TL;DR

While HTTP/2 provides for a number of improvements over HTTP/1.x, via Chaos Testing we discovered that there are situations where HTTP/2 will perform worse than HTTP/1.

When there is packet loss on the network, congestion controls at the TCP layer will throttle the HTTP/2 streams that are multiplexed within fewer TCP connections. Additionally, because of TCP retry logic, packet loss affecting a single TCP connection will simultaneously impact several HTTP/2 streams while retries occur. In other words, head-of-line blocking has effectively moved from layer 7 of the network stack down to layer 4.

Background & the Service Mesh Space

Service meshes are an increasingly common networki …