ovn: Update BFD item in the ovn TODO list.

Update the BFD todo item to clarify where we might use BFD as it
previously seemed to imply we wanted to enable it for all
hypervisor-to-hypervisor tunnels.

Signed-off-by: Russell Bryant <russell@ovn.org>
Acked-By: Kyle Mestery <mestery@mestery.com
Acked-by: Ben Pfaff <blp@ovn.org>

diff --git a/ovn/TODO b/ovn/TODO
index 1f2a73f..a827421 100644 (file)
--- a/ovn/TODO
+++ b/ovn/TODO
@@ -306,11 +306,18 @@ think it does everything else.
    the Multicast_Group table entry in ovn-sb database into
    Mcast_Macs_Remote table configuration in VTEP database.
 
-* Use BFD as tunnel monitor.
+* Consider the use of BFD as tunnel monitor.
 
-   Both ovn-controller and ovn-contorller-vtep should use BFD to
-   monitor the tunnel liveness.  Both ovs-vswitchd schema and
-   VTEP schema supports BFD.
+  The use of BFD for hypervisor-to-hypervisor tunnels is probably not worth it,
+  since there's no alternative to switch to if a tunnel goes down.  It could
+  make sense at a slow rate if someone does OVN monitoring system integration,
+  but not otherwise.
+
+  When OVN gets to supporting HA for gateways (see ovn/OVN-GW-HA.md), BFD is
+  likely needed as a part of that solution.
+
+  There's more commentary in this ML post:
+  http://openvswitch.org/pipermail/dev/2015-November/062385.html
 
 * ACL