cracked it! 🙂 Thanks to some help from Tom Kersten who helped me with testing. Turns out the code isnt the problem. Be warned.. if your client uses any kind of anti-virus software which intercepts web requests, it may cause problems here. In this case, Sophos Endpoint Security, which provides enterprise grade anti-virus and firewall … Read more
The problem is your php. With the way your php script is written, only one message is sent per execution. That’s how it works if you access the php file directly, and that’s how it works if you access the file with an EventSource. So in order to make your php script send multiple messages, … Read more
No, the SSE standard does not allow POST. (For no technical reason, as far as I’ve been able to tell – I think it was just that the designers never saw the use cases: it is not just large data, but if you want to do a custom authentication scheme there are security reasons not … Read more
Ajax polling adds a lot of HTTP overhead since it is constantly establishing and tearing down HTTP connections. As HTML5 Rocks puts it “Server-Sent Events on the other hand, have been designed from the ground up to be efficient.” Server-sent events open a single long-lived HTTP connection. The server then unidirectionally sends data when it … Read more
Others have hinted at this in other answers and comments, but the root problem is that Socket.IO is just a delivery mechanism, and you cannot depend on it alone for reliable delivery. The only person who knows for sure that a message has been successfully delivered to the client is the client itself. For this … Read more
The reason could be every EventSource object initiates the new HTTP session and in fact opens new tcp/ip socket. Because of you’re pushing data from server continuously in infinite loop, the socket keeps open continuously. All web browsers has an upper limit on simultaneous active HTTP/1 connections to the same server. Normally in range of … Read more
Websockets and SSE (Server Sent Events) are both capable of pushing data to browsers, however they are not competing technologies. Websockets connections can both send data to the browser and receive data from the browser. A good example of an application that could use websockets is a chat application. SSE connections can only push data … Read more
In the examples below the client is the browser and the server is the webserver hosting the website. Before you can understand these technologies, you have to understand classic HTTP web traffic first. Regular HTTP: A client requests a webpage from a server. The server calculates the response The server sends the response to the … Read more