At present, there are various interfaces through which services data
can be manipulated - admin interface(nova-manage), extensions
(contrib/services.py), etc. Every interface relies on the servicegroup
layer API is_up() to get details about service live-ness. The proposal
is keep service data in nova database nova.services table and fetch
the live-ness information from the configured servicegroup(SG) driver.
Liveness will be a combination of service live-ness and RPC live-ness,
where the later will be computed based on information in nova.services.
Previously-approved: liberty
Implements: blueprint servicegroup-api-control-plane
Change-Id: I3cae9495373c4334fedb18b64d907f3a6ac5ab92
0090754ebf