Performance Testing Types

Actually speaking performance testing is just a concept and there is no testing called performance testing

Performance Testing for definition sake we can define as "The process of evaluating the application behavior under a various load" is known as performance testing.

Application behavior can be any of the following things

Response Time in seconds
Throughput in bytes
Transactions per seconds etc

Under performance testing following are the types of  testing types conducted to evaluate the performance of the application.

1.Load Testing
2.Stress Testing
3.Volume Testing
4.Stability Testing
5.Reliability Testing
6.Spike Testing
7.Soak Testing

Load Testing : Analyzing and studying the behavior of the application with defined load is nothing but Load Testing.
Here Load is nothing but either "number of users" or "amount of data transfer".
The purpose of load testing is to determine whether my application works fine with the present fixed load.

Stress Testing : Analyzing and studying the behavior of the application with load behind the defined load is nothing but stress testing.
The purpose of load testing is to determine whether my application works fine with the future increased load as per business growth.

Volume Testing:Analyzing and studying the behavior of the application by pumping large volume of data is nothing but volume testing.
This testing is done normally for data repository kind of application.

What type of applications need performance testing

Normally we do performance testing for following types of applications

1.Client/Server application

  When many clients are connected to server
  Each Client software is deployed on one one machine ,  Server side component of the software is deployed    on the server machine

2.Web based application

  All application components are deployed on different machines

Because of the following reasons ,its recommended to do performance testing on the above types of applications


1.Application components are deployed across the different machines

2.Multiple users accessing application at the same time

Performance Testing Life Cycle

Software Architectures

One Tier Architecture :

A simple form of standalone application architecture where everything resides in a single program. Contrast this to 2-tier and 3-tier architectures.

Single-tier architecture is the notion of having the user interface of a web application, the middle ware and the data access all contained in one whole architecture. Usually in Software Engineer you break your application to make them more maintainable and sustainable. If you know that your software will not grow over time, you may want to do a single tier architecture.

 Two Tier Architecture :

In Two-Tier Architecture we have just two layers
1. GUI/ intrface / presentation layar

2. Database layer (where we store/retrieve our data)

Basically this architecture is followed in client/server applications where database and application resides in the same machine or database may in other machine conected thtough network.

Two-tier architecture is a client/server architecture , where a request to do some task is sent to the server and the server responds by performing the task.where as a three-tier or a multi tier architecture has client, server and database. Where the client request is sent to the server and the server in turn sends the request to the database. The database sends back the information/data required to the server which inturn sends it to the client.


  Three Tier Architecture :

In three tier architecture we can find three layers names:


1. Presentation Layer

2. Busness Layer/ Mid Layer

3. Database Layer.

Presentation Layer: GUI/Interface , where a user view or enters the data.

Business Layer: where business login and rules are execute and can accommodate hundreds of users.

Database Layer: Data access layer takes care of connection between the appication and storing the data as a warehouse.This is very important layer in any architecture 'coz finally all data comes to it and maintaining such a huge amount of data is taken care by this layer avoiding concurrency and maintaining scalibility, durability to the application.

Load Testing with LoadRunner

LoadRunner reduces the personnel requirements by replacing human users with virtual users or Vusers. These Vusers emulate the behavior of real users—operating real applications.


Because numerous Vusers can run on a single computer, LoadRunner reduces the hardware requirements.

The LoadRunner Controller allows you to easily and effectively control all the Vusers—from a single point of control
 
The repeatability of the tests are very easy and effective
 
Loadrunner generates effective graphs and reports  for analysing the performance of the applications

Manual Load Testing

   It is expensive, requiring large amounts of both personnel and machinery


   It is complicated, especially coordinating and synchronizing multiple testers

   It involves a high degree of organization, especially to record and analyze results meaningfully

   The repeatability of the manual tests is limited

Understanding Checkpoints

A checkpoint is a verification point that compares a current value for a specified property.

