init

sentinel/sentinel-demo/sentinel-demo-dubbo/README.md

@@ -0,0 +1,112 @@
+# Sentinel Dubbo Demo
+
+Sentinel 提供了与 Dubbo 整合的模块 - Sentinel Dubbo Adapter，主要包括针对 Service Provider 和 Service Consumer 实现的 Filter。使用时用户只需引入以下模块（以 Maven 为例）：
+
+```xml
+<dependency>
+    <groupId>com.alibaba.csp</groupId>
+    <artifactId>sentinel-dubbo-adapter</artifactId>
+    <version>x.y.z</version>
+</dependency>
+```
+
+引入此依赖后，Dubbo 的服务接口和方法（包括调用端和服务端）就会成为 Sentinel 中的资源，在配置了规则后就可以自动享受到 Sentinel 的防护能力。
+
+> **注：若希望接入 Dashboard，请参考后面接入控制台的步骤。只引入 Sentinel Dubbo Adapter 无法接入控制台！**
+
+若不希望开启 Sentinel Dubbo Adapter 中的某个 Filter，可以手动关闭对应的 Filter，比如：
+
+```java
+@Bean
+public ConsumerConfig consumerConfig() {
+    ConsumerConfig consumerConfig = new ConsumerConfig();
+    consumerConfig.setFilter("-sentinel.dubbo.consumer.filter");
+    return consumerConfig;
+}
+```
+
+我们提供了几个具体的 Demo 来分别演示 Provider 和 Consumer 的限流场景。
+
+## Service Provider
+
+Service Provider 用于向外界提供服务，处理各个消费者的调用请求。为了保护 Provider 不被激增的流量拖垮影响稳定性，可以给 Provider 配置 **QPS 模式**的限流，这样当每秒的请求量超过设定的阈值时会自动拒绝多的请求。限流粒度可以是服务接口和服务方法两种粒度。若希望整个服务接口的 QPS 不超过一定数值，则可以为对应服务接口资源（resourceName 为**接口全限定名**）配置 QPS 阈值；若希望服务的某个方法的 QPS 不超过一定数值，则可以为对应服务方法资源（resourceName 为**接口全限定名:方法签名**）配置 QPS 阈值。有关配置详情请参考 [流量控制 | Sentinel](https://github.com/alibaba/Sentinel/wiki/%E6%B5%81%E9%87%8F%E6%8E%A7%E5%88%B6)。
+
+Demo 1 演示了此限流场景，我们看一下这种模式的限流产生的效果。假设我们已经定义了某个服务接口 `com.alibaba.csp.sentinel.demo.dubbo.FooService`，其中有一个方法 `sayHello(java.lang.String)`，Provider 端该方法设定 QPS 阈值为 10。在 Consumer 端在 1s 之内连续发起 15 次调用，可以通过日志文件看到 Provider 端被限流。拦截日志统一记录在 `~/logs/csp/sentinel-block.log` 中：
+
+```
+2018-07-24 17:13:43|1|com.alibaba.csp.sentinel.demo.dubbo.FooService:sayHello(java.lang.String),FlowException,default,|5,0
+```
+
+在 Provider 对应的 metrics 日志中也有记录：
+
+```
+1532423623000|2018-07-24 17:13:43|com.alibaba.csp.sentinel.demo.dubbo.FooService|15|0|15|0|3
+1532423623000|2018-07-24 17:13:43|com.alibaba.csp.sentinel.demo.dubbo.FooService:sayHello(java.lang.String)|10|5|10|0|0
+```
+
+很多场景下，根据**调用方**来限流也是非常重要的。比如有两个服务 A 和 B 都向 Service Provider 发起调用请求，我们希望只对来自服务 B 的请求进行限流，则可以设置限流规则的 `limitApp` 为服务 B 的名称。Sentinel Dubbo Adapter 会自动解析 Dubbo 消费者（调用方）的 application name 作为调用方名称（`origin`），在进行资源保护的时候都会带上调用方名称。若限流规则未配置调用方（`default`），则该限流规则对所有调用方生效。若限流规则配置了调用方则限流规则将仅对指定调用方生效。
+
+> 注：Dubbo 默认通信不携带对端 application name 信息，因此需要开发者在调用端手动将 application name 置入 attachment 中，provider 端进行相应的解析。Sentinel Dubbo Adapter 实现了一个 Filter 用于自动从 consumer 端向 provider 端透传 application name。若调用端未引入 Sentinel Dubbo Adapter，又希望根据调用端限流，可以在调用端手动将 application name 置入 attachment 中，key 为 `dubboApplication`。
+
+在限流日志中会也会记录调用方的名称，如：
+
+```
+2018-07-25 16:26:48|1|com.alibaba.csp.sentinel.demo.dubbo.FooService:sayHello(java.lang.String),FlowException,default,demo-consumer|5,0
+```
+
+其中日志中的 `demo-consumer` 即为调用方名称。
+
+## Service Consumer
+
+> 对服务消费方的流量控制可分为**控制并发线程数**和**服务降级**两个维度。
