Can websocket messages get lost or not?

java tcp websocket java-websocket
Adrian Krebs picture Adrian Krebs · Sep 9, 2015 · Viewed 8.7k times · Source

I'm currently developing a Java WebSocket Client Application and I have to make sure that every message from the server is received by the client. Is it possible that I lose some messages (once they are sent from the server) due to a connection interruption? WebSocket is based on TCP so this shouldn't happen right?

Answer

Takahiko Kawasaki picture Takahiko Kawasaki · Sep 9, 2015

It can happen. TCP guarantees the order of packets, but it does not mean that all packets sent from a server reach a client even when an unrecoverable trouble happens in an underlying network. Imagine someone pulls out your LAN cable or switches off your WiFi access point at the worst timing while your application is communicating with your server. TCP does not overcome such a trouble.

To ensure that every WebSocket message sent from your server reaches your client, you have to implement some kind of SYN/ACK in the application layer.

Related questions

java.net.ConnectException: Connection refused

I'm trying to implement a TCP connection, everything works fine from the server's side but when I run the client program (from client computer) I get the following error: java.net.ConnectException: Connection refused at java.net.PlainSocketImpl.socketConnect(Native …

Read More
When is "java.io.IOException:Connection reset by peer" thrown?

ERROR GServerHandler - java.io.IOException: Connection reset by peer java.io.IOException: Connection reset by peer at sun.nio.ch.FileDispatcher.read0(Native Method) at sun.nio.ch.SocketDispatcher.read(Unknown Source) at sun.nio.ch.IOUtil.readIntoNativeBuffer(Unknown …

Read More
Does a TCP socket connection have a "keep alive"?

I have heard of HTTP keep-alive but for now I want to open a socket connection with a remote server. Now will this socket connection remain open forever or is there a timeout limit associated with it similar to HTTP …

Read More