Oracle User Messaging Service Cluster-Wide Configuration Changes

5-60 Oracle Fusion Middleware High Availability Guide Process Failure This section describes specific considerations for process failure in an Oracle User Messaging Service high availability configuration: ■ Node Manager attempts to restart the managed servers locally if a crash occurs. ■ If whole server migration is configured for the Oracle WebLogic Server managed server to which Oracle UMS components are deployed, and the restart count threshold is exceeded, Oracle WebLogic Server infrastructure attempts to perform a server migration of the managed server to another node in the cluster. After the server migration completes successfully, at the startup time, UMS Server and Drivers go through the startup cycle as previously described, including driver registration. Driver registration is an independent operation and does not have any affect on other available instances. See Chapter 3, High Availability for WebLogic Server for more information about server migration. ■ At restart on the same or different node, the UMS JMS server in the managed server starts producing and consuming messages from its JMS store. ■ If a managed server running UMS Server and Drivers is restarted or migrated, the failover is transparent to the connected UMS Clients. The failover is transparent because UMS components are stateless. Once the servers restart is finished, the Web server starts routing requests to it for Web service clients. Similarly, EJB clients become aware of the server availability and start routing requests to it. This is made possible by Oracle WebLogic clustering infrastructure. Node Failure For information about Oracle UMS node failure, see Section 5.2.2.1, Oracle SOA Service Infrastructure Protection from Failures and Expected Behavior Database Failure For information about Oracle UMS database failure, see Section 5.2.2.1, Oracle SOA Service Infrastructure Protection from Failures and Expected Behavior Protection From External Messaging Gateway Failures Before attempting a message delivery, UMS first persists the message to the database. If an external Messaging Gateway becomes unavailable, the corresponding UMS driver periodically attempts to reconnect to the gateway and deliver any undelivered messages persisted in the database. Alternatively, if the messages are not delivered, administrators can manually resend the messages using the UMS servers Message Status Page in Oracle Fusion Middleware Enterprise Manager.

5.9.2.2 Oracle User Messaging Service Cluster-Wide Configuration Changes

UMS configuration is file-based, standard Java EE deployment descriptors and JMX configuration Mbeans, using a standard JMX framework. Changes are propagated using standard Oracle WebLogic Server Mbean server mechanisms. There are no cluster-wide configuration capabilities. As a result, configuration changes must be repeated on every member of a cluster UMS uses standard Java EE artifacts, configured as part of Oracle WebLogic’s domain in which Oracle UMS is installed. Oracle WebLogic Server clusters provide automatic configuration synchronization for artifacts, such as data sources, across Oracle WebLogic Server domain. At the same time, Oracle WebLogic Server cluster controls synchronization of deployments and libraries used by different Oracle UMS components. Configuring High Availability for Oracle Fusion Middleware SOA Suite 5-61

5.10 Oracle JCA Adapters and High Availability Concepts

The information in this section guides you through the issues and considerations necessary for configuring Oracle JCA Adapters for high availability.

5.10.1 Oracle JCA Adapters Single-Instance Characteristics

Oracle JCA Adapters are JCA binding components that allow the Service Infrastructure to communicate to endpoints using different protocols. Oracle JCA Adapters are deployed as a JCA resource RAR and are not part of the Oracle SOA Service Infrastructure. The run-time component of Oracle JCA Adapters is the J2CA 1.5 resource adapter for the specific back-end application. Oracle JCA Adapters are deployed in J2CA container of Oracle WebLogic Server. Oracle Fusion Middleware integrates with these J2CA 1.5 adapters through the JCA Binding Component, which converts Web service messages into J2CA interactions and back. Adapters can, therefore, fully leverage the scalability and high availability of the underlying Oracle WebLogic Server platform. Figure 5–30 illustrates the services and dependencies of Oracle JCA Adapters single-instance architecture. Figure 5–30 Oracle JCA Adapters Single Instance Architecture