[ovs-dev] [ovs-discuss] [OVN] ovn-controller takes 100% cpu while no changes in sb-db

[Han Zhou]

On Fri, Aug 7, 2020 at 10:05 AM Tony Liu <tonyliu0592 at hotmail.com> wrote:

> Hi,
>
> Here are some logging snippets from ovn-controller.
> ========
> 2020-08-07T16:38:04.020Z|29250|timeval|WARN|Unreasonably long 8954ms poll
> interval (8895ms user, 0ms system)
> ========
> What's that mean? Is it harmless?
>
> ========
> 2020-08-07T16:38:04.021Z|29251|timeval|WARN|context switches: 0 voluntary,
> 6 involuntary
> 2020-08-07T16:38:04.022Z|29252|poll_loop|INFO|wakeup due to [POLLIN] on fd
> 19 (10.6.20.91:60398<->10.6.20.86:6642) at lib/stream-fd.c:157 (99% CPU
> usage)
> ========
> Is this wakeup caused by changes in sb-db?
> Why is ovn-controller so busy?
>
> ========
> 2020-08-07T16:38:04.022Z|29253|reconnect|WARN|tcp:127.0.0.1:6640:
> connection dropped (Broken pipe)
> ========
> Connection to local ovsdb-server is dropped.
> Is this caused by the timeout of inactivity probe?
>
> ========
> 2020-08-07T16:38:04.035Z|29254|poll_loop|INFO|wakeup due to [POLLIN] on fd
> 20 (<->/var/run/openvswitch/br-int.mgmt) at lib/stream-fd.c:157 (99% CPU
> usage)
> ========
> What causes this wakeup?
>
> ========
> 2020-08-07T16:38:04.048Z|29255|poll_loop|INFO|wakeup due to 0-ms timeout
> at lib/ovsdb-idl.c:5391 (99% CPU usage)
> ========
> What's this 0-ms wakeup mean?
>
> ========
> 2020-08-07T16:38:05.022Z|29256|poll_loop|INFO|wakeup due to 962-ms timeout
> at lib/reconnect.c:643 (99% CPU usage)
> 2020-08-07T16:38:05.023Z|29257|reconnect|INFO|tcp:127.0.0.1:6640:
> connecting...
> 2020-08-07T16:38:05.041Z|29258|poll_loop|INFO|wakeup due to [POLLOUT] on
> fd 14 (127.0.0.1:51478<->127.0.0.1:6640) at lib/stream-fd.c:153 (99% CPU
> usage)
> 2020-08-07T16:38:05.041Z|29259|reconnect|INFO|tcp:127.0.0.1:6640:
> connected
> ================
> Retry to connect to local ovsdb-server. A pollout event is triggered
> right after connection is established. What's poolout?
>
> ovn-controller is taking 100% CPU now, and there is no changes in
> sb-db (not busy). It seems that it's busy with local ovsdb-server
> or vswitchd. I'd like to understand why ovn-controller is so busy?
> All inactivity probe intervals are set to 30s.
>
>
Is there change from the local ovsdb? You can enable dbg log to see what is
happening.
For the local ovsdb probe, I have mentioned in the other thread that UNIX
socket is recommended (instead of tcp 127.0.0.1). Using UNIX socket
disables probe by default.

Thanks,
Han