3 OSB Core Concepts

OSB is the layer sandwiched between RSB and WebLogic. OSB provides its capabilities using many components including the important ones described in this chapter.

Proxy Service

Proxy services are Oracle Service Bus definitions of intermediary Web services that Oracle Service Bus implements locally on Oracle WebLogic Server. The service consumers connect to the proxy service. For the service consumer, the proxy service provides the same interface as the application service. The only difference from a service consumer perspective is the endpoint URL. If an existing service is OSB enabled, the only programming change in the service consumer side is the change of existing URL to the proxy service URL. As the name suggests, the proxy service is a ”proxy” of the actual web service.

Business Service

Business services are Oracle Service Bus definitions of the enterprise information services with which you want to exchange messages. Business services are coupled with the actual web service providers. Typically service consumers invoke proxy services. Proxy services invoke business services, which in turn invoke the service providers. This level of indirection helps to decouple the service providers and service consumers. It also helps to introduce any mediation, routing, transformation and instrumentation of the service calls.

Alerts

Alerts are generated by OSB monitoring framework. Alerts help to isolate and diagnose problems when they occur. These are captured and configured to be reported.

The Collector collects the updated statistics from Oracle Service Bus runtime and sends it to Aggregator. The Aggregator aggregates the statistics over the aggregation interval. The aggregated statistics are pushed to the Alert Manager. The Alert Manager triggers alerts based on these statistics. The aggregated statistics are also stored and can be retrieved by the Retriever.

Alerts can be viewed in OSB Console as well as (RIC).

OSB generates two types of alerts - SLA Alerts and Pipeline Alerts. SLA alerts are raised in Oracle Service Bus to indicate potential violation of the Service Level Agreements (SLAs). Pipeline alerts can be raised in the message flow of the proxy service. In RSB, the SLA alerts are called System Alerts and Pipeline Alerts are called Business Alert. The intention of this renaming is to keep the names non-technical.

As the name suggests, the system alerts are non-business alerts and business alerts are caused by the business data. An example of a System Alert is an alert triggered when a request takes more than a specified time to complete. An example of a business alert is an alert triggered when the order total is more than a million dollars. The users can create alert conditions catered to their business requirements.

RSB comes with a default alert for each of the decorators. The alert rule name is ErrorCountAlertRule and the alert condition is Aggregation Interval 0 Hour(s) and 10 Minutes and Error Count > 0. You can view this alert in the SLA Alert Rules tab for Proxy Service in the OSB Console.

RSB does not have any default business alerts. Business alerts (Pipeline alerts) are added in the message flow of the proxy service.

See the developers guide for more information on how to add a business alert to the decorator.

Note: See also Oracle® Fusion Middleware Concepts and Architecture for Oracle Service Bus 12c Release 2 (12.2.1.3.0).

OSB and RSB High Level Architecture

RSB is built on the top of OSB components. In an architectural perspective RSB runtime can be viewed as a layer between OSB and edge applications. RSB adds instrumentation and security among other features to service invocations. Service consumers and providers communicate using RSB-OSB layer. OSB is an infrastructure product while RSB is a retail-specific integration implementation.