On openvswitch based jobs I see also errors like: neutron_lib.exceptions.ProcessExecutionError: Exit code: 255; Cmd: ['ip', 'netns', 'exec', 'qrouter-52946583-4366-4c54-ac83-449968b0c989', 'conntrack', '-D', '-d', '172.24.5.205', '-p', 'udp', '--dport', 1036]; Stdin: ; Stdout: ; Stderr: Cannot open network namespace "qrouter-52946583-4366-4c54-ac83-449968b0c989": No such file or directory Sep 23 22:33:23.187565 ubuntu-focal-ovh-gra1-0020000672 neutron-l3-agent[82060]: ERROR neutron.agent.linux.ip_lib Traceback (most recent call last): Sep 23 22:33:23.187565 ubuntu-focal-ovh-gra1-0020000672 neutron-l3-agent[82060]: ERROR neutron.agent.linux.ip_lib File "/opt/stack/neutron/neutron/agent/linux/ip_lib.py", line 378, in delete_socket_conntrack_state Sep 23 22:33:23.187565 ubuntu-focal-ovh-gra1-0020000672 neutron-l3-agent[82060]: ERROR neutron.agent.linux.ip_lib ip_wrapper.netns.execute(cmd, check_exit_code=True, Sep 23 22:33:23.187565 ubuntu-focal-ovh-gra1-0020000672 neutron-l3-agent[82060]: ERROR neutron.agent.linux.ip_lib File "/opt/stack/neutron/neutron/agent/linux/ip_lib.py", line 721, in execute Sep 23 22:33:23.187565 ubuntu-focal-ovh-gra1-0020000672 neutron-l3-agent[82060]: ERROR neutron.agent.linux.ip_lib return utils.execute(cmd, check_exit_code=check_exit_code, Sep 23 22:33:23.187565 ubuntu-focal-ovh-gra1-0020000672 neutron-l3-agent[82060]: ERROR neutron.agent.linux.ip_lib File "/opt/stack/neutron/neutron/agent/linux/utils.py", line 148, in execute Sep 23 22:33:23.187565 ubuntu-focal-ovh-gra1-0020000672 neutron-l3-agent[82060]: ERROR neutron.agent.linux.ip_lib raise exceptions.ProcessExecutionError(msg, Sep 23 22:33:23.187565 ubuntu-focal-ovh-gra1-0020000672 neutron-l3-agent[82060]: ERROR neutron.agent.linux.ip_lib neutron_lib.exceptions.ProcessExecutionError: Exit code: 255; Cmd: ['ip', 'netns', 'exec', 'qrouter-52946583-4366-4c54-ac83-449968b0c989', 'conntrack', '-D', '-d', '172.24.5.205', '-p', 'udp', '--dport', 1036]; Stdin: ; Stdout: ; Stderr: Cannot open network namespace "qrouter-52946583-4366-4c54-ac83-449968b0c989": No such file or directory Sep 23 22:33:23.187565 ubuntu-focal-ovh-gra1-0020000672 neutron-l3-agent[82060]: ERROR neutron.agent.linux.ip_lib Sep 23 22:33:23.187565 ubuntu-focal-ovh-gra1-0020000672 neutron-l3-agent[82060]: ERROR neutron.agent.linux.ip_lib Sep 23 22:33:23.187565 ubuntu-focal-ovh-gra1-0020000672 neutron-l3-agent[82060]: DEBUG oslo_concurrency.lockutils [None req-03a816ae-d43e-4b16-adf3-5d8007db4152 tempest-PortForwardingTestJSON-811925916 tempest-PortForwardingTestJSON-811925916] Acquired lock "iptables-qrouter-52946583-4366-4c54-ac83-449968b0c989" {{(pid=82060) lock /usr/local/lib/python3.8/dist-packages/oslo_concurrency/lockutils.py:266}} Sep 23 