Kubernetes StatefulSet滚动更新与存储扩容实践

概述目标：在有状态应用中安全地进行滚动更新与在线存储扩容，避免数据损坏与服务中断。适用：数据库、消息队列、缓存集群等。核心与实战存储类允许扩容（StorageClass）：apiVersion: storage.k8s.io/v1 kind: StorageClass metadata: name: fast-ssd provisioner: kubernetes.io/aws-ebs allowVolumeExpansion: true reclaimPolicy: Retain volumeBindingMode: WaitForFirstConsumer StatefulSet定义：apiVersion: apps/v1 kind: StatefulSet metadata: name: db namespace: prod spec: serviceName: db-headless replicas: 3 updateStrategy: type: RollingUpdate selector: matchLabels: { app: db } template: metadata: labels: { app: db } spec: containers: - name: db image: repo/db:1.2.3 volumeMounts: - name: data mountPath: /var/lib/db volumeClaimTemplates: - metadata: name: data spec: accessModes: [ "ReadWriteOnce" ] storageClassName: fast-ssd resources: requests: storage: 50Gi PVC扩容步骤：kubectl -n prod get pvc | select-string -pattern db-data kubectl -n prod patch pvc db-data-db-0 -p '{"spec":{"resources":{"requests":{"storage":"100Gi"}}}}' kubectl -n prod patch pvc db-data-db-1 -p '{"spec":{"resources":{"requests":{"storage":"100Gi"}}}}' kubectl -n prod patch pvc db-data-db-2 -p '{"spec":{"resources":{"requests":{"storage":"100Gi"}}}}' 示例有序滚动更新：kubectl -n prod rollout restart statefulset/db kubectl -n prod rollout status statefulset/db 检查卷大小与节点：kubectl -n prod describe pvc db-data-db-0 | findstr -i capacity 验证与监控应用健康：使用`readinessProbe/livenessProbe`确保滚动期间就绪与健康；观察副本逐个更新。存储后端：验证后端卷支持在线扩容；观察扩容完成事件与文件系统调整。数据一致性：在应对扩容前进行快照/备份；扩容后校验数据完整性。常见误区StorageClass未开启`allowVolumeExpansion`导致扩容失败；需提前配置。一次性扩容所有副本导致负载抖动；应逐个PVC扩容并观察。忽视备份与快照；在生产扩容前需制定恢复方案。结语通过有序滚动与存储扩容，StatefulSet可在生产中保持稳定升级与容量提升，并以验证与监控保障数据安全。