Web Services Interview Questions & Answers

Question 1. What Is Web Services?

Answer :

Web Services are the components that provide functionality via internet, uses standard protocol such as HTTP. Web services use SOAP to expose functionality which is an XML-based protocol that enables 2 disparate components to communicate. So web services hosted on windows platform can easily be consumed Linux and UNIX platform.

Question 2. What Are Smart Web Services?

Answer :

A smart web service understands the situational context and capable of sharing the context with other services. The result of this web service is based on the needs like who, what, when, where it was called.

The customer’s identity, role of a customer, security policies, physical location of a customer, type of client device are some of the number of the situational circumstances of that a smart web service is aware of.

Question 3. Explain Jaxr?

Answer :

JARX is a standard API that are used to access XML registries (list of services available on the web) from the JAVA platform. Client application can use JARX API to query the registries. It acts as a pluggable layer that allows access to registries implemented on different standards such as UDDI.

Question 4. Explain Jax-rpc?

Answer :

JAX-RPC uses SOAP to call remote procedures. JAX-RPC enables JAX-RPC clients to invoke web services developed across heterogeneous platform.

Question 5. Define Uddi, Disco And Wsdl?

Answer :

UDDI, Universal description, discovery and integration:
It is the directory that is used to publish and discover public web services.

DISCO, Discovery:
commonly known as Discovery. Discovery clubs together common services and exposes schema document of the web services.

WSDL, Web Service description language:
This is used to describe web services. The description includes

• URL of web services
• Method and properties supported by web services
• Data type it supports.
• Protocol detail it supports.

Question 6. What Are The Steps To Get A Proxy Object Of A Web Service At The Client Side?

Answer :

Following are the steps to get a proxy object of a web service at the client side.

• Access UDDI node for a list of web services.
• Services thus responded by UDDI have URL pointing to DISCO or WSDL document.
• Parse DISCO and WSDL document and build a proxy object which can communicate with the web service.

Question 7. Explain Jaxm Messaging Models?

Answer :

JAXM messaging models has two types of messaging model, synchronous and asynchronous.

• Synchronous messaging model:

In this type of model, client directly interacts with the source. The client sends a request and waits for the response.

• Asynchronous messaging model:

In this model, client sends message to the messaging provider and returns back. Messaging provider then performs the routing of message to the end source.

Question 8. What Is .net Web Service?

Answer :

• Web service is the way to publish application's function on web that can be accessible to the rest of the world.
• Web services are the components that can be used by other applications
• ASP.NET offers easy way to develop web services, just precede the functions with a special WebMethod ()> attribute in order them to work as Web Service.
• Web services are discovered using UDDI directory services.
• Web services are built on XML standard and use SOAP protocol that allows them to communicate across different platforms and programming languages.
• Web services easily manage to work across corporate firewalls as they use HTTP protocol which is firewall friendly.
• Web services platform elements are
SOAP (Simple Object Access Protocol)
UDDI (Universal Description, Discovery and Integration)
WSDL (Web Services Description Language)
• The web services are built on internet standards that are not platform or language specific.
• The .Net framework provides in-built classes to build and consume web services.
• The components offered by web services are reusable.
• The examples of web service components can be shipment tracking, translation utility, weather forecasting, sports scores etc.

Question 9. Explain The Protocols A .net Web Service Uses?

Answer :

In .Net, a web service is bind with three different protocols such as HTTP/POST, HTTP/GET, and SOAP. This allows client with three options to choose for communication. The protocols are included in the WSDL file that is automatically generated in .NET.

Http-Get and Http-Post can only be used when name/value pairs of data is dealt with. But when data is complex in nature such as ASP.NET dataset, XML notes etc, then we can use SOAP that serializes data in simpler form before sending.

Question 10. Explain When Do We Required Asp.net Web Services?

Answer :

ASP.NET web services are the great way to expose your middle tier components via internet. These components offer no issue communicating across firewalls as they use SOAP as transport protocols that transmit structured data using HTTP channel. Thus, message can be easily exchanged through port 80, i.e. through internet data port without being getting hampered by corporate firewalls or proxy server.

Web services can fit in the situation when we require integrating disparate systems written by separate vendors via internet.
Web services are primarily being used for B2B integration like authorizing employees, supplier, electronically signing of invoice etc.

Question 11. Why Do We Need .net Web Services?

Answer :

We have a number of heterogeneous technologies available on internet. The demand for reusable components across platforms and programming languages are high. Most of the components have the limitation that they can't share or exchange data across different platforms, they are mostly language specific or platform specific. The technologies like COM, RMI, CORBA etc. contributed best to fulfill requirements to some extent, but components result from these said technologies are mostly either language specific or platform specific.
To avoid above problem, we need to have web services. Through web services we have overcome the problem of interoperability between languages and platforms. Web services uses SOAP as transport protocol which uses a text based messaging model, i.e. XML to communicate between disparate systems.

Question 12. Deploying A Web Service?

Answer :

Deploying the .Net Web Services is as simple as any ASP.NET application. Similar to ASP.NET applications, you need to copy or upload the .ASMX file and the .DISCO files to the appropriate directories, and that's it.

Question 13. Explain In Brief Different Distributed Technologies?

Answer :

The need of distributed technologies arises with the requirement of distributed computing applications. The distributed computing allows partitioning of application logic into units and spreading the unit over different computers of a network or across different networks. This helps in spreading out loads over many computers. The components once developed can be reuse by other applications. There are many technologies developed to allow the distribution and reuse of application logic.

Question 14. Advantages Of The Distributed Components?

Answer :

• The key benefit of having distributed components is that they spread out the load over different machines.
• The components can be upgraded without disturbing the clients code.
• The distributed application improves security. For example, a company who has many agents wouldn’t like those agents to have direct access to its database. Instead, these agents can be granted access to the components running on the corporate server which can be controlled and restricted.