22:33:23.187565 ubuntu-focal-ovh-gra1-0020000672 neutron-l3-agent[82060]: DEBUG oslo_concurrency.lockutils [None req-03a816ae-d43e-4b16-adf3-5d8007db4152 tempest-PortForwardingTestJSON-811925916 tempest-PortForwardingTestJSON-811925916] Acquired external semaphore "iptables-qrouter-52946583-4366-4c54-ac83-449968b0c989" {{(pid=82060) lock /usr/local/lib/python3.8/dist-packages/oslo_concurrency/lockutils.py:272}} Sep 23 22:33:23.187565 ubuntu-focal-ovh-gra1-0020000672 neutron-l3-agent[82060]: DEBUG neutron.agent.linux.utils [None req-03a816ae-d43e-4b16-adf3-5d8007db4152 tempest-PortForwardingTestJSON-811925916 tempest-PortForwardingTestJSON-811925916] Running command (rootwrap daemon): ['ip', 'netns', 'exec', 'qrouter-52946583-4366-4c54-ac83-449968b0c989', 'iptables-save'] {{(pid=82060) execute_rootwrap_daemon /opt/stack/neutron/neutron/agent/linux/utils.py:103}} Sep 23 22:33:23.195561 ubuntu-focal-ovh-gra1-0020000672 neutron-l3-agent[82060]: ERROR neutron.agent.linux.utils [None req-03a816ae-d43e-4b16-adf3-5d8007db4152 tempest-PortForwardingTestJSON-811925916 tempest-PortForwardingTestJSON-811925916] Exit code: 255; Cmd: ['ip', 'netns', 'exec', 'qrouter-52946583-4366-4c54-ac83-449968b0c989', 'iptables-save']; Stdin: ; Stdout: ; Stderr: Cannot open network namespace "qrouter-52946583-4366-4c54-ac83-449968b0c989": No such file or directory Sep 23 22:33:23.195561 ubuntu-focal-ovh-gra1-0020000672 neutron-l3-agent[82060]: Sep 23 22:33:23.198635 ubuntu-focal-ovh-gra1-0020000672 neutron-l3-agent[82060]: DEBUG oslo.privsep.daemon [-] privsep: reply[140647323430720]: (4, ['qdhcp-7b309fb3-d5b1-409c-b8cd-46131dff57ac', 'qrouter-dafaa1e8-9b9a-499f-adde-2991c20216d0', 'qdhcp-ca275a31-1bbf-4d9f-a80d-2fd5e3160d61', 'qdhcp-caae75cb-a7a6-4b88-81a0-69fe04d6e03b', 'qrouter-6f1b4d18-c5b3-453a-a101-186d8bb8b829', 'qrouter-2414eb72-3c06-4f23-bacd-cb7addc751e8', 'qdhcp-0a6d5e1f-0a69-4182-9e13-66353edee36b', 'qdhcp-b80a179a-3b5a-4711-ac91-b9db6bebd651', 'qdhcp-caf75c0a-e772-4ca3-b431-ddd40480a312', 'qrouter-272c976a-56f3-4c94-8c1f-c26ba4225d04', 'qdhcp-bb33bfdb-b4fb-43ea-ae8b-dfc0043840b4']) {{(pid=83037) _call_back /usr/local/lib/python3.8/dist-packages/oslo_privsep/daemon.py:510}} Sep 23 22:33:23.199750 ubuntu-focal-ovh-gra1-0020000672 neutron-l3-agent[82060]: ERROR neutron.agent.linux.iptables_manager [None req-03a816ae-d43e-4b16-adf3-5d8007db4152 tempest-PortForwardingTestJSON-811925916 tempest-PortForwardingTestJSON-811925916] Namespace qrouter-52946583-4366-4c54-ac83-449968b0c989 was deleted during IPTables operations.: neutron_lib.exceptions.ProcessExecutionError: Exit code: 255; Cmd: ['ip', 'netns', 'exec', 'qrouter-52946583-4366-4c54-ac83-449968b0c989', 'iptables-save']; Stdin: ; Stdout: ; Stderr: Cannot open