The documentation you are viewing is for Dapr v1.13 which is an older version of Dapr. For up-to-date documentation, see the latest version.

快速入门：服务到组件的弹性

通过状态管理API开始使用Dapr的弹性能力

通过模拟系统故障来观察 Dapr 的弹性能力。在本快速入门中，您将：

执行一个微服务应用程序，通过 Dapr 的状态管理 API 持续地存储和检索状态。
通过模拟系统故障来触发弹性策略。
解决故障，微服务应用程序将恢复。

Diagram showing the resiliency applied to Dapr APIs

在继续快速入门之前，请选择您首选的特定语言 Dapr SDK。

先决条件

对于此示例，您将需要：

Docker Desktop

第1步：设置环境

克隆在Quickstarts存储库中提供的示例。

git clone https://github.com/dapr/quickstarts.git

在一个终端窗口中，导航到 order-processor 目录。

cd ../state_management/python/sdk/order-processor

安装依赖项：

pip3 install -r requirements.txt

步骤 2：运行应用程序

与 Dapr sidecar 一起运行 order-processor 服务。然后 Dapr sidecar 加载位于资源目录中的弹性规范：

apiVersion: dapr.io/v1alpha1
kind: Resiliency
metadata:
  name: myresiliency
scopes:
  - checkout

spec:
  policies:
    retries:
      retryForever:
        policy: constant
        maxInterval: 5s
        maxRetries: -1 

    circuitBreakers:
      simpleCB:
        maxRequests: 1
        timeout: 5s 
        trip: consecutiveFailures >= 5

  targets:
    apps:
      order-processor:
        retry: retryForever
        circuitBreaker: simpleCB

dapr run --app-id order-processor --resources-path ../../../resources/ -- python3

应用程序启动后，order-processor服务将orderId键/值对写入和读取到statestore Redis实例在statestore.yaml组件中定义。

== APP == Saving Order:  { orderId: '1' }
== APP == Getting Order:  { orderId: '1' }
== APP == Saving Order:  { orderId: '2' }
== APP == Getting Order:  { orderId: '2' }
== APP == Saving Order:  { orderId: '3' }
== APP == Getting Order:  { orderId: '3' }
== APP == Saving Order:  { orderId: '4' }
== APP == Getting Order:  { orderId: '4' }

步骤 3：引入故障

在执行 dapr init 时，通过停止在开发机器上初始化的 Redis 容器实例来模拟故障。一旦实例停止，order-processor 服务的写入和读取操作将开始失败。

由于 resiliency.yaml 规范将 statestore 定义为组件目标，所有失败的请求将应用重试和断路器策略：

  targets:
    components:
      statestore:
        outbound:
          retry: retryForever
          circuitBreaker: simpleCB

在新的终端窗口中，运行以下命令以停止Redis：

docker stop dapr_redis

一旦 Redis 停止，请求开始失败，并应用名为 retryForever 的重试策略。下面的输出显示了来自order-processor服务的日志：

INFO[0006] Error processing operation component[statestore] output. Retrying...

根据retryForever策略，重试将无限期地对每个失败的请求进行，每隔5秒一次。

retryForever:
  policy: constant
  maxInterval: 5s
  maxRetries: -1

一旦连续失败5次重试，断路器策略 simpleCB，将被触发，断路器打开，停止所有请求：

INFO[0026] Circuit breaker "simpleCB-statestore" changed state from closed to open

circuitBreakers:
  simpleCB:
  maxRequests: 1
  timeout: 5s 
  trip: consecutiveFailures >= 5

超过5秒后，断路器将切换到半开状态，允许一个请求通过以验证故障是否已解决。如果请求继续失败，将会跳回到打开状态。

INFO[0031] Circuit breaker "simpleCB-statestore" changed state from open to half-open  
INFO[0031] Circuit breaker "simpleCB-statestore" changed state from half-open to open 
INFO[0036] Circuit breaker "simpleCB-statestore" changed state from open to half-open  
INFO[0036] Circuit breaker "simpleCB-statestore" changed state from half-open to closed

只要停止 Redis 容器，这种半开/开放行为将继续下去。

第3步：移除故障

一旦您重新启动您机器上的Redis容器，应用程序将无缝恢复，继续接受订单请求。

docker start dapr_redis

INFO[0036] Recovered processing operation component[statestore] output.  
== APP == Saving Order:  { orderId: '5' }
== APP == Getting Order:  { orderId: '5' }
== APP == Saving Order:  { orderId: '6' }
== APP == Getting Order:  { orderId: '6' }
== APP == Saving Order:  { orderId: '7' }
== APP == Getting Order:  { orderId: '7' }
== APP == Saving Order:  { orderId: '8' }
== APP == Getting Order:  { orderId: '8' }
== APP == Saving Order:  { orderId: '9' }
== APP == Getting Order:  { orderId: '9' }

