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Questions tagged [gen-tcp]

gen_tcp stands for 'Generic TCP' and is a module in Erlang that provides functions for TCP/IP communication.

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gen_tcp receive extremely high CPU

Sorry that I'm an Erlang newbie and may make stupid question. But please help me to solve the issue. I have written an Erlang server to replace the one I'm using with Node.js, which ate all my memory and I'm praying that Erlang could be a way…
Anita
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Erlang simultaneously connect 1M clients

I have a problem: I want to create an Erlang server that can hold 1M simultaneous open tcp connection. I tuned my OS (Oracle Linux 7) to raise the file descriptors. On the server I do gen_tcp:listen // point_1 Socket =…
Ștefan Stan
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Is using Erlang's gen_tcp a scalable way to construct a high traffic socket server

I am trying to learn Erlang to do some simple but scalable network programming. I basically want to write a program that does what servers on the backbone of the internet do--but on a smaller scale. I want to try to set up an intranet with web…
Alex Eftimiades
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gen_tcp smushed messages

I'm using socket_server from this tutorial and the following code for a client and server: Server: -module(echo_server). -export([start/0, loop/1]). % echo_server specific code start() -> spawn(socket_server, start, [?MODULE, 7000, {?MODULE,…
nmichaels
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gen_server closing listening socket

What I'm trying to do is have a gen_server process accept a new client and immediately spawn a new child to handle the next one. The issue that I'm seeing is that when the socket is finished and consequentially terminates, it also closes the…
Refefer
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Half-Established TCP Connections

Half-Established Connections With a half-established connection I mean a connection for which the client's call to connect() returned successfully, but the servers call to accept() didn't. This can happen the following way: The client calls…
jvf
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erlang: to controlling_process(), or not to controlling_process()

Consider the following erlang code of a simple echo server: Echo listener: -module(echo_listener). -export([start_link/1]). -define(TCP_OPTIONS, [binary, {packet, 0}, {reuseaddr, true}, {keepalive, true}, {backlog, 30},…
Romstar
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Erlang: gen_tcp:recv() does not receive packet sent from client?

I modified this server to use gen_tcp:recv inorder to limit the number of bytes for a packet to 50. I commented out the line inet:setopts(Socket, [{active, once}]), because gen_tcp:recv is supposed to be {active,false}. This is the client side erl…
pandoragami
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How to edit echo server to allow many clients to exchange messages

I've created a server with no client code. I just have to type on the terminal telnet 127.0.0.1 4001 and on an other terminal telnet 127.0.0.2 4001 so when I type a message on the first terminal it appears on the same terminal, I know this an echo…
Mariem
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erlang: how to receive HTTP/RTSP messages from socket?

I want to manage HTTP or RTSP sessions with Erlang. For example, a standart session for RTSP protocol looks like: OPTIONS rtsp://192.168.1.55/test/ RTSP/1.0\r\n CSeq: 1\r\n User-Agent: VLC media player (LIVE555 Streaming Media…
Nick Saw
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How can I detect a TCP timeout on an active socket in Elixir with gen_tcp?

I have a GenServerthat is connecting to a remote TCP connection via gen_tcp. opts = [:binary, active: true, packet: :line] {:ok, socket} = :gen_tcp.connect('remote-url', 8000, opts} I'm handling messages with: def handle_info({:tcp, socket, msg},…
user2666425
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gen_tcp:recv/2 returns error, einval

I have a client that creates N processes and all connecting to a server like this: send(State = #state{low = Low, high = Low}) -> NewState = receive_sockets(0, Low, State), NewState; send(State = #state{low = Low}) -> N = Low rem 10, Dest…
listen
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Interrupting gen_tcp:recv in erlang

We have a gen_server process that manages the pool of passive sockets on the client side by creating them and borrowing them for other processes. Any other process can borrow a socket, sends a request to the server using the socket, gets a reply…
Mayya Sharipova
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Erlang TCP sockets get closed

To learn Erlang I am trying to implement a tiny web server based on gen_tcp. Unfortunately, my code seems to trigger some wired behaviour. To demonstrate the problem I have attached a minimised version of my implementation which is sufficient to…
aka
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The difference between passive and once mode of gen_tcp

I'm reading Programming Erlang 2E. In Active and Passive Sockets of Chapter 17, it says: You might think that using passive mode for all servers is the correct approach. Unfortunately, when we’re in passive mode, we can wait for the data from…
an0
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