[ovs-discuss] [OVN] ovn-northd takes much CPU when no configuration update

Han Zhou hzhou at ovn.org
Sun Aug 2 04:11:27 UTC 2020


On Fri, Jul 31, 2020 at 4:14 PM Tony Liu <tonyliu0592 at hotmail.com> wrote:

> Hi,
>
> I see the active ovn-northd takes much CPU (30% - 100%) when there is no
> configuration from OpenStack, nothing happening on all chassis nodes
> either.
>
> Is this expected? What is it busy with?
>
>
Yes, this is expected. It is due to the OVSDB probe between ovn-northd and
NB/SB OVSDB servers, which is used to detect the OVSDB connection failure.
Usually this is not a concern (unlike the probe with a large number of
ovn-controller clients), because ovn-northd is a centralized component and
the CPU cost when there is no configuration change doesn't matter that
much. However, if it is a concern, the probe interval (default 5 sec) can
be changed.
If you change, remember to change on both server side and client side.
For client side (ovn-northd), it is configured in the NB DB's NB_Global
table's options:northd_probe_interval. See man page of ovn-nb(5).
For server side (NB and SB), it is configured in the NB and SB DB's
Connection table's inactivity_probe column.

Thanks,
Han


> ========
> 2020-07-31T23:08:09.511Z|04267|poll_loop|DBG|wakeup due to [POLLIN] on fd
> 8 (10.6.20.84:44358<->10.6.20.84:6641) at lib/stream-fd.c:157 (68% CPU
> usage)
> 2020-07-31T23:08:09.512Z|04268|jsonrpc|DBG|tcp:10.6.20.84:6641: received
> request, method="echo", params=[], id="echo"
> 2020-07-31T23:08:09.512Z|04269|jsonrpc|DBG|tcp:10.6.20.84:6641: send
> reply, result=[], id="echo"
> 2020-07-31T23:08:12.777Z|04270|poll_loop|DBG|wakeup due to [POLLIN] on fd
> 9 (10.6.20.84:49158<->10.6.20.85:6642) at lib/stream-fd.c:157 (34% CPU
> usage)
> 2020-07-31T23:08:12.777Z|04271|reconnect|DBG|tcp:10.6.20.85:6642: idle
> 5002 ms, sending inactivity probe
> 2020-07-31T23:08:12.777Z|04272|reconnect|DBG|tcp:10.6.20.85:6642:
> entering IDLE
> 2020-07-31T23:08:12.777Z|04273|jsonrpc|DBG|tcp:10.6.20.85:6642: send
> request, method="echo", params=[], id="echo"
> 2020-07-31T23:08:12.777Z|04274|jsonrpc|DBG|tcp:10.6.20.85:6642: received
> request, method="echo", params=[], id="echo"
> 2020-07-31T23:08:12.777Z|04275|reconnect|DBG|tcp:10.6.20.85:6642:
> entering ACTIVE
> 2020-07-31T23:08:12.777Z|04276|jsonrpc|DBG|tcp:10.6.20.85:6642: send
> reply, result=[], id="echo"
> 2020-07-31T23:08:13.635Z|04277|poll_loop|DBG|wakeup due to [POLLIN] on fd
> 9 (10.6.20.84:49158<->10.6.20.85:6642) at lib/stream-fd.c:157 (34% CPU
> usage)
> 2020-07-31T23:08:13.635Z|04278|jsonrpc|DBG|tcp:10.6.20.85:6642: received
> reply, result=[], id="echo"
> 2020-07-31T23:08:14.480Z|04279|hmap|DBG|Dropped 129 log messages in last 5
> seconds (most recently, 0 seconds ago) due to excessive rate
