Flow duration is reset upon resetting manager on switch

This is to track the following behaviour (observed as recently as tcp:192.168.56.101:6640):

setup:

• Feature odl-ovsdb-openstack is installed.
• ovsdb.l3.fwd.enabled=yes

Flow durations are now “reset” when the switch is reconnected by resetting the manager on the switch:

E.g.
root@mininet-vm:/root/openvswitch-2.5.0# ovs-vsctl show
708f2ebf-3168-4e0c-8138-cdccb7f1c4e8
Manager "tcp:192.168.56.101:6640"
is_connected: true
Bridge br-ex
Controller "tcp:192.168.56.101:6653"
is_connected: true
fail_mode: secure
Port br-ex
Interface br-ex
type: internal
Bridge br-int
Controller "tcp:192.168.56.101:6653"
is_connected: true
fail_mode: secure
Port br-int
Interface br-int
type: internal
ovs_version: "2.5.0"
root@mininet-vm:/root/openvswitch-2.5.0# ovs-vsctl del-manager
root@mininet-vm:/root/openvswitch-2.5.0# ovs-ofctl dump-flows -O Openflow13 br-ex
OFPST_FLOW reply (OF1.3) (xid=0x2):
cookie=0x0, duration=1743.438s, table=0, n_packets=0, n_bytes=0, dl_type=0x88cc actions=CONTROLLER:65535
cookie=0x0, duration=1743.438s, table=0, n_packets=0, n_bytes=0, priority=0 actions=NORMAL
root@mininet-vm:/root/openvswitch-2.5.0# ovs-vsctl set-manager "tcp:192.168.56.101:6640"
root@mininet-vm:/root/openvswitch-2.5.0# ovs-ofctl dump-flows -O Openflow13 br-ex
OFPST_FLOW reply (OF1.3) (xid=0x2):
cookie=0x0, duration=14.952s, table=0, n_packets=0, n_bytes=0, dl_type=0x88cc actions=CONTROLLER:65535
cookie=0x0, duration=14.939s, table=0, n_packets=0, n_bytes=0, priority=0 actions=NORMAL