Question 15. Web Services Vs. Corba And Dcom?

Answer :

Web services
Web services use HTTP protocol for sending and receiving messages between the applications.
The data encoding in web services is based on XML.
Web services are defined using WSDL (Web Services Description Language).

• Web services are discovered using UDDI (Universal Description, Discovery and Integration).
• Web services are firewalls friendly.
• Web services supports interoperability i.e. cross platform integration is possible.

CORBA and DCOM
• These technologies use non-standard protocol, i.e. CORBA uses IIOP (Inter Internet Object Protocol), and DCOM uses RPC (Remote Procedure Calls)
• CORBA components are defined using CORBA Interface Description Language; DCOM components are defined using Microsoft Interface definition languages
• CORBA components are discovered using the CORBA registry, DCOM using the Registry.
• DCOM is a proprietary protocol that does not support interoperability and has firewall problems as DCOM transfers data in binary format and it uses many ports to call remote functions.
• CORBA uses the IIOP protocol, which is non-Internet friendly.
• CORBA and DCOM are fine for building enterprise applications that runs on the same platform and not good enough for applications that span platforms and languages.

Question 16. Advantages Of .net Web Services?

Answer :

Web Services are supported on a wide range of platforms.

Web services may extend its interface and add new methods without affecting the clients as long as they still provide the old methods and parameters.

• A client makes a request to a web service, the web service returns the result, and the connection is closed. There is no permanent connection. This makes it easy to scale up and support many clients at a time.
• Firewalls can pose a challenge for distributed object technologies. The only thing that almost always gets through firewalls is HTTP traffic on ports 80 and 443. Because web services use HTTP, they can pass through firewalls without explicit configuration.

Question 17. Explain In Brief Web Service Standards?

Answer :

Following are the standards used by web services:

WSDL
WSDL is used to create interface definition for a web services. It describes all about methods to the client, i.e. methods available in a web service, their parameters and return values.

SOAP
SOAP, Simple Object Access Protocol is a communication protocol, a way to structure data, based on XML. The web services use SOAP message format to encode information before sending.

HTTP
The SOAP message format in web services uses HTTP as communication protocol, i.e. SOAP messages are sent over HTTP channels.

DISCO
It is used to create discovery documents that provide links to multiple web service endpoints. The DISCO standard creates a single file that groups a list of related web services. A company can publish a DISCO file on its server that contains links to all the web services it provides.

UDDI
A standard for creating business registries that catalog companies, the web services they provide, and the corresponding URLs for their WSDL contracts.

Question 18. Define The Specifications That Help In The Discovery Of A Web Service?

Answer :

DISCO
DISCO, an abbreviation of discovery, is a file that groups together a list of related web services. A company that offers web services publishes a DISCO file on its server that has links of all the web services it provides. The client requests this file to see all the available web services. This standard is useful when client already know about a company that offers web services. You can also use DISCO standard while working in local network. It is not helpful to find all web services over the internet.

UDDI
UDDI (Universal Description, Discovery, and Integration) offers centralized directory for web services over the internet. It hosts web services from different companies and can be used by the clients to find web services of their specific need. To make web services shared publicly, they have to be published in UDDI.

Question 19. What Are The Data Types Supported By Web Services?

Answer :

.Net web services are built on XML-based standards for exchanging data. This means .NET web services can support only those data types that can be recognized by the XML schema standard. There are many proprietary .Net objects such as FileSteam, Event log etc. are not supported in the web services. These data types are .Net specific types that are not universally recognized, i.e. .Net specific only.

You can even exchange custom objects using .Net web services. The only limitation is that only public data members are transmitted, and all public members and properties must use one of the other supported data types.

You can use DataSet and DataTable to return information from database but can't use other ADO.NET objects such as DataColumns and DataRows.

.Net offers a distributed technology called .Net remoting that can plays around wide range of .Net specific data type. But unfortunately, .Net remoting doesn't support client other than .Net.

Question 20. What Is The Difference Between Xml Web Services Using Asmx And .net Remoting Using Soap?

Answer :

• XML Web services are more restricted than objects exposed over .NET Remoting.
• XML Web services support open standards that target cross-platform use.
• XML Web services are generally easier to create and due to the restricted nature of XML Web services, the design issues are simplified.
• XML Web services support only SOAP message formatting, which uses larger XML text messages.
• Communication with .NET Remoting can be faster than XML Web service communication with a binary formatter.
• XML Web services are designed for use between companies and organizations.
• XML Web services don't require a dedicated hosting program because they are always hosted by ASP.NET.
• Consumers can use XML Web services just as easily as they can download HTML pages from the Internet. Thus there's no need for an administrator to open additional ports on a firewall as they work through MS-IIS and ASP.NET

Question 21. What Is The Transport Protocol You Use To Call A Web Service Soap ?

Answer :

HTTP with SOAP

Question 22. What Does Wsdl Stand For?

Answer :

WSDL stands for Web Services Description Language. There is WSDL.exe that creates a .wsdl Files which defines how an XML Web service behaves and instructs clients as to how to interact with the service.

Question 23. True Or False: To Test A Web Service You Must Create A Windows Application Or Web Application To Consume This Service?

Answer :

False.

Question 24. What Are Vsdisco Files?

Answer :

VSDISCO files are DISCO files that support dynamic discovery of Web services. If you place the following VSDISCO file in a directory on your Web server, for example, it returns   references to all ASMX and DISCO files in the host directory and any subdirectories not noted in <EXCLUDE>elements:

            
                <DYNAMICDISCOVERY
                  xmlns=”urn:schemas-dynamicdiscovery:disco.2000-03-17″>
                  <EXCLUDE path=”_vti_cnf” />
                  <EXCLUDE path=”_vti_pvt” />
                  <EXCLUDE path=”_vti_log” />
                  <EXCLUDE path=”_vti_script” />
                  <EXCLUDE path=”_vti_txt” />
                </DYNAMICDISCOVERY>  

Question 25. How Does Dynamic Discovery Work?

