Talk: DeadlockException

[svseidel]

Setup

• Nextcloud 20.0.4
• custom coturn-sever
• Talk App
• Ubuntu 18.04, PHP 7.2.24
• MariaDB 10.4.17; SELECT @@GLOBAL.tx_isolation, @@tx_isolation; gives

+-----------------------+----------------+
| @@GLOBAL.tx_isolation | @@tx_isolation |
+-----------------------+----------------+
| READ-COMMITTED | READ-COMMITTED |
+-----------------------+----------------+

Problem

I receive an error message, while having a voice call (no video) with more then 8-10 users:

Doctrine\DBAL\Exception\DeadlockException: An exception occurred while executing 'UPDATE oc_talk_participants SET last_ping = ? WHERE (user_id = ?) AND (session_id = ?) AND (room_id = ?)' with params [1610366995, "…", "…", 39]: SQLSTATE[40001]: Serialization failure: 1213 Deadlock found when trying to get lock; try restarting transaction

Then users randomly have to reconnect to the call (if possible).

I have searched a lot and found similar issues but not quite the same (e. g. files app). The most given answer referirng to the transaction isolation level does not work. Is there a fix?

[simonspa]

This has been reported already here: nextcloud/spreed#4093