[erlang-questions] (how) Can a tcp socket get "overloaded"?

Scott Lystig Fritchie <>
Tue Jun 24 22:31:21 CEST 2008


Nicholas, are you assuming that if you use:

    %% Client side
    Size0 = size(Bin),
    gen_tcp:send(Socket, Bin),

And:

    %% Server side
    {ok, Bin1} = gen_tcp:recv(ConnectedSocket, 0),
    Size1 = size(Bin1),
    %% or perhaps we're using active mode?
    Size2 = receive
    		{tcp, ConnectedSocket, B} -> size(B)
	    end,

... that Size0 is exactly equal to Size1 or Size2?  If yes, then you're
mis-using TCP, because TCP communication is a pure byte steam and does
not have a notion of message boundaries.  Any delays on the sender's
side to try to keep hunks-of-the-stream's-bytes separate will eventually
fail when the sender's load increases, or if the OS on either side feels
like rebuffering, or when the network in the middle drops a packet and a
retransmission juggles the receiver's buffering efforts, or ...

-Scott



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