+
+### 并发线程数限流
+
+Service Consumer 作为客户端去调用远程服务。每一个服务都可能会依赖几个下游服务，若某个服务 A 依赖的下游服务 B 出现了不稳定的情况，服务 A 请求服务 B 的响应时间变长，从而服务 A 调用服务 B 的线程就会产生堆积，最终可能耗尽服务 A 的线程数。我们通过用并发线程数来控制对下游服务 B 的访问，来保证下游服务不可靠的时候，不会拖垮服务自身。基于这种场景，推荐给 Consumer 配置**线程数模式**的限流，来保证自身不被不稳定服务所影响。限流粒度同样可以是服务接口和服务方法两种粒度。
+
+采用基于线程数的限流模式后，我们不需要再显式地去进行线程池隔离，Sentinel 会控制资源的线程数，超出的请求直接拒绝，直到堆积的线程处理完成。
+
+Demo 2 演示了此限流场景，我们看一下这种模式的效果。假设当前服务 A 依赖两个远程服务方法 `sayHello(java.lang.String)` 和 `doAnother()`。前者远程调用的响应时间 为 1s-1.5s之间，后者 RT 非常小（30 ms 左右）。服务 A 端设两个远程方法 thread count 为 5。然后每隔 50 ms 左右向线程池投入两个任务，作为消费者分别远程调用对应方法，持续 10 次。可以看到 `sayHello` 方法被限流 5 次，因为后面调用的时候前面的远程调用还未返回（RT 高）；而 `doAnother()` 调用则不受影响。线程数目超出时快速失败能够有效地防止自己被慢调用所影响。
+
+### 服务降级
+
+当服务依赖于多个下游服务，而某个下游服务调用非常慢时，会严重影响当前服务的调用。这里我们可以利用 Sentinel 熔断降级的功能，为调用端配置基于平均 RT 的[降级规则](https://github.com/alibaba/Sentinel/wiki/%E7%86%94%E6%96%AD%E9%99%8D%E7%BA%A7)。这样当调用链路中某个服务调用的平均 RT 升高，在一定的次数内超过配置的 RT 阈值，Sentinel 就会对此调用资源进行降级操作，接下来的调用都会立刻拒绝，直到过了一段设定的时间后才恢复，从而保护服务不被调用端短板所影响。同时可以配合 fallback 功能使用，在被降级的时候提供相应的处理逻辑。
+
+## Fallback
+
+从 0.1.1 版本开始，Sentinel Dubbo Adapter 还支持配置全局的 fallback 函数，可以在 Dubbo 服务被限流/降级/负载保护的时候进行相应的 fallback 处理。用户只需要实现自定义的 [`DubboFallback`](https://github.com/alibaba/Sentinel/blob/master/sentinel-adapter/sentinel-dubbo-adapter/src/main/java/com/alibaba/csp/sentinel/adapter/dubbo/fallback/DubboFallback.java) 接口，并通过 `DubboFallbackRegistry` 注册即可。默认情况会直接将 `BlockException` 包装后抛出。同时，我们还可以配合 [Dubbo 的 fallback 机制](http://dubbo.apache.org/#!/docs/user/demos/local-mock.md?lang=zh-cn) 来为降级的服务提供替代的实现。
+
+Demo 2 的 Consumer 端提供了一个简单的 fallback 示例。
+
+## Sentinel Dashboard
+
+Sentinel 还提供 API 用于获取实时的监控信息，对应文档见[此处](https://github.com/alibaba/Sentinel/wiki/%E5%AE%9E%E6%97%B6%E7%9B%91%E6%8E%A7)。为了便于使用，Sentinel 还提供了一个控制台（Dashboard）用于配置规则、查看监控、机器发现等功能。
+
+接入 Dashboard 的步骤（**缺一不可**）：
+
+1. 按照 [Sentinel 控制台文档](https://github.com/alibaba/Sentinel/wiki/%E6%8E%A7%E5%88%B6%E5%8F%B0) 启动控制台
+2. 应用引入 `sentinel-transport-simple-http` 依赖，以便控制台可以拉取对应应用的相关信息
+3. 给应用添加相关的启动参数，启动应用。需要配置的参数有：
+   - `-Dcsp.sentinel.api.port`：客户端的 port，用于上报相关信息
+   - `-Dcsp.sentinel.dashboard.server`：控制台的地址
+   - `-Dproject.name`：应用名称，会在控制台中显示
+
+注意某些环境下本地运行 Dubbo 服务还需要加上 `-Djava.net.preferIPv4Stack=true` 参数。比如 Service Provider 示例的启动参数：
+
+```bash
+-Djava.net.preferIPv4Stack=true -Dcsp.sentinel.api.port=8720 -Dcsp.sentinel.dashboard.server=localhost:8080 -Dproject.name=dubbo-provider-demo
+```
+
+Service Consumer 示例的启动参数：
+
+```bash
+-Djava.net.preferIPv4Stack=true -Dcsp.sentinel.api.port=8721 -Dcsp.sentinel.dashboard.server=localhost:8080 -Dproject.name=dubbo-consumer-demo
+```
+
+这样在启动 Service Provider 和 Service Consumer 示例以后，就可以在 Sentinel 控制台中找到我们的服务了。可以很方便地在控制台中配置限流规则：
+
+![规则配置](http://dubbo.incubator.apache.org/img/blog/sentinel-dashboard-view-rules.png)
+
+或者查看实时监控数据：
+
+![秒级实时监控](http://dubbo.incubator.apache.org/img/blog/sentinel-dashboard-metrics.png)

