Programming/Kdb/Labs/Feedhandler and kdb tick environment
Feedhandler
Many cryprocurrency exchanges support both the WebSocket and REST APIs.
WebSocket
WebSocket is a computer communications protocol, providing full-duplex communication channels over a single TCP connection. The WebSocket protocol was standardized by the IETF as RFC 6455 in 2011, and the WebSocket API in Web IDL is being standardized by the W3C.
WebSocket is distinct from HTTP. Both protocols are located at layer 7 in the OSI model and depend on TCP at layer 4. Although they are different, RFC 6455 states that WebSocket
is designed to work over HTTP ports 443 and 80 as well as to support HTTP proxies and intermdeiaries,
thus making it compatible with HTTP. To achieve compatibility, the WebSocket handshake uses the HTTP Upgrade header to change from the HTTP protocol to the WebSocket protocol.