Well I thought I would see how Varnish held up under some load. I signed up to Blitz which is a load testing and performance tool which allows you to simulate some load on your server. You get some credits so that you can try it out for free as well. I thought I would go for a pretty simple test to start with so I simulated going from 1 to 250 users checking a page on the site in 60 seconds.
Here is the Analysis for the test:
This rush generated 7,133 successful hits in 1.0 min and we transferred 176.87 MB of data in and out of your app. The average hit rate of 113/second translates to about9,818,581 hits/day.
The average response time was 35 ms.
You’ve got bigger problems, though: 0.03% of the users during this rush experienced timeouts or errors!
The first timeout happened at 47.90 seconds into the test when the number of concurrent users was at 200. Looks like you’ve been rushing with a timeout of 1 second. Timeouts tend to increase with concurrency if you have lock contention of sorts.