快速入门:服务到服务弹性
通过模拟系统故障来观察 Dapr 弹性功能。在本快速入门中,您将:
- 运行两个微服务应用程序:
checkout和order-processor。checkout将持续向order-processor发起 Dapr 服务调用请求。 - 通过模拟系统故障来触发弹性规范。
- 移除故障,使微服务应用程序能够恢复。

在继续快速入门之前,选择您偏好的特定语言的 Dapr SDK。
前置条件
对于此示例,您需要:
步骤 1:设置环境
git clone https://github.com/dapr/quickstarts.git
步骤 2:运行 order-processor 服务
在终端窗口中,从快速入门目录的根目录导航到 order-processor 目录。
cd service_invocation/python/http/order-processor
安装依赖:
pip3 install -r requirements.txt
运行 order-processor 服务以及 Dapr 边车。
dapr run --app-port 8001 --app-id order-processor --resources-path ../../../resources/ --app-protocol http --dapr-http-port 3501 -- python3 app.py
步骤 3:运行 checkout 服务应用程序
在新的终端窗口中,从快速入门目录的根目录导航到 checkout 目录。
cd service_invocation/python/http/checkout
安装依赖:
pip3 install -r requirements.txt
运行 checkout 服务以及 Dapr 边车。
dapr run --app-id checkout --resources-path ../../../resources/ --app-protocol http --dapr-http-port 3500 -- python3 app.py
然后 Dapr 边车将加载位于 resources 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
步骤 4:查看服务调用输出
当两个服务和边车都在运行时,注意订单是如何使用 Dapr 服务调用从 checkout 服务传递到 order-processor 服务的。
checkout 服务输出:
== APP == Order passed: {"orderId": 1}
== APP == Order passed: {"orderId": 2}
== APP == Order passed: {"orderId": 3}
== APP == Order passed: {"orderId": 4}
order-processor 服务输出:
== APP == Order received: {"orderId": 1}
== APP == Order received: {"orderId": 2}
== APP == Order received: {"orderId": 3}
== APP == Order received: {"orderId": 4}
步骤 5:引入故障
通过停止 order-processor 服务来模拟故障。一旦实例停止,来自 checkout 服务的服务调用操作将开始失败。
由于 resiliency.yaml 规范将 order-processor 服务定义为弹性目标,所有失败的请求都将应用重试和断路器策略:
targets:
apps:
order-processor:
retry: retryForever
circuitBreaker: simpleCB
在 order-processor 窗口中,停止服务:
CMD + C
CTRL + C
一旦第一个请求失败,将应用名为 retryForever 的重试策略:
INFO[0005] Error processing operation endpoint[order-processor, order-processor:orders]. Retrying...
对于每个失败的请求,重试将以 5 秒的间隔无限期继续。
retryForever:
policy: constant
maxInterval: 5s
maxRetries: -1
一旦 5 次连续重试失败,断路器策略 simpleCB 将被触发,断路器打开,停止所有请求:
INFO[0025] Circuit breaker "order-processor:orders" 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,电路将跳闸回到打开状态。
INFO[0030] Circuit breaker "order-processor:orders" changed state from open to half-open
INFO[0030] Circuit breaker "order-processor:orders" changed state from half-open to open
INFO[0030] Circuit breaker "order-processor:orders" changed state from open to half-open
INFO[0030] Circuit breaker "order-processor:orders" changed state from half-open to open
只要 order-processor 服务停止,这种半开/打开行为就会持续下去。
步骤 6:移除故障
重新启动 order-processor 服务后,应用程序将无缝恢复,从中断的地方继续接受订单请求。
在 order-processor 服务终端中,重新启动应用程序:
dapr run --app-port 8001 --app-id order-processor --app-protocol http --dapr-http-port 3501 -- python3 app.py
checkout 服务输出:
== APP == Order passed: {"orderId": 5}
== APP == Order passed: {"orderId": 6}
== APP == Order passed: {"orderId": 7}
== APP == Order passed: {"orderId": 8}
== APP == Order passed: {"orderId": 9}
== APP == Order passed: {"orderId": 10}
order-processor 服务输出:
== APP == Order received: {"orderId": 5}
== APP == Order received: {"orderId": 6}
== APP == Order received: {"orderId": 7}
== APP == Order received: {"orderId": 8}
