Error Generator Sping Boot Appliction

A series of code utilities that generate random Java errors.

This code is a variation/offshoot of the OverOps Error Generator: https://github.com/takipi-field/ErrorGenerator

The purpose of this modification is to support automated testing through a READ API. A number of ErrorGenerator calls have been exposed through SpringBoot to allow simple automated testing through scripting or test tools such as jmeter.

The application deploys as a .war file and runs under tomcat.

The test utility can be used to drive a particular mix of arguments:

• Number of concurrent threads/users
• Error Rate as a percentage
• Test Duration in seconds
• Transactions Per Minute (TPM)

The tests can be run individually or by using a provided Jmeter job and accompanying script.

Deploying Error Generator Sping Boot App using Tomcat

You can use the .war in the target folder: ErrorSpringApp.war, or you build it from scratch using maven.

To Build it from scratch

mvn clean package

Enable OverOps to Monitor Tomcat

Edit the CATALINA_OPTS variable in the catalina.sh file:

vi /opt/tomcat/bin/catalina.sh

CATALINA_OPTS="$CATALINA_OPTS -agentpath:/opt/takipi/lib/libTakipiAgent.so -Dtakipi.application.name=TakipiTest -Dtakipi.deployment.name=v1.0 -Dtakipi.no.xmen"

To Deploy the .war file under tomcat

Copy the .war file:

cp ./target/ErrorSpringApp.war /opt/tomcat/webapps/.

Restart tomcat, e.g.,

${tomcat-dir}/bin/shutdown.sh ${tomcat-dir}/bin/startup.sh

To Run the Error Generator Sping Boot App

In a browswer

Enter the following URL in the broswer to generate errors one at a time:

${tomcat-host}:8080/ErrorSpringApp

Select the type of error and click "Submit".

REST API

Use the following URL to execute a single error:

${tomcat-host}:8080/ErrorSpringApp/InvokeError?errorType=${error}

Where ${error} is one of NoError NullPointerException NumberFormatException ParseException UncaughtException

Scripts can be created using curl, e.g.,

curl ${tomcat_host}:8080/ErrorSpringApp/InvokeError?errorType=NullPointerException

Testing with JMeter

Make sure the JMeter executable is in the PATH:

export PATH=$PATH:/opt/jmeter/bin

A JMeter job is included in the scripts folder that executes the Error Generator Spring Boot App with the following characteristics driven by variables:

HOST : The tomcat server host name URLPATH : The application and command (InvokeError) DURATION : Length of the test run in seconds. This value must have a single decimal place, e.g., 60.0 NUM_THREADS: The number of concurrent test threads, simulating concurrent users ERR_RATE : The percentage of error transactions (0 - 100) TPM : The number of transactions per minute. JMeter will throttle accordingly.

The command line to execute the JMeter job will look something like this:

jmeter.sh -n -t OverOps_Spring_Boot_Test.jmx
-Jnum_threads=$nt
-Jno_err_rate=$no_er
-Jerr_rate=$er
-Jtpm=$tpm
-Jhost=${HOST}
-Jpath=${URLPATH}
-Jduration=${DURATION}

Test with the JMeter script

A script file run_jmeter.sh is provided in the scripts folder as well.

This script will run a sequence of tests with variable settings for NUM_THREADS, ERR_RATE and TPM.

Edit the file to set the arguments and arrays as desired for a particular test.