> 2020-07-31T23:08:14.480Z|04280|hmap|DBG|lib/shash.c:112: 2 buckets with 6+
> nodes, including 2 buckets with 6 nodes (32 nodes total across 32 buckets)
> 2020-07-31T23:08:14.513Z|04281|poll_loop|DBG|wakeup due to 27-ms timeout
> at lib/reconnect.c:643 (34% CPU usage)
> 2020-07-31T23:08:14.513Z|04282|reconnect|DBG|tcp:10.6.20.84:6641: idle
> 5001 ms, sending inactivity probe
> 2020-07-31T23:08:14.513Z|04283|reconnect|DBG|tcp:10.6.20.84:6641:
> entering IDLE
> 2020-07-31T23:08:14.513Z|04284|jsonrpc|DBG|tcp:10.6.20.84:6641: send
> request, method="echo", params=[], id="echo"
> 2020-07-31T23:08:15.370Z|04285|poll_loop|DBG|wakeup due to [POLLIN] on fd
> 8 (10.6.20.84:44358<->10.6.20.84:6641) at lib/stream-fd.c:157 (34% CPU
> usage)
> 2020-07-31T23:08:15.370Z|04286|jsonrpc|DBG|tcp:10.6.20.84:6641: received
> request, method="echo", params=[], id="echo"
> 2020-07-31T23:08:15.370Z|04287|reconnect|DBG|tcp:10.6.20.84:6641:
> entering ACTIVE
> 2020-07-31T23:08:15.370Z|04288|jsonrpc|DBG|tcp:10.6.20.84:6641: send
> reply, result=[], id="echo"
> 2020-07-31T23:08:16.236Z|04289|poll_loop|DBG|wakeup due to 0-ms timeout at
> tcp:10.6.20.84:6641 (100% CPU usage)
> 2020-07-31T23:08:16.236Z|04290|jsonrpc|DBG|tcp:10.6.20.84:6641: received
> reply, result=[], id="echo"
> 2020-07-31T23:08:17.778Z|04291|poll_loop|DBG|wakeup due to [POLLIN] on fd
> 9 (10.6.20.84:49158<->10.6.20.85:6642) at lib/stream-fd.c:157 (100% CPU
> usage)
> 2020-07-31T23:08:17.778Z|04292|jsonrpc|DBG|tcp:10.6.20.85:6642: received
> request, method="echo", params=[], id="echo"
> 2020-07-31T23:08:17.778Z|04293|jsonrpc|DBG|tcp:10.6.20.85:6642: send
> reply, result=[], id="echo"
> 2020-07-31T23:08:20.372Z|04294|poll_loop|DBG|wakeup due to [POLLIN] on fd
> 8 (10.6.20.84:44358<->10.6.20.84:6641) at lib/stream-fd.c:157 (41% CPU
> usage)
> 2020-07-31T23:08:20.372Z|04295|reconnect|DBG|tcp:10.6.20.84:6641: idle
> 5002 ms, sending inactivity probe
> 2020-07-31T23:08:20.372Z|04296|reconnect|DBG|tcp:10.6.20.84:6641:
> entering IDLE
> 2020-07-31T23:08:20.372Z|04297|jsonrpc|DBG|tcp:10.6.20.84:6641: send
> request, method="echo", params=[], id="echo"
> 2020-07-31T23:08:20.372Z|04298|jsonrpc|DBG|tcp:10.6.20.84:6641: received
> request, method="echo", params=[], id="echo"
> 2020-07-31T23:08:20.372Z|04299|reconnect|DBG|tcp:10.6.20.84:6641:
> entering ACTIVE
> 2020-07-31T23:08:20.372Z|04300|jsonrpc|DBG|tcp:10.6.20.84:6641: send
> reply, result=[], id="echo"
> 2020-07-31T23:08:20.376Z|04301|hmap|DBG|Dropped 181 log messages in last 6
> seconds (most recently, 1 seconds ago) due to excessive rate
> 2020-07-31T23:08:20.376Z|04302|hmap|DBG|northd/ovn-northd.c:595: 2 buckets
> with 6+ nodes, including 2 buckets with 6 nodes (256 nodes total across 256
> buckets)
> 2020-07-31T23:08:21.222Z|04303|poll_loop|DBG|wakeup due to [POLLIN] on fd
> 8 (10.6.20.84:44358<->10.6.20.84:6641) at lib/stream-fd.c:157 (41% CPU