== APP == Order received: {"orderId": 9}
== APP == Order received: {"orderId": 10}
前置条件
对于此示例,您需要:
步骤 1:设置环境
git clone https://github.com/dapr/quickstarts.git
步骤 2:运行 order-processor 服务
在终端窗口中,从快速入门目录的根目录导航到 order-processor 目录。
cd service_invocation/javascript/http/order-processor
安装依赖:
npm install
运行 order-processor 服务以及 Dapr 边车。
dapr run --app-port 5001 --app-id order-processor --resources-path ../../../resources/ --app-protocol http --dapr-http-port 3501 -- npm start
步骤 3:运行 checkout 服务应用程序
在新的终端窗口中,从快速入门目录的根目录导航到 checkout 目录。
cd service_invocation/javascript/http/checkout
安装依赖:
npm install
运行 checkout 服务以及 Dapr 边车。
dapr run --app-id checkout --resources-path ../../../resources/ --app-protocol http --dapr-http-port 3500 -- npm start
然后 Dapr 边车将加载位于 resources 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
步骤 4:查看服务调用输出
当两个服务和边车都在运行时,注意订单是如何使用 Dapr 服务调用从 checkout 服务传递到 order-processor 服务的。
checkout 服务输出:
== APP == Order passed: {"orderId": 1}
== APP == Order passed: {"orderId": 2}
== APP == Order passed: {"orderId": 3}
== APP == Order passed: {"orderId": 4}
order-processor 服务输出:
== APP == Order received: {"orderId": 1}
== APP == Order received: {"orderId": 2}
== APP == Order received: {"orderId": 3}
== APP == Order received: {"orderId": 4}
步骤 5:引入故障
通过停止 order-processor 服务来模拟故障。一旦实例停止,来自 checkout 服务的服务调用操作将开始失败。
由于 resiliency.yaml 规范将 order-processor 服务定义为弹性目标,所有失败的请求都将应用重试和断路器策略:
targets:
apps:
order-processor:
retry: retryForever
circuitBreaker: simpleCB
在 order-processor 窗口中,停止服务:
CMD + C
CTRL + C
一旦第一个请求失败,将应用名为 retryForever 的重试策略:
INFO[0005] Error processing operation endpoint[order-processor, order-processor:orders]. Retrying...
对于每个失败的请求,重试将以 5 秒的间隔无限期继续。
retryForever:
policy: constant
maxInterval: 5s
maxRetries: -1
一旦 5 次连续重试失败,断路器策略 simpleCB 将被触发,断路器打开,停止所有请求:
INFO[0025] Circuit breaker "order-processor:orders" 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,电路将跳闸回到打开状态。
INFO[0030] Circuit breaker "order-processor:orders" changed state from open to half-open
INFO[0030] Circuit breaker "order-processor:orders" changed state from half-open to open
INFO[0030] Circuit breaker "order-processor:orders" changed state from open to half-open
INFO[0030] Circuit breaker "order-processor:orders" changed state from half-open to open
只要 Redis 容器停止,这种半开/打开行为就会持续下去。
步骤 6:移除故障
重新启动 order-processor 服务后,应用程序将无缝恢复,从中断的地方继续。
在 order-processor 服务终端中,重新启动应用程序:
dapr run --app-port 5001 --app-id order-processor --resources-path ../../../resources/ --app-protocol http --dapr-http-port 3501 -- npm start
checkout 服务输出:
== APP == Order passed: {"orderId": 5}
== APP == Order passed: {"orderId": 6}
== APP == Order passed: {"orderId": 7}
== APP == Order passed: {"orderId": 8}
== APP == Order passed: {"orderId": 9}
== APP == Order passed: {"orderId": 10}
order-processor 服务输出:
== APP == Order received: {"orderId": 5}
== APP == Order received: {"orderId": 6}
== APP == Order received: {"orderId": 7}
== APP == Order received: {"orderId": 8}
== APP == Order received: {"orderId": 9}
== APP == Order received: {"orderId": 10}
前置条件
对于此示例,您需要:
步骤 1:设置环境
git clone https://github.com/dapr/quickstarts.git
步骤 2:运行 order-processor 服务
