Hi, Our (kolla-ansible) CentOS 8 binary (RDO) deploy jobs have been failing on stable/train since added. Because the source jobs were passing, I was kind of hoping it was a packaging issue that would right itself, but no such luck yet. The majority of the job succeeds, but we grep our logs for CRITICAL messages, and nova-scheduler has a few when it starts up that cause us to fail: 2020-04-21 08:59:30.125 24 CRITICAL nova [req-86f6dad1-25f2-4c77-9d7d-ac7422801b4e - - - - -] Unhandled error: RuntimeError: dictionary changed size during iteration 2020-04-21 08:59:30.125 24 ERROR nova Traceback (most recent call last): 2020-04-21 08:59:30.125 24 ERROR nova File "/usr/bin/nova-scheduler", line 10, in <module> 2020-04-21 08:59:30.125 24 ERROR nova sys.exit(main()) 2020-04-21 08:59:30.125 24 ERROR nova File "/usr/lib/python3.6/site-packages/nova/cmd/scheduler.py", line 53, in main 2020-04-21 08:59:30.125 24 ERROR nova service.serve(server, workers=workers) 2020-04-21 08:59:30.125 24 ERROR nova File "/usr/lib/python3.6/site-packages/nova/service.py", line 454, in serve 2020-04-21 08:59:30.125 24 ERROR nova restart_method='mutate') 2020-04-21 08:59:30.125 24 ERROR nova File "/usr/lib/python3.6/site-packages/oslo_service/service.py", line 842, in launch 2020-04-21 08:59:30.125 24 ERROR nova launcher.launch_service(service, workers=workers) 2020-04-21 08:59:30.125 24 ERROR nova File "/usr/lib/python3.6/site-packages/oslo_service/service.py", line 606, in launch_service 2020-04-21 08:59:30.125 24 ERROR nova self._start_child(wrap) 2020-04-21 08:59:30.125 24 ERROR nova File "/usr/lib/python3.6/site-packages/oslo_service/service.py", line 575, in _start_child 2020-04-21 08:59:30.125 24 ERROR nova self.launcher.restart() 2020-04-21 08:59:30.125 24 ERROR nova File "/usr/lib/python3.6/site-packages/oslo_service/service.py", line 311, in restart 2020-04-21 08:59:30.125 24 ERROR nova self.conf.mutate_config_files() 2020-04-21 08:59:30.125 24 ERROR nova File "/usr/lib/python3.6/site-packages/oslo_config/cfg.py", line 3013, in mutate_config_files 2020-04-21 08:59:30.125 24 ERROR nova self._warn_immutability() 2020-04-21 08:59:30.125 24 ERROR nova File "/usr/lib/python3.6/site-packages/oslo_config/cfg.py", line 3040, in _warn_immutability 2020-04-21 08:59:30.125 24 ERROR nova for info, group in self._all_opt_infos(): 2020-04-21 08:59:30.125 24 ERROR nova File "/usr/lib/python3.6/site-packages/oslo_config/cfg.py", line 2502, in _all_opt_infos 2020-04-21 08:59:30.125 24 ERROR nova for info in self._opts.values(): 2020-04-21 08:59:30.125 24 ERROR nova RuntimeError: dictionary changed size during iteration https://storage.bhs.cloud.ovh.net/v1/AUTH_dcaab5e32b234d56b626f72581e3644c/z... The service does appear to start up successfully. It doesn't happen on master. Has anyone seen this before? Cheers, Mark