Answer :

ASP.NET maps the file name extension VSDISCO to an HTTP handler that scans the host directory and subdirectories for ASMX and DISCO files and returns a dynamically generated DISCO document. A client who requests a VSDISCO file gets back what appears to be a static DISCO document.

Question 26. Is It Possible To Prevent A Browser From Caching An Aspx Page?

Answer :

Just call SetNoStore on the HttpCachePolicy object exposed through the Response object’s Cache property, as demonstrated here:
 
        <%@ Page Language=”C#” %>
         
            <%
              Response.Cache.SetNoStore ();
              Response.Write (DateTime.Now.ToLongTimeString ());
            %>
         
SetNoStore works by returning a Cache-Control: private, no-store header in the HTTP response. In this example, it prevents caching of a Web page that shows the current time.

Question 27. Can Two Different Programming Languages Be Mixed In A Single Asmx File?

Answer :

No.

Question 28. How Can A Win Service Developed In .net Be Installed Or Used In Win98?

Answer :

Windows service cannot be installed on Win9x machines even though the .NET framework runs on machine.

Question 29. What Is A Windows Service And How Does Its Lifecycle Differ From A "standard" Exe?

Answer :

Windows service is a application that runs in the background. It is equivalent to a NT service. The executable created is not a Windows application, and hence you can’t just click and run it . it needs to be installed as a service, VB.Net has a facility where we can add an installer to our program and then use a utility to install the service. Whereas this is not the case with standard exe.

Question 30. What Is Wsdl?

Answer :

WSDL is the Web Service Description Language, and it is implemented as a specific XML vocabulary. While it’s very much more complex than what can be described here, there are two important aspects to WSDL with which you should be aware. First, WSDL provides instructions to consumers of Web Services to describe the layout and contents of the SOAP packets the Web Service intends to issue. It’s an interface description document, of sorts. And second, it isn’t intended that you read and interpret the WSDL. Rather, WSDL should be processed by machine, typically to generate proxy source code (.NET) or create dynamic proxies on the fly (the SOAP Toolkit or Web Service Behavior).

Question 31. Does The W3c Support Any Web Service Standards?

Answer :

The World Wide Web Consortium (W3C) is actively pursuing standardization of Web service protocols. In September 2000, the W3C established an XML Protocol Activity. The goal of the group is to establish a formal standard for SOAP. A draft version of SOAP 1.2 is currently under review, and progressing through the official W3C recommendation process.
On January 25, 2002, the W3C also announced the formation of a Web Service Activity. This new activity will include the current SOAP work as well as two new groups. The first new group is the Web Services Description Working Group, which will take up work on WSDL. The second new group is the Web Services Architecture Working Group, which will attempt to create a cohesive framework for Web service protocols.

Question 32. What Is New About Web Services?

Answer :

People have been using Remote Procedure Calls (RPC) for some time now, and they long ago discovered how to send such calls over HTTP.
So, what is really new about Web services? The answer is XML.
XML lies at the core of Web services, and provides a common language for describing Remote Procedure Calls, Web services, and Web service directories.
Prior to XML, one could share data among different applications, but XML makes this so much easier to do. In the same vein, one can share services and code without Web services, but XML makes it easier to do these as well.
By standardizing on XML, different applications can more easily talk to one another, and this makes software a whole lot more interesting.

Question 33. What Is The Use Of Soap (simple Object Access Protocol) In .net Web Services?

Answer :

The Simple Object Access Protocol (SOAP) is a platform-independent protocol that uses XML to make remote procedure calls.

Each request and response is packaged in a SOAP message containing the information that a Web service requires to process the message.

SOAP supports an extensive set of types like the primitive types, DataSet, DateTime, XmlNode and others. SOAP can also transmit arrays of these types and objects of user-defined types.

Question 34. Can You Use User-defined Types In Web Services?

Answer :

It is possible to process user-defined types (also known as custom types) in a Web service. These types can be passed to or returned from Web methods. Web service clients also can use these user-defined types, because the proxy class created for the client contains these type definitions.

Custom types that are sent to or from a Web service are serialized, enabling them to be passed in XML format. This process is referred to as XML serialization.

Question 35. What Are The Web Services In Asp.net?

Answer :

A Web service is a class that allows its methods to be called by methods on other machines via common data formats and protocols, such as XML and HTTP. In .NET, the over-the-network method calls are commonly implemented through the Simple Object Access Protocol (SOAP), an XML-based protocol describing how to mark up requests and responses so that they can be transferred via protocols such as HTTP. Using SOAP, applications represent and transmit data in a standardized XML-based format.

Question 36. How Do I Get Started With Web Services?

Answer :

The easiest way to get started with Web services is to learn XML-RPC. Check out the XML-RPC specification or read my book, Web Services Essentials. O'Reilly has also recently released a book on Programming Web Services with XML-RPC by Simon St.Laurent, Joe Johnston, and Edd Dumbill.

Once you have learned the basics of XML-RPC, move onto SOAP, WSDL, and UDDI. These topics are also covered in Web Services Essentials. For a comprehensive treatment of SOAP, check out O'Reilly's Programming Web Services with SOAP, by Doug Tidwell, James Snell, and Pavel Kulchenko.

Question 37. What Is Xml-rpc?