> usage)
> 2020-07-31T23:08:21.223Z|04304|jsonrpc|DBG|tcp:10.6.20.84:6641: received
> reply, result=[], id="echo"
> 2020-07-31T23:08:22.779Z|04305|poll_loop|DBG|wakeup due to 706-ms timeout
> at lib/reconnect.c:643 (41% CPU usage)
> 2020-07-31T23:08:22.779Z|04306|reconnect|DBG|tcp:10.6.20.85:6642: idle
> 5001 ms, sending inactivity probe
> 2020-07-31T23:08:22.779Z|04307|reconnect|DBG|tcp:10.6.20.85:6642:
> entering IDLE
> 2020-07-31T23:08:22.779Z|04308|jsonrpc|DBG|tcp:10.6.20.85:6642: send
> request, method="echo", params=[], id="echo"
> 2020-07-31T23:08:23.632Z|04309|poll_loop|DBG|wakeup due to [POLLIN] on fd
> 9 (10.6.20.84:49158<->10.6.20.85:6642) at lib/stream-fd.c:157 (79% CPU
> usage)
> 2020-07-31T23:08:23.632Z|04310|jsonrpc|DBG|tcp:10.6.20.85:6642: received
> request, method="echo", params=[], id="echo"
> 2020-07-31T23:08:23.632Z|04311|reconnect|DBG|tcp:10.6.20.85:6642:
> entering ACTIVE
> 2020-07-31T23:08:23.632Z|04312|jsonrpc|DBG|tcp:10.6.20.85:6642: send
> reply, result=[], id="echo"
> 2020-07-31T23:08:24.481Z|04313|poll_loop|DBG|wakeup due to 0-ms timeout at
> tcp:10.6.20.85:6642 (79% CPU usage)
> 2020-07-31T23:08:24.481Z|04314|jsonrpc|DBG|tcp:10.6.20.85:6642: received
> reply, result=[], id="echo"
> 2020-07-31T23:08:25.372Z|04315|poll_loop|DBG|wakeup due to [POLLIN] on fd
> 8 (10.6.20.84:44358<->10.6.20.84:6641) at lib/stream-fd.c:157 (79% CPU
> usage)
> 2020-07-31T23:08:25.372Z|04316|jsonrpc|DBG|tcp:10.6.20.84:6641: received
> request, method="echo", params=[], id="echo"
> 2020-07-31T23:08:25.372Z|04317|jsonrpc|DBG|tcp:10.6.20.84:6641: send
> reply, result=[], id="echo"
> 2020-07-31T23:08:28.634Z|04318|poll_loop|DBG|wakeup due to [POLLIN] on fd
> 9 (10.6.20.84:49158<->10.6.20.85:6642) at lib/stream-fd.c:157 (50% CPU
> usage)
> 2020-07-31T23:08:28.634Z|04319|reconnect|DBG|tcp:10.6.20.85:6642: idle
> 5002 ms, sending inactivity probe
> 2020-07-31T23:08:28.634Z|04320|reconnect|DBG|tcp:10.6.20.85:6642:
> entering IDLE
> 2020-07-31T23:08:28.634Z|04321|jsonrpc|DBG|tcp:10.6.20.85:6642: send
> request, method="echo", params=[], id="echo"
> 2020-07-31T23:08:28.634Z|04322|jsonrpc|DBG|tcp:10.6.20.85:6642: received
> request, method="echo", params=[], id="echo"
> 2020-07-31T23:08:28.634Z|04323|reconnect|DBG|tcp:10.6.20.85:6642:
> entering ACTIVE
> 2020-07-31T23:08:28.634Z|04324|jsonrpc|DBG|tcp:10.6.20.85:6642: send
> reply, result=[], id="echo"
> 2020-07-31T23:08:28.638Z|04325|hmap|DBG|Dropped 266 log messages in last 9
> seconds (most recently, 3 seconds ago) due to excessive rate
> 2020-07-31T23:08:28.638Z|04326|hmap|DBG|northd/ovn-northd.c:595: 2 buckets
> with 6+ nodes, including 2 buckets with 6 nodes (256 nodes total across 256
> buckets)
> ========
>
> Thanks!
>
> Tony
>
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