Load Testing

Why we need it?What tools to use?

Load Testing Goals- Checking maximum simultaneous requests (Determining infrastructure limits)

- Verifying acceptance of response time during high load

- Verifying system stability under load - look for memory leaks in long tests

- Predict future resource needs and architectural improvements

- Verifying system behaviour after high load

- Evaluating current capacity against defined requirements

More reasons are listed at http://performance-testing.org/performance-testing-reasons

Open Source Tools

- JMeter

- Yandex Tank

- Taurus

JMeterThe Apache JMeter™ application is open source software,

a 100% pure Java application

Steps to start load testing1)Launch application (jmeter.sh for Unix-based systems and

jmeter.bat for Windows)

2)Right-button click on Test Plan and select Add > Threads (Users) > Thread group (preferably jp@gc - Ultimate Thread Group)

3)Configure Start Thread Count (amount of virtual users which will load your website), Startup Time (time for reaching amount of VU defined), Hold Load For (time for holding peak amount of VU defined), Shutdown Time (time for decreasing VUs by stopping requests)

JMeter - Step 2 - Select Ultimate Thread Group

JMeter - Step 3 - Thread’s configuration

Steps to start load testing (part 2)4) Right-button click on Thread and select Add > Config Element > HTTP Request Default

5) Configure Server Name or IP (e.g. youwebsite.com or 123.231.321.123), Port Number (e.g. 80) and Protocol (http or https)

JMeter - Step 4 - select HTTP Request Defaults

JMeter - Step 5 - Configure HTTP Request Defaults

Steps to start load testing (part 3)6) Right-button click on Thread and select Add > Sampler > HTTP Request

7) Configure Path (link to page you would like to test; e.g. /login.php or /blog/about) and specify Method GET

JMeter - Step 6 - Select Sampler HTTP Request

JMeter - Step 7 - Configure Sampler HTTP Request

Steps to start load testing (part 4)8) Right-button click on Thread and select

Add > Listener > jp@gc - Hits per Second

Add > Listener > jp@gc - Response Times vs Threads

Add > Listener > jp@gc - Response Latencies Over Time

Add > Listener > jp@gc - Response Codes per Second

9) Finally… Run test plan by clicking on Start

JMeter - Step 8 - Configure Sampler HTTP Request

JMeter - 30 VUs - Hits per second

JMeter - 30 VUs - Response Time Over Time

JMeter - 30 VUs - Latencies Over Time

JMeter - 30 VUs - Response Codes per Second

NotesUser “Run” > “Clear All” before starting new test

Once you identified the issue with server responses try to decrease Start Threads Count and increase Startup Time to get to accurate value of allowed concurrent connections

IssuesHow to identify issues with JMeter

JMeter - 50 VUs - 500 Response codes

Server is down...

Really down...

Short term solutionsRestart Servers

Tune configuration of web servers

Add more servers

Long term solutionsConsider moving infrastructure to the Cloud

Use CDN

Use different domains for static resources (and fast web servers for them; e.g. Ngnix or lighttpd)

Use memcached for storing mostly used DB queries

Use downstream cacheability headers

Consider moving part of the application logic to microservices

Setup auto-scale at your Cloud provider

Cloud Solutions

Only JMeter?What other tools can be used for load testing?

Load Testing Tools

- JMeter

- Yandex.Tank

- Gatling

- Locust

- Taurus

- The Grinder

Find more at http://alternativeto.net/

Commercial Solutions

Popular Commercial SolutionsSOASTA

https://www.soasta.com/

BlazeMeter

https://www.blazemeter.com/

What Else? (topics for future slides)

Topics related to Load Testing- Functional Tests in JMeter (using runnable JAR files to automate

functional and load testing)

- PDF Reporting. BlazeMeter Sense (former Loadosophia)

- Response Data validation

- Continuous Load Testing. Configuring CI with headless JMeter

- Configuration of Master / Slave nodes to perform load testing using multiple workstations

Thank youQuestions?