tidaldb/k8s/cluster/statefulset.yaml

# The tidalDB CLUSTER: ONE StatefulSet, every pod a region (m11p5 §4).
#
# MUTUALLY EXCLUSIVE with the standalone set in k8s/ (namespace `tidaldb`,
# replicas: 1, `standalone` subcommand). This is namespace `tidaldb-cluster`,
# replicas: 3, the `cluster --region` subcommand, real quorum-ack writes,
# automatic election, and elastic membership. Deploy ONE or the OTHER per
# namespace — never both.
#
# WHY ONE StatefulSet (not one-per-region): the m11p5 bind/advertise split lets
# every pod mount the SAME topology ConfigMap (peers are advertised by per-pod
# DNS; the local socket binds 0.0.0.0), so a single StatefulSet with stable pod
# identities tidaldb-{0,1,2} IS the three regions. Scaling is `kubectl scale`
# (see docs/runbooks/kubernetes.md): pod N>=3 auto-seed-joins as a learner and
# auto-promotes to a voter — no file edits, no per-pod manifests.
apiVersion: apps/v1
kind: StatefulSet
metadata:
  name: tidaldb
  namespace: tidaldb-cluster
  labels:
    app.kubernetes.io/name: tidaldb
    app.kubernetes.io/component: cluster-node
spec:
  serviceName: tidaldb-peers  # the headless peer Service — stable per-pod DNS
  replicas: 3                 # the initial voter set; scale up/down per the runbook
  # Parallel: bring all pods up at once. There is no ordered-bootstrap
  # dependency — siblings boot in any order (an unreachable-at-startup peer is
  # normal; the election + catch-up timer converge them). Ordered start would
  # only serialize a 3-region cold boot for no benefit.
  podManagementPolicy: Parallel
  selector:
    matchLabels:
      app.kubernetes.io/name: tidaldb
      app.kubernetes.io/component: cluster-node
  template:
    metadata:
      labels:
        app.kubernetes.io/name: tidaldb
        app.kubernetes.io/component: cluster-node
      annotations:
        # Plain-Prometheus scrape hints (per-pod :9091, unauthenticated — keep
        # cluster-internal). The Operator-native path is a PodMonitor/ServiceMonitor.
        prometheus.io/scrape: "true"
        prometheus.io/port: "9091"
        prometheus.io/path: "/metrics"
    spec:
      # SIGTERM flips readiness to 503 (pod leaves the client Service), drains
      # in-flight requests, then checkpoints + fsyncs the WAL before exit. The
      # cluster path also wants the leader-lease/heartbeat windows to lapse so a
      # successor is elected cleanly. 60s covers the whole sequence.
      terminationGracePeriodSeconds: 60
      # Spread the three pods across distinct nodes so a single node loss takes
      # at most one voter — preserving quorum (2 of 3). ScheduleAnyway (not
      # DoNotSchedule) so a smaller cluster still schedules, just less spread.
      topologySpreadConstraints:
        - maxSkew: 1
          topologyKey: kubernetes.io/hostname
          whenUnsatisfiable: ScheduleAnyway
          labelSelector:
            matchLabels:
              app.kubernetes.io/name: tidaldb
              app.kubernetes.io/component: cluster-node
      securityContext:
        runAsNonRoot: true
        runAsUser: 10001        # the fixed `tidal` uid (docker/deploy/Dockerfile)
        runAsGroup: 10001
        fsGroup: 10001          # makes the mounted PVC group-writable by the runtime user
        seccompProfile:
          type: RuntimeDefault
      initContainers:
        - name: init-datadir
          image: busybox:1.36
          imagePullPolicy: IfNotPresent
          command: ["sh", "-c", "mkdir -p /data/db && chown -R 10001:10001 /data/db"]
          securityContext:
            allowPrivilegeEscalation: false
            runAsUser: 10001
            runAsGroup: 10001
          volumeMounts:
            - name: data
              mountPath: /data
      containers:
        - name: tidaldb
          image: registry.threesix.ai/tidal/server@sha256:173e803082beea479c48f3729f998e7332766ebcef55786da12f15719648f4fa  # m11p5
