> Thanks for your reply,.<br/><br/>Yes, I don't do repeated request. Maybe come > a request, then next one come an hour later. But the requests are latency > concered(should be less than 50ms) . <br/><br/>If every request comes, then > make a new connection to the server, the total cost of the request would > probably exceed 50ms due to tcp handshake.<br/><br/>So I hope to keep the > underlying connection in libcurl cache to stay as long as possible, such that > once a request comes, <br/>there's a 'ready' connection(no need to establish > from srcatch) to handle it.
Are you using HTTP/2 or plain HTTP? For HTTP/2 there's https://curl.se/libcurl/c/curl_easy_upkeep.html which is designed to keep a long-lived connection alive to a server by sending periodic HTTP/2 PING frames. Otherwise it sounds like you might have to configure the TCP keepalive settings of the host to keep the connection alive for longer; or, write your client in such a way that it periodically sends keepalive requests to the server (perhaps by sending OPTIONS to the server). -- Unsubscribe: https://lists.haxx.se/listinfo/curl-library Etiquette: https://curl.haxx.se/mail/etiquette.html
