168 lines
5.9 KiB
Markdown
168 lines
5.9 KiB
Markdown
---
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title: 扩缩 StatefulSet
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content_type: task
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---
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<!-- overview -->
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<!--
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This task shows how to scale a StatefulSet. Scaling a StatefulSet refers to increasing or decreasing the number of replicas.
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-->
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本文介绍如何扩缩StatefulSet。StatefulSet 的扩缩指的是增加或者减少副本个数。
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## {{% heading "prerequisites" %}}
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<!--
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* StatefulSets are only available in Kubernetes version 1.5 or later.
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To check your version of Kubernetes, run `kubectl version`.
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* Not all stateful applications scale nicely. If you are unsure about whether to scale your StatefulSets, see [StatefulSet concepts](/docs/concepts/workloads/controllers/statefulset/) or [StatefulSet tutorial](/docs/tutorials/stateful-application/basic-stateful-set/) for further information.
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* You should perform scaling only when you are confident that your stateful application
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cluster is completely healthy.
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-->
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* StatefulSets 仅适用于 Kubernetes 1.5 及以上版本。
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* 不是所有 Stateful 应用都能很好地执行扩缩操作。
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如果你不是很确定是否要扩缩你的 StatefulSet，可先参阅
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[StatefulSet 概念](/zh/docs/concepts/workloads/controllers/statefulset/)
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或者 [StatefulSet 教程](/zh/docs/tutorials/stateful-application/basic-stateful-set/)。
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* 仅当你确定你的有状态应用的集群是完全健康的，才可执行扩缩操作.
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<!-- steps -->
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<!--
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## Scaling StatefulSets
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### Use kubectl to scale StatefulSets
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First, find the StatefulSet you want to scale.
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```shell
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kubectl get statefulsets <stateful-set-name>
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```
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-->
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## 扩缩 StatefulSet {#scaling-statefulset}
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## 使用 `kubectl` 扩缩 StatefulSet
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首先，找到你要扩缩的 StatefulSet。
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```shell
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kubectl get statefulsets <statefulset 名称>
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```
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<!--
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Change the number of replicas of your StatefulSet:
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```shell
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kubectl scale statefulsets <stateful-set-name> --replicas=<new-replicas>
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```
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-->
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更改 StatefulSet 中副本个数：
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```shell
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kubectl scale statefulsets <statefulset 名称> --replicas=<新的副本数>
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```
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<!--
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### Make in-place updates on your StatefulSets
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Alternatively, you can do [in-place updates](/docs/concepts/cluster-administration/manage-deployment/#in-place-updates-of-resources) on your StatefulSets.
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If your StatefulSet was initially created with `kubectl apply`,
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update `.spec.replicas` of the StatefulSet manifests, and then do a `kubectl apply`:
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-->
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### 对 StatefulSet 执行就地更新
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另外, 你可以[就地更新](/zh/docs/concepts/cluster-administration/manage-deployment/#in-place-updates-of-resources) StatefulSet。
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如果你的 StatefulSet 最初通过 `kubectl apply` 或 `kubectl create --save-config` 创建,
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你可以更新 StatefulSet 清单中的 `.spec.replicas`, 然后执行命令 `kubectl apply`:
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<!--
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```shell
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kubectl apply -f <stateful-set-file-updated>
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```
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Otherwise, edit that field with `kubectl edit`:
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```shell
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kubectl edit statefulsets <stateful-set-name>
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```
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Or use `kubectl patch`:
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```shell
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kubectl patch statefulsets <stateful-set-name> -p '{"spec":{"replicas":<new-replicas>}}'
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```
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-->
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```shell
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kubectl apply -f <更新后的 statefulset 文件>
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```
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否则，可以使用 `kubectl edit` 编辑副本字段：
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```shell
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kubectl edit statefulsets <statefulset 名称>
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```
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或者使用 `kubectl patch`：
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```shell
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kubectl patch statefulsets <statefulset 名称> -p '{"spec":{"replicas":<new-replicas>}}'
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```
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<!--
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## Troubleshooting
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### Scaling down does not work right
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-->
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## 故障排查 {#troubleshooting}
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### 缩容操作无法正常工作
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<!--
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You cannot scale down a StatefulSet when any of the stateful Pods it manages is unhealthy. Scaling down only takes place
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after those stateful Pods become running and ready.
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If spec.replicas > 1, Kubernetes cannot determine the reason for an unhealthy Pod. It might be the result of a permanent fault or of a transient fault. A transient fault can be caused by a restart required by upgrading or maintenance.
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-->
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当 Stateful 所管理的任何 Pod 不健康时，你不能对该 StatefulSet 执行缩容操作。
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仅当 StatefulSet 的所有 Pod 都处于运行状态和 Ready 状况后才可缩容.
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如果 `spec.replicas` 大于 1，Kubernetes 无法判定 Pod 不健康的原因。
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Pod 不健康可能是由于永久性故障造成也可能是瞬态故障。
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瞬态故障可能是节点升级或维护而引起的节点重启造成的。
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<!--
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If the Pod is unhealthy due to a permanent fault, scaling
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without correcting the fault may lead to a state where the StatefulSet membership
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drops below a certain minimum number of replicas that are needed to function
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correctly. This may cause your StatefulSet to become unavailable.
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-->
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如果该 Pod 不健康是由于永久性故障导致, 则在不纠正该故障的情况下进行缩容可能会导致
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StatefulSet 进入一种状态，其成员 Pod 数量低于应正常运行的副本数。
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这种状态也许会导致 StatefulSet 不可用。
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<!--
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If the Pod is unhealthy due to a transient fault and the Pod might become available again,
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the transient error may interfere with your scale-up or scale-down operation. Some distributed
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databases have issues when nodes join and leave at the same time. It is better
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to reason about scaling operations at the application level in these cases, and
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perform scaling only when you are sure that your stateful application cluster is
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completely healthy.
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-->
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如果由于瞬态故障而导致 Pod 不健康并且 Pod 可能再次变为可用，那么瞬态错误可能会干扰
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你对 StatefulSet 的扩容/缩容操作。 一些分布式数据库在同时有节点加入和离开时
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会遇到问题。在这些情况下，最好是在应用级别进行分析扩缩操作的状态, 并且只有在确保
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Stateful 应用的集群是完全健康时才执行扩缩操作。
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## {{% heading "whatsnext" %}}
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<!--
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* Learn more about [deleting a StatefulSet](/docs/tasks/run-application/delete-stateful-set/).
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-->
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* 进一步了解[删除 StatefulSet](/zh/docs/tasks/run-application/delete-stateful-set/)
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