In Dart HTTP Client, an option is required to set the IPv4 or IPv6 for DNS resolution for the developer

[SijuKJ]

This feature is a related dart HTTP client, I raised a new feature request in Flutter GitHub ( flutter/flutter#116537). They asked to raise in Dart SDK GitHub as it is a bug in the dart HTTP client.

Target Platform: Android
Target OS version/browser: Android 12+
Devices:

Many Flutter-based Android and iOS apps are very slow during HTTP service calls in the Wifi networks due to failed IPv6 DNS resolution.
As I am requesting this feature as a solution for the three important issues reported by Flutter developers.

1. In Android 12+, the REST API calls are very slow in flutter, In WiFi that takes 10 seconds whereas in mobile data it is less than a second flutter/flutter#116477
2. Flutter: API Calls are so slow in flutter, taking more than 20s to load with WiFi and less than a sec with Mobile Data flutter/flutter#112285
3. Slow HttpClient operation caused by DNS resolution failure on iOS #41451

In essence, we are facing slowness in the API call execution while using Wifi networks due to failed IPv6 DNS resolution, thereafter it fallback to IPv4 DNS resolution. Hence each API call execution is getting delayed a minimum of 10+ seconds.

It would be great If there would be a feature for manually specifying IPv4 or IPv6 versions during HTTP client initialization.

So I request your kind attention on this important issue, as we are developing business-critical applications using Flutter, for iOS/ Android, and Windows.

[mraleph]

For iOS this was supposed to be fixed by d7483c3, so you should not see it. We could enable it on Android as well.

/cc @brianquinlan

[Sreeharikr]

Any update in this issue? I'm also facing the same.... Tried to use same http client after initializing once... But connection is losing after some time.... 🤕

[bugrevealingbme]

++

[mraleph]

Seems like a high impact issue for anybody who uses default IO client.

/cc @a-siva

[nswim]

critical issue for my app
any update?

[EdsonMello-code]

Any solution?

[iamsureshsharma]

I am also facing the same issue

[mammuthone]

Same issue here.
On Android app works at speed of light, on iOS emulator app works at speed of light.
On physical device iPhone app become slower as crazy during http requests

[brianquinlan]

Could someone experiencing this issue on Android please try running this code and report the output:

    // Test IPv4 performance
    final start = DateTime.now();
    InternetAddress.lookup(<whatever host that you use that is slow>, type: InternetAddressType.IPv4)
        .then((_) => print(DateTime.now().difference(start)));

and then, after rebooting your device:

    // Test IPv6 performance
    final start = DateTime.now();
    InternetAddress.lookup(<whatever host that you use that is slow>, type: InternetAddressType.IPv6)
        .then((_) => print(DateTime.now().difference(start)));

I just want to confirm that the issue is with IPv6 lookup.