Cronet exception: m.ms: Exception in CronetUrlRequest: net::ERR_CONNECTION_CLOSED, ErrorCode=5

[JSBmanD]

Package

cronet_http

Version

1.2.1

Operating-System

Android

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! Doctor found issues in 2 categories.

Dart Version

3.3.4

Steps to Reproduce

1. Create long polling client (that will make requests one after another for a period of time)
2. Start making requests

Expected Result

Requests succeed

Actual Result

After some time requests will fail with Cronet exception: m.ms: Exception in CronetUrlRequest: net::ERR_CONNECTION_CLOSED, ErrorCode=5, InternalErrorCode=-100, Retryable=true, uri=https://***/v1/polling.getUpdates?ts=***,statusCode: null,cause: DioException [unknown]: null

Devices distribution (out of 30k events):

Full log

Cronet exception: m.ms: Exception in CronetUrlRequest: net::ERR_CONNECTION_CLOSED, ErrorCode=5, InternalErrorCode=-100, Retryable=true, uri=https://alive.go-rhino.com/v1/polling.getUpdates?ts=1717011232038) | *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***
pid: 27540, tid: 27615, name 1.ui
os: android arch: arm64 comp: yes sim: no
build_id: 'b866ace18fa006c0f7dae5b7963c0614'
isolate_dso_base: 797e36f000, vm_dso_base: 797e36f000
isolate_instructions: 797e5b5580, vm_instructions: 797e59f000
    #00 abs 000000797ead0d0b virt 0000000000761d0b _kDartIsolateSnapshotInstructions+0x51b78b
    #01 abs 000000797ead0073 virt 0000000000761073 _kDartIsolateSnapshotInstructions+0x51aaf3
    #02 abs 000000797e71adcb virt 00000000003abdcb _kDartIsolateSnapshotInstructions+0x16584b
    #03 abs 000000797eb2fcfb virt 00000000007c0cfb _kDartIsolateSnapshotInstructions+0x57a77b
    #04 abs 000000797eb2fafb virt 00000000007c0afb _kDartIsolateSnapshotInstructions+0x57a57b
<asynchronous suspension>

[brianquinlan]

How are you using package:cronet_http? I see DioException in your logs.

[AlexV525]

How are you using package:cronet_http? I see DioException in your logs.

We have package:native_dio_adapter that can connects cronet_http and cupertino_http with the Dio instance.

[escamoteur]

I now see this exceptions too in our app and we don't use dio.

V13.3

[brianquinlan]

-100 seems to mean ILLEGAL_ARGUMENT:
https://chromium.googlesource.com/chromium/src/+/master/components/cronet/native/cronet.idl#205

5 means ERROR_CONNECTION_CLOSED:
https://chromium.googlesource.com/chromium/src/+/master/components/cronet/native/cronet.idl#87

Does anyone have a traceback that indicates the line of code that this exception is originating from?

[escamoteur]

It happens on a polling GET call to our backend. Nothing special besides that we call this URL every 30s Am 25. Apr. 2025, 18:16 -0500 schrieb Brian Quinlan ***@***.***>:

…

brianquinlan left a comment (dart-lang/http#1217) -100 seems to mean ILLEGAL_ARGUMENT: https://chromium.googlesource.com/chromium/src/+/master/components/cronet/native/cronet.idl#205 5 means ERROR_CONNECTION_CLOSED: https://chromium.googlesource.com/chromium/src/+/master/components/cronet/native/cronet.idl#87 Does anyone have a traceback that indicates the line of code that this exception is originating from? — Reply to this email directly, view it on GitHub, or unsubscribe. You are receiving this because you commented.Message ID: ***@***.***>

[techouse]

I noticed that I get this when my app goes into the background and tries to make a REST call to an API (i.e. every 30 seconds):

ClientException: Cronet exception: m.kt: Exception in CronetUrlRequest: net::ERR_NAME_NOT_RESOLVED, ErrorCode=1, InternalErrorCode=-105, Retryable=false, uri=http://my-fancy-server.com

As soon as I bring it back to the foreground everything is back to normal.

---

Tested on a Google Pixel 6

[brianquinlan]

Could someone post a stack trace so I can see what line of code in the cronet_http package this is coming from?

[techouse]

Could someone post a stack trace so I can see what line of code in the cronet_http package this is coming from?

The stack trace is not really helpful and most of it just mentions from what part of my app this originates

Non-fatal Exception: io.flutter.plugins.firebase.crashlytics.FlutterError: ClientException: Cronet exception: m.kt: Exception in CronetUrlRequest: net::ERR_NAME_NOT_RESOLVED, ErrorCode=1, InternalErrorCode=-105, Retryable=false, uri=https://my-fancy-server.com/user. Error thrown Error refreshing User resources.
#00 pc 0xe28597 com.example.app (FirebaseCrashlytics.recordError [firebase_crashlytics.dart:119]) (BuildId: cde83d06fccce350ccbd75ad4c3ac952)
#01 pc 0xe2838f com.example.app (LoggingMixin._recordError [logging_mixin.dart:107]) (BuildId: cde83d06fccce350ccbd75ad4c3ac952)
#02 pc 0xe2f1cf com.example.app (LoadResources.reloadAll [logging_mixin.dart:66]) (BuildId: cde83d06fccce350ccbd75ad4c3ac952)
#03 pc 0xe2f093 com.example.app (PreventConcurrencyMixin.preventConcurrentRuns [prevent_concurrency_mixin.dart:10]) (BuildId: cde83d06fccce350ccbd75ad4c3ac952)
#04 pc 0xe2ef67 com.example.app (LoadResources.reloadAllPeriodically [load_resources.dart:263]) (BuildId: cde83d06fccce350ccbd75ad4c3ac952)

The only line in cronet_http that mentions "Cronet exception: " is this one

http/pkgs/cronet_http/lib/src/cronet_client.dart

Line 265 in 63c477b

'Cronet exception: ${cronetException.toString()}', request.url);