在终端窗口中,从快速入门目录的根目录导航到 order-processor 目录。
cd service_invocation/csharp/http/order-processor
安装依赖:
dotnet restore
dotnet build
运行 order-processor 服务以及 Dapr 边车。
dapr run --app-port 7001 --app-id order-processor --resources-path ../../../resources/ --app-protocol http --dapr-http-port 3501 -- dotnet run
步骤 3:运行 checkout 服务应用程序
在新的终端窗口中,从快速入门目录的根目录导航到 checkout 目录。
cd service_invocation/csharp/http/checkout
安装依赖:
dotnet restore
dotnet build
运行 checkout 服务以及 Dapr 边车。
dapr run --app-id checkout --resources-path ../../../resources/ --app-protocol http --dapr-http-port 3500 -- dotnet run
然后 Dapr 边车将加载位于 resources 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
步骤 4:查看服务调用输出
当两个服务和边车都在运行时,注意订单是如何使用 Dapr 服务调用从 checkout 服务传递到 order-processor 服务的。
checkout 服务输出:
== APP == Order passed: {"orderId": 1}
== APP == Order passed: {"orderId": 2}
== APP == Order passed: {"orderId": 3}
== APP == Order passed: {"orderId": 4}
order-processor 服务输出:
== APP == Order received: {"orderId": 1}
== APP == Order received: {"orderId": 2}
== APP == Order received: {"orderId": 3}
== APP == Order received: {"orderId": 4}
步骤 5:引入故障
通过停止 order-processor 服务来模拟故障。一旦实例停止,来自 checkout 服务的服务调用操作将开始失败。
由于 resiliency.yaml 规范将 order-processor 服务定义为弹性目标,所有失败的请求都将应用重试和断路器策略:
targets:
apps:
order-processor:
retry: retryForever
circuitBreaker: simpleCB
在 order-processor 窗口中,停止服务:
CMD + C
CTRL + C
一旦第一个请求失败,将应用名为 retryForever 的重试策略:
INFO[0005] Error processing operation endpoint[order-processor, order-processor:orders]. Retrying...
对于每个失败的请求,重试将以 5 秒的间隔无限期继续。
retryForever:
policy: constant
maxInterval: 5s
maxRetries: -1
一旦 5 次连续重试失败,断路器策略 simpleCB 将被触发,断路器打开,停止所有请求:
INFO[0025] Circuit breaker "order-processor:orders" 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,电路将跳闸回到打开状态。
INFO[0030] Circuit breaker "order-processor:orders" changed state from open to half-open
INFO[0030] Circuit breaker "order-processor:orders" changed state from half-open to open
INFO[0030] Circuit breaker "order-processor:orders" changed state from open to half-open
INFO[0030] Circuit breaker "order-processor:orders" changed state from half-open to open
只要 Redis 容器停止,这种半开/打开行为就会持续下去。
步骤 6:移除故障
重新启动 order-processor 服务后,应用程序将无缝恢复,从中断的地方继续。
在 order-processor 服务终端中,重新启动应用程序:
dapr run --app-port 7001 --app-id order-processor --app-protocol http --dapr-http-port 3501 -- dotnet run
checkout 服务输出:
== APP == Order passed: {"orderId": 5}
== APP == Order passed: {"orderId": 6}
== APP == Order passed: {"orderId": 7}
== APP == Order passed: {"orderId": 8}
== APP == Order passed: {"orderId": 9}
== APP == Order passed: {"orderId": 10}
order-processor 服务输出:
== APP == Order received: {"orderId": 5}
== APP == Order received: {"orderId": 6}
== APP == Order received: {"orderId": 7}
== APP == Order received: {"orderId": 8}
== APP == Order received: {"orderId": 9}
== APP == Order received: {"orderId": 10}
前置条件
对于此示例,您需要:
- Dapr CLI 和已初始化的环境。
- Java JDK 17(或更高版本):
- Oracle JDK,或
- OpenJDK
- Apache Maven,版本 3.x。
步骤 1:设置环境
git clone https://github.com/dapr/quickstarts.git
步骤 2:运行 order-processor 服务
在终端窗口中,从快速入门目录的根目录导航到 order-processor 目录。
cd service_invocation/java/http/order-processor