Answer :

XML-RPC is a protocol that uses XML messages to perform Remote Procedure Calls. Requests are encoded in XML and sent via HTTP POST; XML responses are embedded in the body of the HTTP response. More succinctly, XML-RPC = HTTP + XML + Remote Procedure Calls. Because XML-RPC is platform independent, diverse applications can communicate with one another. For example, a Java client can speak XML-RPC to a Perl server.

To get a quick sense of XML-RPC, here is a sample XML-RPC request to a weather service (with the HTTP Headers omitted):
<?xml version="1.0" encoding="ISO-8859-1"?>
<methodCall>
<methodName>weather.getWeather</methodName>
<params>
<param><value>10016</value></param>
</params>
</methodCall>
The request consists of a simple element, which specifies the method name (getWeather) and any method parameters (zip code).

Question 38. Explain Webmethod Attribute In Asp.net Web Service?

Answer :

Attaching the WebMethod attribute to a Public method indicates that you want the method exposed as part of the XML Web service. The WebMethod attribute tells .NET that a particular public method should be exposed as a web-callable method. The WebMethod attribute has six associated properties to document and change the behavior of your web method. They are:

• Description
• MessageName
• EnableSession
• CacheDuration
• TransactionOption
• BufferResponse

The first two properties are used to document a web method, while the others affect its behavior.

Question 39. Define Web Service?

Answer :

Web service is like software which makes it available on the web. The consistent XML messaging system is used by web services. To use a web service, a message is invoked by the client, and a request is sent to the server in XML format and a response is given to the client in XML file format by the server. Web services are not dependent on the platform and any application can access it which is developed in any programming language.

Question 40. Define Soap?

Answer :

The abbreviation of SOAP is Simple Object Access Protocol, which is protocol exchanging information between computers. Complete transaction depends on XML, which is also a platform independent. It is a different way of messaging a system and communicates using transport protocol.

Question 41. Define Wsdl?

Answer :

The full form of WSDL is Web Services Description Language which represents a layer in the protocol stack of web service. Data types for all XML messages are contained in WSDL and the information about all XML messages are provided in it. Address information of locating services is given by WSDL.

Question 42. Define .net Web Services?

Answer :

Web service is like a component sharing information on the web and makes application development easy. The facility to make web method means the functioning you implemented in your service is offered by ASP .net. While gaining access the service, a request is sent to client in XML format and input value is passed to web method as a parameter, the response of the server is also in the XML format. One thing is essential that services are running on the web.

Question 43. Define Uddi?

Answer :

The abbreviation of UDDI is universal description, discovery and integration. It is a directory to store web services information to determine, find businesses and publish. The communication of UDDI is possible using CORBA, SOAP and Java RMI protocol. The interfaces of UDDI web services are described by WSDL. UDDI is built in the platform of Microsoft .net. UDDI is an open industry which is an enterprise enabling business to find each other and describe the way they interact on web.

Question 44. Define Windows Services?

Answer :

Earlier, a windows service was known as NT services are the applications which are installed in computers as system services. These are the services running in the background with an operating system as windows. The key usage of windows services is to decrease consumption of memory essential for doing backend operations. Let us consider an example to understand perfectly. Suppose you are interested in doing multiple functions like monitoring you computer or any application for performance then the status of an application is checked and several devices are managed like printers. Here, windows services are used to reduce the consumption of memory. Additionally, windows services can run on your systems even if you do not log into the system. Also, these services do not have a user interface.

Question 45. What Are The Characteristics Of Web Services?

Answer :

The characteristics of web services are:

XML – based:
It is based on XML which is platform independent and effectively runs on all the operating systems and it is language independent.

Loosely coupled:
Loosely coupled is nothing but web service consumers are not attached directly to the web services. Here, the client and server logic is closely attached to each other.

Coarse-grained:
Coarse-grained facility is provided by it for programs and methods in Java.

Supports to Remote Procedure Calls:
Remote procedure calls are supported by web services when the transaction takes place while exchanging documents.

Ability to be asynchronous and synchronous:
When the client is interested in executing web services, the facility to bind the client is provided by synchronized. Thus, the service is synchronously used by the client. The client is allowed to invoke web service using asynchronous operations, when the client is interested in executing other functions.

Interoperability:
Without external effort, it offers system to system work.

Question 46. What Are The Advantages Of Web Services?

Answer :

The advantages of web services are:

Reusability:
Open standards and protocols are used by the web services. Deploying services is easy as they are not component-based model of an application for development. Thus, it is very easy to reuse components of web service as suitable in other services.

Ability to deploy:
Web services are deployed on the internet and without any independent and mapping issues, any user can use it.

Interoperability:
It is the vital benefit of web services, which works outside private networks and provide developers to find solutions in an effective way. Interoperability is provided between several software’s which are running on multiple platforms. Virtually, web services do not depend on platform.

Usability:
Reuse of components and services in an infrastructure is allowed by web services. Business logic of multiple platforms is allowed by web services and it is exposed over web. Thus, provides facility of using web services anywhere for various platforms.

Question 47. What Are Web Services Disadvantages?

Answer :

• Web services have poor performance when it is compared with other distribution applications such as CORBA, RMI and DCOM.
• Clearly XML is not considered among design goals either brevity of encoding or parsing efficiency.
• When a request is made to the server by the client and before responding to the request if power had gone then it results in system crash.

Question 48. Sharing A Process Between Windows Services Is Possible?

Answer :

Yes it is possible. A process can be shared between windows services.

Question 49. Name The Parent Class To Create All Windows Service In .net?

Answer :

To create all the windows service, ServiceBase class is parent class.

Question 50. For Installing Windows Service, Which .net Class Is Used?

Answer :

Windows services can be installed using Service Installer class which is also called as project installer class.

Question 51. Explain The Services Provided By Uddi To Web Applications?

