The forward upgrade to 26.7.3 was zero downtime across 87 samples, and since databasechangelog stayed at 210 the rollback to 26.7.0 also succeeded, which narrows D-2's conclusion: rolling back fails when the schema moved, not because of the version number. The row count is the check.
Role changes never reach the upstream through request repetition; the session is a snapshot taken at login and only a new session picks up the new claim. Auditing the docs also surfaced that Prometheus scrapes only keycloak, kubelet, node-exporter and itself, so the B-layer experiments have no metrics to screenshot rather than missing screenshots.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Dropping the schema left Keycloak serving realm metadata and JWKS from its Infinispan cache, so the front door stayed at 200 while only the paths that read the database failed. That is a different shape from A-2, where the connection itself broke and readiness pulled the pods out of the Service; here the connection is fine and the tables are simply gone, which the health check does not notice.
Restoring the pg_dump took one second with zero errors and no pod restart, and the row counts matched the backup exactly, sessions included. The real RPO is the backup interval plus the synchronous_commit loss measured in A-3, and this dump sits in the host's /tmp, which is the same failure domain as the thing it protects.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
