CODEWITHSUNDEEP
javascriptphpwebsocketlatency
Liakos
Liakos

Reputation: 572

Websocket Communication Latency Questions

3 mini questions regarding websocket connections

  1. When the client sends data to the server there is latency. When the server sends data to the client is there latency or it is instant?

  2. If the client sends data to the server VERY FAST in a specific row - let's say [1, 2, 3], is there any chance that, due to latency or other reasons, the data to be received by the server in a different row? ( like [2, 1, 3] )

  3. (Same as question #2, but when the server sends the data)

Upvotes: 1

Views: 609

Answers (1)

Matt Styles
Matt Styles

Reputation: 2452

  1. Yes, there is latency. Its still a connection and there is still a chain to navigate. Latency only matters when things are changing and given that it takes X amount of time for the message to reach the client and another X ms for the client to do anything about it, its quite possible the state will change during those ms. In the same way that HTTP requests (WebSockets are just about the same thing) become 'hot', I believe the latency will diminish (all other things being equal) but it will still exist.

  2. No, WebSockets are via TCP, so they'll be in order. UDP transport is fire-and-forget, it doesnt send any notification of receipt and it doesnt regenerate the packets using timing information, so you can send messages faster but can make no assumptions regarding receipt or order or events. Page impressions would be a great example of where you dont care really in what order and you probably dont care too much about when the server receives such a message, WebRTC may bring UDP connections between JS and server but the standard is still emerging. For now, WebSockets connect via an HTTP upgrade, meaning they are TCP, where order information and receipt confirmation is a thing (larger and more messages being sent to and fro).

  3. Same answer! It all happens over TCP so the whole trip is a round-trip, but order is assured.

Upvotes: 2

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