JMeter Fundamentals

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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

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

JMeter - Simple Data Writer.png JMeter - Results In Separate Instance.png

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)

JMeter Running Threads Consecutively.png

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

JMeter Average Standard Devaition and Median.jpg