sentinel/sentinel-demo/sentinel-demo-dubbo/pom.xml

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+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <parent>
+        <artifactId>sentinel-demo</artifactId>
+        <groupId>com.alibaba.csp</groupId>
+        <version>1.8.3</version>
+    </parent>
+    <modelVersion>4.0.0</modelVersion>
+
+    <artifactId>sentinel-demo-dubbo</artifactId>
+
+    <dependencies>
+        <!-- Demo use Dubbo 2.6.x, since it supports JDK 1.7 -->
+        <dependency>
+            <groupId>com.alibaba</groupId>
+            <artifactId>dubbo</artifactId>
+            <version>2.6.6</version>
+        </dependency>
+
+        <!-- Dubbo provides qos plugin since 2.5.8 and is enable by default. -->
+        <!-- The dubbo-qos module is optional and it depends Netty 4.x, so add it explicitly -->
+        <!-- @see http://dubbo.apache.org/zh-cn/docs/user/references/qos.html -->
+        <dependency>
+            <groupId>io.netty</groupId>
+            <artifactId>netty-all</artifactId>
+            <version>4.1.42.Final</version>
+        </dependency>
+
+        <!-- As demo use @DubboComponentScan to config, which is implemented in dubbo-config-spring module -->
+        <!-- The dubbo-config-spring module is optional and it depends spring-context-support, so add it explicitly-->
+        <!-- @see https://github.com/apache/incubator-dubbo/issues/2869 -->
+        <dependency>
+            <groupId>com.alibaba.spring</groupId>
+            <artifactId>spring-context-support</artifactId>
+            <version>1.0.2</version>
+        </dependency>
+
+        <!-- Sentinel adapter and transport -->
+        <dependency>
+            <groupId>com.alibaba.csp</groupId>
+            <artifactId>sentinel-dubbo-adapter</artifactId>
+            <version>${project.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>com.alibaba.csp</groupId>
+            <artifactId>sentinel-transport-simple-http</artifactId>
+            <version>${project.version}</version>
+        </dependency>
+    </dependencies>
+
+</project>

sentinel/sentinel-demo/sentinel-demo-dubbo/src/main/java/com/alibaba/csp/sentinel/demo/dubbo/FooService.java

