»HAProxy 2.4 adds exciting features such as support for HTTP/2 WebSockets, authorization and routing of MQTT and FIX (Financial Information Exchange) protocol messages, DNS resolution over TCP, server timeouts that you can change on the fly, dynamic SSL certificate storage for client certificates sent to backend servers, and an improved cache; it adds a built-in OpenTracing integration, new Prometheus metrics, and circuit breaking improvements.«

This release of HAProxy comes with many improvements; its changes in the connection layer lays the foundation for support for HTTP/3 / QUIC.