Comment 10 for bug 1194026

I think I found the possible cause of issue.

see
http://paste.openstack.org/show/40156/

line starts from **** Get is RPC message log.
line starts from [[[[[ Process is when l3-agent start processing rpc messages.
(I added rpc message number for debugging)

so we expected all RPC call is executed serialized way.
However it is executed in random order!

We are using semaphore in eventlet, but it looks we should use queue instead of queue.
We should also combine RPC messages.
Because when we get concurrent request, l3-agent processes one by one.
so sometimes, the process for the new ip will be delayed long time.