Comment 0 for bug 1899536

On a non-ha juju controller, with just the default model, but managing machines with lots of network devices (openstack neutron) being created or deleted, upgrading to 2.8.3 ended up with a very slow controller, which errors when just trying to get a juju status on the default model:

ERROR could not fetch IP addresses and link layer devices: cannot get all link layer devices

https://pastebin.canonical.com/p/hXkDM32dTn/

The linklayerdevices collection:
   From `db.linklayerdevices.find().explain("executionStats")`:
     "totalDocsExamined" : 795837
   is suspicious.

These are all the qvb*, tap*, qvo*, qbr* interfaces.

We started investigating with manadart (to whom I proveided a dump) and achilleasa. This bug is to capture further investigations.