Support for Configurable Timeout for Downstream Connections in HTTP/1.1

[ermakov-oleg]

What is the problem your feature solves, or the need it fulfills?

I have several applications that, for various reasons, may open numerous connections and fail to close them properly. As a result, memory usage gradually increases in both the applications and in the Pingora-based proxy due to these open connections. While the main issue originates in the applications, it would be helpful to have protective measures at the proxy level to prevent excessive memory consumption caused by such open connections.

Describe the solution you’d like

It would be helpful to have a downstream setting that configures the keepalive status for connections, so as to limit the time that a connection remains active.

Additional context

Currently, each time a downstream connection is reused, a new ServerSession is created via ServerSession::new_http1, where keepalive_timeout is set to KeepaliveStatus:Off. Then, in HttpSession::read_request in pingora-core/src/protocols/http/v1/server.rs, there is an indefinite wait for data from the socket.