Socket, build communication between two process or application through TCP/IP protocol, layer 4 in OSI model . One acts as client process, another acts as server process. Server will do bind(), listen(), accept(), then read(), write(). Client do connect(), then read(), write().
read timeout, client hasn’t received data from server after [READ_TIMEOUT] time. Normally is SO_TIMEOUT in socket.
write timeout, client hasn’t been able to write successfully to server after [WRITE_TIMEOUT] time.
connection timeout, 3 steps handshake is not finished within [CONNECTION_TIMEOUT].
Below 3 are all on client side.
keep alive timeout(client side), it is part of HTTP Header. if client hasn’t received from server for [KEEP_ALIVE_TIMEOUT], client sends a request to server to see if server is still alive. If yes, client will still wait; if not, client will close the HTTP connection.
request timeout(server side HTTP), client needs to periodically send data to server. If server hasn’t received data from client for [REQUEST_TIMEOUT] time, server drops the connection.
TTL is the number in a IP packet. Meaning how long time this packet can be alive and router doesn’t drop it.