Answer :

The following types of services are provided to web applications:
• XML schema for the descriptions of business includes specifications and service publisher on web service.
• Web registry of web services include service, business and binding information for web service.

Question 52. Briefly Explain The Concept Of Web Services?

Answer :

It is a self-sustained and independent unit of software application that is hosted on internet and specific functionalities are implemented to perform business logic. Multiple functionalities are offered by a web service like computing tax, giving updated news, generating pay slips for employees and broadcasting weather report. Application is allowed to exchange data or share information using web service with various applications on different hardware and operating systems. Thus, web service carries out work to unit software by swapping data irrespective of programming language, hardware and operating system used in the development process. The data transferred by the XML is in the XML format and for communication purpose it uses SOAP, which is a protocol based on XML. Universal Description, Discover and Integration UDDI and Web Services Description Language (WSDL) are used by the web services to describe themselves.

Question 53. Can You Prevent Your Web Services From Illegal Access?

Answer :

You can prevent web services from illegal access using following ways:
• Using security based on message and encryption.
• Access controls and authentication can also prevent illegal access.

Question 54. Give Me The Advantages Of Web Services Over Com And Dcom?

Answer :

The following are the advantages of web services over COM and DCOM:
• It is simple and easy to use web services and it is implemented on different platforms.
• The web services are loosely coupled and their methods and interfaces can be extended.
• Stat information is not carried by web services so that numerous requests are processed simultaneously.

Question 55. What Attracted You To The Web Services Field?

Answer :

Web services is at its core software that can be accessed online that uses an XML messaging system, which encodes the communications in web services. 

Question 56. How Have You Improved Your Knowledge Of Web Services Recently?

Answer :

Since there are many operating systems and programming languages involved in web services, try to talk about how you have improved your knowledge of a few, such as Java, Perl, Unix applications or Windows applications. If you know any of these are more prominently used in the company you’re applying for, talk about them.

Question 57. How Do You Plan To Continue Expanding Your Web Services Knowledge In The Future?

Answer :

If there are any aspects of web services, particularly programming languages and operating systems, that you are not as familiar with, say this and then talk about your desire to work more with them to expand your knowledge. Also, talk about how you would take advantage of any extra training offered by the company.

Question 58. What Are The Main Web Services Skills That You Possess That Relate To This Position?

Answer :

This is where your research of the position will really pay off. XML, for example, is a relatively new concept in web services that is starting to become used more widely. If you know this company uses XML, talk about your training and experience with it.

Question 59. What Are Windows Services?

Answer :

Windows services, previously known as NT services, are applications that are installed on the system as system services. In other words, Windows services are applications that run in the background with the Windows operating system. The primary use of Windows services is to reduce the consumption of memory required for performing backend operations. Let's take an example to understand this easily. Suppose you want to perform a variety of functions, such as monitor the performance of your computer or application, check the status of an application, and manage various devices, such as printers.

In such a case, you can use Windows services to reduce memory consumption. In addition, Windows services can run on your system even if you have not logged on to your computer. In addition, these services do not have any user interface.

Question 60. Can You Share A Process Between Windows Services?

Answer :

Yes, you can share a process between Windows services.

Question 61. In .net, Which Is The Parent Class To Create All Windows Services?

Answer :

The ServiceBase class is the parent class to create all Windows services.

Question 62. Which Class In .net Is Used To Install A Windows Service?

Answer :

The ServiceInstaller class, also known as the project installer class, is used to install a Windows service.

Question 63. While Installing A Windows Service, An Eventloginstaller Class Is Automatically Created To Install The Event Log Related To The Particular Service. Is It True?

Answer :

Yes, it is true.

Question 64. Which Property Of The Servicebase Class Can Be Used To Specify Whether A Service Can Be Paused And Resumed?

Answer :

The CanPauseAndContinue property provides such type of service.

Question 65. Describe The Services That Uddi Provides To Web Applications?

Answer :

UDDI provides the following types of services to a Web application:
• XML Schema for business descriptions - Includes information about the service publisher (contact name, address, and so on) and specifications on the Web service.
• Web registry of Web services - Includes business, service, and binding information for the Web service.

Question 66. Write The File Extension For A Web Service?

Answer :

A Web service file extension is .asm file. For example, service1.asmx is a Web service file.

Question 67. Which Method Is Used To Uninstall The Windows Services?

Answer :

The Uninstall() method is used to uninstall the Windows services.

Question 68. What Is The Use Of The Mustunderstand Attribute In The Header Element Of A Soap Message?

Answer :

The mustUnderstand attribute indicates that a header entry is either required or optional for the recipient to process further.

Question 69. What Advantage Uddi Has Over Disco?

Answer :

The UDDI directory has an advantage over a DISCO file, as it provides a single location where a client can find the Web services offered by different organizations.

Question 70. How Can You Ensure That Only Authorized Users Access Your Web Service?

Answer :

You should use the <authorization> element to ensure that only authorized user’s access your Web service. This element allows or denies access to your Web service according to their role.

Question 71. Describe The Eventlog Class?

Answer :

The EventLog class is used to access the Windows event logs from Windows services. Using EventLog, you can also customize Windows event logs that record information about important software and hardware events, such as the events of the .NET controls, keyboard, or other hardware devices.

The EventLog class allows you to read or write to event logs, delete logs, and create as well as delete event sources. You can use the EventLog class to create event logs while creating an event source. An event source can be used to write to only one event log at a particular time. However, it is possible to associate one event log to multiple sources.

Question 72. How Can You Prevent Your Web Services From Unauthorized Access?

Answer :

The following are the ways to prevent your Web service from unauthorized access:
• Using encryption and message-based security.
• Using authentication and access controls for the Web service.

Question 73. Explain The Concept Of Web Services In Brief?