@@ -0,0 +1,25 @@
+/*
+ * Copyright 1999-2018 Alibaba Group Holding Ltd.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.alibaba.csp.sentinel.demo.dubbo;
+
+/**
+ * @author Eric Zhao
+ */
+public interface FooService {
+    String sayHello(String name);
+
+    String doAnother();
+}

sentinel/sentinel-demo/sentinel-demo-dubbo/src/main/java/com/alibaba/csp/sentinel/demo/dubbo/consumer/ConsumerConfiguration.java

@@ -0,0 +1,58 @@
+/*
+ * Copyright 1999-2018 Alibaba Group Holding Ltd.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.alibaba.csp.sentinel.demo.dubbo.consumer;
+
+import com.alibaba.dubbo.config.ApplicationConfig;
+import com.alibaba.dubbo.config.ConsumerConfig;
+import com.alibaba.dubbo.config.RegistryConfig;
+import com.alibaba.dubbo.config.spring.context.annotation.DubboComponentScan;
+
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+
+/**
+ * @author Eric Zhao
+ */
+@Configuration
+@DubboComponentScan
+public class ConsumerConfiguration {
+    @Bean
+    public ApplicationConfig applicationConfig() {
+        ApplicationConfig applicationConfig = new ApplicationConfig();
+        applicationConfig.setName("demo-consumer");
+        return applicationConfig;
+    }
+
+    @Bean
+    public RegistryConfig registryConfig() {
+        RegistryConfig registryConfig = new RegistryConfig();
+        registryConfig.setAddress("multicast://224.5.6.7:1234");
+        return registryConfig;
+    }
+
+    @Bean
+    public ConsumerConfig consumerConfig() {
+        ConsumerConfig consumerConfig = new ConsumerConfig();
+        // Uncomment below line if you don't want to enable Sentinel for Dubbo service consumers.
+        // consumerConfig.setFilter("-sentinel.dubbo.consumer.filter");
+        return consumerConfig;
+    }
+
+    @Bean
+    public FooServiceConsumer annotationDemoServiceConsumer() {
+        return new FooServiceConsumer();
+    }
+}

sentinel/sentinel-demo/sentinel-demo-dubbo/src/main/java/com/alibaba/csp/sentinel/demo/dubbo/consumer/FooServiceConsumer.java

@@ -0,0 +1,36 @@
+/*
+ * Copyright 1999-2018 Alibaba Group Holding Ltd.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.alibaba.csp.sentinel.demo.dubbo.consumer;
+
+import com.alibaba.csp.sentinel.demo.dubbo.FooService;
+import com.alibaba.dubbo.config.annotation.Reference;
+
+/**
+ * @author Eric Zhao
+ */
+public class FooServiceConsumer {
+
+    @Reference(url = "dubbo://127.0.0.1:25758", timeout = 3000)
+    private FooService fooService;
+
+    public String sayHello(String name) {
+        return fooService.sayHello(name);
+    }
+
+    public String doAnother() {
+        return fooService.doAnother();
+    }
+}

sentinel/sentinel-demo/sentinel-demo-dubbo/src/main/java/com/alibaba/csp/sentinel/demo/dubbo/demo1/FooConsumerBootstrap.java

@@ -0,0 +1,54 @@
+/*
+ * Copyright 1999-2018 Alibaba Group Holding Ltd.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.alibaba.csp.sentinel.demo.dubbo.demo1;
+
+import com.alibaba.csp.sentinel.demo.dubbo.consumer.ConsumerConfiguration;
+import com.alibaba.csp.sentinel.demo.dubbo.consumer.FooServiceConsumer;
+import com.alibaba.csp.sentinel.slots.block.SentinelRpcException;
+
+import org.springframework.context.annotation.AnnotationConfigApplicationContext;
+
+/**
+ * Please add the following VM arguments:
+ * <pre>
+ * -Djava.net.preferIPv4Stack=true
+ * -Dcsp.sentinel.api.port=8721
+ * -Dproject.name=dubbo-consumer-demo
+ * </pre>
+ *
+ * @author Eric Zhao
+ */
+public class FooConsumerBootstrap {
+
+    public static void main(String[] args) {
+        AnnotationConfigApplicationContext consumerContext = new AnnotationConfigApplicationContext();
+        consumerContext.register(ConsumerConfiguration.class);
+        consumerContext.refresh();
+
+        FooServiceConsumer service = consumerContext.getBean(FooServiceConsumer.class);
+
+        for (int i = 0; i < 15; i++) {
+            try {
+                String message = service.sayHello("Eric");
+                System.out.println("Success: " + message);
+            } catch (SentinelRpcException ex) {
+                System.out.println("Blocked");
+            } catch (Exception ex) {
+                ex.printStackTrace();
+            }
+        }
+    }
+}

