In our app, there is a scenario where we write and delete approximately 100MB of files to the iCloud server at once using NSPersistentCloudkItContainer(CoreData). While write, read, and delete operations are immediately reflected in the local database, there is a noticeable delay when accessing the CloudKit Database dashboard.
Here is the testing approach we have tried:
Data Insert Test
Prepare around 100MB of data.
Write the data to CoreData on device A.
When launching the app on device B, it takes about 5 minutes for the data to be fully synchronized.
Data Deletion Test
Remove all the added data on device A (immediately reflected in local storage.)
After performing step 1, leaving device A idle takes about 3 minutes for the deletion to be reflected on device B.
if the app is deleted on device A after step 1, deletion information does not reach device B. Upon reinstalling the app on device A, the deleted data reappears on device B (synchronized data).
The ongoing occurrence of these issues has raised several questions regarding cloud synchronization and synchronization speed:
Is the synchronization speed of the Testflight app the same as the one received from the AppStore?
Are there traffic limitations per account or device?
Despite different perceived speeds for each account or device, is there any factor influencing synchronization speed other than network conditions?