Secure Backups are never completed, drain battery and data

[korg91]

Guidelines

• I have searched searched open and closed issues for duplicates
• I am submitting a bug report for existing functionality that does not work as intended
• This isn't a feature request or a discussion topic

Bug description

When I enable Secure Backups (text + all media), the backup starts and I can see the progress bar working as intended, but it looks like the backup is never completed: after some time the progress bar jumps back to a smaller step and the backup continues in loop. I have about 10 GB of data, but if I try to leave it on overnight it will upload 50+ GB and still not be finished.

Moreover, if I stop the ongoing backup (with the cross button next to the progress bar within the "Secure Backups" settings) it sometimes happens that the backup is still ongoing, although the UI within Signal does not show any ongoing backup. I can tell that the backup is actually still ongoing because 1/ I still get a persistent notification with title "Backing up media" and a progress bar (which does progress) and 2/ I can see that the phone is uploading a lot of data. To stop the ongoing backup, I need to manually start the backup ("Back up now") and then stop it again.

Finally, even if I stop the backup, the UI does not show any error: it just shows both the date and size of the last backup, suggesting that the backup was successful -- which is unlikely, although I haven't actually tried to restore it.

I've tried Secure Backups about three times in the past weeks since they were first rolled out and I always faced the same issue. Today I also tried to uninstall and re-install Signal, restore a local backup, and then try again to create a Secure Backup: the issue is still there.

Note: in the past I've played with https://github.com/bepaald/signalbackup-tools to import my Telegram data into my Signal backup and then restoring it. I guess there's a small chance that some data imported via signalbackup-tools is somehow corrupted and this makes Secure Backups fail. However, I've never experienced any issue with normal use nor with local backups.

Screenshots

No response

Device

Pixel 9 Pro

Android version

Android 16

Signal version

7.68.5

Link to debug log

https://debuglogs.org/android/7.68.5/23ca519a4a442c3f46d311c98a534df5b21451db6c17efec036c01796ad6d85c

[greyson-signal]

Hey there, looks like you have at least several attachments that are failing to upload because they're too large. I'm guessing these are attachments you imported from Telegram that go beyond the limit allowed in Signal. We're not currently handling this error correctly, causing us to retry it over and over. We'll make the change to account for this 👍 We will never be able to back up these "illegal" attachments, but we at least should never infinitely retry.

[korg91]

Oh, that explains it, thanks! I've removed some files and I'm down to a maximum of 499 MB, but I still have the bug. What's the max attachment size? I can't find an official figure anywhere and the app itself is not very informative either: when I try to attach a 1GB file it just drops the error One or more items were too large.

[greyson-signal]

The maximum attachment size is currently 100MiB

[greyson-signal]

But fwiw 7.69 should allow your backup to complete, it'll just be unable to back up the attachments over the size limit.

[korg91]

Just reporting back that it seems to work now on 7.69.2. Thanks for fixing this!