Answer :

A Web service may be defined as an independent and self-sustained unit of a software application that is hosted on the Web and implement specific functionalities to execute the business logic. A Web service provides so many functionalities, such as generating pay slips for employees, computing tax, broadcasting weather report, and providing updated news. The Web service allows application to share information or exchange data with other applications across different operating systems and hardware.

Therefore, the work of a Web service is to unite software by exchanging data irrespective of their operating systems, supported hardware, and programming language used in their development. The Web services transfer data in the XML format and use Simple Object Access Protocol (SOAP) to communicate. It is an XML based protocol. The Web services use Web Services Description Language (WSDL) and Universal Description, Discovery, and Integration (UDDI) to describe itself.

Question 74. What Advantages Have Web Services Over Component Object Model (com) And Distributed Component Object Model (dcom)?

Answer :

The advantages of Web services over COM and DCOM are as follows:
• Web services are simple to use and can be implemented on varied platforms.
• Web services are loosely coupled; as a result, their interfaces and methods can be extended.
• Web services do not carry any state information with them so that multiple requests can be processed simultaneously.

Question 75. Mention The Namespace That You Must Import In Code To Build A Web Service?

Answer :

System.Web.Services is the elementary namespace, which must be imported to develop code of a Web service.

Question 76. What Does The Porttype Element Of A Wsdl Document Contain?

Answer :

The portType element contains the operations exposed by the Web service, and the messages involved in the communication between the Web service and its consumers.

Question 77. What Is Disco?

Answer :

DISCO is a technology developed by Microsoft to publish and discover Web services. It discovers URLs of all XML Web services located on a Web server and creates a list of these Web services in a file called as a DISCO file.

Question 78. Which Two Methods Are Used To Discover The Url Of Web Services?

Answer :

The two methods to discover the URL of Web services are Web service discovery tool (Disco.exe) and UDDI.

Question 79. Which Step Is Necessary To Perform Before A Web Service Can Be Consumed?

Answer :

It is necessary to build a proxy class by using the wsdl.exe utility before a Web service can be consumed.

Question 80. Which Property Of The Webmethod Attribute Allows You To Maintain The State Of Objects Across Sessions In A Web Method?

Answer :

The WebMethod attribute's EnableSession property enables you to enable session state for a Web method.

Question 81. Write The Names Of Public Properties Defined In The Webservice Class?

Answer :

There are many properties defined in the WebServices class:
• Application - Obtains the application object for the current HTTP request.
• Context - Obtains the HttpContext object for the current request, which encapsulates all HTTP-specific context used by the HTTP server to process Web requests.
• Server - Obtains the HttpServerUtility object for the current request.
• Session - Obtains the HttpSessionState object for the current request.
• SoapVersion - Obtains the version of the SOAP protocol used to make the SOAP request to a Web service.
• User - Obtains the Server User Object. This property can be used to authenticate whether a user is authorized to execute the request.

Question 82. What Do You Understand By Soap Encoding?

Answer :

The Serialization of the types, such as integers and strings, inside a SOAP message is called encoding. The SOAP objects use XML elements and attributes to serialized data, for example, encodingStyle is an attribute of theEnvelop element, which is used to specify the encoding rules for a SOAP object.

Question 83. What Is The Use Of A .disco File?

Answer :

A client application uses a .disco file to locate or discover the documents that contain the description of a Web service. The .disco file contains links to other resources, which describe essential features, such as capabilities of a Web service. The links contained in a .disco file can refer to other discovery documents or XSD schemas. The description about the services and capabilities of a Web service is written in Web services Description Language (WSDL). A .disco file can also contain the information about other XML Web services that reside on the same or a different Web server.

Question 84. Mention The Name Of The Directory Where It Is Necessary To Locate The Proxy File To Use A Web Service?

Answer :

The proxy file must be stored in the /bin directory. This directory is situated under the root directory of the application.

Question 85. Does A Web Service Have State?

Answer :

The Web services do not have any technique to maintain state. However, it can access ASP.NET objects, such as application and session if they extend from the WebService base class.

Question 86. Which Namespace Must Be Included In A Code That Enables A Xml Web Service To Write Events In An Event Log File?

Answer :

The System.Diagnostics is the namespace, which must be included in a code to enable a Web service for writing events in an event log file.

Question 87. Which Tool Installs The Dll On Your Local Computer And Installs The Windows Service In A Transactional Manner?

Answer :

The Installutil.exe tool.

Question 88. What Is Web Hosting?

Answer :

Web hosting is the act of renting space and bandwidth through a company so that you may publish your web site online.

Question 89. What Is Virtual Hosting?

Answer :

Also known as shared hosting, this form of web hosting should suffice for most everyone. Virtual hosting simple refers to the fact that your site is on one server, and that this server hosts multiple sites. You are virtually shared - your site will not be the only one on this specific server. Very few sites would actually need the power of a dedicated server, so this option provides to be a reliable and cheap solution.

Question 90. What Is A Domain Name?

Answer :

A domain name is a word along with a TLD that uniquely identifies your website.

Question 91. What Is Uptime?

Answer :

Uptime is the percentage of time that a web site is working. For example, if some host has an uptime average of 99.86%, this means that your site will be down for a total about 1 hour each month, We monitor uptime of customer websites of many web hosts and we display this data on the hosts details page. Some hosts also offer “uptime guarantees” but this is not as valuable as it might appear.

Question 92. How Do I Upload My Site?

Answer :

The main method of uploading files to your site’s account is by using FTP. When you sign up with a host, you will probably get an FTP account that lets you access files in your account (usually ftp.yoursitename.com, your main account name and password). Then you can use a built-in Windows or Internet Explorer FTP client, or some other software that supports FTP such as CuteFTP. WS_FTP, or Total Commander, to transfer files from your hard drive to your account. If you don’t get an FTP account or if you prefer a Web interface, you can use your account control panel’s File Manager instead.

