Since the release of kdb+ 3.0 in September 2012, it has been possible to make use of WebSockets when connecting to a kdb+ process. This has significant implications for how one can build front-end applications that use a kdb+ back-end, in particular for applications wanting to display real-time information.
In the latest in an ongoing series of kdb+ technical white papers published on the KX Developer’s site, KX engineer Michael Gracey has updated a previous 2014 paper about kdb+ and WebSockets written by Chris Scott. As part of this revision, the paper now also documents new message handlers for opening and closing WebSocket connections, and debugging techniques that can be used to view traffic over these connections.
The revised paper also includes a full working example (including code) of a simple web application which uses kdb+ to provide real-time updating of tables based on user queries. You can read the full paper here.