[ovs-dev] Query with respect to OVSDB and vswitchd

RishiRaj Maulick rishi.raj2509 at gmail.com
Mon Aug 31 03:40:19 UTC 2015

Hi ,

I have been very recently using the OVSDB for one of our projects . I am
able to create my own schema and operate on it . However to better
understand things , I was also looking at the behavior of vswitchd on the
default schema.

I am confused with the events of things that happened -

1) I am monitoring the "Bridge" table through ovsdb-client
2) Using ovs-vsctl , whenever I add a bridge ( say br0 ) , on the monitor
console I see that there are 2 activities - one of which is the initial
"insert" and the next is an update for the "datapath id " that gets
allocated by the vswitchd.
This is understandable. In the update the _version field and the datapath
id field gets mutated to new values.
3) However, if I add a second bridge ( say br1 ) , in the monitor console ,
apart from the above operations pertaining to the new bridge being added (
br1 ) , I am also seeing that the entry for the previously added bridge br0
also gets mutated and the only change is the _version field.

My understanding of the  _uuid and _version fields is that these are
maintained by the DB for internal purposes and the ovsdb-client cannot
mutate these.

So I wanted to understand , why ( or what is the need ) the change of
*_version* for all of the existing bridges are required , whenever we are
adding a new bridge.

Thanks and regards,
Rishi Raj

More information about the dev mailing list