WebSockets and AJAX: an initial comparison

websockets_ajax_0.md

WebSockets and AJAX: an initial comparison

AJAX (i.e. HTTP) advantages

• namespacing (URL)
  • WebSockets only have global events
    • might actually be global ("shut down server")
    • might be context-sensitive ("add an item to the current to-do list")
• request & response cycle, with semantics
  • WebSockets only have one-off messages
    • intrinsically carry the same meaning whether sent from the server or client
    • responding to a specific message is outside the scope of the protocol
• protocol includes provision for metadata (headers)

WebSockets advantages

• persistent connection with state
  • no need to directly manage session state
    • reconstructing session state from a data store
    • validating currency of session between server and client
      • cf. "when user logs out in client, server must destroy session"

Shared disadvantages

• data payloads are untyped strings
  • application must estabish its own convention for enforcing type
    • parsing & validation
    • error response