Switch disk_config extension to use one DB query

A response through this extension can have many servers and making one
query per server can slow down response time dramatically. This change
switches the extension to use one DB query instead of many queries.
It also avoids queries when the key is already populated, such as when
the results include responses from a remote zone.

This change reduces a 'nova list' of 21 servers from 14 seconds to 1
second on my (relatively slow) development system.

Change-Id: I8476dbca0f87ff2a3d69bd7b8f51c296e41e3388

0 files changed, 0 insertions, 0 deletions