Thanks Austin.
Seems the issue is connectivity to rabbitmq though nothing altered manually.
2021-06-18T04:37:58.675414124Z
 stdout F 2021-06-18 04:37:58.672 1 INFO nova.scheduler.manager 
[req-25ec038c-661d-41fa-ac07-57a2eeb2fd6c 
d9f7048c1cd947cfa8ecef128a6cee89 e8813293073545f99658adbec2f80c1d - 
default default] Got no allocation candidates from the Placement API. 
This could be due to insufficient resources or a temporary occurrence as
 compute nodes start up.
2021-06-18T04:37:58.67589708Z stdout F 
2021-06-18 04:37:58.672 1 INFO nova.scheduler.manager 
[req-25ec038c-661d-41fa-ac07-57a2eeb2fd6c 
d9f7048c1cd947cfa8ecef128a6cee89 e8813293073545f99658adbec2f80c1d - 
default default] Got no allocation candidates from the Placement API. 
This could be due to insufficient resources or a temporary occurrence as
 compute nodes start up.
2021-06-18T04:37:59.291144415Z
 stdout F 2021-06-18 04:37:59.289 1 WARNING nova.scheduler.utils 
[req-25ec038c-661d-41fa-ac07-57a2eeb2fd6c 
d9f7048c1cd947cfa8ecef128a6cee89 e8813293073545f99658adbec2f80c1d - 
default default] [instance: 3dbd2298-acf5-4123-a6e5-608113b0dbb7] 
Setting instance to ERROR state.: 
nova.exception_Remote.NoValidHost_Remote: No valid host was found. 
2021-06-18T04:37:59.533353963Z
 stdout F 2021-06-18 04:37:59.532 1 ERROR 
oslo.messaging._drivers.impl_rabbit 
[req-25ec038c-661d-41fa-ac07-57a2eeb2fd6c 
d9f7048c1cd947cfa8ecef128a6cee89 e8813293073545f99658adbec2f80c1d - 
default default] Connection failed: failed to resolve broker hostname 
(retrying in 0 seconds): OSError: failed to resolve broker hostname
controller-0:/var/log/pods$ sudo rabbitmqctl cluster_status
Password: 
Cluster status of node rabbit@localhost ...
[{nodes,[{disc,[rabbit@localhost]}]},
 {running_nodes,[rabbit@localhost]},
 {cluster_name,<<"rabbit@controller-0">>},
 {partitions,[]},
 {alarms,[{rabbit@localhost,[]}]}]