[ovs-discuss] Scaling ovsdb-idl's update notification

Ben Pfaff blp at nicira.com
Sun Aug 2 19:06:36 UTC 2015

On Fri, Jul 31, 2015 at 08:03:41PM +0000, Ansari, Shad wrote:
> Ovsdb-idl notifies a client that "something" changed; it does not track "what" changed. The client then typically either reconfigures itself by scanning the idl to determine what changed, or - simply reloads the entire idl. This presumably works since the ovs schema tables aren't typically large.
> In a use-case where ovsdb is used with a schema that can have very large tables (imagine route table), the current ovsdb-idl notification mechanism doesn't appear to scale - clients need to do a lot of processing to determine the exact change delta.
> I would like to hear from others if they have any views/insights on how to handle this scalability use-case. Obviously, this will require changes in ovsdb-idl, possibly on the lines of:
> -        Supporting more granular sequence numbers (table, row, column)
> -        Giving client visibility to the update (so that the client can view both the old, new data)

I'm welcome to discussion and proposals in this area.  I've expected for
years that we'd eventually need something like this for ovs-vswitchd
(although so far it isn't a big deal), and the same could be true for
ovn-controller as OVN begins to scale.

More information about the discuss mailing list