Performance testing your Drupal website

Load testing verifies the system performance under the expected peak load.  The peak load needs to set by a series of parameters that you have benchmarked targets.  For example, these parameters could include:

Load testing:

• 20,000 concurrent users; and
• response time of under 4 seconds

Stress testing:

• Verifies the server performance under extreme load.  Test this through examining how many users are required to bring your server

Endurance testing:

Load test over an extended period of time

Check with your hosting provider

Before you begin to performance test - check with your hosting provider if their infrastructure allows for performance testing.  In some environments, hosting providers won't allow for performance testing even on dedicated server.

Action plan:

Step 1:

• Complete your benchmarking documentation.  Unless you have something to target what is the point
• Infrastructure monitoring and profiling to identify bottlenecks and potential failures
  • Out of resources (bandwidth, memory, CPU, database)
  • Configuration including server and code (such as Apache and PHP)

Step 2: Tool selection

• Protocol
  • CURL request
    • Note the testing doesn't load like a regular person forgoing images and AJAX requests
    • Open source tools - JMeter, Locust, Gatling
    • SAAS - BlazeMeter, Flood.io
• Browser
  • Load the full page - there including images, AJAX requests.  This is important if your site uses client side requests.  However, concurrency is limited
  • Open source tools - Selenium

Step 3: Script creation

• Language type - javascript, python, etc
• Scripts can be
  • Simple: visit home page, search page or content pages
  • Complex - Login as a user

Step 4: Monitor performance

• Number of users.  Start low and ramp up.  For example, begin with 100 and ramp up to 5000.  If this is an initial test, then have lower presets.
• Trace response time in real life.  Check how many users against time.
• Look at the apache and memory performance
• Check the logs