sentinel/sentinel-demo/sentinel-demo-dubbo/src/main/java/com/alibaba/csp/sentinel/demo/dubbo/demo1/FooProviderBootstrap.java

@@ -0,0 +1,63 @@
+/*
+ * Copyright 1999-2018 Alibaba Group Holding Ltd.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.alibaba.csp.sentinel.demo.dubbo.demo1;
+
+import java.util.Collections;
+
+import com.alibaba.csp.sentinel.init.InitExecutor;
+import com.alibaba.csp.sentinel.slots.block.RuleConstant;
+import com.alibaba.csp.sentinel.slots.block.flow.FlowRule;
+import com.alibaba.csp.sentinel.slots.block.flow.FlowRuleManager;
+
+import org.springframework.context.annotation.AnnotationConfigApplicationContext;
+
+/**
+ * Please add the following VM arguments:
+ * <pre>
+ * -Djava.net.preferIPv4Stack=true
+ * -Dcsp.sentinel.api.port=8720
+ * -Dproject.name=dubbo-provider-demo
+ * </pre>
+ *
+ * @author Eric Zhao
+ */
+public class FooProviderBootstrap {
+
+    private static final String RES_KEY = "com.alibaba.csp.sentinel.demo.dubbo.FooService:sayHello(java.lang.String)";
+    private static final String INTERFACE_RES_KEY = "com.alibaba.csp.sentinel.demo.dubbo.FooService";
+
+    public static void main(String[] args) {
+        // Users don't need to manually call this method.
+        InitExecutor.doInit();
+
+        initFlowRule();
+
+        AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext();
+        context.register(ProviderConfiguration.class);
+        context.refresh();
+
+        System.out.println("Service provider is ready");
+    }
+
+    private static void initFlowRule() {
+        FlowRule flowRule = new FlowRule();
+        flowRule.setResource(RES_KEY);
+        flowRule.setCount(10);
+        flowRule.setGrade(RuleConstant.FLOW_GRADE_QPS);
+        flowRule.setLimitApp("default");
+        FlowRuleManager.loadRules(Collections.singletonList(flowRule));
+    }
+}

sentinel/sentinel-demo/sentinel-demo-dubbo/src/main/java/com/alibaba/csp/sentinel/demo/dubbo/demo1/FooServiceImpl.java

@@ -0,0 +1,38 @@
+/*
+ * Copyright 1999-2018 Alibaba Group Holding Ltd.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.alibaba.csp.sentinel.demo.dubbo.demo1;
+
+import java.time.LocalDateTime;
+
+import com.alibaba.csp.sentinel.demo.dubbo.FooService;
+import com.alibaba.dubbo.config.annotation.Service;
+
+/**
+ * @author Eric Zhao
+ */
+@Service
+public class FooServiceImpl implements FooService {
+
+    @Override
+    public String sayHello(String name) {
+        return String.format("Hello, %s at %s", name, LocalDateTime.now());
+    }
+
+    @Override
+    public String doAnother() {
+        return LocalDateTime.now().toString();
+    }
+}

sentinel/sentinel-demo/sentinel-demo-dubbo/src/main/java/com/alibaba/csp/sentinel/demo/dubbo/demo1/ProviderConfiguration.java

