Basic concepts of Performance Testing

 Performance Testing

• Performance testing is a type of software testing that is used to evaluate the speed, scalability, and stability of a system. It is used to ensure that the system can handle the expected load and volume of traffic.

Types:

1. Load Testing
2. Stress Testing
3. Data/Volume Testing
4. Scalability testing
5. Endurance testing
6. Spike testing

Load Testing:

• Load testing is a generic term covering Performance Testing and Stress Testing.
• Testing the app with the maximum number of users.
• To measure the performance under the expected load.

Stress Testing:

• The system is under extreme load conditions, such as peak user activity or maximum transaction throughput.
• Testing the application with MORE than the maximum number of users.
• To measure performance under a load much higher than expected.

Endurance Testing:

• Endurance Testing is done to ensure the software can handle the EXPECTED load over a long period.

Spike Testing:

• System by SUDDENLY increasing the load (e.g. the number of users or transactions) to check how it responds.

Data/Volume Testing:

• System by increasing the number of users or transactions over a PERIOD OF TIME.

Scalability testing:

• The system performs when the workload increases or decreases.

Common Performance Problem:

• Most performance problems revolve around speed, response time, load time, and poor scalability.
• A slow-running application will lose potential users.
• Long Load time - While some applications are impossible to make load in under a minute, Load time should be kept under a few seconds if possible.
• Poor response time - Response time is the time it takes from when a user inputs data into the application until the application outputs a response to that input. Generally, this should be very quick. Again if a user has to wait too long, they lose interest.
• Poor scalability - A software product suffers from poor scalability when it cannot handle the expected number of users or when it does not accommodate a wide enough range of users.
• Bottlenecking  - Bottlenecking is when either coding errors or hardware issues cause a decrease in throughput under certain loads.

Common performance bottlenecks are:

• CPU utilization
• Memory utilization
• Network utilization
• Operating System limitations
• Disk usage