Public bug reported:

I have an ovs-vswitchd process consuming 100% CPU in a very lightly used
Openstack Rocky cloud running on Bionic. The version in question is
openvswitch-switch 2.10.0-0ubuntu2~cloud0

ovs-vswitchd is running alongside various neutron processes
(lbaasv2-agent, metadata-agent, l3-agent, dhcp-agent, openvswitch-agent)
inside an LXC container on a physical host. There is a single neutron
router, and the entire environment including br-tun, br-ex, and br-int
traffic barely goes over 200KiB/s TX/RX combined.

The issue appears to have arisen on its own after the host was hard
rebooted. On restart ovs-vswitchd came up with high load and it has not
diminished since then.


The thread that is consuming CPU looks like this in ps and shows up with the 
name 'handler89':

UID          PID    SPID    PPID  C STIME TTY          TIME CMD
root        7267    7454       1 99 Apr23 ?        8-03:38:14 ovs-vswitchd 
unix:/var/run/openvswitch/db.sock -vconsole:emer -vsyslog:err -vfile:info 
--mlockall --no-chdir --log-file=/var/log/openvswitch/ovs-vswitchd.log 
--pidfile=/var/run/openvswitch/ovs-vswitchd.pid --detach


Logs in /var/log/openvswitch/ovs-vswitchd.log show ~14000 entries like this per 
day - roughly one per second:

2019-05-01T18:34:30.110Z|237220|poll_loop(handler89)|INFO|Dropped
1092844 log messages in last 6 seconds (most recently, 0 seconds ago)
due to excessive rate

2019-05-01T18:34:30.110Z|237221|poll_loop(handler89)|INFO|wakeup due to
[POLLIN] on fd 42 (unknown anon_inode:[eventpoll]) at ../lib/dpif-
netlink.c:2786 (99% CPU usage)


Logs in /var/log/neutron/neutron-openvswitch-agent.log show entries like
this, again one set per second for ~14000 per day:

2019-05-01 18:35:31.174 13621 DEBUG
neutron.plugins.ml2.drivers.openvswitch.agent.ovs_neutron_agent [req-
7e354ade-55a3-46ba-adf4-db49a51e5218 - - - - -] Agent rpc_loop -
iteration:355070 started rpc_loop /usr/lib/python3/dist-
packages/neutron/plugins/ml2/drivers/openvswitch/agent/ovs_neutron_agent.py:2086

2019-05-01 18:35:31.177 13621 DEBUG
neutron.plugins.ml2.drivers.openvswitch.agent.openflow.native.ofswitch
[req-7e354ade-55a3-46ba-adf4-db49a51e5218 - - - - -] ofctl request
version=0x4,msg_type=0x12,msg_len=0x38,xid=0x81826d95,OFPFlowStatsRequest(cookie=0,cookie_mask=0,flags=0,match=OFPMatch(oxm_fields={}),out_group=4294967295,out_port=4294967295,table_id=23,type=1)
result
[OFPFlowStatsReply(body=[OFPFlowStats(byte_count=0,cookie=13408676230369642694,duration_nsec=724000000,duration_sec=710697,flags=0,hard_timeout=0,idle_timeout=0,instructions=[],length=56,match=OFPMatch(oxm_fields={}),packet_count=0,priority=0,table_id=23)],flags=0,type=1)]
_send_msg /usr/lib/python3/dist-
packages/neutron/plugins/ml2/drivers/openvswitch/agent/openflow/native/ofswitch.py:114

2019-05-01 18:35:31.179 13621 DEBUG
neutron.plugins.ml2.drivers.openvswitch.agent.ovs_neutron_agent [req-
7e354ade-55a3-46ba-adf4-db49a51e5218 - - - - -] Agent rpc_loop -
iteration:355070 completed. Processed ports statistics: {'regular':
{'added': 0, 'updated': 0, 'removed': 0}}. Elapsed:0.005
loop_count_and_wait /usr/lib/python3/dist-
packages/neutron/plugins/ml2/drivers/openvswitch/agent/ovs_neutron_agent.py:1875


I'm not sure what else information to add here but am happy to gather more 
diagnostic data to try to pin this down. I did come across 
https://mail.openvswitch.org/pipermail/ovs-discuss/2018-October/047558.html 
which is the same version as mine and the symptoms appear to be the same. 


Below are various ovs-dpctl/ofctl show reports:


root@juju-df624b-4-lxd-10:~# ovs-dpctl show
system@ovs-system:
  lookups: hit:223561120 missed:5768546 lost:798
  flows: 131
  masks: hit:2284286371 total:15 hit/pkt:9.96
  port 0: ovs-system (internal)
  port 1: br-ex (internal)
  port 2: eth1
  port 3: gre_sys (gre: packet_type=ptap)
  port 4: br-tun (internal)
  port 5: br-int (internal)
  port 6: tapa062d6f1-40
  port 7: tapf90e3ab6-13
  port 8: tap45ba891c-4c


