Reproduced the same tests in 1.5. All issues are solved. Setup is returning conistent results. 

Moving this to TODO until we can pick up BS 1.34.0

How was this tested?

• Installed an RHDH instance with RBAC enabled, Keycloak authentication, users ingestion, a few catalog resources registered and Redis Cache enabled.
  Scaled the deployments to 3 pods.
  Changed the Openshift route traffic policy to round-robin (the scenario needed to be forced, ensuring that all pods would receive incoming requests).
  Added a static token to the app-config to perform API call in an automated way.
• Sent batches of 10, 30, 50, 100 REST API calls to add a new location with a random GUID as User-Agent header.
  Verified the pods logs to ensure all the pods were responding to those requests.
  Observed behaviour was: pods replied with a '201 Created' status code only once, 500 and 409 Conflict for all the other requests; meaning the backstage backend is correctly handling the conflicts.
• Performed a batch of 50 requests to get the Location just created, all pods responded with the correct resource; meaning all pods are acting in sync.
• Edited the Opensihft service to serve traffic from one pod at a time (by changing the label selectors): created a new location again, UI is showing consistent results across all pods.
• Performed step 1-2-3-4 again, but creating a RBAC Role instead. The results were not consistent and the pods were not aligned.
  When creating the Role via UI, only the pod that actually created the resource was serving it after. The other pods didn’t show the new role.
  When creating the role via REST API, only the pod that actually created the role would return it afterwards; the other pods would return a 404 error.

The RBAC sync behaviour should have been fixed with this PR (https://github.com/janus-idp/backstage-plugins/pull/1757), but seems like it’s not working with RHDH 1.3.1. Opened a bug to track it: https://issues.redhat.com/browse/RHIDP-4734 
As already commented by Kim, DB failover is out of scope for automated testing since it may be difficult to achieve and performance testing is already covered.
Cache tests have already covered by https://github.com/janus-idp/backstage-showcase/pull/1480

As discussed in our office hours today, DB failover is out of scope for automated testing since it may be difficult to achieve.   We can consider it for manual testing in the future but we'll consider it a lower priority for now

As far as perf testing is concerned, they should have been covered as part of https://issues.redhat.com/browse/RHIDP-641