Web Services Interview Questions and Answers Part-2
11.Do Web services supports Remote Procedure Calls(RPCs)?
Web services allow clients to invoke procedures, functions, and methods on remote objects using an XML-based protocol. Remote procedures expose input and output parameters that a web service must support.
Component development through Enterprise JavaBeans (EJBs) and .NET Components has increasingly become a part of architectures and enterprise deployments over the past couple of years. Both technologies are distributed and accessible through a variety of RPC mechanisms.
A web service supports RPC by providing services of its own, equivalent to those of a traditional component, or by translating incoming invocations into an invocation of an EJB or a .NET component.
12.What are the behavioral characteristics of web services?
Web services have the following special behavioral characteristics −
XML-Based − Web Services uses XML at data representation and data transportation layers.
Loosely Coupled − A consumer of a web service is not tied to that web service directly.
Coarse-Grained − Businesses and the interfaces that they expose should be coarse-grained. Web services technology provides a natural way of defining coarse-grained services that access the right amount of business logic.
Ability to be Synchronous or Asynchronous − Asynchronous clients retrieve their result at a later point in time, while synchronous clients receive their result when the service has completed. Asynchronous capability is a key factor in enabling loosely coupled systems.
Supports Remote Procedure Calls(RPCs) − A web service supports RPC by providing services of its own, equivalent to those of a traditional component, or by translating incoming invocations into an invocation of an EJB or a .NET component.
Supports Document Exchange − Web services support the transparent exchange of documents to facilitate business integration.
13.What are the benefits of having XML based WEB services?
Using XML eliminates any networking, operating system, or platform binding. So Web Services based applications are highly interoperable application at their core level.
14.What is the benefit of a Web services being loosely coupled?
The web service interface can change over time without compromising the client’s ability to interact with the service. A tightly coupled system implies that the client and server logic are closely tied to one another, implying that if one interface changes, the other must be updated. Adopting a loosely coupled architecture tends to make software systems more manageable and allows simpler integration between different systems.
15.What is Synchronicity?
Synchronicity refers to the binding of the client to the execution of the service. In synchronous invocations, the client blocks and waits for the service to complete its operation before continuing. Asynchronous operations allow a client to invoke a service and then execute other functions.
16.What are the core Roles in Web Service architecture?
There are three major roles within the web service architecture −
17.What is the purpose of Service Provider in Web Service architecture?
This is the provider of the web service. The service provider implements the service and makes it available on the Internet.
18.What is the purpose of Service Requestor in Web Service architecture?
This is any consumer of the web service. The requestor utilizes an existing web service by opening a network connection and sending an XML request.
19.What is the purpose of Service Registry in Web Service architecture?
This is a logically centralized directory of services. The registry provides a central place where developers can publish new services or find existing ones. It therefore serves as a centralized clearing house for companies and their services.
20.What are the core layers in Web Service Protocol Stack?
The Web Service Protocol Stack is still evolving, but currently has four main layers −