jakman85
f338e91770
All three CNPG Clusters ran `instances: 1`. Longhorn's 3-way replication saves the DATA when a node dies; it does not save the SERVICE — a single instance has to be rescheduled, re-attach its volume and replay WAL before Postgres accepts a connection again. With nothing in the spec keeping them apart, all three primaries had drifted onto ONE node (k3s-prod-2 on prod, k3s-dev-3 on dev). On 2026-09-07 that node took SSO, Nextcloud and Semaphore down together, and with SSO went kubectl OIDC, Grafana, Headlamp, Gitea and forward-auth. Three instances give each Cluster a streaming standby CNPG can promote in seconds, repointing the -rw Service with no volume re-attach and no restore. UNBLOCKED BY WORKING BACKUPS, NOT A SUBSTITUTE FOR THEM. Standbys replicate corruption and deletions faithfully; only the Barman archive is a backup, and adding standbys while archive_mode=on with a failing archive_command would have multiplied the disk-full clock, not hedged it. All three Clusters on both k3s-prod and k3s-dev now report ContinuousArchiving=True with a real firstRecoverabilityPoint (verified read-only, 2026-09-07). Scaling out is non-disruptive on its own: CNPG creates -2 then -3 sequentially, each seeded by pg_basebackup from the RUNNING primary. The primary is not restarted and clients are not disconnected. The anti-affinity change that DOES cause a switchover is deliberately the next commit. DEV IMPACT: identical — dev is on the same shape (three single-instance DBs, all on k3s-dev-3) and gets the same scale-out. Dev has three untainted nodes and Longhorn headroom for it (see the next commit's message for the numbers). Cost: 2 extra 5Gi PVCs per Cluster; ~30 GiB provisioned cluster-wide against live pgdata of ~600 MiB each, on Longhorn with 200% over-provisioning. Verified: yamllint clean; `kubectl kustomize --load-restrictor LoadRestrictionsNone platform-config` and `kubectl kustomize apps/wave-0` both render `instances: 3`. Co-Authored-By: Claude Opus 5 <[email protected]> (cherry picked from commit ed6fe6cb019b96f677a92448a0347f979d1a6d02)