The blog provides the commonly asked Oracle Service Bus (OSB) Interview questions & answers to be helpful for beginners and experienced professionals.

What is the purpose of stages in Oracle Service Bus (OSB) ?

Stages are OSB Message Flow component used to contain the actions

What type of exceptions are handled by BPEL Transport Error Handling in Oracle Service Bus (OSB) ?

The BPEL Transport provides the support to communicate with the Oracle BPEL Process Manager and handles the below given exceptions:

• Application Errors: 
• Connection Errors
• Other Errors

Which option to be enabled in Transport Configuration for Application retry in Oracle Service Bus (OSB) ?

The Retry Application Errors option on the transport configuration page to turn
application retries on and off

What are Routing Nodes in Oracle Service Bus (OSB) ?

The below given actions are performed by the Routing Node:

• The Route Node is the last node in the Proxy Service
• The Routing Node is used to route the message from Business Service and handle the response received 
• Container for routing options are  Routing, Dynamic Routing, and Routing Table

What is Routing Table in Oracle Service Bus (OSB) ? 

The Routing Table performs the below given actions:

• The Routing Table allows to select different routes based upon the result of a single XQuery expression
• The Routing Table provides the set of routes wrapped in a switch-style condition table
• Each Route includes one Routing

What is Dynamic Routing in Oracle Service Bus (OSB) ?

The Dynamic Routing is used when it is not known which service is to be invoked and to be determined at run-time of the pipeline. The dynamic routing performs the below given actions:

• The dynamic routing is applicable for Abstracts WSDLs only
• The Proxy Service or Business Service using the Abstract WSDL can be included for dynamic routing
• If isProxy is set to True, the Dynamic Routing is enabled for Proxy Service
• If isProxy is set to False, the Dynamic Routing is enabled for Business Service

<ctx: route>
<ctx: service isProxy='false'> {$routingtable/row[logical/text()=
$logicalidentifier]/physical/text()}
</ctx: service>
</ctx: route>

What are the Transport Exception Connection Errors ?

• Naming Exception
• Remote Exception

What is the purpose of “MessageID” or “Relates To” in Oracle Service Bus (OSB) ?

“MessageID” and “RelatesTo” are used for storing the conversation ID between Service Bus and Oracle BPEL Process Manager and ensures that all related messages
remain in the same conversation

What is the Publishing Node ? 

The Publishing Node is used to identify the target service and to configure how the message is packaged and sent to the service

What is the Publishing Table ?

The Publishing Table is used to publish a message to Zero or more  specified target services

What is Throttling in Oracle Service Bus (OSB) ?

Throttling in OSB  is termed as “regulate the flow” and helps in controlling the number of requests sent to target service

What is VETRO concept in Oracle Service Bus (OSB)?

VETRO stands for
V – Virtualization/Validation
E – Enrichment
T – Transform
R – Route
O – Operate

Which action can be used to move from one stage to another stage other than conditional logic in OSB?

The OSB provides the Skip Action which can be used at the end of the stage to move to another stage without using the conditional logic (if-then-else)

Is it possible to connect to Database without using JCA adapter ?

XQuery execute-sql() function can be used to connect to database but recommended approach is to use JCA Adapter to Database Connectivity.

How Parallel processing of the message can be achieved in Oracle Service Bus (OSB) ?

OSB provides Spilt – Join for Parallel Processing of the message. 

How the File Polling can be achieved in Oracle Service Bus (OSB) ?

The Oracle Service Bus provides the File Transport  with the usage of below given components for file polling process

• File Mask
• Polling Interval
• Read Limit
• Post Read Action

What operations can be performed using File Transport / FTP Transport when used with Proxy Service and Business Service in OSB ?

The File Transport / FTP Transport can be used for both Proxy Service and Business Service

The File Transport / FTP Transport with Proxy Service is used for Reading the Files.

The File Transport / FTP Transport with Business Service is used for Writing the Files.

What nodes can be used for reporting in Oracle Service Bus (OSB) ?

The reporting in OSB can be done using the below nodes:

• Alert
• Log
• Report

What nodes can be used for Flow Control in Oracle Service Bus (OSB) ?

The Flow Control in OSB can be done using the below nodes:

• For Each
• If Then
• Raise Error
• Reply
• Skip
• Resume

What nodes can be used for routing  in Oracle Service Bus (OSB) ?

The Routing in OSB can be done using the below nodes:

• Routing
• Dynamic Routing
• Routing Table

What nodes can be used for Message Flow in Oracle Service Bus (OSB) ?

The Message Flow  in OSB can be done using the below nodes:

• Pipeline Pair
• Conditional Branch
• Operational Branch
• Stage
• Route
• Error Handler

Does OSB supports Global Variable in the Proxy Service Message Flow to be accessed by another Proxy Service? 

No, The Message Flow variable are restricted to the same Proxy Service.

What are the types of Split-Join in Oracle Service Bus (OSB) ?

The Split-Join can be categorized in 2 types:

• Static 
• Dynamic

Does multiple route nodes supported in Oracle Service Bus (OSB) ?

No, The message flow is always associated to single Route nodes to pass the message to the Defined Business Service and get the response back.

Does OSB supports Meta Data Store (MDS) ? 

No

Does OSB supports Domain Value Map (DVM) ?

No

Does OSB provides the supports for securing the web services ? 

Yes, OSB services can be secured using OWSM policies.

How the secured web services be invoked from OSB ? 

The OSB Client Policy need to be used to invoke the secured web services? 

How the OSB Services can be applied with security policies ?

The OSB Service Policy can be applied to Proxy Service for enforcing OWSM Policies

In which scenario Service Account should be used in Oracle Service Bus (OSB) ? 

The service which are enabled with the static authentication are invoked using the service account

Does OSB supports the invocation for the Restful Services ?

Yes, Restful Services can be invoked from OSB

What is SLA alert in Oracle Service Bus (OSB)?

SLA in Oracle Service Bus stands for the ‘Service Level Agreement’ which is a contract between the Service Provider and the Service Consumer. The violation of the SLA results in SLA Alert in OSB

Does OSB supports moving large files without reading the content ? 

Yes, the Content Steaming Option in the File Transport can be used for moving large file in OSB

Does OSB allows to expose Business Service to External Services for invocation ?

No, Business Services can not be exposed. The external services can invoke the exposed Proxy Service which in turn calls the defined Business Service.