先决条件

对于此示例，您将需要：

Docker Desktop

第1步：设置环境

克隆在Quickstarts存储库中提供的示例。

git clone https://github.com/dapr/quickstarts.git

在一个终端窗口中，导航到 order-processor 目录。

cd ../state_management/javascript/sdk/order-processor

安装依赖项：

npm install

步骤 2：运行应用程序

与 Dapr sidecar 一起运行 order-processor 服务。然后 Dapr sidecar 加载位于资源目录中的弹性规范：

apiVersion: dapr.io/v1alpha1
kind: Resiliency
metadata:
  name: myresiliency
scopes:
  - checkout

spec:
  policies:
    retries:
      retryForever:
        policy: constant
        maxInterval: 5s
        maxRetries: -1 

    circuitBreakers:
      simpleCB:
        maxRequests: 1
        timeout: 5s 
        trip: consecutiveFailures >= 5

  targets:
    apps:
      order-processor:
        retry: retryForever
        circuitBreaker: simpleCB

dapr run --app-id order-processor --resources-path ../../../resources/ -- npm start

应用程序启动后，order-processor服务将orderId键/值对写入和读取到statestore Redis实例在statestore.yaml组件中定义。

== APP == Saving Order:  { orderId: '1' }
== APP == Getting Order:  { orderId: '1' }
== APP == Saving Order:  { orderId: '2' }
== APP == Getting Order:  { orderId: '2' }
== APP == Saving Order:  { orderId: '3' }
== APP == Getting Order:  { orderId: '3' }
== APP == Saving Order:  { orderId: '4' }
== APP == Getting Order:  { orderId: '4' }

步骤 3：引入故障

在执行 dapr init 时，通过停止在开发机器上初始化的 Redis 容器实例来模拟故障。一旦实例停止，order-processor 服务的写入和读取操作将开始失败。

由于 resiliency.yaml 规范将 statestore 定义为组件目标，所有失败的请求将应用重试和断路器策略：

  targets:
    components:
      statestore:
        outbound:
          retry: retryForever
          circuitBreaker: simpleCB

在新的终端窗口中，运行以下命令以停止Redis：

docker stop dapr_redis

一旦 Redis 停止，请求开始失败，并应用名为 retryForever 的重试策略。下面的输出显示了来自order-processor服务的日志：

INFO[0006] Error processing operation component[statestore] output. Retrying...

根据retryForever策略，重试将无限期地对每个失败的请求进行，每隔5秒一次。

retryForever:
  policy: constant
  maxInterval: 5s
  maxRetries: -1

一旦连续失败5次重试，断路器策略 simpleCB，将被触发，断路器打开，停止所有请求：

INFO[0026] Circuit breaker "simpleCB-statestore" changed state from closed to open

circuitBreakers:
  simpleCB:
  maxRequests: 1
  timeout: 5s 
  trip: consecutiveFailures >= 5

超过5秒后，断路器将切换到半开状态，允许一个请求通过以验证故障是否已解决。如果请求继续失败，将会跳回到打开状态。

INFO[0031] Circuit breaker "simpleCB-statestore" changed state from open to half-open  
INFO[0031] Circuit breaker "simpleCB-statestore" changed state from half-open to open 
INFO[0036] Circuit breaker "simpleCB-statestore" changed state from open to half-open  
INFO[0036] Circuit breaker "simpleCB-statestore" changed state from half-open to closed

只要停止 Redis 容器，这种半开/开放行为将继续下去。

第3步：移除故障

一旦您重新启动您机器上的Redis容器，应用程序将无缝恢复，继续接受订单请求。

docker start dapr_redis

INFO[0036] Recovered processing operation component[statestore] output.  
== APP == Saving Order:  { orderId: '5' }
== APP == Getting Order:  { orderId: '5' }
== APP == Saving Order:  { orderId: '6' }
== APP == Getting Order:  { orderId: '6' }
== APP == Saving Order:  { orderId: '7' }
== APP == Getting Order:  { orderId: '7' }
== APP == Saving Order:  { orderId: '8' }
== APP == Getting Order:  { orderId: '8' }
== APP == Saving Order:  { orderId: '9' }
== APP == Getting Order:  { orderId: '9' }

