Benchmark design

Benchmark is representative workload used during performance test run.
Benchmark is provided by client.

Introduction to Load Runner

Load Runner is a commercial performance and load testing tool for examining how software application behaves while placed under load.

LoadRunner emulates the load generated by any number of users from few to many thousand.

Performance Testing

Definition:
Performance testing determines how fast the System Performs operations under a particular workload in software engineering

Performance testing is just a theoretical concept whereas load and stress testing are practically used in software testing process.

Load testing on application enables developers to isolate bottlenecks in any component of the infrastructure.
Example: Measures application ability to sustain concurrent users while maintaining adequate response time.

Components of Load Testing
Load Balancers: They take incoming load of the client requests and distribute the load across multiple server resources.
Load Generator: It is a machine which serves as a host for running Vusers.

Load Testing Process

1. Plan the Test: We develop a test plan to ensure that test scenario's will accomplish load-testing objectives.

2. Create Vusers: We create Vuser Scripts that contain

1. Task performed by each Vuser
2. Task performed by all the Vusers
3. Tasks measured as Transactions

3. Creating the Scenario:

Scenario describes events that occur during testing session. Scenarios include

1. List of machines
2. Scripts
3. Vusers that run during the scenario

Scenarios are created using Load Runner Controller.

4. Running the Scenario
5. Monitoring the Scenario
6. Analyzing the Test Results: We use graphs and reports to analyze the application's performance.

Load Runner

Components of Load Runner

1. Virtual User Generator (VuGen): It is used to develop scripts for variety of application types and communication protocols.

Virtual User Script is divided into 3 sections:

1. Vuser_init: These actions are performed when Vuser is loaded or initialised.
2. Actions: These actions are performed when Vuser is in "Running" state
3. Vuser_end: These actions are performed when Vuser finishes or stops.

2. Controller: It is used to manage the test scripts and create scenarios. Scenarios means Scripts, Host Machines and Number of Virtual Users.

3. Analysis: It is used to examine the test Results. It yields a series of graphs and reports that helps summarize and present end-to-end test summary results. We can create cross scenario comparison graphs.

4. Launcher: It provides a single point of access for all load runner components.

Types of Performance Testing

There are three types of performance Testing
1. Load Testing
2. Stress Testing
3. Capacity Testing

Load Testing
To determine or validate application's behavior when it is under normal or peak load conditions.
Load testing can be done in two ways.
a. Endurance Testing: Evaluates the system ability to handle constant, moderate work load for a long time.
b. Volume Testing: Evaluates the system ability to handle heavy work load, for a limited time period

Stress Testing
To determine or validate application's behavior when it is pushed behind normal or peak load conditions.

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

Scalability Testing
To test the application with different user load and identify the system behavoiur at different time intervals.

Spyke Testing
To test the application, by increasing the users suddenly and identify the system behaviour