network namespace "qrouter-52946583-4366-4c54-ac83-449968b0c989": No such file or directory Sep 23 22:33:23.200286 ubuntu-focal-ovh-gra1-0020000672 neutron-l3-agent[82060]: DEBUG oslo_concurrency.lockutils [None req-03a816ae-d43e-4b16-adf3-5d8007db4152 tempest-PortForwardingTestJSON-811925916 tempest-PortForwardingTestJSON-811925916] Releasing lock "iptables-qrouter-52946583-4366-4c54-ac83-449968b0c989" {{(pid=82060) lock /usr/local/lib/python3.8/dist-packages/oslo_concurrency/lockutils.py:282}} Sep 23 22:33:23.200811 ubuntu-focal-ovh-gra1-0020000672 neutron-l3-agent[82060]: DEBUG neutron.api.rpc.handlers.resources_rpc [None req-03a816ae-d43e-4b16-adf3-5d8007db4152 tempest-PortForwardingTestJSON-811925916 tempest-PortForwardingTestJSON-811925916] neutron.api.rpc.handlers.resources_rpc.ResourcesPullRpcApi method bulk_pull called with arguments (, 'PortForwarding') {'filter_kwargs': {'floatingip_id': ['a13a0e8c-9a70-4e1a-8ba4-0b55037a85eb']}} {{(pid=82060) wrapper /usr/local/lib/python3.8/dist-packages/oslo_log/helpers.py:65}} Sep 23 22:33:23.230697 ubuntu-focal-ovh-gra1-0020000672 neutron-l3-agent[82060]: DEBUG oslo.privsep.daemon [-] privsep: reply[140647323428640]: (4, None) {{(pid=83037) _call_back /usr/local/lib/python3.8/dist-packages/oslo_privsep/daemon.py:510}} Sep 23 22:33:23.231444 ubuntu-focal-ovh-gra1-0020000672 neutron-l3-agent[82060]: DEBUG neutron.agent.linux.utils [-] Running command (rootwrap daemon): ['ip', 'netns', 'exec', 'qrouter-dafaa1e8-9b9a-499f-adde-2991c20216d0', 'conntrack', '-D', '-d', '172.24.5.149'] {{(pid=82060) execute_rootwrap_daemon /opt/stack/neutron/neutron/agent/linux/utils.py:103}} Sep 23 22:33:23.240188 ubuntu-focal-ovh-gra1-0020000672 neutron-l3-agent[82060]: DEBUG oslo.privsep.daemon [-] privsep: Exception during request[140647323430720]: Network namespace qrouter-52946583-4366-4c54-ac83-449968b0c989 could not be found. {{(pid=83037) _process_cmd /usr/local/lib/python3.8/dist-packages/oslo_privsep/daemon.py:488}} Sep 23 22:33:23.240188 ubuntu-focal-ovh-gra1-0020000672 neutron-l3-agent[82060]: Traceback (most recent call last): Sep 23 22:33:23.240188 ubuntu-focal-ovh-gra1-0020000672 neutron-l3-agent[82060]: File "/opt/stack/neutron/neutron/privileged/agent/linux/ip_lib.py", line 289, in _run_iproute_addr Sep 23 22:33:23.240188 ubuntu-focal-ovh-gra1-0020000672 neutron-l3-agent[82060]: with get_iproute(namespace) as ip: Sep 23 22:33:23.240188 ubuntu-focal-ovh-gra1-0020000672 neutron-l3-agent[82060]: File "/opt/stack/neutron/neutron/privileged/agent/linux/ip_lib.py", line 193, in get_iproute Sep 23 22:33:23.240188 ubuntu-focal-ovh-gra1-0020000672 neutron-l3-agent[82060]: return pyroute2.NetNS(namespace, flags=0, libc=priv_linux.get_cdll()) Sep 23 22:33:23.240188 ubuntu-focal-ovh-gra1-0020000672 neutron-l3-agent[82060]: File "/usr/local/lib/python3.8/dist-packages/pyroute2/netns/nslink.py", line 164, in __init__ Sep 23 22:33:23.240188 ubuntu-focal-ovh-gra1-0020000672 neutron-l3-agent[82060]: super(NetNS, self).