Team, please respond: Connection timeout on Android

[idevchandra]

Describe the bug
Android connection is timingout. But, iOS is fine.

Environment:

Server: Node.js
Client: Flutter with Adhara socket.io
iOS Emulators: iOS 14.2 iPhone 12 Pro and iPhone 12 mini
Android Emulators tried: Pixel 3a API 30. Pixel 4 API 30.

Have you tried reproducing the issue with example available in this repo?
Yes

To Reproduce
Steps to reproduce the behavior:

1. Have the below simple node.js server

// server.js
var express = require('express');
var app = express();
var server = require('http').createServer(app);
var io = require('socket.io')(server);

io.sockets.on("connection", function (socket) {
    console.log("Connected " + socket.id);

  socket.on('disconnect', function () {
    console.log('client disconnect...', socket.id)
  })
});

listen_port = process.env.PORT || 7000;
server.listen(listen_port);

2. On Terminal, run node server.js

3. On Terminal run adb -s emulator-5554 reverse tcp:7000 tcp:7000
   The behavior of the app is same with or without running the above command.

4. Change this repo example, as shown below, with the actual server URL - localhost.
   Because, it is Android emulator, I used 10.0.2.2. I also tried with localhost, 127.0. 0.1 too. With all the three, it is same behavior - "Connection Timeout"

    String URI = Platform.isIOS ? 'http://localhost' : 'http://10.0.2.2';
    ...
    ...
    SocketIO socket = await manager.createInstance(SocketOptions(
        URI,
        nameSpace: (identifier == "namespaced") ? "/adhara" : "/",
        query: {
          "timestamp": DateTime.now().toString()
        },
        enableLogging: true,  // I am sure this has nothing to do with connection. I tried `true` too!
        transports: [
          Transports.WEB_SOCKET 
        ] 
        ));

5. Run the app on iOS and Android simulators.

Expected behavior
iOS Simulator and Android Emulators should be able to connect to server.

Device details:

• Device Type: Android Emulator
• Model: Pixel 4
• OS: Android API 30
• Package Version adhara_socket_io: ^0.4.1

Relevant Logs

I/flutter ( 7913): Connecting to socket...
W/a4m.flutter_ap( 7913): Accessing hidden method Ldalvik/system/CloseGuard;->get()Ldalvik/system/CloseGuard; (greylist,core-platform-api, reflection, allowed)
W/a4m.flutter_ap( 7913): Accessing hidden method Ldalvik/system/CloseGuard;->open(Ljava/lang/String;)V (greylist,core-platform-api, reflection, allowed)
W/a4m.flutter_ap( 7913): Accessing hidden method Ldalvik/system/CloseGuard;->warnIfOpen()V (greylist,core-platform-api, reflection, allowed)
I/flutter ( 7913): Log: onConnectError. Reason -> io.socket.client.SocketIOException: timeout
I/flutter ( 7913): Log: onConnectTimeout: Reason -> 20000
I/flutter ( 7913): Log: onConnectError. Reason -> io.socket.client.SocketIOException: timeout
I/flutter ( 7913): Log: onConnectTimeout: Reason -> 20000

[vikas-shrma]

@idevchandra did your connection timeout randomly or after particular time interval?

[vikas-shrma]

try using this dependencies

 adhara_socket_io:
    git:
      url: https://github.com/aslamanver/flutter_socket_io

[Danish777]

yes, I am facing same issue

[SmartNodeAutomation]

Yes, I am facing same issue. cannot connect socket with Android phone.

[tiholic]

@idevchandra @vksBhardwaj @Danish777 @SmartNodeAutomation

It could possibly be due to usage higher socket.io version on server side.

Currently this package supports only v2 socket.io

Please track v3/v4 support here: #160

[tanmoydas61999]

Socket connection works fine when connected to localhost(Ex - http://172.20.10.3:4000/),
but when connected to url which is hosted on heroku,it stops working.
Please help.

[vikas-shrma]

Nothing to worry You need to add some header's Get Outlook for Android<https://aka.ms/AAb9ysg>

…

________________________________ From: tanmoydas61999 ***@***.***> Sent: Friday, June 18, 2021 2:19:58 PM To: infitio/flutter_socket_io ***@***.***> Cc: Vikas Sharma ***@***.***>; Mention ***@***.***> Subject: Re: [infitio/flutter_socket_io] Team, please respond: Connection timeout on Android (#151) Socket connection works fine when connected to localhost(Ex - http://172.20.10.3:4000/), but when connected to url which is hosted on heroku,it stops working. Please help. — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub<#151 (comment)>, or unsubscribe<https://github.com/notifications/unsubscribe-auth/ACPKC3S3FFLPJ55CKE5PVWLTTMCDNANCNFSM4WWTI7UA>.

[tanmoydas61999]

Which headers?
Help is very much appreciated

[tiholic]

@tanmoydas61999 we do add additional configuration when hosting socket server in AWS to allow upgrade to socket from http: #21 (comment)

May be something similar has to be done with heroku too?