Question 93. What Is Full-service Web Hosting?

Answer :

“Full-service” can refer to a variety of services offered in addition to providing web space, transfer, and emails for a web site. For example, it could be 24/7 toll free phone support, web design services, or web site content maintenance services.

Question 94. What Is Domain Parking?

Answer :

Domain parking lets you cheaply reserve a domain name for future use and display an “under construction” default page on it. You can register a domain and not park it anywhere hut then your site will simply be inaccessible until you get a web host. Some registrar let you park your domain for free.

Question 95. Can I Run My Own Software On My Site?

Answer :

This depends on a web host and a plan. Most plans will allow running scripts in languages such as Perl or PHP. Some plans will also allow you to compile program in C/C++ and run them. Some Unix plans will also allow you to run “cron” which enables you to automatically execute programs or scripts at a specific time and date. However to get a full control over all aspects of your server, you will need a dedicated or co-located server instead of a shared plan.

Question 96. What Is The Difference Between Unix Hosting And Windows Hosting?

Answer :

If you need to support Microsoft products such as ASP, MS Access, or VBScript, then Windows hosting would be better Further more, if you are comfortable with 11S and do not have the time to understand how UNIX works, Windows hosting would again be a better choice.

Question 97. What Is Cpanel?

Answer :

cPanel is a Unix based web hosting control panel that provides a graphical interface and automation tools designed to simplify the process of hosting a web site. cPanel utilizes a 3 tier structure that provides functionality for administrators, resellers, and end-user website owners to control the various aspects of website and server administration through a standard web browser.

Question 98. What Is Webhost Manager (wiim)?

Answer :

WebHost Manager (WI-EM) is a web-based tool used by server administrators and resellers to manage hosting accounts on a web server. WI-IM listens on ports 2086 and 2087 by default.

Question 99. What Is A Vector Space Query?

Answer :

A multiple-word query where the weight can be assigned to each of the search words. For example, if you want to fight information on ‘black hole’, but would prefer to give more weight to the word hole, you can enter black hole into the search window.

Question 100. For The Document Of Size I Nib, What Size Would You Expect The Index To Be With Indexing Service?

Answer :

150-300 KB, 15-30% is a reasonable expectation.

Question 101. Where Is Asp Cache Located On Iis 6.0?

Answer :

On disk, as opposed to memory, as it used to be in IIS 5.

Question 102. What Is The Role Of Http.sys In Iis?

Answer :

It is the point of contact for all incoming HTTP requests. It listens for requests and queues them until they are all processed, no more queues are available, or the Web server is shut down.

Question 103. What Is The Relation Between Ssl And Tls?

Answer :

Transport Layer Security (TLS) extends SSL by providing cryptographic authentication.

Question 104. What Secure Authentication And Encryption Mechanisms Are Supported By Iis 6.0?

Answer :

Basic authentication, Digest authentication, Advanced digest authentication, Certificate- based Web transactions that use PKCS #7/PKCS #10, Fortezza, SSL, Server-Gated Cryptography, Transport Layer Security.

Question 105. What Is The Name Of The User Who Connects To The Web Site Anonymously?

Answer :

IUSR_computername.

Question 106. What Script Ship With Iis 6.0?

Answer :

iisweb.vsb to create, delete, start, stop, and list Web sites, iisffp.vsb to create, delete, start, stop, and list FTP sites, iisdir.vsb to create, delete, start, stop, and display virtual directories, iisftpdr.vsb to create, delete, start, stop, and display virtual directories under an FTP root, iiscnfg.vbs to export and import IIS configuration to an XML file.

Question 107. What Is The Difference Between The Basic Disk And Dynamic Disk?

Answer :

The basic type contains partitions, extended partitions, logical drivers, and an assortment of static volumes.

The dynamic type does not use partitions but dynamically manages volumes and provides advanced storage options.

Question 108. Can Windows Server 2003 Function As A Bridge?

Answer :

Yes, and it’s a new feature for the 2003 product. You can combine several networks and devices connected via several adapters by enabling IP routing.

Question 109. Does Windows Server 2003 Support Ipv6?

Answer :

Yes, run ipv6.exe from command line to disable it.

Question 110. What Is Presentation Layer Responsible For In The Osi Model?

Answer :

The presentation layer establishes the data format prior to passing it along to the network application’s interface. TCP/IP networks perform this task at the application layer.

Question 111. What Are The Properties Of Application Pool In Iis?

Answer :

The properties of application Pool in IIS is:

• Recycling
• Performance
• Health
• Identity

Question 112. What Is The Difference Between Iis 5.1 And Iis 6 Administration?

Answer :

IIS 5.1 is for Windows XP.

IIS 6 is for Windows Server, We can create separate application pool with worker process for a separate website in IIS 6.0 Server only.

Question 113. What Is App Pool And App Domain? What Is The Difference Between The Two In Iis?

Answer :

• Application pool is created the each and every website.
• Application domain is created to one domain purpose.

Question 114. How Many Times Are Working In Iis Server?

Answer :

24 Hours.

Question 115. Can We Run Multiple Websites With Same Port Number And Different Ip Address?

Answer :

Yes, We can use multiple websites with same port number and different IP address.

Question 116. How To Install Our Web Application In Iis Web Server?

Answer :

There are different way to deploy the web application in web server like:

1. X Copy deployment.
2. create setup package and install the server machine.
3. use the deployment tools and configure the server repository and drag and drop all files in your machine to virtual folder of server machine.

Question 117. What Is Plug-in?