先决条件

对于此示例，您将需要：

Docker Desktop

第1步：设置环境

克隆在Quickstarts存储库中提供的示例。

git clone https://github.com/dapr/quickstarts.git

在一个终端窗口中，导航到 order-processor 目录。

cd ../state_management/csharp/sdk/order-processor

安装依赖项：

dotnet restore
dotnet build

步骤 2：运行应用程序

与 Dapr sidecar 一起运行 order-processor 服务。然后 Dapr sidecar 加载位于资源目录中的弹性规范：

apiVersion: dapr.io/v1alpha1
kind: Resiliency
metadata:
  name: myresiliency
scopes:
  - checkout

spec:
  policies:
    retries:
      retryForever:
        policy: constant
        maxInterval: 5s
        maxRetries: -1 

    circuitBreakers:
      simpleCB:
        maxRequests: 1
        timeout: 5s 
        trip: consecutiveFailures >= 5

  targets:
    apps:
      order-processor:
        retry: retryForever
        circuitBreaker: simpleCB

dapr run --app-id order-processor --resources-path ../../../resources/ -- dotnet run

应用程序启动后，order-processor服务将orderId键/值对写入和读取到statestore Redis实例在statestore.yaml组件中定义。

== APP == Saving Order:  { orderId: '1' }
== APP == Getting Order:  { orderId: '1' }
== APP == Saving Order:  { orderId: '2' }
== APP == Getting Order:  { orderId: '2' }
== APP == Saving Order:  { orderId: '3' }
== APP == Getting Order:  { orderId: '3' }
== APP == Saving Order:  { orderId: '4' }
== APP == Getting Order:  { orderId: '4' }

步骤 3：引入故障

在执行 dapr init 时，通过停止在开发机器上初始化的 Redis 容器实例来模拟故障。一旦实例停止，order-processor 服务的写入和读取操作将开始失败。

由于 resiliency.yaml 规范将 statestore 定义为组件目标，所有失败的请求将应用重试和断路器策略：

  targets:
    components:
      statestore:
        outbound:
          retry: retryForever
          circuitBreaker: simpleCB

在新的终端窗口中，运行以下命令以停止Redis：

docker stop dapr_redis

一旦 Redis 停止，请求开始失败，并应用名为 retryForever 的重试策略。下面的输出显示了来自order-processor服务的日志：

INFO[0006] Error processing operation component[statestore] output. Retrying...

根据retryForever策略，重试将无限期地对每个失败的请求进行，每隔5秒一次。

retryForever:
  policy: constant
  maxInterval: 5s
  maxRetries: -1

一旦连续失败5次重试，断路器策略 simpleCB，将被触发，断路器打开，停止所有请求：

INFO[0026] Circuit breaker "simpleCB-statestore" changed state from closed to open

circuitBreakers:
  simpleCB:
  maxRequests: 1
  timeout: 5s 
  trip: consecutiveFailures >= 5

超过5秒后，断路器将切换到半开状态，允许一个请求通过以验证故障是否已解决。如果请求继续失败，将会跳回到打开状态。

INFO[0031] Circuit breaker "simpleCB-statestore" changed state from open to half-open  
INFO[0031] Circuit breaker "simpleCB-statestore" changed state from half-open to open 
INFO[0036] Circuit breaker "simpleCB-statestore" changed state from open to half-open  
INFO[0036] Circuit breaker "simpleCB-statestore" changed state from half-open to closed

只要停止 Redis 容器，这种半开/开放行为将继续下去。

第3步：移除故障

一旦您重新启动您机器上的Redis容器，应用程序将无缝恢复，继续接受订单请求。

docker start dapr_redis

INFO[0036] Recovered processing operation component[statestore] output.  
== APP == Saving Order:  { orderId: '5' }
== APP == Getting Order:  { orderId: '5' }
== APP == Saving Order:  { orderId: '6' }
== APP == Getting Order:  { orderId: '6' }
== APP == Saving Order:  { orderId: '7' }
== APP == Getting Order:  { orderId: '7' }
== APP == Saving Order:  { orderId: '8' }
== APP == Getting Order:  { orderId: '8' }
== APP == Saving Order:  { orderId: '9' }
== APP == Getting Order:  { orderId: '9' }

先决条件

对于此示例，您将需要：

Dapr CLI 和初始化环境.
Java JDK 11（或更高版本）：
- Oracle JDK，或者
- OpenJDK
Apache Maven，3.x版本。

