Open Stack

Hi,

A quick query if anyone is using the neutron metering agent to measure
traffic in/out of routers:

When adding the metering label and rules, on some, but not all, of our
routers, I get a traceback in the metering_agent.log pointing at 
"TRACE neutron.openstack.common.rpc.amqp TypeError: cannot concatenate
'str' and 'NoneType' objects".

After that error, the router no longer passes traffic other than ping
until we stop the metering agent, and restart the L3 agent.

This doesn't seem to affect routers with only one subnet, and only one
router in the tenant - but I may be completely misunderstanding the
whole thing here.  It appears as soon as we get a router with more than
one network (plus gateway) we get trouble.

We're using Havana on Trusty, and the current Cloud Archive packages.

The rules are a simple egress and ingress, 0.0.0.0/0, both on the same
meter-label.

Anyone had similar experiences, or got tips for diagnosing this?

I will be reading the code over the next few days :)