177 lines
9.7 KiB
Markdown
177 lines
9.7 KiB
Markdown
---
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layout: blog
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title: '在 Kubernetes 上对 gRPC 服务器进行健康检查'
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date: 2018-10-01
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slug: health-checking-grpc-servers-on-kubernetes
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---
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<!--
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layout: blog
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title: 'Health checking gRPC servers on Kubernetes'
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date: 2018-10-01
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--->
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<!--
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**Author**: [Ahmet Alp Balkan](https://twitter.com/ahmetb) (Google)
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--->
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**作者**： [Ahmet Alp Balkan](https://twitter.com/ahmetb) (Google)
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<!--
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**Update (December 2021):** _Kubernetes now has built-in gRPC health probes starting in v1.23.
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To learn more, see [Configure Liveness, Readiness and Startup Probes](/docs/tasks/configure-pod-container/configure-liveness-readiness-startup-probes/#define-a-grpc-liveness-probe).
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This article was originally written about an external tool to achieve the same task._
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-->
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**更新（2021 年 12 月）：** “Kubernetes 从 v1.23 开始具有内置 gRPC 健康探测。
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了解更多信息，请参阅[配置存活探针、就绪探针和启动探针](/zh-cn/docs/tasks/configure-pod-container/configure-liveness-readiness-startup-probes/#define-a-grpc-liveness-probe)。
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本文最初是为有关实现相同任务的外部工具所写。”
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<!--
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[gRPC](https://grpc.io) is on its way to becoming the lingua franca for
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communication between cloud-native microservices. If you are deploying gRPC
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applications to Kubernetes today, you may be wondering about the best way to
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configure health checks. In this article, we will talk about
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[grpc-health-probe](https://github.com/grpc-ecosystem/grpc-health-probe/), a
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Kubernetes-native way to health check gRPC apps.
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--->
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[gRPC](https://grpc.io) 将成为本地云微服务间进行通信的通用语言。如果您现在将 gRPC 应用程序部署到 Kubernetes，您可能会想要了解配置健康检查的最佳方法。在本文中，我们将介绍 [grpc-health-probe](https://github.com/grpc-ecosystem/grpc-health-probe/)，这是 Kubernetes 原生的健康检查 gRPC 应用程序的方法。
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<!--
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If you're unfamiliar, Kubernetes [health
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checks](/docs/tasks/configure-pod-container/configure-liveness-readiness-probes/)
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(liveness and readiness probes) is what's keeping your applications available
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while you're sleeping. They detect unresponsive pods, mark them unhealthy, and
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cause these pods to be restarted or rescheduled.
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--->
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如果您不熟悉，Kubernetes的 [健康检查](/docs/tasks/configure-pod-container/configure-liveness-readiness-probes/)（存活探针和就绪探针）可以使您的应用程序在睡眠时保持可用状态。当检测到没有回应的 Pod 时，会将其标记为不健康，并使这些 Pod 重新启动或重新安排。
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<!--
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Kubernetes [does not
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support](https://github.com/kubernetes/kubernetes/issues/21493) gRPC health
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checks natively. This leaves the gRPC developers with the following three
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approaches when they deploy to Kubernetes:
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[](/images/blog/2019-09-30-health-checking-grpc/options.png)
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--->
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Kubernetes 原本 [不支持](https://github.com/kubernetes/kubernetes/issues/21493) gRPC 健康检查。gRPC 的开发人员在 Kubernetes 中部署时可以采用以下三种方法：
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[](/images/blog/2019-09-30-health-checking-grpc/options.png)
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<!--
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1. **httpGet probe:** Cannot be natively used with gRPC. You need to refactor
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your app to serve both gRPC and HTTP/1.1 protocols (on different port
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numbers).
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2. **tcpSocket probe:** Opening a socket to gRPC server is not meaningful,
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since it cannot read the response body.
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3. **exec probe:** This invokes a program in a container's ecosystem
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periodically. In the case of gRPC, this means you implement a health RPC
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yourself, then write and ship a client tool with your container.
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Can we do better? Absolutely.
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--->
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1. **httpGet prob：** 不能与 gRPC 一起使用。您需要重构您的应用程序，必须同时支持 gRPC 和 HTTP/1.1 协议（在不同的端口号上）。
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2. **tcpSocket probe：** 打开 gRPC 服务器的 Socket 是没有意义的，因为它无法读取响应主体。
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3. **exec probe：** 将定期调用容器生态系统中的程序。对于 gRPC，这意味着您要自己实现健康 RPC，然后使用容器编写并交付客户端工具。
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我们可以做得更好吗？这是肯定的。
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<!--
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## Introducing “grpc-health-probe”
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To standardize the "exec probe" approach mentioned above, we need:
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- a **standard** health check "protocol" that can be implemented in any gRPC
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server easily.
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- a **standard** health check "tool" that can query the health protocol easily.
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--->
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## 介绍 “grpc-health-probe”
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为了使上述 "exec probe" 方法标准化，我们需要：
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- 可以在任何 gRPC 服务器中轻松实现的 **标准** 健康检查 "协议" 。
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- 一种 **标准** 健康检查 "工具" ，可以轻松查询健康协议。
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<!--
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Thankfully, gRPC has a [standard health checking
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protocol](https://github.com/grpc/grpc/blob/v1.15.0/doc/health-checking.md). It
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can be used easily from any language. Generated code and the utilities for
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setting the health status are shipped in nearly all language implementations of
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gRPC.