root@juju-df624b-4-lxd-10:~# ovs-ofctl show br-int
OFPT_FEATURES_REPLY (xid=0x2): dpid:00003643edb09542
n_tables:254, n_buffers:0
capabilities: FLOW_STATS TABLE_STATS PORT_STATS QUEUE_STATS ARP_MATCH_IP
actions: output enqueue set_vlan_vid set_vlan_pcp strip_vlan mod_dl_src 
mod_dl_dst mod_nw_src mod_nw_dst mod_nw_tos mod_tp_src mod_tp_dst
 1(int-br-ex): addr:4a:b4:cc:dd:aa:ac
     config:     0
     state:      0
     speed: 0 Mbps now, 0 Mbps max
 2(patch-tun): addr:7a:36:76:1f:47:6e
     config:     0
     state:      0
     speed: 0 Mbps now, 0 Mbps max
 3(tapa062d6f1-40): addr:92:d4:6c:26:55:0a
     config:     0
     state:      0
     current:    10GB-FD COPPER
     speed: 10000 Mbps now, 0 Mbps max
 4(tapf90e3ab6-13): addr:9e:8b:4f:ae:8f:ba
     config:     0
     state:      0
     current:    10GB-FD COPPER
     speed: 10000 Mbps now, 0 Mbps max
 5(tap45ba891c-4c): addr:76:45:39:c8:d7:e0
     config:     0
     state:      0
     current:    10GB-FD COPPER
     speed: 10000 Mbps now, 0 Mbps max
 LOCAL(br-int): addr:36:43:ed:b0:95:42
     config:     PORT_DOWN
     state:      LINK_DOWN
     speed: 0 Mbps now, 0 Mbps max
OFPT_GET_CONFIG_REPLY (xid=0x4): frags=normal miss_send_len=0


root@juju-df624b-4-lxd-10:~# ovs-ofctl show br-tun
OFPT_FEATURES_REPLY (xid=0x2): dpid:000092c6c8f4a545
n_tables:254, n_buffers:0
capabilities: FLOW_STATS TABLE_STATS PORT_STATS QUEUE_STATS ARP_MATCH_IP
actions: output enqueue set_vlan_vid set_vlan_pcp strip_vlan mod_dl_src 
mod_dl_dst mod_nw_src mod_nw_dst mod_nw_tos mod_tp_src mod_tp_dst
 1(patch-int): addr:02:1d:bc:ec:0c:3b
     config:     0
     state:      0
     speed: 0 Mbps now, 0 Mbps max
 2(gre-0a30029b): addr:fe:09:61:11:92:8b
     config:     0
     state:      0
     speed: 0 Mbps now, 0 Mbps max
 3(gre-0a3002a2): addr:a2:64:93:48:e2:82
     config:     0
     state:      0
     speed: 0 Mbps now, 0 Mbps max
 4(gre-0a30029d): addr:12:b1:73:32:19:d4
     config:     0
     state:      0
     speed: 0 Mbps now, 0 Mbps max
 5(gre-0a3002ce): addr:ca:10:51:f2:0f:05
     config:     0
     state:      0
     speed: 0 Mbps now, 0 Mbps max
 6(gre-0a3002a1): addr:de:fe:95:33:d9:67
     config:     0
     state:      0
     speed: 0 Mbps now, 0 Mbps max
 7(gre-0a30029e): addr:5a:fa:ce:15:7b:5c
     config:     0
     state:      0
     speed: 0 Mbps now, 0 Mbps max
 8(gre-0a3002c3): addr:b6:87:66:09:fc:04
     config:     0
     state:      0
     speed: 0 Mbps now, 0 Mbps max
 10(gre-0a3002a0): addr:ce:79:f2:bf:a8:94
     config:     0
     state:      0
     speed: 0 Mbps now, 0 Mbps max
 14(gre-0a30029f): addr:b6:b0:84:7d:9f:aa
     config:     0
     state:      0
     speed: 0 Mbps now, 0 Mbps max
 18(gre-0a30029c): addr:da:14:12:54:1c:ec
     config:     0
     state:      0
     speed: 0 Mbps now, 0 Mbps max
 LOCAL(br-tun): addr:92:c6:c8:f4:a5:45
     config:     PORT_DOWN
     state:      LINK_DOWN
     speed: 0 Mbps now, 0 Mbps max
OFPT_GET_CONFIG_REPLY (xid=0x4): frags=normal miss_send_len=0


root@juju-df624b-4-lxd-10:~# ovs-ofctl show br-ex
OFPT_FEATURES_REPLY (xid=0x2): dpid:000000163e9a47a2
n_tables:254, n_buffers:0
capabilities: FLOW_STATS TABLE_STATS PORT_STATS QUEUE_STATS ARP_MATCH_IP
actions: output enqueue set_vlan_vid set_vlan_pcp strip_vlan mod_dl_src 
mod_dl_dst mod_nw_src mod_nw_dst mod_nw_tos mod_tp_src mod_tp_dst
 1(eth1): addr:00:16:3e:9a:47:a2
     config:     0
     state:      0
     current:    10GB-FD COPPER
     speed: 10000 Mbps now, 0 Mbps max
 2(phy-br-ex): addr:ce:a8:6a:25:55:0e
     config:     0
     state:      0
     speed: 0 Mbps now, 0 Mbps max
 LOCAL(br-ex): addr:00:16:3e:9a:47:a2
     config:     0
     state:      0
     speed: 0 Mbps now, 0 Mbps max
OFPT_GET_CONFIG_REPLY (xid=0x4): frags=normal miss_send_len=0

** Affects: openvswitch (Ubuntu)
     Importance: Undecided
         Status: New

-- 
You received this bug notification because you are a member of Ubuntu
Bugs, which is subscribed to Ubuntu.
https://bugs.launchpad.net/bugs/1827264

Title:
  ovs-vswitchd thread consuming 100% CPU

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/openvswitch/+bug/1827264/+subscriptions

-- 
ubuntu-bugs mailing list
ubuntu-bugs@lists.ubuntu.com
https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs

Reply via email to