Hello, Not sure if this is the root cause of your problem, but that could: - https://mariadb.com/resources/blog/isolation-level-violation-testing-and-deb... - https://jira.mariadb.org/browse/MDEV-35124 End of last week we noticed strange behaviours due to this new transactional model, see https://bugs.launchpad.net/nova/+bug/2116186/. Le lun. 14 juil. 2025 à 19:43, Winicius Allan <winiciusab12@gmail.com> a écrit :
Hi community o/
Suddenly, I noticed that the login on the dashboard wasn't working, so I checked the keystone logs. I saw some entries like that:
2025-07-10 00:53:45.120 23 ERROR sqlalchemy.pool.impl.QueuePool oslo_db.exception.DBDeadlock: (pymysql.err.OperationalError) (1205, 'Lock wait timeout exceeded; try restarting transaction')
Nova-conductor was also showing messages like these.
At the same time, blazer-manager was logging after every _process_event calling:
ERROR sqlalchemy.exc.TimeoutError: QueuePool limit of size 1 overflow 50 reached, connection timed out, timeout 30.00
I do not know if it's related to the _process_event method that batches events concurrently[1], and the DB was locked. Well... I increased the max_pool_size from 1 to 2 on blazar-manager, and that message stops showing. Does anyone know what can cause this deadlock generally?
I'd like to ask another question: I have three controllers in my environment. Why do controllers with no active VIP address bind connections on the MySQL port, for example:
tcp ESTAB 0 0 10.0.0.105:3306 10.0.0.107:50642 users:(("mariadbd",pid=977010,fd=1089))
[1] https://github.com/openstack/blazar/blob/stable/2024.1/blazar/manager/servic...
Best regards.
-- Hervé Beraud Principal Software Engineer at Red Hat irc: hberaud https://github.com/4383/