When we build any custom solution in Salesforce, key is to write an efficient and meaningful Apex test classes for sure. However sometime we may need to test how custom application would behave in maximum operating capacity. Here, I am talking about Load Testing of custom applications built on top of Force.com platform. Recently I needed to push my code to its limit to know how many concurrent users can use it before hitting any governor limits. Quickly I realize that its time to call my friends Selenium and TestNG.
Before doing any extensive stress or load testing on Salesforce, we must need to contact Salesforce support and explain them what we are trying to achieve. More detail available in this official Salesforce blog post.
I have published some blog posts about Selenium in past as well however whats different this time ? I need to determine after how many simultaneous user interactions, I would hit Concurrent Apex Limit error as shown in below image.