[ovs-git] [openvswitch/ovs] a5837e: ovn-controller: Fix chassisredirect port flapping ...

[numansiddique]

  Branch: refs/heads/branch-2.11
  Home:   https://github.com/openvswitch/ovs
  Commit: a5837eacaa6677e7556632452da646f3f5b0709b
      https://github.com/openvswitch/ovs/commit/a5837eacaa6677e7556632452da646f3f5b0709b
  Author: Numan Siddique <nusiddiq at redhat.com>
  Date:   2019-02-04 (Mon, 04 Feb 2019)

  Changed paths:
    M ovn/controller/ofctrl.c
    M ovn/controller/ofctrl.h
    M ovn/controller/ovn-controller.c
    M tests/ovn.at

  Log Message:
  -----------
  ovn-controller: Fix chassisredirect port flapping when ovs-vswitchd crashes

On a chassis when ovs-vswitchd crashes for some reason, the BFD status doesn't
get updated in the ovs db. ovn-controller will be reading the old BFD status
even though ovs-vswitchd is crashed. This results in the chassiredirect port
claim flapping between the master chassis and the chasiss with the next higher
priority if ovs-vswitchd crashes in the master chassis.

All the other chassis notices the BFD status down with the master chassis
and hence the next higher priority claims the port. But according to
the master chassis, the BFD status is fine and it again claims back the
chassisredirect port. And this results in flapping. The issue gets resolved
when ovs-vswitchd comes back but until then it leads to lot of SB DB
transactions and high CPU usage in ovn-controller's.

This patch fixes the issue by checking the OF connection status of the
ovn-controller with ovs-vswitchd and calculates the active bfd tunnels
only if it's connected.

Signed-off-by: Numan Siddique <nusiddiq at redhat.com>
Acked-by: Mark Michelson <mmichels at redhat.com>
Signed-off-by: Ben Pfaff <blp at ovn.org>