This document shows how you can use JMeter to perform more automated (non-interactive) testing.

Requirements

This article assumes that you:

  • know the basics of JMeter
  • have an existing test plan
  • have a bit of knowledge on using variables in test plans
  • have touched on remote testing (from GUI is fine)

Set up

  • In your existing test plan, make sure that any variations in testing make use of functions or variables. For example, if running a HTTP sampler, use HTTP Request Defaults to specify a host as ${+P(targetHost,localhost)}. Other useful places for parameterisation might include number of threads, ramp-up period or scheduler duration in a thread group, using a format of ${+P(threadgroup.threads,500)} (The +P function is shorthand for +property. See the [http://jmeter.apache.org/usermanual/functions.html#__P user manual] for more info on using this function).

  • Save your test plan and properties file to a directory.
  • Create a properties file containing all your variables. E.g. mytest.properties could contain threadgroup.threads=100, targetHost=my-target-host.com
  • The test plan does not need Listeners, as this will be configured via parameters. This will improve performance on the testing.
  • Run the test mode in stand-alone mode (i.e. no remote servers): jmeter -n -t load_test.jmx -l load_test_report.jtl -q mytest.properties -j mytest.log
  • The "-q" parameter defines an additional property file, which is the equivalent of setting properties for the contents of the file using the -J parameter. These parameters are not sent to remote servers; for that one can use the -G parameter. The -G parameter can reference either a property in the format of -Gprop=val or a properties file, such as -G./myglobal.properties
  • Properties can be referenced anywhere in the test plan using the +P() function - e.g. ${+P(propname)}
  • There is no way currently to predefine variables, however the User Defined Variables table on the Test Plan can be used to create variables from properties. For example:

Name:

Value:

HOST

${__P(host,localhost)}

  • On all client machines, start up JMeter server, ensuring that firewall is not blocking connections (clients must all be on the same subnet).
  • On JMeter controller (the host initializing the test), run the test with the -R parameter (can be run using -r and specfiying hosts in jmeter properties file):
    jmeter -n -t load_test.jmx -l load_test_report.jtl -Gmytest.properties -j mytest.log -R remotehost1,remotehost2 ${GLOBAL_VARS}

Note that load injection to targets will be a increased as a ratio of number of threads per thread group multiplied by number of client machines.

A bash script similar to the following could be used to start up jmeter (called jmeter_test_wrapper.sh for example):

#!/bin/sh

loadtest="myloadtest"
GLOBAL_VARS=""
REPORT_DIR=/tmp
JMETER_PROPERTIES=jmeter.properties
JMETER_CUSTOM_PROPERTIES=mytest.properties
# If set as an environment var, then use it, otherwise leave it unset.
HOST_LIST=${HOST_LIST:+"-R ${HOST_LIST}"}

# Had an issue with -Gglobal.properties file, so parsed this into individual properties.
for var in `grep -vE "^#|^$" ${JMETER_CUSTOM_PROPERTIES}`; do
        GLOBAL_VARS="-G${var} ${GLOBAL_VARS}"
done

# But after testing, it does work as expected.
GLOBAL_VARS="-G${JMETER_CUSTOM_PROPERTIES}"

if [ -f ${loadtest}.jmx ]; then
        echo "Running ${loadtest} with:"
        echo -e "               -----------------------
        $JMETER -n
                -t ${loadtest}.jmx
                -l ${REPORT_DIR}/${loadtest}.jtl
                -p ${JMETER_PROPERTIES}
                ${GLOBAL_VARS}
                ${HOST_LIST}
                -j ${REPORT_DIR}/_${loadtest}.log
        -----------------------"
        $JMETER -n \
                -t ${loadtest}.jmx \
                -l ${REPORT_DIR}/${loadtest}.jtl \
                -p ${JMETER_PROPERTIES} \
                ${GLOBAL_VARS} \
                ${HOST_LIST} \
                -j ${REPORT_DIR}/_${loadtest}.log
else
        echo "Could not find test plan for ${loadtest}"
fi

For a local test, you could run: ./jmeter_test_wrapper.sh
For a remote test, it can be modified as HOST_LIST="192.168.1.10,192.168.1.12" ./jmeter_test_wrapper.sh
Now all you need to do is make sure the servers are running and add the above command into scheduler.

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