[Bug]: Client hangs when syncing large folder

[mgscreativa]

⚠️ Before submitting, please verify the following: ⚠️

• This is a bug, not a question or a configuration issue.
• This issue is not already reported on Github (I've searched it).
• Nextcloud Server and Desktop Client are up to date. See Server Maintenance and Release Schedule and Desktop Releases for supported versions.
• I agree to follow Nextcloud's Code of Conduct

Bug description

Trying to sync very large folder hangs the client rendering it completely unresponsive. Sync never ends.
...

Steps to reproduce

1. Create sync connection with very large folder
2. Wait some minutes then the client completely hangs
   ...

Expected behavior

Sync should end as always did.
...

Which files are affected by this bug

Operating system

Linux

Which version of the operating system you are running.

Linux Mint 21.3 Cinnamon

Package

Distro package manager

Nextcloud Server version

29.0.1

Nextcloud Desktop Client version

3.13.0

Is this bug present after an update or on a fresh install?

Fresh desktop client install

Are you using the Nextcloud Server Encryption module?

Encryption is Disabled

Are you using an external user-backend?

• Default internal user-backend
• LDAP/ Active Directory
• SSO - SAML
• Other

Nextcloud Server logs

2024-06-04T15:00:24.808544252Z 172.27.0.3 - martinb 04/Jun/2024:15:00:24 +0000 "PROPFIND /remote.php" 207
2024-06-04T15:00:24.810104300Z 172.27.0.3 - martinb 04/Jun/2024:15:00:24 +0000 "PROPFIND /remote.php" 207
2024-06-04T15:00:24.824831865Z 172.27.0.3 - martinb 04/Jun/2024:15:00:24 +0000 "PROPFIND /remote.php" 207
2024-06-04T15:00:24.847812666Z 172.27.0.3 - martinb 04/Jun/2024:15:00:24 +0000 "PROPFIND /remote.php" 207
2024-06-04T15:00:24.851268949Z 172.27.0.3 - martinb 04/Jun/2024:15:00:24 +0000 "PROPFIND /remote.php" 207
2024-06-04T15:00:24.887534163Z 172.27.0.3 - martinb 04/Jun/2024:15:00:24 +0000 "PROPFIND /remote.php" 207

Additional info

As mentioned in #6349, changing the bandwidth limit to 512 KB/s didn't solve the issue, and as mentioned in #5779 I can't tell if some of my local files have this issue, but the sync succeeded last week ¿¿??, and experiencing the same reported here #6791.

The only major change I've made is migrated my server hardware to a new box, but as I use docker for my NC setup, I think everything may be the same.,

Just to mention that I've uninstalled clean all my NC client packages, also deleted the NC client folders in my home directory and also went to every folder formerly synced and deleted all sync dot files and such, then reinstalled NC client with apt from scratch.

Large folder details

Sync config of the client

debug_archive.zip

[mgscreativa]

Bumpity bump?

[mgscreativa]

Issue reported here is almost the same. I had to downgrade to v3.4.2 and sync succeded!

[smokingwheels]

@mgscreativa
Is your server on a HDD?

[mgscreativa]

Hi! No, mi home lab uses nvme drives

[smokingwheels]

Hi ! After reading your issue...

I ran a test and found that the client gives up on the server if it takes too long and sends the file again, but then there is 2 files with the same name on the server...it fails.

I made a long video as well of what happens. https://youtu.be/t1mY3lr8OPs

I would be interested in the results of these 3 commands on your server?
My 5400 rpm HDD benchmarks at 24.3 MB/s

dd if=/dev/zero of=/tmp/test.img bs=1G count=1 oflag=dsync
dd if=/dev/zero of=/tmp/test.img bs=1G count=10 oflag=dsync
dd if=/dev/zero of=/tmp/test.img bs=1G count=100 oflag=dsync

Note: Thats 100 GB of free space.
Please delete after test.

Also have you tuned the network settings on your server?
Also2 I seen the Nexcloud server needs double the storage bandwidth against network traffic. (If that makes sense). Its not 1:1.

[mgscreativa]

Thanks for the time to reply! here you go.

dd if=/dev/zero of=/tmp/test.img bs=1G count=1 oflag=dsync 380 MB/s
dd if=/dev/zero of=/tmp/test.img bs=1G count=10 oflag=dsync 96.9 MB/s
dd if=/dev/zero of=/tmp/test.img bs=1G count=100 oflag=dsync 65 MB/s

One thing I did about a month ago is to move my server from a desktop PC to a HP Pro Desk that I now use as homelab, I copied the NC data drive over the LAN with RSYNC and double checked that all permissions and CHOWN stick the same as the old server, but I think that's not an issue because NC server started as always without warning and I can create/edit files on the web GUI

[smokingwheels]

Thanks for the reply!

Did a rough calculation https://www.omnicalculator.com/other/download-time

My best guess! With out knowing the file count.
Say 4 hours + 1 second a file. ( I hope it takes less than 32 hours).

Do you have the app Versions enabled?

[mgscreativa]

FYI, the sync is already done (after downgrading), but after installing back 3.13.0, it hangs again...
Yes I guess!

[mgies]

Experiencing a similar issue on Nextcloud Desktop-Client 3.15.2 on Arch linux.

I generally have a large amount of data in my account. When adding a folder with 110GB, about 150.000 files and 17.000 subdirs, things get quirky. The folder is synced once properly. Then, when working and changing files the client hangs in endless sync loops until finally exiting silently. After restarting the client syncs again properly once until I start changing only one file in my whole Nextcloud dir.