Keep-alive connections still require processing a full HTTP request for every request. This is documented in RFC6202 https://tools.ietf.org/html/rfc6202#section

Keep-alive connections still require processing a full HTTP request for every request. This is documented in RFC6202 https://tools.ietf.org/html/rfc6202#section-2.2 https://tools.ietf.org/html/rfc6202#section-2.2 The connection overhead is removed but that is only one of the various overheads that exist. edit: I understand your question a bit differently after reflecting on it more. I think you may be saying that 1 connection never ends in long-polling. This is not the case and is only this way if keep-alive is used. Each server->client data exchange happens by "completing" the request and the client is configured to immediately make a new request. This means every message (or groups of messages depending on your tolerances) is a completed HTTP request.