🐛 Bug Report: Subscribing Multiple Times with a Single Realtime Instance Results in Null Subscription #156

stnguyen90 · 2023-06-20T16:51:07Z

👟 Reproduction steps

Instantiate a Realtime instance
Subscribe to a channel
Subscribe to another channel

👍 Expected behavior

You get 2 separate working subscriptions

👎 Actual Behavior

log:

subscription: null

The subscriptions don't receive any events.

It looks like the 2nd subscribe closes the websocket, which triggers:

sdk-for-flutter/lib/src/realtime_mixin.dart

Lines 85 to 86 in 54f30fa

 _channels.clear(); 

 _closeConnection();

The _closeConnection() results in the _lastUrl being set to null:

sdk-for-flutter/lib/src/realtime_mixin.dart

Line 27 in 54f30fa

_lastUrl = null;

and the _channels.clear() prevents future events from being dispatched properly:

sdk-for-flutter/lib/src/realtime_mixin.dart

Lines 71 to 75 in 54f30fa

 if (_channels[channel] != null) { 

 for( var stream in _channels[channel]!) { 

 stream.sink.add(message); 

 } 

 }

🎲 Appwrite version

Different version (specify in environment)

💻 Operating system

Linux

🧱 Your Environment

Tested with SDK version 9.0.0 and Appwrite version 1.3.4. For some reason, this only happens on mobile and not on flutter web.

👀 Have you spent some time to check if this issue has been raised before?

I checked and didn't find similar issue

🏢 Have you read the Code of Conduct?

I have read the Code of Conduct

The text was updated successfully, but these errors were encountered:

stnguyen90 · 2023-06-23T18:36:18Z

For now, the best thing to do is to use a separate Realtime instance for each subscription.

lohanidamodar · 2023-06-29T01:02:55Z

@stnguyen90 what is the behavior with other SDKs?

stnguyen90 · 2023-08-03T02:02:24Z

@lohanidamodar, it works fine in other SDKs. You can use 1 realtime instance and make multiple subscribe calls. The problem with our Flutter SDK is how we handle reconnects.

rvndsngwn · 2023-10-03T01:06:16Z

Same issue with me

Schrolli91 · 2023-11-08T06:29:29Z

Same here.
Is there any milestone, when this will be fixed?

puntiz · 2023-11-10T22:08:00Z

This needs addressing, really handicaps one of the most useful features.

moshOntong-IT · 2023-12-05T00:23:37Z

Same here, what is the status of this issue?

Sokratesli · 2023-12-05T09:42:54Z

same here. Thank you for the work.

lohanidamodar · 2023-12-17T00:59:48Z

Hey, we have a work in progress fix for this issue, if you could test the SDK from this branch and let us know that would be great
https://github.com/appwrite/sdk-for-flutter/tree/fix-realtime-multiple-subscription

dependencies:
	appwrite:
		git:
			url: https://github.com/appwrite/sdk-for-flutter
			ref: fix-realtime-multiple-subscription

rvndsngwn · 2023-12-18T08:53:31Z

Hi @lohanidamodar

I have just tested the SDK from the fix-realtime-multiple-subscription branch and now multiple subscriptions are working. Your help is greatly appreciated.

lohanidamodar · 2023-12-19T07:24:01Z

Hi @lohanidamodar

I have just tested the SDK from the fix-realtime-multiple-subscription branch and now multiple subscriptions are working. Your help is greatly appreciated.

Thank you for your validation. Will work to get it released soon.

Andree98 · 2023-12-29T15:15:39Z

Hey, we have a work in progress fix for this issue, if you could test the SDK from this branch and let us know that would be great https://github.com/appwrite/sdk-for-flutter/tree/fix-realtime-multiple-subscription
dependencies:
	appwrite:
		git:
			url: https://github.com/appwrite/sdk-for-flutter
			ref: fix-realtime-multiple-subscription

I tried this patch and an error occurs when restarting the realtime stream whenever it closes