安装依赖:
mvn clean install
运行 order-processor 服务以及 Dapr 边车。
dapr run --app-id order-processor --resources-path ../../../resources/ --app-port 9001 --app-protocol http --dapr-http-port 3501 -- java -jar target/OrderProcessingService-0.0.1-SNAPSHOT.jar
步骤 3:运行 checkout 服务应用程序
在新的终端窗口中,从快速入门目录的根目录导航到 checkout 目录。
cd service_invocation/java/http/checkout
安装依赖:
mvn clean install
运行 checkout 服务以及 Dapr 边车。
dapr run --app-id checkout --resources-path ../../../resources/ --app-protocol http --dapr-http-port 3500 -- java -jar target/CheckoutService-0.0.1-SNAPSHOT.jar
然后 Dapr 边车将加载位于 resources 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
步骤 4:查看服务调用输出
当两个服务和边车都在运行时,注意订单是如何使用 Dapr 服务调用从 checkout 服务传递到 order-processor 服务的。
checkout 服务输出:
== APP == Order passed: {"orderId": 1}
== APP == Order passed: {"orderId": 2}
== APP == Order passed: {"orderId": 3}
== APP == Order passed: {"orderId": 4}
order-processor 服务输出:
== APP == Order received: {"orderId": 1}
== APP == Order received: {"orderId": 2}
== APP == Order received: {"orderId": 3}
== APP == Order received: {"orderId": 4}
步骤 5:引入故障
通过停止 order-processor 服务来模拟故障。一旦实例停止,来自 checkout 服务的服务调用操作将开始失败。
由于 resiliency.yaml 规范将 order-processor 服务定义为弹性目标,所有失败的请求都将应用重试和断路器策略:
targets:
apps:
order-processor:
retry: retryForever
circuitBreaker: simpleCB
在 order-processor 窗口中,停止服务:
CMD + C
CTRL + C
一旦第一个请求失败,将应用名为 retryForever 的重试策略:
INFO[0005] Error processing operation endpoint[order-processor, order-processor:orders]. Retrying...
对于每个失败的请求,重试将以 5 秒的间隔无限期继续。
retryForever:
policy: constant
maxInterval: 5s
maxRetries: -1
一旦 5 次连续重试失败,断路器策略 simpleCB 将被触发,断路器打开,停止所有请求:
INFO[0025] Circuit breaker "order-processor:orders" 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,电路将跳闸回到打开状态。
INFO[0030] Circuit breaker "order-processor:orders" changed state from open to half-open
INFO[0030] Circuit breaker "order-processor:orders" changed state from half-open to open
INFO[0030] Circuit breaker "order-processor:orders" changed state from open to half-open
INFO[0030] Circuit breaker "order-processor:orders" changed state from half-open to open
只要 Redis 容器停止,这种半开/打开行为就会持续下去。
步骤 6:移除故障
重新启动 order-processor 服务后,应用程序将无缝恢复,从中断的地方继续。
在 order-processor 服务终端中,重新启动应用程序:
dapr run --app-id order-processor --resources-path ../../../resources/ --app-port 9001 --app-protocol http --dapr-http-port 3501 -- java -jar target/OrderProcessingService-0.0.1-SNAPSHOT.jar
checkout 服务输出:
== APP == Order passed: {"orderId": 5}
== APP == Order passed: {"orderId": 6}
== APP == Order passed: {"orderId": 7}
== APP == Order passed: {"orderId": 8}
== APP == Order passed: {"orderId": 9}
== APP == Order passed: {"orderId": 10}
order-processor 服务输出:
== APP == Order received: {"orderId": 5}
== APP == Order received: {"orderId": 6}
== APP == Order received: {"orderId": 7}
== APP == Order received: {"orderId": 8}
== APP == Order received: {"orderId": 9}
== APP == Order received: {"orderId": 10}
前置条件
对于此示例,您需要:
步骤 1:设置环境
git clone https://github.com/dapr/quickstarts.git
步骤 2:运行 order-processor 服务
在终端窗口中,从快速入门目录的根目录导航到 order-processor 目录。
cd service_invocation/go/http/order-processor
安装依赖:
go build .