@@ -0,0 +1,54 @@
+/*
+ * Copyright 1999-2018 Alibaba Group Holding Ltd.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.alibaba.csp.sentinel.demo.dubbo.demo1;
+
+import com.alibaba.dubbo.config.ApplicationConfig;
+import com.alibaba.dubbo.config.ProtocolConfig;
+import com.alibaba.dubbo.config.RegistryConfig;
+import com.alibaba.dubbo.config.spring.context.annotation.DubboComponentScan;
+
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+
+/**
+ * @author Eric Zhao
+ */
+@Configuration
+@DubboComponentScan("com.alibaba.csp.sentinel.demo.dubbo.demo1")
+public class ProviderConfiguration {
+
+    @Bean
+    public ApplicationConfig applicationConfig() {
+        ApplicationConfig applicationConfig = new ApplicationConfig();
+        applicationConfig.setName("demo-provider");
+        return applicationConfig;
+    }
+
+    @Bean
+    public RegistryConfig registryConfig() {
+        RegistryConfig registryConfig = new RegistryConfig();
+        registryConfig.setAddress("multicast://224.5.6.7:1234");
+        return registryConfig;
+    }
+
+    @Bean
+    public ProtocolConfig protocolConfig() {
+        ProtocolConfig protocolConfig = new ProtocolConfig();
+        protocolConfig.setName("dubbo");
+        protocolConfig.setPort(25758);
+        return protocolConfig;
+    }
+}

sentinel/sentinel-demo/sentinel-demo-dubbo/src/main/java/com/alibaba/csp/sentinel/demo/dubbo/demo2/FooConsumerBootstrap.java

@@ -0,0 +1,92 @@
+/*
+ * Copyright 1999-2018 Alibaba Group Holding Ltd.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.alibaba.csp.sentinel.demo.dubbo.demo2;
+
+import java.util.Collections;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+
+import com.alibaba.csp.sentinel.adapter.dubbo.DubboAdapterGlobalConfig;
+import com.alibaba.csp.sentinel.concurrent.NamedThreadFactory;
+import com.alibaba.csp.sentinel.demo.dubbo.consumer.ConsumerConfiguration;
+import com.alibaba.csp.sentinel.demo.dubbo.consumer.FooServiceConsumer;
+import com.alibaba.csp.sentinel.slots.block.RuleConstant;
+import com.alibaba.csp.sentinel.slots.block.SentinelRpcException;
+import com.alibaba.csp.sentinel.slots.block.flow.FlowRule;
+import com.alibaba.csp.sentinel.slots.block.flow.FlowRuleManager;
+import com.alibaba.dubbo.rpc.RpcResult;
+
+import org.springframework.context.annotation.AnnotationConfigApplicationContext;
+
+/**
+ * Please add the following VM arguments:
+ * <pre>
+ * -Djava.net.preferIPv4Stack=true
+ * -Dcsp.sentinel.api.port=8721
+ * -Dproject.name=dubbo-consumer-demo
+ * </pre>
+ *
+ * @author Eric Zhao
+ */
+public class FooConsumerBootstrap {
+
+    private static final String RES_KEY = "com.alibaba.csp.sentinel.demo.dubbo.FooService:sayHello(java.lang.String)";
+    private static final String INTERFACE_RES_KEY = "com.alibaba.csp.sentinel.demo.dubbo.FooService";
+
+    @SuppressWarnings("PMD.ThreadPoolCreationRule")
+    private static final ExecutorService pool = Executors.newFixedThreadPool(10,
+        new NamedThreadFactory("dubbo-consumer-pool"));
+
+    public static void main(String[] args) {
+        initFlowRule();
+
+        AnnotationConfigApplicationContext consumerContext = new AnnotationConfigApplicationContext();
+        consumerContext.register(ConsumerConfiguration.class);
+        consumerContext.refresh();
+
+        FooServiceConsumer service = consumerContext.getBean(FooServiceConsumer.class);
+        for (int i = 0; i < 10; i++) {
+            pool.submit(() -> {
+                try {
+                    String message = service.sayHello("Eric");
+                    System.out.println("Success: " + message);
+                } catch (SentinelRpcException ex) {
+                    System.out.println("Blocked");
+                } catch (Exception ex) {
+                    ex.printStackTrace();
+                }
+            });
+            pool.submit(() -> System.out.println("Another: " + service.doAnother()));
+        }
+    }
+
+    private static void initFlowRule() {
+        FlowRule flowRule = new FlowRule();
+        flowRule.setResource(RES_KEY);
+        flowRule.setCount(5);
+        flowRule.setGrade(RuleConstant.FLOW_GRADE_THREAD);
+        flowRule.setLimitApp("default");
+        FlowRuleManager.loadRules(Collections.singletonList(flowRule));
+    }
+
+    private static void registerFallback() {
+        // Register fallback handler for consumer.
+        // If you only want to handle degrading, you need to
+        // check the type of BlockException.
+        DubboAdapterGlobalConfig.setConsumerFallback((a, b, ex) ->
+            new RpcResult("Error: " + ex.getClass().getTypeName()));
+    }
+}

