Friday, 24 October 2014

Top 5 Oracle Service Bus fundamental Questions



Top 5 Oracle Service Bus fundamental Questions.

Q1. What is OSB and why we need OSB?
Ans – In simple answer it’s a middleware tool provided by Oracle. It stands for Oracle Service Bus. It is used to delivers low-cost, standards-based integration for mission critical SOA environments where extreme performance and scalability are requirements. It simply transforms any complex architecture to simple by connecting different application and service.  

Q2. What is Proxy Service?
Ans - Proxy service is a service which you can exposed to the outside world. Instead of publishing the actual service to real world we can publish the proxy service with additional / optimized business logic. Proxy service can call any other proxy service (ps), local proxy service (lps) and business service (bs). It often called over http protocol.

Q3. What is Business Service?
Ans – Business service is nothing but it defines the WSDL. As a standard business service never called from outside world. It’s always called by proxy service. It directly communicates with the business.

Q4. What is Local Proxy Service?
Ans – Local proxy service is treated as internal service. It’s not exposed to outside world. It’s normally used for internal validation and it’s always used internal between proxy service, local proxy and business services. It always called over “local” protocol. They do not have an endpoint which a consumer sitting outside the OSB can invoke. In order to invoke a internal proxy service the consumer will have to invoke an external proxy service which in turn will have to route it to the internal service.

Q5. What is VETO pattern?
Ans – VETO stands for Validation, Enrich, Transform and Operate. All logic in ESB / OSB should be followed by VETO pattern. The "Validate" step is usually the first part of any ESB process. Since validations are normally done in business services thus this step is not required in ESB. Moreover validations are expensive operation in ESB. The "Enrich" step involves adding additional data to a message to make it more meaningful and useful to a target service or application. The "Transform" step converts the message to a target format. The "Operate" step is the invocation of the target service or an interaction with the target application.