运行 order-processor 服务以及 Dapr 边车。
dapr run --app-port 6001 --app-id order-processor --resources-path ../../../resources/ --app-protocol http --dapr-http-port 3501 -- go run .
步骤 3:运行 checkout 服务应用程序
在新的终端窗口中,从快速入门目录的根目录导航到 checkout 目录。
cd service_invocation/go/http/checkout
安装依赖:
go build .
运行 checkout 服务以及 Dapr 边车。
dapr run --app-id checkout --resources-path ../../../resources/ --app-protocol http --dapr-http-port 3500 -- go run .
然后 Dapr 边车将加载位于 resources 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
步骤 4:查看服务调用输出
当两个服务和边车都在运行时,注意订单是如何使用 Dapr 服务调用从 checkout 服务传递到 order-processor 服务的。
checkout 服务输出:
== APP == Order passed: {"orderId": 1}
== APP == Order passed: {"orderId": 2}
== APP == Order passed: {"orderId": 3}
== APP == Order passed: {"orderId": 4}
order-processor 服务输出:
== APP == Order received: {"orderId": 1}
== APP == Order received: {"orderId": 2}
== APP == Order received: {"orderId": 3}
== APP == Order received: {"orderId": 4}
步骤 5:引入故障
通过停止 order-processor 服务来模拟故障。一旦实例停止,来自 checkout 服务的服务调用操作将开始失败。
由于 resiliency.yaml 规范将 order-processor 服务定义为弹性目标,所有失败的请求都将应用重试和断路器策略:
targets:
apps:
order-processor:
retry: retryForever
circuitBreaker: simpleCB
在 order-processor 窗口中,停止服务:
CMD + C
CTRL + C
一旦第一个请求失败,将应用名为 retryForever 的重试策略:
INFO[0005] Error processing operation endpoint[order-processor, order-processor:orders]. Retrying...
对于每个失败的请求,重试将以 5 秒的间隔无限期继续。
retryForever:
policy: constant
maxInterval: 5s
maxRetries: -1
一旦 5 次连续重试失败,断路器策略 simpleCB 将被触发,断路器打开,停止所有请求:
INFO[0025] Circuit breaker "order-processor:orders" 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,电路将跳闸回到打开状态。
INFO[0030] Circuit breaker "order-processor:orders" changed state from open to half-open
INFO[0030] Circuit breaker "order-processor:orders" changed state from half-open to open
INFO[0030] Circuit breaker "order-processor:orders" changed state from open to half-open
INFO[0030] Circuit breaker "order-processor:orders" changed state from half-open to open
只要 Redis 容器停止,这种半开/打开行为就会持续下去。
步骤 6:移除故障
重新启动 order-processor 服务后,应用程序将无缝恢复,从中断的地方继续。
在 order-processor 服务终端中,重新启动应用程序:
dapr run --app-port 6001 --app-id order-processor --resources-path ../../../resources/ --app-protocol http --dapr-http-port 3501 -- go run .
checkout 服务输出:
== APP == Order passed: {"orderId": 5}
== APP == Order passed: {"orderId": 6}
== APP == Order passed: {"orderId": 7}
== APP == Order passed: {"orderId": 8}
== APP == Order passed: {"orderId": 9}
== APP == Order passed: {"orderId": 10}
order-processor 服务输出:
== APP == Order received: {"orderId": 5}
== APP == Order received: {"orderId": 6}
== APP == Order received: {"orderId": 7}
== APP == Order received: {"orderId": 8}
== APP == Order received: {"orderId": 9}
== APP == Order received: {"orderId": 10}
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