Oracle SOA - Interview Questions Part-5

Oracle SOA - Interview Questions Part-5

What is a throw activity? What it is ?

Throw activity will explicitly throw the fault and this fault will get caught by the catch block and the corresponding actions will get executed.

What is Web service?

Web services are application components, which are self-contained and self-describing and provide services based on the open protocol communication (i.e. SOAP UI, HTTP over the net).

Difference between URI and URL?

A URI is an identifier for some resource, but a URL gives you specific information as to obtain that resource. A URI is a URL and as one commenter pointed out, it is now considered incorrect to use URL when describing applications. Generally, if the URL describes both the location and name of a resource, the term to use is URI. Since this is generally the case most of us encounter every day, URI is the correct term.

 What is Mediator?

The Mediator is in charge of interconnecting, within an SOA composite application, components that expose different interfaces. In addition, the Mediator can perform duties such as filtering and making routing decisions.

The composite editor in JDeveloper gives you the flexibility to define the interface now, to choose an existing interface, or to define the interface later as you wire components to the Mediator.

Transforming data from one representation to another is, along with routing, one of the key functions of the Mediator.

Difference between ESB and Mediator?

In 10g for routing, separate router need to keep along with ESB for routing and filter expressions.

Where as in 11g mediator contains routing rules and filter expressions itself.

What is the difference between concrete and abstract wsdl?

Concrete: Besides the information about how to communicate to the web service, it the information on where the service exist. It has Bindings (Protocol the message should be sent) and Services(has endpoint for each bindings) .

Abstract: It has information about how to communicate to the web service like types (Schema), Message (input and output messages service accepts) ,Operations (operation that can be performed on this service) and port Type.

What is SOAP and what are the binding protocols available?

Simple object access protocol and it is a protocol specification for the communication happens between the web services over the network and binding protocol is HTTP.

What is the difference between Async and Sync activity on wsdl level?

·               Async wsdl-It has only input messages for the operation and it has 2 operations one for sending the request and other for call back.

·               Sync wsdl-It has 2 messages input and output messages for the wsdl operation.

What are the WSDL structure?

Following are the wsdl structure

·                definitions

·                Types

·                 Messages

·                 Operation

·                 Port type

·                 Bindings

·                 Services

·                 Ports

What is the significance of target Namespace in a wsdl?

It is the one which uniquely identifies the WSDL and when the WSDL is used it should be identified using its Target Namespace.

What is structure of SOAP message?

The structure of a SOAP message: A SOAP message is encoded as an XML document, consisting of an element, which contains an optional element, and a mandatory element. The element, contained within the , is used for reporting errors.

The SOAP envelope-The SOAP is the root element in every SOAP message, and contains two child elements, an optional and a mandatory.

The SOAP header-The SOAP is an optional sub-element of the SOAP envelope, and is used to pass application-related information that is to be processed by SOAP nodes along the message path.

The SOAP body-The SOAP is a mandatory sub-element of the SOAP envelope, which contains information intended for the ultimate recipient of the message.

The SOAP fault-The SOAP is a sub-element of the SOAP body, which is used for reporting errors.

 Why do we need to have messages in WSDL, aren't operations and types enough to describe the parameters for a web service?

Messages consist of one or more logical parts. Each part is associated with a type from some type system using a message-typing attribute. The set of message-typing attributes is extensible.

·          The element describes the data being exchanged between the Web service providers and consumers.   Each Web Service has two messages: input and output.

·          The input describes the parameters for the Web Service and the output describes the return data from the Web Service.

·          Each message contains zero or more parameters, one for each parameter of the Web Service's function.

·          Each parameter associates with a concrete type defined in the container element. So describing the parameters cannot performed by operations and types this is the main need of Messages.

What is a inline schema?

Schemas can be included inside of XML file is called Inline Schemas.

What is the difference between xsd:import and xsd:include?

The fundamental difference between include and import is that you must use import to refer to declarations or definitions that are in a different target namespace and you must use include to refer to declarations or definitions that are (or will be) in the same target namespace.

What is BAM?

Business Activity Monitoring is a tool that is useful in monitoring business services and processes. It actively collects data, applies rules and reports information to users. When something goes wrong in business processes, BAM can be configured to take corrective measures such as emailing administrators/support team.

How to send the data to BAM from SOA?

The Oracle BAM Adapter is a Java Connector Architecture (JCA)-compliant adapter which can be used from a Java EE client to send data and events to the Oracle BAM Server. Oracle BAM Adapter is configured in Oracle Weblogic Server Administration Console to provide any of these connection pools. Oracle BAM Adapter provides three mechanisms by which you can send data to Oracle BAM Active Data Cache from an SOA composite application.

What are the ways to publish the data to BAM?

There are two ways to publish the data to BAM

·            BAM Adapter.

·            BAM Sensor activity level.

What are the roles in BAM?

·            Architect

·            Administrator

·            Active Viewer

·            Active Studio

What is forward delay in JMS Queue?

In the clustered environment where JMS queues are used, when for the queues in any one of the Managed server doesn’t have the consumer, once messages reaches  the forward delay time it gets moved  to the other managed server where consumer is present.

What is redelivery limit in JMS Queue?

When the message gets failed to get processed ,then it will be re-tried will the redelivery limit exhausts and once after the redelivery limit the message can b e either moved to the error Queue are it can be discarded.

What is timetodeliver in JMS Queue?

When Messages enqueued to the JMS queue, it will be immediately consumed by the JMS Subscribers, if any delay needs to be induced for the message consuming by the Subscribers then timetodelivery needs to set. The JMS message will not be subscribed until timetodelivery exhausts.

Difference between JMS Queues and Topics?

Queue-Message will be subscribed by one subscriber.

Topic-Message will be subscribed by more than one subscriber.