An alternative to WebSockets

The example we presented in this chapter is possible to be implemented using an older, lesser-known technology named Server-Sent Events (SSE). SSE allows for one-way communication from the server to client over HTTP. It is much simpler than WebSockets but has a built-in support for things such as automatic reconnection and event identifiers. WebSockets are definitely more powerful, but are not the only way to pass events, so when you need to implement some notifications from the server side, remember about SSE.

Another option is to explore the mechanisms oriented around the Comet techniques. Multiple implementations are available and most of them use different methods of transportation to achieve their goals. A comprehensive comparison is available at http://cometdaily.com/maturity.html.