Um pequeno adendo, desde o HTTP/1.1 conexões são persistentes por padrão, isso é, a não ser que o cliente seja HTTP/1.0 não há grandes motivos para enviar o header Connection: keep-alive para o servidor. – Anthony Accioly 13/01/17 às 17:45

Keep-Alive should ALWAYS be enabled. There is no downside to enabling HTTP keep-alive when it comes to improving your website speed. Using a keep-alive connection will almost always speed up your website. Enabled by default – but not always. In most cases keep-alive is enabled by default on web servers. But in some cases it’s not. Keepalive: A keepalive is a signal sent from one device to another to maintain a connection between the two devices. This may be between a client and a server, but it could apply to any number of devices or technologies. Keepalives are used in network environments to maintain an open communication pathway, or to regularly check the status of a Jun 21, 2017 · The Connection Keep-Alive feature helps preventing connections to be closed due to time-outs of this kind by periodically executing a simple SELECT statement. Network connections may be terminated for other reasons than a time-out in the database or at the network layer, e.g due to a restart of the database or a network element. Mar 13, 2019 · Keep-Alive is build with the idea of sending multiple HTTP requests/responses via one TCP connection thus significantly reducing the time needed for the web browser to load files from the web server. Keep-Alive is utilized to the fullest when dealing with static content like images as it allows the requestor to get all of the images from the

The Connection header needs to be set to "keep-alive" for this header to have any meaning. Also, Connection and Keep-Alive are ignored in HTTP/2; connection management is handled by other mechanisms there.

Connection: keep-alive Connection: close Directives close Indicates that either the client or the server would like to close the connection. This is the default on HTTP/1.0 requests. any comma-separated list of HTTP headers [Usually keep-alive only] Indicates that the client would like to keep the connection open.

Each persistent connection applies to only one transport link. A proxy server MUST NOT establish a HTTP/1.1 persistent connection with an HTTP/1.0 client (but see RFC 2068 [33] for information and discussion of the problems with the Keep-Alive header implemented by many HTTP/1.0 clients). 8.1.4 Practical Considerations

Um pequeno adendo, desde o HTTP/1.1 conexões são persistentes por padrão, isso é, a não ser que o cliente seja HTTP/1.0 não há grandes motivos para enviar o header Connection: keep-alive para o servidor. – Anthony Accioly 13/01/17 às 17:45