Performance Testing With Jmeter

Slide 1: Performance Testing with JMeter Adam Goucher http://adam.goucher.ca adam_goucher@hotmail.com

Slide 2: Lecture Objective Give students an introduction to performance testing concepts and implementation using JMeter.

Slide 3: Definitions

Slide 4: Performance Testing Performance testing determines or validates the speed of the AUT (X per T)

Slide 5: Load Testing Load testing identifies the maximum operating capacity of an application as well as any bottlenecks that might interfere with its operating at capacity (Or, when does it blow up?)

Slide 6: Stress Testing Stress testing is focused on determining an application’s robustness, availability, and reliability under extreme conditions • heavy loads • high concurrency • limited computational resources

Slide 7: Scalability Scalability testing determines or validates whether adding another Y resource (database, memory, disk, CPU, etc) increases speed of X proportionally

Slide 8: Pre-testing Activities

Slide 9: Design Review The cheapest performance issues to address are ones that are never put into the code. Testers should review the application design to see if there are any obvious potential performance problems.

Slide 10: Environment Prep - Network Performance testing is often a network intensive activity which can affect others in the organization Testing should be done on a separate, segregated network.

Slide 11: Environment Prep - Hardware Depending on what your goals are for your testing, different hardware is appropriate for both the AUT and load generators. Testers should acquire and configure the correct hardware.

Slide 12: Environment Prep - Software Generating load is not as easy as it sounds. Testers should acquire or create load generators and configure them for their desired goal

Slide 13: Mission Performance testing without a Mission is just throwing load at a server to see what is going to happen. Testers should determine Why they are doing their testing.

Slide 14: Audience Determining who you are generating numbers for, will largely dictate what you do • Development • Marketing • Operations

Slide 15: Metrics Performance testing is all about numbers and metrics. Testers should determine which metrics they are concerned about and how to get them.

Slide 16: Give Warning Let anyone who might be affected by your testing advance warning.

Slide 17: Generic Testing Steps 1. Create / Record Test 2. Add measurement hooks 3. Data drive script 4. Add logging 5. Build workload profile 6. Execute test

Slide 18: JMeter

Slide 19: JMeter JMeter is a free, open-source performance measurement tool written in Java

Slide 20: Thread Groups The Thread Group is the basic element of a JMeter Test Plan Each thread represents a user  setting a thread group to 1000 simulates 1000 users

Slide 21: Samplers Samplers do the actual work in JMeter and interact with the server you are loading There are a number Samplers in JMeter by default. For web testing, use ‘HTTP Request'

Slide 22: Listeners The information produced by Samplers is consumed by Listeners Popular listeners are: • Graph Results • View Results Tree • Simple Data Writer

Slide 23: Logic Controllers Logic Controllers determine the order that Samplers are processed More complex scripts will make use of • Loops • Interleave • Random • If

Slide 24: Assertions A test isn’t a test unless it checks something. Assertions are what do the checking For web applications, these are the useful ones • Response • Duration • HTML Assertion

Slide 25: Configuration Elements Configuration Elements set default values for other parts of the Test Plan as well as configure variables • CSV Data Set Config allows you do to DDT within JMeter • HTTP Cookie Manager will automatically intercept and sent cookies with requests • HTTP Request Defaults saves you time when doing lots of HTTP Samplers

Slide 26: Variables In JMeter, you can reference variables as such ${VARIABLE}

Slide 27: Batch JMeter can run in a non-gui mode to save resources on the load generating machines

Slide 28: Recording There is a way to record tests (as in LoadRunner) but I find it easier to build scripts one element at a time