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--->
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幸运的是，gRPC 具有 [标准的健康检查协议](https://github.com/grpc/grpc/blob/v1.15.0/doc/health-checking.md)。可以用任何语言轻松调用它。几乎所有实现 gRPC 的语言都附带了生成的代码和用于设置健康状态的实用程序。
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<!--
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If you
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[implement](https://github.com/grpc/grpc/blob/v1.15.0/src/proto/grpc/health/v1/health.proto)
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this health check protocol in your gRPC apps, you can then use a standard/common
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tool to invoke this `Check()` method to determine server status.
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--->
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如果您在 gRPC 应用程序中 [实现](https://github.com/grpc/grpc/blob/v1.15.0/src/proto/grpc/health/v1/health.proto) 此健康检查协议，那么可以使用标准或通用工具调用 `Check()` 方法来确定服务器状态。
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<!--
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The next thing you need is the "standard tool", and it's the
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[**grpc-health-probe**](https://github.com/grpc-ecosystem/grpc-health-probe/).
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--->
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接下来您需要的是 "标准工具" [**grpc-health-probe**](https://github.com/grpc-ecosystem/grpc-health-probe/)。
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<a href='/images/blog/2019-09-30-health-checking-grpc/grpc_health_probe.png'>
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<img width="768" title='grpc-health-probe on kubernetes'
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src='/images/blog/2019-09-30-health-checking-grpc/grpc_health_probe.png'/>
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</a>
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<!--
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With this tool, you can use the same health check configuration in all your gRPC
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applications. This approach requires you to:
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--->
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使用此工具，您可以在所有 gRPC 应用程序中使用相同的健康检查配置。这种方法有以下要求：
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<!--
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1. Find the gRPC "health" module in your favorite language and start using it
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(example [Go library](https://godoc.org/github.com/grpc/grpc-go/health)).
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2. Ship the
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[grpc_health_probe](https://github.com/grpc-ecosystem/grpc-health-probe/)
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binary in your container.
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3. [Configure](https://github.com/grpc-ecosystem/grpc-health-probe/tree/1329d682b4232c102600b5e7886df8ffdcaf9e26#example-grpc-health-checking-on-kubernetes)
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Kubernetes "exec" probe to invoke the "grpc_health_probe" tool in the
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container.
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--->
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1. 用您喜欢的语言找到 gRPC 的 "健康" 模块并开始使用它（例如 [Go 库](https://godoc.org/github.com/grpc/grpc-go/health)）。
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2. 将二进制文件 [grpc_health_probe](https://github.com/grpc-ecosystem/grpc-health-probe/) 送到容器中。
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3. [配置](https://github.com/grpc-ecosystem/grpc-health-probe/tree/1329d682b4232c102600b5e7886df8ffdcaf9e26#example-grpc-health-checking-on-kubernetes) Kubernetes 的 "exec" 检查模块来调用容器中的 "grpc_health_probe" 工具。
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<!--
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In this case, executing "grpc_health_probe" will call your gRPC server over
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`localhost`, since they are in the same pod.
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--->
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在这种情况下，执行 "grpc_health_probe" 将通过 `localhost` 调用您的 gRPC 服务器，因为它们位于同一个容器中。
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<!--
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## What's next
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**grpc-health-probe** project is still in its early days and it needs your
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feedback. It supports a variety of features like communicating with TLS servers
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and configurable connection/RPC timeouts.
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--->
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## 下一步工作
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**grpc-health-probe** 项目仍处于初期阶段，需要您的反馈。它支持多种功能，例如与 TLS 服务器通信和配置延时连接/RPC。
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<!--
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If you are running a gRPC server on Kubernetes today, try using the gRPC Health
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Protocol and try the grpc-health-probe in your deployments, and [give
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feedback](https://github.com/grpc-ecosystem/grpc-health-probe/).
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--->
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如果您最近要在 Kubernetes 上运行 gRPC 服务器，请尝试使用 gRPC Health Protocol，并在您的 Deployment 中尝试 grpc-health-probe，然后 [进行反馈](https://github.com/grpc-ecosystem/grpc-health-probe/)。
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<!--
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## Further reading
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- Protocol: [GRPC Health Checking Protocol](https://github.com/grpc/grpc/blob/v1.15.0/doc/health-checking.md) ([health.proto](https://github.com/grpc/grpc/blob/v1.15.0/src/proto/grpc/health/v1/health.proto))
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- Documentation: [Kubernetes liveness and readiness probes](/docs/tasks/configure-pod-container/configure-liveness-readiness-probes/)
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- Article: [Advanced Kubernetes Health Check Patterns](https://ahmet.im/blog/advanced-kubernetes-health-checks/)
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--->
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## 更多内容
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- 协议： [GRPC Health Checking Protocol](https://github.com/grpc/grpc/blob/v1.15.0/doc/health-checking.md) ([health.proto](https://github.com/grpc/grpc/blob/v1.15.0/src/proto/grpc/health/v1/health.proto))
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- 文档： [Kubernetes 存活和就绪探针](/docs/tasks/configure-pod-container/configure-liveness-readiness-probes/)
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- 文章： [升级版 Kubernetes 健康检查模式](https://ahmet.im/blog/advanced-kubernetes-health-checks/)
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