I educated as a classical musician. But, because life is short and there are many great things to do, instead of playing the clarinet in a symphonic orchestra, I decided to enter the world of IT. I started as a NOC monitoring specialist at Allegro, the biggest e-commerce platform in Poland. Currently, I work as a Systems Engineer at Allegro in a team responsible for web cache. When I am not working, I go back to my musical roots and play the piano with my daughter and spend time with my family.
With over 12 million of active users and up to 20Gbps traffic to serve, ensuring the stability and speed of the Allegro platform requires a reliable caching layer. Having the right tool do the right job is crucial. For that reason, we use both Varnish and nginx in our reverse caching proxy clusters depending on what we want to achieve. In our presentation, we will talk about how we route traffic and how we perform operations on HTTP headers and why we sometimes use SQL in VCL. We will talk about some of the tools we develop internally and about our open source Varnish cluster management tool called VaaS. We will also spend some time describing how we monitor our caching infrastructure. On the nginx side of things, we will demonstrate how things like trim, page cache, sendfile affect caching and why they matter. We will tell you how we reduced our image caching farm by half to serve twice as much traffic by choosing the right solution. We will also demonstrate how to feed empty cache quickly without impacting backend performance.