Performance Testing

Performance Testing Load Runner Pune October 2008 Parish Sharma

Contents Day 1

Session 1: Planning an Effective Load Test.

Session 2: Load Runner Flow and Architecture

Session 3: Introduction to Scenarios

Session 4: VuGen and Scripting

06/09/09 Author: Parish Sharma

Session 1 Planning an Effective Load Test 06/09/09 Author: Parish Sharma

Types of Performance Test

1. Performance Test

2. Load Test

3. Stress Test

4. Capacity Test

Performance Test

Purpose:

To determine or validate speed, scalability, and/or stability.

Load test

Purpose:

To verify application behavior under normal and peak load conditions.

Stress Test

Purpose:

To determine or validate an application’s behavior when it is pushed beyond normal or peak load conditions.

Capacity Test

Purpose:

To determine how many users and/or transactions a given system will support and still meet performance goals.

Need for Load Test

User support for a New System.

Upgrade/Scale a System

To know the Speed and Response of the System

To know the behavior at normal and peak loads.

To identify where system breaks.

Cont..

Most load tests are executed with false intentions, (performance barometer).

Understanding the impact of response times for predictable behavioral conditions and scenarios.

Understanding the impact of response times for patterns of adoption and growth.

Goals & Objectives

Performance Testing Objectives

Performance Objectives

Performance Targets

Performance Thresholds

Performance Budgets

Measurable Goals

1. Transaction Response Time

2, Resource Utilization

3. Memory Leaks

4. Deadlocks

5. Throughput

6. Capacity Planning

7. Product Evaluation

8. Acceptance

Information to Start

1. Hardware and Software Details

2. Load to be tested

3. Expected Response Time

4. Suitable time to load test.

5. Critical Business Scenarios.

6. Priority and Flow of scenarios.

END OF SESSION -1 QUESTIONS?? 06/09/09 Author: Parish Sharma

Session 2 Load Runner Flow and Architecture 06/09/09 Author: Parish Sharma

Load Runner Components

1. Virtual User Generator

2. Controller

3. Load Generator Agent

4. Analysis

Plan Test Create Scripts Scenario Creation Scenario Execution Result Analysis Load Testing Flow Performance Tuning

Test Planning

1. Test Planning - Before we run load testing

- Setup goals

Measure application response time

Configuration sizing

Capacity planning

Regression

Reliability

- Type of testing

Load Testing (System performance testing with SLA target load)

Stress Testing (Capacity testing to find out breaking point)

Duration Testing (Reliability testing to test the system under load)

Create Scripts

2. Create Scripts

- Automate business processes in LoadRunner VUGen (Virtual User Generator):

Scripts are C, C++-like code

Scripts are different with different protocol/technology

LoadRunner has about 50 protocols, including WAP

Record user actions

Need assistance of SME/Functional Testing group

Add programming and test data in the scripts

E.g. add correlation to handle dynamic data, e.g. session id

Test data may need lot of work from project team

Scenario Creation

3. Create Test Scenario

- Build test scenario according to usage information in Business Profile

Load Calculation

Can use rendezvous point, etc.

- Run-Time setting

Think time

Pacing

Browser Emulation: simulate browser cache, new user each iteration

Browser version, bandwidth, etc.

Test Execution

4. Execute Load Testing

Execute test scenarios with automated test scripts in LoadRunner Controller

Isolate top time transactions with low load

Overdrive test (120% of full load) to isolate SW & HW limitations

- Work with Internal Support Team to monitor the whole system, e.g., web server, DB server, middleware, etc.

Result Analysis

5. Analyze Test Result - Analysis

- Collect statistics and graphs from LoadRunner

- Report results

- Most commonly requested results:

Transaction Response time

Throughput

Hits per sec

HTTP response

Network Delay

*Server Performance

- Merge graphs to make it more meaningful

Transaction response time under load

Response time/Vuser vs CPU utilization

Cross scenario graphs

Result Reporting

6. Test Report

- Don’t send LoadRunner result and graphs directly

- Send summary to the whole team

- Report key performance data and back end performance data

- Add notes for each test run

- Keep test history: for team to compare test runs

Architecture Overview 06/09/09 Author: Parish Sharma

How it Works 06/09/09 Author: Parish Sharma

Session 3 Introduction to Scenario 06/09/09 Author: Parish Sharma

Elements making a Scenario

1. Business Requirements

2. User Load

3. Ramp Up / Ramp Down

4. Steady Run Time

5. Actions of the Users

Scenario

Using LoadRunner, we divide the application performance testing requirements into scenarios.

A scenario defines the events that occur during each testing sessions.

For example, a scenario defines and controls the number of users to emulate, the actions that they perform and the machines on which they run the emulations.

Types of Scenario

1. Manual

2. Goal Based

Types of Execution

20% of Full Load - flush out transaction problems, effectively debug transaction

Full Load - flush out system problems, effectively debug system

120% of Full Load (Overdrive) - provide a margin of error as well as future scalability

Session 3 VuGen and Scripting 06/09/09 Author: Parish Sharma

Virtual Users

Virtual users or Vusers emulate the steps of real users. The steps that Vusers perform are recorded in a Vuser Script.

Virtual User Generator

VuGen records Vuser scripts that emulate the steps of real users using the application.

VuGen not only records VuGen scripts but also runs them. Running scripts from VuGen is useful for debugging.

VuGen records sessions on Windows platforms only. However a recorded Vuser script can run on both Windows and Unix Platforms.

Developing Vuser Script

Record a basic script.

Enhance/Edit the script.

Configure the run time settings.

Run the script in Stand Alone mode.

Integrate the Vuser script into the test.

Vuser Scripts

Each Vuser script has 3 sections:

Vuser_init{()

Actions() {One or more actions can be there}

Vuser_End()

Enhancing the scripts

After recording the basic script, it can be enhanced with the following:

General Vuser Functions.

Protocol specific Vuser Functions

Standard ANSI C Functions

Inserting Transactions into the script.

Sending Messages to the output

Handling errors.

Parameterization

Corelation

Run Time Settings

Think Time

Run Logic

Pacing

Log

Standard

Extended

Miscellaneous.

QUIZ TIME!!!!!!!! 06/09/09 Author: Parish Sharma

Questions?

[email_address]

[email_address]

Tel: (020)2620-7710 (desk)

09922429552 (cell)

Performance Testing

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