Comment 3 for bug 1342313

The issue is reproducible when project (tenant) contains more than 170 networks and all these networks plugged into a single router.

Steps to reproduce on devstack:
 * create networks and subnets inside tenant, plug them into the router:
for i in $(seq 1 170);
do
  neutron net-create "skynet_$i"
  neutron subnet-create --name "skysubnet_$i" "skynet_$i" "13.0.$i.0/24"
  neutron router-interface-add router1 "skysubnet_$i"
done
 * launch VM and plug into any network
 * from VM's VNC console do curl http://169.254.169.254/latest/meta-data/instance-id

Observed behavior:
 * the request fails with HTTP 500 error
 * stacktrace in logs of neutron metadata agent (q-meta screen):
    RequestURITooLong: An unknown exception occurred.