sentinel/sentinel-demo/sentinel-demo-dubbo/src/main/java/com/alibaba/csp/sentinel/demo/dubbo/demo2/FooProviderBootstrap.java

@@ -0,0 +1,44 @@
+/*
+ * Copyright 1999-2018 Alibaba Group Holding Ltd.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.alibaba.csp.sentinel.demo.dubbo.demo2;
+
+import com.alibaba.csp.sentinel.init.InitExecutor;
+
+import org.springframework.context.annotation.AnnotationConfigApplicationContext;
+
+/**
+ * Please add the following VM arguments:
+ * <pre>
+ * -Djava.net.preferIPv4Stack=true
+ * -Dcsp.sentinel.api.port=8720
+ * -Dproject.name=dubbo-provider-demo
+ * </pre>
+ *
+ * @author Eric Zhao
+ */
+public class FooProviderBootstrap {
+
+    public static void main(String[] args) {
+        // Users don't need to manually call this method.
+        InitExecutor.doInit();
+
+        AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext();
+        context.register(ProviderConfiguration.class);
+        context.refresh();
+
+        System.out.println("Service provider is ready");
+    }
+}

sentinel/sentinel-demo/sentinel-demo-dubbo/src/main/java/com/alibaba/csp/sentinel/demo/dubbo/demo2/FooServiceImpl.java

@@ -0,0 +1,38 @@
+/*
+ * Copyright 1999-2018 Alibaba Group Holding Ltd.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.alibaba.csp.sentinel.demo.dubbo.demo2;
+
+import java.time.LocalDateTime;
+
+import com.alibaba.csp.sentinel.demo.dubbo.FooService;
+import com.alibaba.dubbo.config.annotation.Service;
+
+/**
+ * @author Eric Zhao
+ */
+@Service
+public class FooServiceImpl implements FooService {
+
+    @Override
+    public String sayHello(String name) {
+        return String.format("Hello, %s at %s", name, LocalDateTime.now());
+    }
+
+    @Override
+    public String doAnother() {
+        return LocalDateTime.now().toString();
+    }
+}

sentinel/sentinel-demo/sentinel-demo-dubbo/src/main/java/com/alibaba/csp/sentinel/demo/dubbo/demo2/ProviderConfiguration.java

@@ -0,0 +1,54 @@
+/*
+ * Copyright 1999-2018 Alibaba Group Holding Ltd.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.alibaba.csp.sentinel.demo.dubbo.demo2;
+
+import com.alibaba.dubbo.config.ApplicationConfig;
+import com.alibaba.dubbo.config.ProtocolConfig;
+import com.alibaba.dubbo.config.RegistryConfig;
+import com.alibaba.dubbo.config.spring.context.annotation.DubboComponentScan;
+
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+
+/**
+ * @author Eric Zhao
+ */
+@Configuration
+@DubboComponentScan("com.alibaba.csp.sentinel.demo.dubbo.demo2")
+public class ProviderConfiguration {
+
+    @Bean
+    public ApplicationConfig applicationConfig() {
+        ApplicationConfig applicationConfig = new ApplicationConfig();
+        applicationConfig.setName("demo-provider");
+        return applicationConfig;
+    }
+
+    @Bean
+    public RegistryConfig registryConfig() {
+        RegistryConfig registryConfig = new RegistryConfig();
+        registryConfig.setAddress("multicast://224.5.6.7:1234");
+        return registryConfig;
+    }
+
+    @Bean
+    public ProtocolConfig protocolConfig() {
+        ProtocolConfig protocolConfig = new ProtocolConfig();
+        protocolConfig.setName("dubbo");
+        protocolConfig.setPort(25758);
+        return protocolConfig;
+    }
+}