DVR process flow not installed on physical bridge for shared tenant network
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
Ubuntu Cloud Archive |
Fix Released
|
Critical
|
Unassigned | ||
Pike |
Invalid
|
Undecided
|
Unassigned | ||
Queens |
Fix Released
|
Critical
|
Unassigned | ||
Rocky |
Fix Released
|
Critical
|
Unassigned | ||
neutron |
Fix Released
|
Critical
|
Swaminathan Vasudevan | ||
neutron (Ubuntu) |
Fix Released
|
Critical
|
Unassigned | ||
Bionic |
Fix Released
|
Critical
|
Unassigned | ||
Cosmic |
Fix Released
|
Critical
|
Unassigned |
Bug Description
Seems like collateral from https:/
In DVR, the distributed gateway port's IP and MAC are shared in the qrouter across all hosts.
The dvr_process_flow on the physical bridge (which replaces the shared router_distributed MAC address with the unique per-host MAC when its the source), is missing, and so is the drop rule which instructs the bridge to drop all traffic destined for the shared distributed MAC.
Because of this, we are seeing the router MAC on the network infrastructure, causing it on flap on br-int on every compute host:
root@milhouse:~# ovs-appctl fdb/show br-int | grep fa:16:3e:42:a2:ec
11 4 fa:16:3e:42:a2:ec 1
root@milhouse:~# ovs-appctl fdb/show br-int | grep fa:16:3e:42:a2:ec
11 4 fa:16:3e:42:a2:ec 2
root@milhouse:~# ovs-appctl fdb/show br-int | grep fa:16:3e:42:a2:ec
1 4 fa:16:3e:42:a2:ec 0
root@milhouse:~# ovs-appctl fdb/show br-int | grep fa:16:3e:42:a2:ec
11 4 fa:16:3e:42:a2:ec 0
root@milhouse:~# ovs-appctl fdb/show br-int | grep fa:16:3e:42:a2:ec
11 4 fa:16:3e:42:a2:ec 0
root@milhouse:~# ovs-appctl fdb/show br-int | grep fa:16:3e:42:a2:ec
1 4 fa:16:3e:42:a2:ec 0
root@milhouse:~# ovs-appctl fdb/show br-int | grep fa:16:3e:42:a2:ec
1 4 fa:16:3e:42:a2:ec 0
root@milhouse:~# ovs-appctl fdb/show br-int | grep fa:16:3e:42:a2:ec
1 4 fa:16:3e:42:a2:ec 0
root@milhouse:~# ovs-appctl fdb/show br-int | grep fa:16:3e:42:a2:ec
1 4 fa:16:3e:42:a2:ec 1
root@milhouse:~# ovs-appctl fdb/show br-int | grep fa:16:3e:42:a2:ec
11 4 fa:16:3e:42:a2:ec 0
root@milhouse:~# ovs-appctl fdb/show br-int | grep fa:16:3e:42:a2:ec
11 4 fa:16:3e:42:a2:ec 0
root@milhouse:~# ovs-appctl fdb/show br-int | grep fa:16:3e:42:a2:ec
11 4 fa:16:3e:42:a2:ec 0
Where port 1 is phy-br-vlan, connecting to the physical bridge, and port 11 is the correct local qr-interface. Because these dvr flows are missing on br-vlan, pkts w/ source mac ingress into the host and br-int learns it upstream.
The symptom is when pinging a VM's floating IP, we see occasional packet loss (10-30%), and sometimes the responses are sent upstream by br-int instead of the qrouter, so the ICMP replies come with fixed IP of the replier since no NAT'ing took place, and on the tenant network rather than external network.
When I force net_shared_only to False here, the problem goes away: https:/
It should we noted we *ONLY* need to do this on our dvr_snat host. The dvr process's are missing on every compute host. But if we shut qrouter on the snat host, FIP functionality works and DVR mac stops flapping on others. Or if we apply fix only to snat host, it works. Perhaps there is something on SNAT node that is unique
Ubuntu SRU details:
-------------------
[Impact]
See above
[Test Case]
Deploy OpenStack with dvr enabled and then follow the steps above.
[Regression Potential]
The patches that are backported have already landed upstream in the corresponding stable branches, helping to minimize any regression potential.
Changed in neutron: | |
assignee: | nobody → Arjun Baindur (abaindur) |
Changed in neutron: | |
assignee: | Arjun Baindur (abaindur) → Swaminathan Vasudevan (swaminathan-vasudevan) |
status: | Confirmed → In Progress |
tags: | added: neutron-proactive-backport-potential |
Changed in neutron (Ubuntu Bionic): | |
status: | New → Triaged |
Changed in neutron (Ubuntu Cosmic): | |
importance: | Undecided → High |
Changed in neutron (Ubuntu Bionic): | |
importance: | Undecided → High |
Changed in neutron (Ubuntu Cosmic): | |
status: | New → Triaged |
Changed in neutron (Ubuntu Cosmic): | |
importance: | High → Critical |
Changed in neutron (Ubuntu Bionic): | |
importance: | High → Critical |
description: | updated |
I noticed the log says tunnel bridge. Was this not intended to ever happen for VLAN/physical bridges?
if net_shared_only:
LOG. debug(" Not applying DVR rules to tunnel bridge because %s "
"is a shared network", subnet_ info.get( 'network_ id'))
https:/ /github. com/openstack/ neutron/ blob/stable/ pike/neutron/ plugins/ ml2/drivers/ openvswitch/ agent/ovs_ dvr_neutron_ agent.py# L436