HTTP Keep-Alive, Pipelining, Multiplexing and Connection Pooling
Persistent connections allow HAProxy to optimize resource usage, lower latency on both the client and server side, and support connection pooling. HTTP is a layer 7 protocol that’s transmitted over a TCP connection. It works in a client-server model and follows the request-response paradigm, which means that a client sends a request to a server, which then replies with a response. From this statement, you can infer two different ways of operating.