When developing a web project, a very curious question arises sometimes: what could the maximum possible performance be? Or, in other words, how many concurrent visitors can the current configuration serve until the delay becomes unacceptably apparent?

For example: a web project was properly optimized for high loads and hosted on a high performance server. Conventional tests showed acceptable results for emulated 3.000.000 daily hits: the average page generation time of 0.5 sec, the average web page transmission time of 1 sec. However, what the limit can be?

This test may show that, for example, the maximum possible performance is 5.500.000 daily hits with the average page generation time of 1 sec and the average web page transmission time of 3 sec. It is quite obvious that such values ensure the system has almost two-fold redundancy and will hold.

Open "Settings > Performance > Performance Panel > Scalability" and run the stress test using the following initial values:

- Initial Concurrent Connections: 1
- Final Concurrent Connections: 5
- Increment Concurrent Connections By: 1
- Maximum Test Duration: 5 minutes
- Page: the main or index page (e.g. /index.php). You can specify any other popular page.

The page generation time should not exceed 0.5 sec. and should not be increasing too fast with the growing concurrent connections. No errors must occur. The minimum number of pages per second should match the expected daily hits divided by 86400. The page acquisition time should not exceed 1 sec.