__init__(trnsp_in, trnsp_out) Sep 23 22:33:23.240188 ubuntu-focal-ovh-gra1-0020000672 neutron-l3-agent[82060]: File "/usr/local/lib/python3.8/dist-packages/pyroute2/iproute/linux.py", line 134, in __init__ Sep 23 22:33:23.240188 ubuntu-focal-ovh-gra1-0020000672 neutron-l3-agent[82060]: super(RTNL_API, self).__init__(*argv, **kwarg) Sep 23 22:33:23.240188 ubuntu-focal-ovh-gra1-0020000672 neutron-l3-agent[82060]: File "/usr/local/lib/python3.8/dist-packages/pyroute2/remote/__init__.py", line 225, in __init__ Sep 23 22:33:23.240188 ubuntu-focal-ovh-gra1-0020000672 neutron-l3-agent[82060]: raise init['error'] Sep 23 22:33:23.240188 ubuntu-focal-ovh-gra1-0020000672 neutron-l3-agent[82060]: FileNotFoundError: [Errno 2] No such file or directory: b'/var/run/netns/qrouter-52946583-4366-4c54-ac83-449968b0c989' Sep 23 22:33:23.240188 ubuntu-focal-ovh-gra1-0020000672 neutron-l3-agent[82060]: During handling of the above exception, another exception occurred: Sep 23 22:33:23.240188 ubuntu-focal-ovh-gra1-0020000672 neutron-l3-agent[82060]: Traceback (most recent call last): Sep 23 22:33:23.240188 ubuntu-focal-ovh-gra1-0020000672 neutron-l3-agent[82060]: File "/usr/local/lib/python3.8/dist-packages/oslo_privsep/daemon.py", line 485, in _process_cmd Sep 23 22:33:23.240188 ubuntu-focal-ovh-gra1-0020000672 neutron-l3-agent[82060]: ret = func(*f_args, **f_kwargs) Sep 23 22:33:23.240188 ubuntu-focal-ovh-gra1-0020000672 neutron-l3-agent[82060]: File "/usr/local/lib/python3.8/dist-packages/oslo_privsep/priv_context.py", line 249, in _wrap Sep 23 22:33:23.240188 ubuntu-focal-ovh-gra1-0020000672 neutron-l3-agent[82060]: return func(*args, **kwargs) Sep 23 22:33:23.240188 ubuntu-focal-ovh-gra1-0020000672 neutron-l3-agent[82060]: File "/opt/stack/neutron/neutron/privileged/agent/linux/ip_lib.py", line 324, in delete_ip_address Sep 23 22:33:23.240188 ubuntu-focal-ovh-gra1-0020000672 neutron-l3-agent[82060]: _run_iproute_addr("delete", Sep 23 22:33:23.240188 ubuntu-focal-ovh-gra1-0020000672 neutron-l3-agent[82060]: File "/opt/stack/neutron/neutron/privileged/agent/linux/ip_lib.py", line 297, in _run_iproute_addr Sep 23 22:33:23.240188 ubuntu-focal-ovh-gra1-0020000672 neutron-l3-agent[82060]: raise NetworkNamespaceNotFound(netns_name=namespace) Sep 23 22:33:23.240188 ubuntu-focal-ovh-gra1-0020000672 neutron-l3-agent[82060]: neutron.privileged.agent.linux.ip_lib.NetworkNamespaceNotFound: Network namespace qrouter-52946583-4366-4c54-ac83-449968b0c989 could not be found.