Uploads are processed concurrently not only 1 at a time on iOS

[omardoma]

Uploads are processed concurrently not only 1 at a time on iOS

[l0stpenguin]

On ios the queue management is done by the system daemon. The concurrent limit has been hardcoded to 1 as seen here:
https://github.com/spoonconsulting/cordova-plugin-background-upload/blob/master/src/ios/FileTransferBackground.m#L221

According to apple docs, using HTTPMaximumConnectionsPerHost will limit the concurrent connections.
https://developer.apple.com/documentation/foundation/nsurlsessionconfiguration/1407597-httpmaximumconnectionsperhost?language=objc

Are you trying to upload to different hosts?

[omardoma]

No I am uploading to the same exact serverUrl but uploads queue only on Android, on iOS all of them start right away

[omardoma]

I guess this is the reason: https://stackoverflow.com/questions/51607333/nsurlsession-httpmaximumconnectionsperhost-not-working-as-expected

I am using HTTP 2

[omardoma]

HTTP 2 uses only 1 Connection and multiplexes a lot of requests on it, that's why to the plugin I am indeed using 1 connection only.

Queueing will only work with HTTP 1.1 on iOS