Hi Pierre, my OpenStack version is 2024.1 (Caracal). The deployment type is Kolla, and the operating system base is Ubuntu. I don’t have a clear idea of how to reproduce the error, but it seems to be related to many unresolved connections—though that’s just a guess. I’ll send my blazar.conf as it is to see if it helps with anything.

https://paste.openstack.org/show/830681/

This is my Blazar Manager configuration file, in case it helps with anything else.

Em seg., 26 de jan. de 2026 às 13:42, Pierre Riteau <pierre@stackhpc.com> escreveu:

Hi Eduardo,

Thank you for raising this issue. More information may be required to understand or reproduce the issue. Can you please share:

- OpenStack version

- type of deployment (kolla?)

- operating system

- any hints on how to reproduce

Can you please open a new bug at https://bugs.launchpad.net/blazar and include all these extra details?

Thanks,

Pierre

On Mon, 26 Jan 2026 at 16:20, Eduardo Morais <eduardo.morais@lsd.ufcg.edu.br> wrote:

The first time the problem appeared, it wouldn’t allow listing the leases. So I went to check the logs and this log showed up. I restarted the service, and less than a week later the same thing happened again.Does anyone have any idea why this error keeps happening, and what the possible consequences would be of increasing the maximum number of connections?

LOG:

ERROR oslo.service.loopingcall sqlalchemy.exc.TimeoutError: QueuePool limit of size 2 overflow 50 reached, connection timed out, timeout 30.00 (Background on this error at: https://sqlalche.me/e/14/3o7r)
2026-01-26 15:11:45.671 7 ERROR oslo.service.loopingcall
2026-01-26 15:11:45.672 7 WARNING oslo.service.loopingcall [None req-3c69a13f-1bf2-4ace-9b7e-81249a6db22b - - - - - -] Function 'blazar.manager.service.ManagerService._process_events' run outlasted interval by 20.00 sec
2026-01-26 15:11:45.673 7 DEBUG blazar.manager.service [None req-3c69a13f-1bf2-4ace-9b7e-81249a6db22b - - - - - -] Trying to get events from DB. _process_events /var/lib/kolla/venv/lib/python3.10/site-packages/blazar/manager/service.py:233
2026-01-26 15:12:15.675 7 ERROR oslo.service.loopingcall [None req-3c69a13f-1bf2-4ace-9b7e-81249a6db22b - - - - - -] Fixed interval looping call 'blazar.manager.service.ManagerService._process_events' failed: sqlalchemy.exc.TimeoutError: QueuePool limit of size 2 overflow 50 reached, connection timed out, timeout 30.00 (Background on this error at: https://sqlalche.me/e/14/3o7r)
2026-01-26 15:12:15.675 7 ERROR oslo.service.loopingcall Traceback (most recent call last):
2026-01-26 15:12:15.675 7 ERROR oslo.service.loopingcall   File "/var/lib/kolla/venv/lib/python3.10/site-packages/oslo_service/loopingcall.py", line 67, in func
2026-01-26 15:12:15.675 7 ERROR oslo.service.loopingcall     return f(*args, **kwargs)
2026-01-26 15:12:15.675 7 ERROR oslo.service.loopingcall   File "/var/lib/kolla/venv/lib/python3.10/site-packages/blazar/manager/service.py", line 234, in _process_events
2026-01-26 15:12:15.675 7 ERROR oslo.service.loopingcall     events = db_api.event_get_all_sorted_by_filters(
2026-01-26 15:12:15.675 7 ERROR oslo.service.loopingcall   File "/var/lib/kolla/venv/lib/python3.10/site-packages/blazar/db/api.py", line 102, in decorator
2026-01-26 15:12:15.675 7 ERROR oslo.service.loopingcall     res = func(*args, **kwargs)
2026-01-26 15:12:15.675 7 ERROR oslo.service.loopingcall   File "/var/lib/kolla/venv/lib/python3.10/site-packages/blazar/db/api.py", line 227, in event_get_all_sorted_by_filters
2026-01-26 15:12:15.675 7 ERROR oslo.service.loopingcall     return IMPL.event_get_all_sorted_by_filters(sort_key, sort_dir,
2026-01-26 15:12:15.675 7 ERROR oslo.service.loopingcall   File "/var/lib/kolla/venv/lib/python3.10/site-packages/blazar/db/sqlalchemy/api.py", line 355, in event_get_all_sorted_by_filters