[ovs-discuss] Primary controllers reconnection clear flow table

[sparveriusae at gmail.com]

On 3/12/2013 1:57 AM, Ben Pfaff wrote:
> On Mon, Mar 11, 2013 at 12:17:52PM +0800, sparveriusae at gmail.com wrote:
>> I was trying to set up multiple controllers in OVS. According to the
>> ovs-vswitchd.conf.db document, if I add another primary controller to
>> supplement an existing primary controller, or removing only one of the
>> two primary controllers, it should have no effect on the flow table.
>> However, it seems that whenever I terminate one of the two connections
>> between OVS and my two controllers and reconnect again, the flow table
>> would always be cleared. Is there any way to prevent this from happening?
> 
> Either you are encountering a bug, or you do not understand how to
> change the controllers without clearing the flow table.  The latter
> seems more likely.  How are you changing the controllers?
> 
Hi Ben,

Thanks for the reply, my scenario looks like this.

[1] Use "ovs-vsctl" to set OVS fail-mode to secure mode.

[2] Controller A connects to OVS.

[3] Controller B connects to OVS.

[4] Controller A sends a OFP_FLOW_MOD packet to OVS to insert a flow
entry on the flow table, also verified with "ovs-ofctl dump-flows".
e.g. ( cookie=0x0, duration=1.169s, table=0, n_packets=0, n_bytes=0,
in_port=1 actions=output:2 )

[5] Controller A disconnects from OVS. The flow entry still remains on
the flow table.

[6] Controller A connects again to OVS. This time all the flow entries
are cleared from the flow table. The same scenario also occurs when
disconnecting and reconnecting Controller B instead. (For reference,
both controllers are POX)