JMeter Fundamentals

What is JMeter

• Open Source Project (released March 2001)
• Created for Automated Performance testing saves time and money
• Functional (though it is not the best tool, Regression and Load testing from
• JMeter files are simple XML
• Strong community
• Constant updates and improvements
• http://jmeter.apache.org/

What can you test in JMeter

• JMeter tests all kind of application (not only Java)
  • Web Application
  • SOAP Web Services, REST, XML-RPC
  • JAR files
  • LDAP
  • Databases (via JDBC)
  • JMS
  • SMTP
  • FTP

Installing JMeter

Windows

• Install JRE
• Download latest version http://jakarta.apache.org/site/downloads/
• Uncompress it
• go to bin folder
• Run jmeter.cmd

Linux

• apt-get install jmeter
• run jmeter
• If you want to have the newest version download it from the jmeter site

JMeter and Logs

• JMeter does not use pop-ups
• All errors and status is spewed out into a log file
• Log file is always located in the directory the jmeter command was invoked

Running JMeter Tests in Windows

GUI

• jmeterw.cmd - run JMeter in GUI using javaw (no terminal window)
• jmeter.bat - run JMeter in GUI mode
• jmeter-t.cmd - drop a JMX file on this to load it in GUI mode (t for Test)

CLI (Non GUI)

• jmeter-n.cmd - drop a JMX file on this to run a non-GUI test (n for non-GUI)
• jmeter-n-r.cmd - drop a JMX file on this to run a non-GUI test remotely
• jmeter-server.bat - start JMeter in server mode
• shutdown.cmd - Run the Shutdown client to stop a non-GUI instance gracefully
• stoptest.cmd - Run the Shutdown client to stop a non-GUI instance abruptly

Note: the special name LAST can be used with jmeter-n.cmd, jmeter-t.cmd and jmeter-n-r.cmd and means the last test plan that was run interactively.

Running JMeter Tests in Unix

• jmeter - run JMeter in GUI (JVM options specified)
• jmeter.sh - very basic JMeter script with no JVM options specified.
• jmeter-server - start JMeter in server mode
• shutdown.sh - Run the Shutdown client to stop a non-GUI instance gracefully
• stoptest.sh - Run the Shutdown client to stop a non-GUI instance abruptly

The Elements of a JMeter Test Plan

• Test Plan and WorkBench
• Thread Group
• Samplers
• Listeners
• Assertions
• Cookie Controller
• HTTP Defaults
• HTTP Headers Defaults

Test Plan vs WorkBench

• Test Plan is saved and where can run the script
• WorkBench is not saved with the Test Plan

Thread Group

• a group of instructions or actions representing one “actor” using your application
• always process instructions within them in chronological order
• allow you to specify simultaneous testing scenarios

Samplers

• Only within a Thread Group
• Samplers perform the actual work of JMeter
• Each sampler (except Test Action) generates one or more sample results
• The sample results can be viewed in listeners

Listeners

• Report back test results to you (in GUI or save them to a file)
• Listeners can work real time or use saved results

Assertions

• These are criteria you can set which the test must meet in order to pass
• E.g. Results of a samplers should not contain "Critical Error" phrase

Simple Controles

TODO Description TODO Screen shot

Creating Simple Test Plan

• Create a Thread Group
• Create a Sampler hitting localhost root page
• Run the test
• Check the log files
• Add the View Results Tree Listener and analyse the result

TODO: Put a screenshot here and jmx file

Running the Test Plan

• Top Right Corner of the GUI will show e.g. 20/40
• 40 is the total number of concurrent threads
• 20 is the number of concurrent threads currently running

TODO: Put a screenshot here

Recording Scenario

• Create a Proxy Server
• Configure Your Browser
• Use "1st Sample only"
• Start Recording
• Rename Samples are you record

Using different options of Proxy Server

TODO

Timers

• Specify a delay before an action (usually sampler) can occur
• Times should mimic human (or system) waiting time
• The best idea is to use logs to determine the distribution and distribution parameters of the waiting time
• Timers can be put in scope
• If two timers are put in the same level, the execution time add up

Saving Results

• Save results to a file
• Use another instance of JMeter to analyse results
• Saving Errors Only
• Saving Full Responses for one sample or group of samples

Biscuits manager

• Try to record the scenario where user:
  • logs
  • browses the front page
  • logs out
• Play the scenario
• Check wether the user really was logged in

Assertions

• Create an assertion which checks wether user is really logged in
• Apply the assertion to all of the samples

Testing different Browsers

• HTTP Headers
• HTTP Headers defaults

Switching Servers

• HTTP Defaults

Functional Testing

• Run Thread Groups consecutively (one group at a time)

Reusing Elements

• Merging (Merge Proxy Server)
• Module Controller
• Include Controller (don't use it)

Variables

• Config Elements > User Defined Variables
• ${VARIABLENAME}

Variables from command line

HOST             ${__P(host,www.example.com)}
THREADS          ${__P(threads,10)}
LOOPS            ${__P(loops,20)}
jmeter ... -Jhost=www3.example.org -Jloops=13

 jmeter-n "Test Plan1.jmx" -JCNT=10

Variable Substitution During Recording

• Setup a variable USER and set it to admin
• Login as an admin
• Look into the recorded samples

Dynamic Variables

• Pre Processors > User Parameters
• CSV

Running Test Periodically

• Run Test From Command Line
• ./jmeter -n -t TestPlan.jmx -j /dev/console
• JTL Report
• Creating User Report

Extractors

• Extractors allows you to save part of response in a variable for the future use
• Common Uses
  • Security Tokens
  • Dynamic data creation

Extractors Examples

Text in HTML:

name="file" value="readme.txt"

RegExp:

name="file" value="(.+?)"

• ( and ) - brackets enclose the portion of the match string to be returned
• . - match any character
• + - one or more times
• ? - don't be greedy, i.e. stop when first match succeeds

Extractors Exercises

• Record and run following sequence (remember about Cookie Manager)
• User access the content (node/add)
• User atrainer logs into the application
• User access the content (node/add)
• User logs out
• User access the content (node/add)

Loops and Counters

• Define a counter
• Create a page with title "Tile 1", "Title 2".... "Title 10"
• Run the script consecrative
• Create a script which runs it in parallel (extra exercise)

Stress Testing

• Ramp-up Time
• Summary Report
• Graph Summary

Understanding Statistics