Neutron SFC port chain delete fails

[Deepak S]

I'm experimenting with Neutron SFC. The chain creation happens successfully whereas the chain deletion doesn't succeed always. For the first couple of times, I was able to delete the chains successfully however once it fails, it mostly never succeeds again.
When it failed for the first time, I had to manually delete the port chain entry from DB. Even though the successive chain creations happen successfully, the deletion continuously fails. Once I remove the port chain entry from DB, other things like flow classifier, port pairs, port pair groups can be removed through CLI.

Environment: Multi-node devstack with 1 controller and 2 computes where VMs are launched in the same compute.
OS: Ubuntu 16.04
Kernel: 4.4.0-59-generic
OVS: 2.6.1
Devstack and SFC: Newton
All my neutron agents are alive.

Steps to create chain
    openstack network create net11
    openstack subnet create --subnet-range 11.0.0.0/24 --network net11 sub11
    openstack network create net12
    openstack subnet create --subnet-range 12.0.0.0/24 --network net12 sub12

    openstack router create sfc-router
    openstack router add subnet sfc-router sub11
    openstack router add subnet sfc-router sub12

    openstack port create --network net11 p1
    openstack port create --network net12 p2
    openstack server create --nic port-id=p1 --nic port-id=p2 --flavor 3 --image vyos sf-vm

    sleep 5
    openstack port pair create --ingress p1 --egress p2 pp1
    openstack port pair group create --port-pair pp1 ppg1

    openstack flow classifier create --source-ip-prefix 11.0.0.0/24 --destination-ip-prefix\
     12.0.0.0/24 --source-port 1:65535 --destination-port 80:80 --protocol TCP \
     --logical-source-port $(neutron port-list | grep \"11.0.0.1\" | awk '{print $2}') fc1

    openstack port chain create --port-pair-group ppg1 --flow-classifier fc1 pc1

Steps to delete chain
    openstack server delete sf-vm

    openstack port chain delete pc1
    openstack flow classifier delete fc1
    openstack port pair group delete ppg1
    openstack port pair delete pp1
    openstack port delete p1
    openstack port delete p2

    openstack router remove subnet sfc-router sub11
    openstack router remove subnet sfc-router sub12
    openstack subnet delete sub11
    openstack subnet delete sub12
    openstack router delete sfc-router
    openstack network delete net11
    openstack network delete net12

Expected Output
    Successful completion of step "openstack port chain delete pc1" and other obvious success messages.

Actual Output
    delete_port_chain failed.
    Neutron server returns request_ids: ['req-eea26895-dcf5-4c31-a858-4da5ffe40b14']

This is a blocker for me.

Neutron Log: http://paste.openstack.org/show/597125/
Controller OVS agent LOG: http://paste.openstack.org/show/597126/
Compute OVS agent LOG: http://paste.openstack.org/show/597127/

[vks1 (vikash-kumar)]

Looks like bug need to be in [networking-sfc]. In any case, if the server is deleted after port-chain, there should not be any issue. But this also needs to get handled.

[cheng (tangch318)]

It can't reproduce on recently master branch.