Introduction to web application performance testing

1. Performance Testing
By Tharinda Liyanage

2. What is Performance Testing
• Testing to determine how a system performs
in terms of responsiveness and stability under
a particular workload.
• It can also serve to investigate
scalability, reliability and resource usage.

3. Why we do performance testing
• To demonstrate that the system meets performance criteria.
• To compare two systems to find which performs better.
• To measure what parts of the system or workload causes the
system to perform badly.
– Speed - Does the application respond quickly enough for the intended
users?
– Scalability – Will the application handle the expected user load and
beyond? (AKA Capacity)
– Stability – Is the application stable under expected and unexpected
user loads? (AKA Robustness)
– Confidence – Are you sure that users will have a positive experience
on go-live day?

4. Types of testing
• Load Testing
– behavior of the system under a specific expected
load
• Concurrency
• Speed/Throughput
• Stress Testing
– the upper limits of capacity within the system
• Scalability/Stability

5. Types of testing
• Benchmark testing
• Compare competitive product
• Check performance with previous builds

6. What we measure
• Response time
– User concerns
• Throughput
– Business concerns
• Resource utilizations
– System concerns

7. Phases of Performance Testing
• Project assessment
– Goals/Scoping: “What do you want to achieve?”
• Methodology/Planning
– “How do you plan to achieve it?”
• Implementation/Execution
– “Doing what you planned”
• Validation/Evaluation
– “Did you achieve your goals?”
• Results/Interpretation
– “What does the output of the testing mean?”

8. Tools
• Free/Open source tools • Other useful tools
– JMeter • Httpwatch
• Commercial tools • YSlow
– Load Runner
– Webload