Testing Apache configuration changes

Question

We are switching to using WSGI daemon processes for different Apache virtual hosts on the same server and would like to assess the performance impact of the change.

Ideally, we would like to have web-server specific performance/load testing results and application level performance/load testing results.

Up until now, we've only used locust and a couple specific experimental load testing scenarios.

How do you usually test this kind of web server configuration change impact? What tools do you use for web server and application performance testing? What metrics should we take into account and present as results?

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One of the quick and "free" ideas we currently have is to see how an end-to-end test battery execution time will change for this environment.

Answer 1

I believe the fastest and the easiest way would be simply replaying your production traffic using i.e. Apache JMeter. It comes with Access Log Sampler so if your access logs are compliant with the common log format you will be able to create a script in a few seconds. If not - it is still possible, but you will have to pre-process the access log so JMeter could understand it.

References:

• Access log sampler Step-by-step
• Stop Making Assumptions! Learn How to Replay Your Production Traffic With JMeter

With regards to metrics, JMeter is capable of generating HTML Reporting dashboard which has all the necessary metrics and KPIs in form of tables and charts. I would also recommend monitoring your Apache instance health using JMeter PerfMon plugin (if you don't have other and/or better monitoring options in place already)

Answer 2

There are two options:

• With Siege(https://github.com/JoeDog/siege), simulate the load and test for individual nodes.
• Jmeter (http://jmeter.apache.org/)- for application.
  1. Record the application flow and create script.
  2. Add the individual node's IP in the hosts file.
  3. Execute the script with the #of users.(Based on application's analytics, it should be finalized in capacity planning phase).
  4. Check the results.
  5. Comment out the entered node's IP and add the next node.
  6. Repeat the steps from 2 to 5 for each node.