When you add a checkpoint, QuickTest adds a checkpoint to the current row in the Keyword View and adds a Check Checkpoint statement in the Expert View.
When you run the test or component, Quickest compares the expected results of the checkpoint to the current results.
If the results do not match, the checkpoint fails.
You can view the results of the checkpoint in the Test Results window with the expected value for that property.
If you want to retrieve the return value of a checkpoint (a Boolean value that indicates whether the checkpoint passed or failed), you must add parentheses around the checkpoint argument in the statement in the Expert View. For example: a = browser("MyBrowser").page("MyPage").check (checkPoint("MyProperty"))

Check Points
1.Standard Check point
Check values of the object's property
2.Image Check point
Checks the property values of the image
3.Table Check point
Checks information in the table
4.Page Check point
Check the characteristics of the web page
5.Text/Text Area Check point
Checks that a text string is displayed in the appropriate place or application window

Adding Check points to Test
You can add checkpoints during a recording session or while editing your test or component. It is generally more convenient to define checks once the initial test or component has been recorded.

Quickest adds a checkpoint to the current row in the Keyword View and adds a Check Checkpoint statement in the Expert View.

To add checkpoints while recording or editing:

Use the commands on the Insert menu, or click the arrow beside the Insert Checkpoint button on the Testing toolbar. This displays a menu of checkpoint options that are relevant to the selected step in the Keyword View
To add a checkpoint while editing only:
Right-click the step in the Keyword View where you want to add the checkpoint and choose
Insert Standard Checkpoint

Right-click any object in the Active Screen and choose Insert Standard Checkpoint. This option can be used to create checkpoints for any object in the Active Screen (even if the object is not part of any step in the Keyword View).

Understanding the checkpoint property dialog box

Different type of checkpoints in detail:

Standard Checkpoint
Standard checkpoints are supported for all add-in environments.
The standard checkpoint checks a variety of objects such as buttons, radio buttons, combo boxes, lists, etc.
Example : you can check that a radio button is activated after it is selected or you can check the value of an edit field.
Page Checkpoint
checks the characteristics of a Web page. For example, you can check how long a Web page takes to load or whether a Web page contains broken links. You create a page checkpoint by inserting a standard checkpoint on a page object.
Note :- Page checkpoints are supported for the Web environment only
Image Checkpoint

checks the value of an image in your application or Web page. For example, you can check that a selected image’s source file is correct.
Note: You create an image checkpoint by inserting a standard checkpoint on an image object.
Text Checkpoint
Checks that a text string is displayed in the appropriate place in your application or on a Web page.
Example  suppose your application or Web page displays the sentence Flight departing from New York to San Francisco. You can create a text checkpoint that checks that the words “New York” are displayed between “Flight departing from” and “to San Francisco”.

Text Area Checkpoint

Checks that a text string is displayed within a defined area in a Windows application, according to specified criteria.
Suppose your Visual Basic application has a button that says View Doc , where is replaced by the four digit code entered in a form elsewhere in the application.
You can create a text area checkpoint to confirm that the number displayed on the button is the same as the number entered in the form
Accessibility Checkpoint
identifies areas of your Web site that may not
conform to the World Wide Web Consortium (W3C) Web Content Accessibility Guidelines.

 Bitmap Checkpoint
Checks an area of your Web page or application as a bitmap.
Suppose you have a Web site that can display a map of a city the user specifies. The map has control keys for zooming. You can record the new map that is displayed after one click on the control key that zooms in the map. Using the bitmap checkpoint, you can check that the map zooms in correctly.
Table Checkpoint
checks information within a table. For example, suppose
our application or Web site contains a table listing all available flights from New York to San Francisco. You can add a table checkpoint to check that the time of the first flight in the table is correct.
Note: You create a table checkpoint by inserting a standard checkpoint on a table object.

Database Checkpoint

Checks the contents of a database accessed by your application. For example, you can use a database checkpoint to check the contents of a database containing flight information for your Web site.
XML Checkpoint
Checks the data content of XML documents in XML files or XML documents in Web pages and frames