App Sync performance

[smediomike]

Describe the bug

on iPhone 8 with 16.1 OS version, save item into data store, it will very slow to sync to server side. this issue happen on iPhone 8 and iPhone X only, iPhone 12/13/14 etc can not reproduce.

Steps To Reproduce

Steps to reproduce the behavior:
1. upload content into s3 storage on iPhone 8/iphoneX
2. after finished step#1, save item information into data store
3. wait for such "create" subscription event from this model
4. it need take about 4s (but iphone12 just take 0.1s)

Expected behavior

can show on server side at once after save item into data store in mobile application side.

Amplify Framework Version

2.26.1

Amplify Categories

DataStore

Dependency manager

Swift PM

Swift version

5.9

CLI version

12.1.1

Xcode version

16.2

Relevant log output

Is this a regression?

No

Regression additional context

No response

Platforms

No response

OS Version

16.1

Device

iphone8/iphonx

Specific to simulators

No response

Additional context

whether I can set some configuration to resolve such issue? thank you very much!

[thisisabhash]

Thank you for posting this - can you try out the latest version of Amplify
https://github.com/aws-amplify/amplify-swift/releases/tag/2.47.0
as there have been many improvements shipped since the version being used 2.26.1.

Since this is device dependent, is there anything different on the devices iPhone 8/X w.r.t network configuration?

[smediomike]

based on 2.26.1 version, we found the root cause, when s3 uploading threads take more CPU and network, will impact app sync (local datastore -> server); and when reduce uploading ahead number and network usage, this issue will be gone or improve.

and we still upgrade SDK to 2.47.0 to verify this issue.

[harsh62]

@smediomike

when s3 uploading threads take more CPU and network, will impact app sync (local datastore -> server)

Is this still only happening on the devices you mentioned "this issue happen on iPhone 8 and iPhone X only"?