The /os-hypervisors/detail API endpoint was experiencing significant
performance issues in environments with many compute nodes when using
microversion 2.88 or higher, as it made sequential RPC calls to gather
uptime information from each compute node.
This change optimizes uptime retrieval by:
* Adding uptime to periodic resource updates sent by nova-compute to the
database, eliminating synchronous RPC calls during API requests
* Restricting RPC-based uptime retrieval to hypervisor types that support
it (libvirt and z/VM), avoiding unnecessary calls that would always fail
* Preferring cached database uptime data over RPC calls when available
Closes-Bug: #2122036
Assisted-By: Claude <noreply@anthropic.com>
Change-Id: I5723320f578192f7e0beead7d5df5d7e47d54d2b
Co-Authored-By: Sylvain Bauza <sbauza@redhat.com>
Signed-off-by: Sean Mooney <work@seanmooney.info>
567dbe1867