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+> Per AI Blitz Plan §claude. Layer: 1. Repo: devops-infra-helm-charts.
+
+# 02 — Cluster fleet
+
+The repo's cluster directories under `helm-overrides/<cluster>/` are the canonical list of clusters this platform serves. Naming follows three patterns; each implies a different scheduling primitive set, which is why **schedule fields are never copy-pasted between clusters** (see [`../docs/global/SANCTITY_RULES.md`](../docs/global/SANCTITY_RULES.md)).
+
+## Naming taxonomy
+
+### `k8s-<bu>-prd-ase1[c]`
+
+Standard GKE prod cluster, BU-owned. All in `asia-southeast1`, fleet `meesho-admin-prd-0622`. Trailing `c` denotes a secondary cluster for the same BU.
+
+Known BUs in this repo:
+
+- `central`, `central-mqkafka`
+- `supply`, `supply-dev`
+- `demand`
+- `dataengg`, `datascience`, `dengspark`, `dengspark-di`, `dengspark-notebook`, `dscispark`
+- `dsgpu`
+- `farmiso`
+- `ml-platform`
+- `admin`, `sec-admin`, `devops-admin`
+
+A few of these are GKE **Autopilot** clusters (different scheduling primitives — see below):
+- `k8s-central-prd-ase1`
+- `k8s-dsgpu-prd-ase1`
+- `k8s-shared-int-ase1`
+
+The rest are **standard** GKE.
+
+### `k8s-shared-int-ase1`
+
+Shared **integration** (pre-prod) cluster — the only non-prod cluster in the repo. Used for integration testing of platform changes before they hit any prod cluster. Autopilot.
+
+### `k8s-aurva-prd-ase1`
+
+Aurva integration (third-party security tooling). Minimal override set.
+
+### `db-<numeric-id>-...`
+
+Auto-named dataplane / data-tier clusters. Each carries a minimal override set, typically `kube-state-metrics` and `victoria-metrics-agent` only. The `fullnameOverride` convention here is `<kind>-dbc-<bu>-prd` so that metrics labels stay legible across the data-tier fleet.
+
+## Autopilot vs standard scheduling
+
+This is the dominant reason scheduling fields cannot be copy-pasted across clusters.
+
+### Standard GKE clusters
+
+Use:
+- `nodeSelector.dedicated: <pool-tag>`
+- `tolerations[].key: dedicated`
+- Node pools are explicitly provisioned per workload class.
+
+### Autopilot clusters
+
+Use:
+- `nodeSelector."cloud.google.com/compute-class": <ComputeClass-name>`
+- `tolerations[].key: cloud.google.com/compute-class` (when applicable)
+- A `ComputeClass` raw manifest is dropped at `helm-overrides/<cluster>/<app>/computeclass/*-cc.yaml` to declare the class. See [`../docs/platform/schemas/raw-manifest-sidecar-schema.md`](../docs/platform/schemas/raw-manifest-sidecar-schema.md).
+
+Mismatched fields → pods strand on the wrong nodes or stay `Pending`. Diagnosis flow: [`../docs/platform/runbooks/pod-pending-scheduling.md`](../docs/platform/runbooks/pod-pending-scheduling.md). Background: [`../wiki/analyses/ADR-A3-per-cluster-scheduling.md`](../wiki/analyses/ADR-A3-per-cluster-scheduling.md).
+
+## Multi-Contour scheduling
+
+Multi-Contour clusters run `contour-external`, `contour-external-1`, `contour-internal-0`, `contour-internal-1`, `contour-internal-intra-0`, `contour-internal-intra-1` — each a separate Helm release pinned to its own node pool / dedicated taint or compute class. The per-cluster matrix (which Contour goes where) is documented in the repo-root `contour-nodeselector-tolerations-summary.md`. **Always cross-reference that file before touching a Contour values override.**
+
+## Cluster onboarding
+
+Adding a new cluster directory is Layer-1 *high-risk*. The procedure (paired PR with the sister repo's `ApplicationSet`) is in [`../docs/platform/procedures/onboard-new-cluster.md`](../docs/platform/procedures/onboard-new-cluster.md).
+
+## Cluster deboarding
+
+Removing a cluster is rare and requires draining Argo Applications first. There is no in-repo procedure today; escalate to the primary owner — see [`../docs/global/escalation-matrix.md`](../docs/global/escalation-matrix.md).
+
+## See also
+
+- [`./03-chart-inventory.md`](./03-chart-inventory.md) — versioned siblings + multi-Contour pattern
+- [`./04-override-hierarchy.md`](./04-override-hierarchy.md) — how cluster + chart compose
+- [`./07-singletons-and-blast-radius.md`](./07-singletons-and-blast-radius.md) — `manifests/priorityclass/<cluster>/`
+- [`../contour-nodeselector-tolerations-summary.md`](../contour-nodeselector-tolerations-summary.md)