Here's the stacktrace

Concurrent modification during iteration: _Map len:2.
      #0      _CompactIterator.moveNext (dart:collection-patch/compact_hash.dart:714:7)
      #1      RealtimeMixin._createSocket.<anonymous closure> (package:appwrite/src/realtime_mixin.dart:88:49)
      #2      _rootRun (dart:async/zone.dart:1391:47)
      #3      _CustomZone.run (dart:async/zone.dart:1301:19)
      #4      _CustomZone.runGuarded (dart:async/zone.dart:1209:7)
      #5      _BufferingStreamSubscription._sendDone.sendDone (dart:async/stream_impl.dart:392:13)
      #6      _BufferingStreamSubscription._sendDone (dart:async/stream_impl.dart:402:7)
      #7      _BufferingStreamSubscription._close (dart:async/stream_impl.dart:291:7)
      #8      _ForwardingStream._handleDone (dart:async/stream_pipe.dart:99:10)
      #9      _ForwardingStreamSubscription._handleDone (dart:async/stream_pipe.dart:161:13)
      #10     _rootRun (dart:async/zone.dart:1391:47)
      #11     _CustomZone.run (dart:async/zone.dart:1301:19)
      #12     _CustomZone.runGuarded (dart:async/zone.dart:1209:7)
      #13     _BufferingStreamSubscription._sendDone.sendDone (dart:async/stream_impl.dart:392:13)
      #14     _BufferingStreamSubscription._sendDone (dart:async/stream_impl.dart:402:7)
      #15     _BufferingStreamSubscription._close (dart:async/stream_impl.dart:291:7)
      #16     _SyncStreamControllerDispatch._sendDone (dart:async/stream_controller.dart:792:19)
      #17     _StreamController._closeUnchecked (dart:async/stream_controller.dart:647:7)
      #18     _StreamController.close (dart:async/stream_controller.dart:640:5)
      #19     new _WebSocketImpl._fromSocket.<anonymous closure> (dart:_http/websocket_impl.dart:1171:19)
      #20     _rootRun (dart:async/zone.dart:1391:47)
      #21     _CustomZone.run (dart:async/zone.dart:1301:19)
      #22     _CustomZone.runGuarded (dart:async/zone.dart:1209:7)
      #23     _BufferingStreamSubscription._sendDone.sendDone (dart:async/stream_impl.dart:392:13)
      #24     _BufferingStreamSubscription._sendDone (dart:async/stream_impl.dart:402:7)
      #25     _BufferingStreamSubscription._close (dart:async/stream_impl.dart:291:7)
      #26     _SinkTransformerStreamSubscription._close (dart:async/stream_transformers.dart:87:11)
      #27     _EventSinkWrapper.close (dart:async/stream_transformers.dart:21:11)
      #28     _WebSocketProtocolTransformer.close (dart:_http/websocket_impl.dart:118:17)
      #29     _SinkTransformerStreamSubscription._handleDone (dart:async/stream_transformers.dart:132:24)
      #30     _rootRun (dart:async/zone.dart:1391:47)
      #31     _CustomZone.run (dart:async/zone.dart:1301:19)
      #32     _CustomZone.runGuarded (dart:async/zone.dart:1209:7)
      #33     _BufferingStreamSubscription._sendDone.sendDone (dart:async/stream_impl.dart:392:13)
      #34     _BufferingStreamSubscription._sendDone (dart:async/stream_impl.dart:402:7)
      #35     _BufferingStreamSubscription._close (dart:async/stream_impl.dart:291:7)
      #36     _SyncStreamControllerDispatch._sendDone (dart:async/stream_controller.dart:792:19)
      #37     _StreamController._closeUnchecked (dart:async/stream_controller.dart:647:7)
      #38     _StreamController.close (dart:async/stream_controller.dart:640:5)
      #39     _Socket._onData (dart:io-patch/socket_patch.dart:2454:21)
      #40     _rootRunUnary (dart:async/zone.dart:1407:47)
      #41     _CustomZone.runUnary (dart:async/zone.dart:1308:19)
      #42     _CustomZone.runUnaryGuarded (dart:async/zone.dart:1217:7)
      #43     _BufferingStreamSubscription._sendData (dart:async/stream_impl.dart:339:11)
      #44     _BufferingStreamSubscription._add (dart:async/stream_impl.dart:271:7)
      #45     _SyncStreamControllerDispatch._sendData (dart:async/stream_controller.dart:784:19)
      #46     _StreamController._add (dart:async/stream_controller.dart:658:7)
      #47     _StreamController.add (dart:async/stream_controller.dart:606:5)
      #48     _RawSecureSocket._closeHandler (dart:io/secure_socket.dart:899:21)
      #49     _RawSecureSocket._tryFilter (dart:io/secure_socket.dart:1029:11)
      <asynchronous suspension>

lohanidamodar · 2024-01-02T01:37:58Z

@Andree98 can you share code to reproduce this error

Andree98 · 2024-01-02T07:56:54Z

@lohanidamodar I'm able to reproduce the stacktrace with this code

@override
void initState() {
  super.initState();

  final realtime = Realtime(clientInstance);

  final subscription1 = realtime.subscribe([channel1]);
  final subscription2 = realtime.subscribe([channel2]);

  subscription1.stream.listen(print);
  subscription2.stream.listen(print);
}

Run the app and wait for the subscription to be killed. For me this takes 2-3 minutes using Cloudflare proxy. when the subscriptions are killed the stacktrace will appear in the console

