based services using Oracle B2B and Oracle Service Bus 11g. Besides "plain" SOAP Web Services, ebMS is part of the Dutch government standards to exchange messages and expose services between organizations in the public sector. You can read more about implementing ebMS-based services using Oracle B2B, Oracle Service Bus and Oracle SOA Suite in this presentation.

The ebMS standard makes extensive use of SOAP headers to facilitate features such as guaranteed delivery and to avoid duplicate messages. The following snippet shows part of an ebMS message header.

One of the identifiers used in the ebMS message exchange is the manifest id. According to the ebMS specification maintained by OASIS this needs to be XML NCName type. This type has some restrictions; for example that its values cannot start with a number. In Oracle B2B 11g PS2 the manifest id value is prefixed with the text oracle. This prefix is removed in 11g PS5 resulting in the following error from the B2B trading partner at runtime:

09:06:00 Local Listener(8914) Result: "Error" "Fault sent:<SOAP:Fault><faultcode>SOAP:Client</faultcode><faultstring>org.xml.sax.SAXParseException: cvc-datatype-valid.1.2.1: '0A1A1A1A1A1A1A1A1A1A1A1A1A1A1A1A' is not a valid value for 'NCName'.</faultstring></SOAP:Fault>"

Luckily there is an easy-to-apply patch that solves this problem; see article 1497168.1 on Oracle Support. After applying the patch, the manifest id is prefixed with a text value again.

Changing namespaces in WSDLs and XSDs of JAX-WS Web Services

The environment that was patched contains several Java applications running on WebLogic Server. These applications expose Web Services using JAX-WS. A meet-in-the-middle approach was used to create them: the business logic implemented in Stateless Session Beans and JPA (EclipseLink) is integrated with the Java classes generated from the predesigned WSDLs and XSDs.

Depending on the developer that created the Web Service, deployment descriptors such as webservices.xml and weblogic-webservices.xml were added to the application. Descriptors are used for configuration, overriding default settings, and adding metadata. For Web Services this can be the endpoint, port configuration, linkage of the Web Service to EJB components, and so on. When deployed, the WSDL location of Web Services is listed in the WebLogic Console and the WSDL can be retrieved at runtime.

After the patch we noticed that these artifacts weren't identical to the original WSDLs and XSDs. More specifically, the namespaces of the XSD elements in the request and response message definitions were changed to the namespace of the service itself. At runtime however, the service accepted requests and responses as defined by the original contract. This makes it difficult to test these Web Services using clients that inspect the runtime WSDL; for example when creating a default project in soapUI.

This issue was resolved by removing the webservices.xml and weblogic-webservices.xml deployment descriptors from the Java archive and redeploying the Web Services to WebLogic Server. The WSDL that can be retrieved at runtime matches the original designed WSDL again.

1 comment:

  1. That's an insightful post on patches to PS5. Thanks a lot Ronald.