Docker Desktop

第1步：设置环境

克隆在Quickstarts存储库中提供的示例。

git clone https://github.com/dapr/quickstarts.git

在一个终端窗口中，导航到 order-processor 目录。

cd ../state_management/java/sdk/order-processor

安装依赖项：

mvn clean install

步骤 2：运行应用程序

与 Dapr sidecar 一起运行 order-processor 服务。然后 Dapr sidecar 加载位于资源目录中的弹性规范：

apiVersion: dapr.io/v1alpha1
kind: Resiliency
metadata:
  name: myresiliency
scopes:
  - checkout

spec:
  policies:
    retries:
      retryForever:
        policy: constant
        maxInterval: 5s
        maxRetries: -1 

    circuitBreakers:
      simpleCB:
        maxRequests: 1
        timeout: 5s 
        trip: consecutiveFailures >= 5

  targets:
    apps:
      order-processor:
        retry: retryForever
        circuitBreaker: simpleCB

dapr run --app-id order-processor --resources-path ../../../resources/ -- java -jar target/OrderProcessingService-0.0.1-SNAPSHOT.jar

应用程序启动后，order-processor服务将orderId键/值对写入和读取到statestore Redis实例在statestore.yaml组件中定义。

== APP == Saving Order:  { orderId: '1' }
== APP == Getting Order:  { orderId: '1' }
== APP == Saving Order:  { orderId: '2' }
== APP == Getting Order:  { orderId: '2' }
== APP == Saving Order:  { orderId: '3' }
== APP == Getting Order:  { orderId: '3' }
== APP == Saving Order:  { orderId: '4' }
== APP == Getting Order:  { orderId: '4' }

步骤 3：引入故障

在执行 dapr init 时，通过停止在开发机器上初始化的 Redis 容器实例来模拟故障。一旦实例停止，order-processor 服务的写入和读取操作将开始失败。

由于 resiliency.yaml 规范将 statestore 定义为组件目标，所有失败的请求将应用重试和断路器策略：

  targets:
    components:
      statestore:
        outbound:
          retry: retryForever
          circuitBreaker: simpleCB

在新的终端窗口中，运行以下命令以停止Redis：

docker stop dapr_redis

一旦 Redis 停止，请求开始失败，并应用名为 retryForever 的重试策略。下面的输出显示了来自order-processor服务的日志：

INFO[0006] Error processing operation component[statestore] output. Retrying...

根据retryForever策略，重试将无限期地对每个失败的请求进行，每隔5秒一次。

retryForever:
  policy: constant
  maxInterval: 5s
  maxRetries: -1

一旦连续失败5次重试，断路器策略 simpleCB，将被触发，断路器打开，停止所有请求：

INFO[0026] Circuit breaker "simpleCB-statestore" changed state from closed to open

circuitBreakers:
  simpleCB:
  maxRequests: 1
  timeout: 5s 
  trip: consecutiveFailures >= 5

超过5秒后，断路器将切换到半开状态，允许一个请求通过以验证故障是否已解决。如果请求继续失败，将会跳回到打开状态。

INFO[0031] Circuit breaker "simpleCB-statestore" changed state from open to half-open  
INFO[0031] Circuit breaker "simpleCB-statestore" changed state from half-open to open 
INFO[0036] Circuit breaker "simpleCB-statestore" changed state from open to half-open  
INFO[0036] Circuit breaker "simpleCB-statestore" changed state from half-open to closed

只要停止 Redis 容器，这种半开/开放行为将继续下去。

第3步：移除故障

一旦您重新启动您机器上的Redis容器，应用程序将无缝恢复，继续接受订单请求。

docker start dapr_redis

INFO[0036] Recovered processing operation component[statestore] output.  
== APP == Saving Order:  { orderId: '5' }
== APP == Getting Order:  { orderId: '5' }
== APP == Saving Order:  { orderId: '6' }
== APP == Getting Order:  { orderId: '6' }
== APP == Saving Order:  { orderId: '7' }
== APP == Getting Order:  { orderId: '7' }
== APP == Saving Order:  { orderId: '8' }
== APP == Getting Order:  { orderId: '8' }
== APP == Saving Order:  { orderId: '9' }
== APP == Getting Order:  { orderId: '9' }

先决条件

对于此示例，您将需要：

Docker Desktop

第1步：设置环境

克隆在Quickstarts存储库中提供的示例。

git clone https://github.com/dapr/quickstarts.git

在一个终端窗口中，导航到 order-processor 目录。

cd ../state_management/go/sdk/order-processor

安装依赖项：

go build .