SafakB · 2024-04-12T08:25:12Z

@lohanidamodar Same issue with me, is the work in progress? Thanks

lohanidamodar · 2024-04-25T02:04:24Z

Latest release should resolve this issue.

KiloNovemberDelta · 2024-04-28T17:32:40Z

Latest release should resolve this issue.

Hello and thank you for your help!
Do you mean 12.0.3 ? Or next release ?
Because I have the same issue on 12.0.3 :(

stnguyen90 added the bug Something isn't working label Jun 20, 2023

stnguyen90 mentioned this issue Jul 22, 2023

Create GH workflow to generate github metrics appwrite/.github#23

Merged

This was referenced Jul 25, 2023

Issues Opened in June 2023 appwrite/.github#35

Closed

Issues Opened in June 2023 appwrite/.github#41

Closed

Issues Opened in June 2023 appwrite/.github#47

Closed

Issues Opened in June 2023 appwrite/.github#53

Closed

joeyouss assigned lohanidamodar and joeyouss Aug 8, 2023

lohanidamodar mentioned this issue Dec 17, 2023

fix for realtime calling subscription multiple time - Appwrite 1.4.x appwrite/sdk-generator#713

Open

lohanidamodar mentioned this issue Apr 25, 2024

Fix for realtime subscriptions #196

Merged

stnguyen90 closed this as completed Apr 25, 2024

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🐛 Bug Report: Subscribing Multiple Times with a Single Realtime Instance Results in Null Subscription #156

🐛 Bug Report: Subscribing Multiple Times with a Single Realtime Instance Results in Null Subscription #156

stnguyen90 commented Jun 20, 2023 •

edited

stnguyen90 commented Jun 23, 2023

lohanidamodar commented Jun 29, 2023

stnguyen90 commented Aug 3, 2023

rvndsngwn commented Oct 3, 2023

Schrolli91 commented Nov 8, 2023

puntiz commented Nov 10, 2023

moshOntong-IT commented Dec 5, 2023

Sokratesli commented Dec 5, 2023

lohanidamodar commented Dec 17, 2023

rvndsngwn commented Dec 18, 2023

lohanidamodar commented Dec 19, 2023

Andree98 commented Dec 29, 2023

lohanidamodar commented Jan 2, 2024

Andree98 commented Jan 2, 2024

SafakB commented Apr 12, 2024

lohanidamodar commented Apr 25, 2024

KiloNovemberDelta commented Apr 28, 2024

🐛 Bug Report: Subscribing Multiple Times with a Single Realtime Instance Results in Null Subscription #156

🐛 Bug Report: Subscribing Multiple Times with a Single Realtime Instance Results in Null Subscription #156

Comments

stnguyen90 commented Jun 20, 2023 • edited

👟 Reproduction steps

👍 Expected behavior

👎 Actual Behavior

🎲 Appwrite version

💻 Operating system

🧱 Your Environment

👀 Have you spent some time to check if this issue has been raised before?

🏢 Have you read the Code of Conduct?

stnguyen90 commented Jun 23, 2023

lohanidamodar commented Jun 29, 2023

stnguyen90 commented Aug 3, 2023

rvndsngwn commented Oct 3, 2023

Schrolli91 commented Nov 8, 2023

puntiz commented Nov 10, 2023

moshOntong-IT commented Dec 5, 2023

Sokratesli commented Dec 5, 2023

lohanidamodar commented Dec 17, 2023

rvndsngwn commented Dec 18, 2023

lohanidamodar commented Dec 19, 2023

Andree98 commented Dec 29, 2023

lohanidamodar commented Jan 2, 2024

Andree98 commented Jan 2, 2024

SafakB commented Apr 12, 2024

lohanidamodar commented Apr 25, 2024

KiloNovemberDelta commented Apr 28, 2024

stnguyen90 commented Jun 20, 2023 •

edited