[ovs-discuss] OVS disconnecting from controller when under heavy load.

[Ben Pfaff]

Perhaps the traffic on your network is high enough that it is delaying
the echo request or reply enough to cause the connection to be
dropped, or perhaps NOX is too busy to reply to the request promptly.

You can always increase the timeout interval to whatever works best
for you, or disable the feature entirely.

On Thu, Mar 15, 2012 at 10:55:35PM +0500, junaid khalid wrote:
> I was running OVS (ovs-1.1.2 in kernel mode, on a core i7 machine with 4GB
> of RAM) under several Gbps of load. I noticed some unexpected behavior; OVS
> would disconnect from Controller (NOX 0.9 zaku) under heavy load conditions
> and re-establish the connection when the load was reduced (the behavior did
> not have a particular pattern but seemed to become rare for under 2Gbps).
> The reason for the disconnection was a lack of echo-request/reply packets
> being exchanged between the controller and ovs.
> Each time the experiment was run, ovs had about 10k flows in its flow table
> (added pro-actively) and the controller was not being invoked for packet-in
> events (all the relevant flows had already been written). I was unable to
> find any relevant posts on the mailing lists regarding similar issue
> (controller disconnecting when ovs is under gigabits per second of
> traffic). I have no idea what could be causing this behavior, and hope that
> someone can enlighten me.
> 
> Regards,
> junaid

> _______________________________________________
> discuss mailing list
> discuss at openvswitch.org
> http://openvswitch.org/mailman/listinfo/discuss