Server Sent Events

• one request, but the response is very long, never ending

• client can handle and parse this response

  • spot the chunks and initiate some code

• Using content-type: Chunk-stream or event-stream

• Designed for http and req/resp

• overcomes issues of push

What

• A response has start and end

• Client sends a request

• Server sends logical events as part of response

  • event has a start and end which the client can recognise and unfold to use

• Server never writes the end of the response

• It is still a request but an unending response

• Client parses the streams data looking for events

• Works with request/response (HTTP)

PRo

• real time

• Compatible with req/resp

Cons

• Client must be online

• Might not be able to handle all these events

  • similar to push

  • client might disconnect

  • The server will have to handle this problem

• polling is preferred for lighter clients

• Using http 1.1 issue

  • can only make 6 connections to a domain

  • only one request per connection, and until the request is finished cannot send anything else on that connection

  • so if all 6 req are server side events, it will be blocked

• Better to use http2

  • can send multiple streams in same connnection