步骤 2：运行应用程序

与 Dapr sidecar 一起运行 order-processor 服务。然后 Dapr sidecar 加载位于资源目录中的弹性规范：

apiVersion: dapr.io/v1alpha1
kind: Resiliency
metadata:
  name: myresiliency
scopes:
  - checkout

spec:
  policies:
    retries:
      retryForever:
        policy: constant
        maxInterval: 5s
        maxRetries: -1 

    circuitBreakers:
      simpleCB:
        maxRequests: 1
        timeout: 5s 
        trip: consecutiveFailures >= 5

  targets:
    apps:
      order-processor:
        retry: retryForever
        circuitBreaker: simpleCB

dapr run --app-id order-processor --resources-path ../../../resources -- go run .

应用程序启动后，order-processor服务将orderId键/值对写入和读取到statestore Redis实例在statestore.yaml组件中定义。

== APP == Saving Order:  { orderId: '1' }
== APP == Getting Order:  { orderId: '1' }
== APP == Saving Order:  { orderId: '2' }
== APP == Getting Order:  { orderId: '2' }
== APP == Saving Order:  { orderId: '3' }
== APP == Getting Order:  { orderId: '3' }
== APP == Saving Order:  { orderId: '4' }
== APP == Getting Order:  { orderId: '4' }

步骤 3：引入故障

在执行 dapr init 时，通过停止在开发机器上初始化的 Redis 容器实例来模拟故障。一旦实例停止，order-processor 服务的写入和读取操作将开始失败。

由于 resiliency.yaml 规范将 statestore 定义为组件目标，所有失败的请求将应用重试和断路器策略：

  targets:
    components:
      statestore:
        outbound:
          retry: retryForever
          circuitBreaker: simpleCB

在新的终端窗口中，运行以下命令以停止Redis：

docker stop dapr_redis

一旦 Redis 停止，请求开始失败，并应用名为 retryForever 的重试策略。下面的输出显示了来自 order-processor 服务的日志:

INFO[0006] Error processing operation component[statestore] output. Retrying...

根据retryForever策略，重试将无限期地对每个失败的请求进行，每隔5秒一次。

retryForever:
  policy: constant
  maxInterval: 5s
  maxRetries: -1

一旦连续失败5次重试，断路器策略 simpleCB，将被触发，断路器打开，停止所有请求：

INFO[0026] Circuit breaker "simpleCB-statestore" changed state from closed to open

circuitBreakers:
  simpleCB:
  maxRequests: 1
  timeout: 5s 
  trip: consecutiveFailures >= 5

超过5秒后，断路器将切换到半开状态，允许一个请求通过以验证故障是否已解决。如果请求继续失败，将会跳回到打开状态。

INFO[0031] Circuit breaker "simpleCB-statestore" changed state from open to half-open  
INFO[0031] Circuit breaker "simpleCB-statestore" changed state from half-open to open 
INFO[0036] Circuit breaker "simpleCB-statestore" changed state from open to half-open  
INFO[0036] Circuit breaker "simpleCB-statestore" changed state from half-open to closed

只要停止 Redis 容器，这种半开/开放行为将继续下去。

第3步：移除故障

一旦您重新启动您机器上的Redis容器，应用程序将无缝恢复，继续接受订单请求。

docker start dapr_redis

INFO[0036] Recovered processing operation component[statestore] output.  
== APP == Saving Order:  { orderId: '5' }
== APP == Getting Order:  { orderId: '5' }
== APP == Saving Order:  { orderId: '6' }
== APP == Getting Order:  { orderId: '6' }
== APP == Saving Order:  { orderId: '7' }
== APP == Getting Order:  { orderId: '7' }
== APP == Saving Order:  { orderId: '8' }
== APP == Getting Order:  { orderId: '8' }
== APP == Saving Order:  { orderId: '9' }
== APP == Getting Order:  { orderId: '9' }

告诉我们您的想法

我们一直在努力改进我们的快速入门示例，并重视您的反馈。您觉得此快速入门有帮助吗？您有改进的建议吗？

加入我们的discord频道参与讨论。

下一步

了解有关弹性功能以及它如何与Dapr的构建块API一起工作。

探索 Dapr 教程 >>

Feedback

Was this page helpful?

Glad to hear it! Please tell us how we can improve.

Sorry to hear that. Please tell us how we can improve.