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Massive amount (>1,300) of parallel download connections from iCloud in iOS app #32747
Description
I have searched the existing issues, both open and closed, to make sure this is not a duplicate report.
- Yes
The bug
I have a large photo library, with many photos only on iCloud, not on the device.
When backing up this photo library, the Immich mobile app opens many simultaneous connections to download photos from iCloud, leading to slow download speeds and many stalled connection. I observed over 1,300 open connections on my phone at the same time.
My suggestion is to limit the number of simultaneous connections to a very low number, such as four, or alternatively to make it a setting in the Backup options.
The OS that Immich Server is running on
Debian
Version of Immich Server
v3.3.5
Version of Immich Mobile App
v3.3.5 build 26
Platform with the issue
- Server
- Web
- Mobile
Device make and model
iPhone 16 Pro
Your docker-compose.yml content
(not shared as the bug seems not to be affected by server deployment)Your .env content
(not shared as the bug seems not to be affected by server deployment)Reproduction steps
- Have a large (>40,000) iCloud library with most originals not on your mobile device
- Start downloading a large album (e.g. “Recents”) and wait until the system has uploaded most device images and turns to downloading media from iCloud
- In the backup screen, click “Show details” to reveal the currently active connections.
- Keep the screen open and watch the number grow.
Relevant log output
Additional information
Activity
agg23 commentedon Oct 27, 2026
The Immich app itself doesn't open any connections to iCloud. This is entirely done through
PhotoKit, which is intended to mediate between "Optimize Storage" and assets that are only stored remotely.Immich is hard coded to deal with 3 asset uploads at once. If that asset isn't on the device, it will request an iCloud download, waiting until that download completes before uploading and moving to a new one. Because of that, Immich can only trigger 3 iCloud downloads at once.
The number you see (1308) is not the number of active downloads. You also do have 4 assets in your screenshot at >0%. This is likely due to a visual bug on our side where failures to download are not removed from the list; it still doesn't indicate that many downloads are happening simultaneously. This count will keep growing, but there's still at most 3 things being downloaded
crenz commentedon Oct 27, 2026
Thank you for the clarification. So this means the bug on Immich's side is purely a display issue. I'm still wondering why so many iCloud downloads never finish even on a high-speed connection.
agg23 commentedon Oct 27, 2026
That is a good question. We are in the process of checking over all of our upload logic, particularly with that with iCloud. Hopefully we can resolve the failure issue (and fix the count too).
bo0tzz commentedon Oct 27, 2026
@agg23 should we track this as a bug, or a duplicate of #29676?