Answer :

In web browsers, a plug-in (also called plugin, addin, add-in, addon, add-on, snap-in or snapin) consists of a computer program that interacts with a host application (a web browser or an email client, for example) to provide a certain, usually very specific, function “on demand”. Add-on is often considered the general term comprising plug-ins, extensions, and themes as subcategories.

Question 118. What You Know About Mozilla Firefox?

Answer :

Mozilla Firefox is a free and open source web browser descended from the Mozilla Application Suite and managed by Mozilla Corporation. A Net Applications statistic put Firefox at 24.41% of the recorded usage share of web browsers as of January 2010, making it the second most popular browser in terms of current use worldwide after Microsoft’s Internet Explorer, and the most used browser independent of any one operating system. Other sources put Firefox’s usage share at between 21% and 32% and generally trending upward.

Question 119. Have You Any Idea About Netscape?

Answer :

Netscape’s web browser was once dominant in terms of usage share, but lost most of that share to internet Explorer during the first browser war. By the end of 2006, the usage share of Netscape browsers had fallen, from over 90% in the mid 1990s, to less than 1%. Netscape developed the Secure Sockets Layer Protocol (SSL) for securing online Communication, which is still widely, used, as well as JavaScript, the most widely-used language for client-side scripting of web pages.

Question 120. Explain About Safari (web Browser)?

Answer :

Safari is a web browser developed by Apple. First released as a public beta on January 7, 2003 on the company’s Mac OS X operating system, it became Apple’s default browser beginning with Mac OS X vlO.3 “Panther.” Safari is also the native browser for the iPhone OS. A version of Safari for the Microsoft Windows operating system, first released on June 11, 2007, supports Windows XP, Windows Vista, and Windows 7. The current stable release of the browser is 4.0.4 for both Mac OS X and Windows.

Question 121. Explain About Opera (web Browser)?

Answer :

Opera is a web browser and Internet suite developed by the Opera Software company. The browser handles common Internet-related tasks such as displaying web sites, sending and receiving e-mail messages, managing contacts, chatting on IRC clients, downloading files via BitTorrent, and reading Web feeds. Opera is offered free of charge for personal computers and mobile phones.

Question 122. What Is Hyperlink?

Answer :

In computing, a hyperlink (or link) is a reference to a document that the reader can directly follow, or that is followed automatically. The reference points to a whole document or to a specific element within a document. Hypertext is text with hyperlinks. Such text is usually viewed with a computer. A software system for viewing and creating hypertext is a hypertext system. To hyperlink (or simply to link) is to create a hyperlink. A user following hyperlinks is said to navigate or browse the hypertext.

Question 123. What Is Cross-site Scripting?

Answer :

An attack technique that forces a web site to echo client-supplied data, which execute in a users web browser. When a user is Cross-Site Scripted, the attacker will have access to all web browser content (cookies, history, application version, etc). XSS attacks do not typically directly target the web server or application, but are rather aimed at the client. The web server is merely used as a conduit for the XSS data to be presented to the end client. 

Question 124. Which Is The Fastest Web Browser?

Answer :

Microsoft Internet Explorer usually has the fastest startup time on Microsoft Windows machines, although this is mostly because the real “price” of starting it up is paid during the booting of your Microsoft Windows system, Opera is the fastest browser in terms of placing minimal demands on an older computer. Firefox is a very fast descendant of Mozilla, well-tuned for real-world browsing experiences, with an interface that speeds up the way you get things done in a web browser by offering features like tabbed browsing and a more elegant “find” feature --another relevant kind of speed.

Question 125. What Is Ssl (secure Sockets Layer)?

Answer :

SSL (Secure Sockets Layer) is a secure communications protocol used by browsers, websites, and applications to protect information sent over the internet. SSL protocol uses encryption and authentication technologies to make sure only the intended parties can read the information.

Question 126. What Are Http And Https?

Answer :

HTTP (HyperText Transfer Protocol) is a protocol used to send data over the internet. HTTPS (HyperText Transfer Protocol using Secure Socket Layer) is a protocol that encrypts data to send it over the internet more safely. When you enter a URL into a browser, the address will begin with either HTTP or HTTPS.

Question 127. What Is A Safer Web Browser?

Answer :

A safer browser has the following characteristics:

• Latest version.
• Automatic software patches and upgrades.
• Anti-phishing functionality to notify you when you try to access a suspected fake website.
• 128-bit encryption that protects data during transmission.

Question 128. What Is A Web Browser?

Answer :

A web browser is a software application for viewing webpages. Microsoft Internet Explorer, Mozilla FireFox, Opera, and Apple Safari are the most common web browsers.

Question 129. Testing And Consuming A .net Web Service?

Answer :

Testing a Web Service
.NET has a test web page that ASP.NET uses automatically when you request the URL of an .asmx file in a browser. This page uses reflection to read and show information about the web services, such as the names of the methods it provides.

Consuming a Web Service
Web services are built on XML standard. So, a client needs to equip itself to understand XML-based message in order to exchange messages. The .Net framework provides proxy component that enable clients to interact with web services. The proxy has all necessary information that can be utilized by the client application to share data with web services.

Question 130. What Are The Various Ways Of Accessing A Web Service ?

Answer :

Asynchronous Call
Application can make a call to the Webservice and then continue to do whatever it wants to do.When the service is ready it will notify the application. Application can use BEGIN and END method to make asynchronous call to the web method. We can use either a WaitHandle or a Delegate object when making asynchronous call.The WaitHandle class share resources between several objects. It provides several methods which will wait for the resources to become available. The easiest and most powerful way to implement an asynchronous call is using a delegate object. A delegate object wraps up a callback function. The idea is to pass a method in the invocation of the web method. When the webmethod has finished it will call this callback function to process the result.

Synchronous Call
Application has to wait until has completed.