RowNotFound: Cannot find Bridge with name=tbr-XXXXXXXX-X when using trunk bridges with DPDK vhostusermode
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
neutron |
Fix Released
|
High
|
Nate Johnston |
Bug Description
DPDK vhostuser mode (DPDK/vhu) means that when an instance is powered
off the port is deleted, and when an instance is powered on a port is
created. This means a reboot is functionally a super fast
delete-then-create. Neutron trunking mode in combination with DPDK/vhu
implements a trunk bridge for each tenant, and the ports for the
instances are created as subports of that bridge. The standard way a
trunk bridge works is that when all the subports are deleted, a thread
is spawned to delete the trunk bridge, because that is an expensive and
time-consuming operation. That means that if the port in question is
the only port on the trunk on that compute node, this happens:
1. The port is deleted
2. A thread is spawned to delete the trunk
3. The port is recreated
If the trunk is deleted after #3 happens then the instance has no
networking and is inaccessible; this is the scenario that was dealt with
in a previous change [1]. But there continue to be issues with errors
"RowNotFound: Cannot find Bridge with name=tbr-
2020-03-02 10:37:45.929 6278 ERROR ovsdbapp.
2020-03-02 10:37:45.929 6278 ERROR ovsdbapp.
2020-03-02 10:37:45.929 6278 ERROR ovsdbapp.
2020-03-02 10:37:45.929 6278 ERROR ovsdbapp.
2020-03-02 10:37:45.929 6278 ERROR ovsdbapp.
2020-03-02 10:37:45.929 6278 ERROR ovsdbapp.
2020-03-02 10:37:45.929 6278 ERROR ovsdbapp.
2020-03-02 10:37:45.929 6278 ERROR ovsdbapp.
2020-03-02 10:37:45.929 6278 ERROR ovsdbapp.
2020-03-02 10:37:45.929 6278 ERROR ovsdbapp.
2020-03-02 10:37:45.932 6278 ERROR neutron.
What I believe is happening in this case is that the trunk is being
deleted in the middle of the execution of #3, so that it stops
existing in the middle of the port creation logic but before the
port is actually recreated.
This issue was observed in setups running Queens.
tags: | added: trunk |
Changed in neutron: | |
status: | New → In Progress |
importance: | Undecided → High |
tags: | added: neutron-proactive-backport-potential |
Where I think [1] is https:/ /review. opendev. org/#/q/ I70b9c26990e690 2f8888449bfd748 3c25e5bff46