          imagePullPolicy: IfNotPresent
          # The image ENTRYPOINT is the bare binary. We override the command with
          # a tiny /bin/sh wrapper (the bookworm-slim runtime HAS a shell) so we
          # can branch on the pod ordinal: pods 0-2 are the initial voter set
          # (plain topology boot); pods >=3 are SCALE-UP and must seed-join as
          # learners. Keeping this in args (no initContainer, no extra image)
          # means the whole scale story is readable in this one file.
          #
          # POD_NAME is e.g. "tidaldb-4"; ORD is its trailing ordinal. For ORD<3
          # we boot from the topology file (the region IS this pod's name). For
          # ORD>=3 we ALSO pass --seed (any peer; the headless Service load-
          # balances to a live one) + this pod's advertised DNS addresses, and
          # the node learns its roster/id/term from a seed and joins as a learner.
          # The topology ConfigMap is STILL mounted+passed for the behavioral knob
          # blocks (replication/election/...), required even for a --seed boot
          # (m11p5 §3.5); its regions: list is ignored for a seed joiner's roster.
          command: ["/bin/sh", "-c"]
          args:
            - |
              set -eu
              ORD="${POD_NAME##*-}"
              DOMAIN="tidaldb-peers.tidaldb-cluster.svc.cluster.local"
              # Common args for every pod.
              set -- cluster \
                --listen 0.0.0.0:9500 \
                --data-dir /data/db \
                --schema /etc/tidal-server/schema/schema.yaml \
                --topology /etc/tidal-server/cluster-topology.yaml \
                --experimental-cluster
              if [ "$ORD" -ge 3 ]; then
                # SCALE-UP pod: seed-join as a learner. Advertise THIS pod's
                # stable per-pod DNS for gRPC (9601) and HTTP (9500); point --seed
                # at the headless Service (it resolves to a live peer). --metrics
                # gives the joiner a metrics listener (it has no topology entry).
                set -- "$@" \
                  --seed "http://${DOMAIN}:9500" \
                  --advertise-grpc "${POD_NAME}.${DOMAIN}:9601" \
                  --advertise-http "${POD_NAME}.${DOMAIN}:9500" \
                  --metrics 0.0.0.0:9091
              fi
              exec tidal-server "$@"              
          env:
            # Region identity == pod name (tidaldb-0/1/2/...). For ORD<3 this
            # MUST match a region declared in the topology ConfigMap; the names
            # line up by construction (regions are named after the pod identities).
            - name: POD_NAME
              valueFrom:
                fieldRef:
                  fieldPath: metadata.name
            - name: TIDAL_REGION
              valueFrom:
                fieldRef:
                  fieldPath: metadata.name
            - name: TIDAL_API_KEY
              valueFrom:
                secretKeyRef:
                  name: tidaldb-credentials
                  key: TIDAL_API_KEY
            # m11p7: the cluster key (mints/verifies per-node internal tokens that
            # authenticate inter-node HTTP). A file mount (not an inline env) so a
            # rotation of the Secret is picked up WITHOUT a pod restart by the
            # credential poller. Distinct secret data key from the bearer.
            - name: TIDAL_CLUSTER_KEY_FILE
              value: /etc/tidaldb/cluster-key/cluster-key
            - name: TIDAL_SERVER_LOG
              value: info
            - name: TIDAL_ALLOW_EXPERIMENTAL_CLUSTER
              value: "1"
          ports:
            - name: http
              containerPort: 9500
            - name: grpc
              containerPort: 9601
            - name: metrics
              containerPort: 9091
          # Three probes map to the three health endpoints. The readinessProbe is
          # now CLUSTER-AWARE (m11p5 §4): /health returns 503 while shutting down,
          # quarantined, removed/decommissioned, or a joiner/install boot has not
          # yet first-converged (lag <= learner_promote_lag, sticky-ready after).
          # A restarted PVC-retained voter is Ready on today's terms (no
          # regression). The full predicate is documented in the kubernetes.md
          # runbook so probe behavior is diagnosable.
          startupProbe:
            httpGet:
              path: /health/startup
              port: http
            periodSeconds: 5
            failureThreshold: 60     # ~5 min for large-DB WAL replay / index load
          livenessProbe:
            httpGet:
              path: /health/live
              port: http
            periodSeconds: 10
            timeoutSeconds: 3
            failureThreshold: 3
          readinessProbe:
            httpGet:
              path: /health          # cluster-aware: 503 joiner/quarantined/draining
              port: http
            periodSeconds: 10
            timeoutSeconds: 3
            failureThreshold: 3
          resources:
            requests:
              cpu: "250m"
              memory: 256Mi
            limits:
              cpu: "2"
              memory: 2Gi           # size from docs/ops/capacity-planning.md
          securityContext:
            allowPrivilegeEscalation: false
            readOnlyRootFilesystem: true   # writes only /data (PVC) and /tmp (emptyDir)
            capabilities:
              drop: ["ALL"]
          volumeMounts:
            - name: data
              mountPath: /data
            - name: schema
              mountPath: /etc/tidal-server/schema
              readOnly: true
            - name: topology
              mountPath: /etc/tidal-server/cluster-topology.yaml
              subPath: cluster-topology.yaml
              readOnly: true
            # m11p7 inter-node TLS material (cert-manager Secret). The grpc_tls
            # block in the topology points at these paths. A renewal rewrites the
            # Secret; the kubelet swaps the `..data` symlink and tidalDB's cert
            # poller hot-swaps with zero connection drop.
            - name: cluster-tls
              mountPath: /etc/tidaldb/tls
              readOnly: true
            - name: cluster-key
              mountPath: /etc/tidaldb/cluster-key
              readOnly: true
            - name: tmp
              mountPath: /tmp
      volumes:
        - name: schema
          configMap:
            name: tidaldb-schema
        - name: topology
          configMap:
            name: tidaldb-cluster-topology
        # m11p7: the cert-manager-issued node cert (tls.crt/tls.key/ca.crt).
        - name: cluster-tls
          secret:
            secretName: tidaldb-cluster-tls
        # m11p7: the cluster key for per-node internal tokens (own Secret key).
        - name: cluster-key
          secret:
            secretName: tidaldb-credentials
            items:
              - key: TIDAL_CLUSTER_KEY
                path: cluster-key
        - name: tmp
          emptyDir: {}
  volumeClaimTemplates:
    - metadata:
        name: data
        labels:
          app.kubernetes.io/name: tidaldb
      spec:
        accessModes: ["ReadWriteOnce"]
        storageClassName: local-path
        resources:
          requests:
            storage: 5Gi