neutron/neutron/plugins/ml2/drivers/l2pop
LIU Yulong 62fe7852bb More accurate agent restart state transfer
Ovs-agent can be very time-consuming in handling a large number
of ports. At this point, the ovs-agent status report may have
exceeded the set timeout value. Some flows updating operations
will not be triggerred. This results in flows loss during agent
restart, especially for hosts to hosts of vxlan tunnel flow.

This fix will let the ovs-agent explicitly, in the first rpc loop,
indicate that the status is restarted. Then l2pop will be required
to update fdb entries.

Conflicts:
	neutron/plugins/ml2/rpc.py

Conflicts:
	neutron/plugins/ml2/drivers/l2pop/mech_driver.py

Closes-Bug: #1813703
Closes-Bug: #1813714
Closes-Bug: #1813715
Closes-Bug: #1794991
Closes-Bug: #1799178

Change-Id: I8edc2deb509216add1fb21e1893f1c17dda80961
(cherry picked from commit a5244d6d44)
(cherry picked from commit cc49ab5501)
(cherry picked from commit 5ffca49668)
2019-03-29 22:12:00 +08:00
..
rpc_manager Removed deprecated class LocalVLANMapping 2016-11-07 20:24:06 +00:00
README Implement local ARP responder onto OVS agent 2014-05-19 21:42:11 +02:00
__init__.py Empty files should not contain copyright or license 2014-10-20 00:50:32 +00:00
db.py Use subqueryload in l2pop DB for binding ports 2017-06-30 02:17:38 -07:00
mech_driver.py More accurate agent restart state transfer 2019-03-29 22:12:00 +08:00
rpc.py Get rid of marshall_fdb_entries 2016-02-03 00:16:45 -08:00

README

Neutron ML2 l2 population Mechanism Drivers

l2 population (l2pop) mechanism drivers implements the ML2 driver to improve
open source plugins overlay implementations (VXLAN with Linux bridge and
GRE/VXLAN with OVS). This mechanism driver is implemented in ML2 to propagate
the forwarding information among agents using a common RPC API.

More informations could be found on the wiki page [1].

VXLAN Linux kernel:
-------------------
The VXLAN Linux kernel module provide all necessary functionalities to populate
the forwarding table and local ARP responder tables. This module appears on
release 3.7 of the vanilla Linux kernel in experimental:
- 3.8: first stable release, no edge replication (multicast necessary),
- 3.9: edge replication only for the broadcasted packets,
- 3.11: edge replication for broadcast, multicast and unknown packets.

Note: Some distributions (like RHEL) have backported this module on precedent
      kernel version.

OpenvSwitch:
------------
The OVS OpenFlow tables provide all of the necessary functionality to populate
the forwarding table and local ARP responder tables.
A wiki page describe how the flow tables did evolve on OVS agents:
- [2] without local ARP responder
- [3] with local ARP responder. /!\ This functionality is only available since
                                    the development branch 2.1. It's possible
                                    to disable (enable by default) it through
                                    the flag 'arp_responder'. /!\


Note: A difference persists between the LB and OVS agents when they are used
      with the l2-pop mechanism driver (and local ARP responder available). The
      LB agent will drop unknown unicast (VXLAN bridge mode), whereas the OVS
      agent will flood it.

[1] https://wiki.openstack.org/wiki/L2population_blueprint
[2] https://wiki.openstack.org/wiki/Ovs-flow-logic#OVS_flows_logic
[3] https://wiki.openstack.org/wiki/Ovs-flow-logic#OVS_flows_logic_with_local_ARP_responder