Sentinel生产环境实践

来自杨三超wiki

1、功能描述

API 限流

sentinel默认会探测所有API，但需要注意，Sentinel 会在客户端首次调用时候进行初始化，开始向控制台发送心跳包。因此需要确保客户端有访问量，才能在控制台上看到监控数据。

RPC限流粒度

可以是服务接口和服务方法两种粒度：

• 服务接口：resourceName 为 

  接口全限定名

  ，如 

  com.alibaba.csp.sentinel.demo.dubbo.FooService

• 服务方法：resourceName 为 

  接口全限定名:方法签名

  ，如 

  com.alibaba.csp.sentinel.demo.dubbo.FooService:sayHello(java.lang.String)

存在问题

1、规则持久化

支持基于 ZooKeeper / Nacos / Apollo 的数据源规则持久化，但需要改造；

2、统一异常处理；

需要自己改造；

3、监控数据持久化；

需要自己改造；

2、Dashboard改造部署

1、修改路由规则

第一步：修改dashboad.flowV1为dashboad.flow；

第二步：FlowServiceV1修改为FlowServiceV2；

2、支持规则持久化

sentinel支持限流、降级、热点、系统、授权五种规则，目前常用的功能是限流和降级、基于zookeeper实现持久化规则；

dashboad默认规则都是内存，同时需要修改对应的Controller；

3、监控日志持久化    

默认监控日志仅在内容保留5分钟

4、部署

• 编译jar包：https://github.com/alibaba/Sentinel/releases
• 启动：java -Dserver.port=8100 -Dproject.name=sentinel-dashboard -jar sentinel-dashboard-1.6.2.jar 

  • -Dserver.port=8080

     用于指定 Sentinel 控制台端口为 

    8100

    。
• 扩展阅读 Sentinel 控制台： https://github.com/alibaba/Sentinel/wiki/%E6%8E%A7%E5%88%B6%E5%8F%B0

3、服务如何使用

1、添加相关pom

1.1 springboot2.x添加pom

<!--sentinel start--> <!-- https://mvnrepository.com/artifact/com.alibaba.cloud/spring-cloud-starter-alibaba-sentinel --> < dependency > < groupId >com.alibaba.cloud</ groupId > < artifactId >spring-cloud-starter-alibaba-sentinel</ artifactId > < version >2.1.0.RELEASE</ version > < exclusions > < exclusion > < artifactId >sentinel-core</ artifactId > < groupId >com.alibaba.csp</ groupId > </ exclusion > < exclusion > < artifactId >fastjson</ artifactId > < groupId >com.alibaba</ groupId > </ exclusion > </ exclusions > </ dependency > <!-- https://mvnrepository.com/artifact/com.alibaba.csp/sentinel-datasource-zookeeper --> < dependency > < groupId >com.alibaba.csp</ groupId > < artifactId >sentinel-datasource-zookeeper</ artifactId > < version >1.6.3</ version > < exclusions > < exclusion > < artifactId >sentinel-datasource-extension</ artifactId > < groupId >com.alibaba.csp</ groupId > </ exclusion > < exclusion > < artifactId >zookeeper</ artifactId > < groupId >org.apache.zookeeper</ groupId > </ exclusion > </ exclusions > </ dependency > <!-- https://mvnrepository.com/artifact/com.alibaba.csp/sentinel-dubbo-adapter --> < dependency > < groupId >com.alibaba.csp</ groupId > < artifactId >sentinel-dubbo-adapter</ artifactId > < version >1.6.3</ version > </ dependency > < dependency > < groupId >org.apache.curator</ groupId > < artifactId >curator-framework</ artifactId > < version >2.11.0</ version > </ dependency > < dependency > < groupId >org.apache.curator</ groupId > < artifactId >curator-client</ artifactId > < version >2.11.0</ version > </ dependency > < dependency > < groupId >org.apache.curator</ groupId > < artifactId >curator-recipes</ artifactId > < version >2.11.0</ version > </ dependency > <!--sentinel end-->

1.2 springboot1.5.x添加pom

 折叠源码

<!--sentinel start--> <!--https://mvnrepository.com/artifact/com.alibaba.cloud/spring-cloud-starter-alibaba-sentinel --> < dependency > < groupId >com.alibaba.cloud</ groupId > < artifactId >spring-cloud-starter-alibaba-sentinel</ artifactId > < version >1.5.1.RELEASE</ version > </ dependency > < dependency > < groupId >com.alibaba.csp</ groupId > < artifactId >sentinel-cluster-client-default</ artifactId > < version >1.5.1</ version > </ dependency > < dependency > < groupId >com.alibaba.csp</ groupId > < artifactId >sentinel-cluster-common-default</ artifactId > < version >1.5.1</ version > </ dependency > < dependency > < groupId >com.alibaba.csp</ groupId > < artifactId >sentinel-cluster-server-default</ artifactId > < version >1.5.1</ version > </ dependency > < dependency > < groupId >com.alibaba.csp</ groupId > < artifactId >sentinel-datasource-extension</ artifactId > < version >1.5.1</ version > </ dependency > < dependency > < groupId >com.alibaba.csp</ groupId > < artifactId >sentinel-parameter-flow-control</ artifactId > < version >1.5.1</ version > </ dependency > < dependency > < groupId >com.alibaba.csp</ groupId > < artifactId >sentinel-transport-common</ artifactId > < version >1.5.1</ version > </ dependency > < dependency > < groupId >com.alibaba.csp</ groupId > < artifactId >sentinel-transport-simple-http</ artifactId > < version >1.5.1</ version > </ dependency > < dependency > < groupId >com.alibaba.csp</ groupId > < artifactId >sentinel-web-servlet</ artifactId > < version >1.5.1</ version > </ dependency > < dependency > < groupId >com.alibaba.csp</ groupId > < artifactId >sentinel-core</ artifactId > < version >1.5.1</ version > </ dependency > < dependency > < groupId >com.alibaba.csp</ groupId > < artifactId >sentinel-annotation-aspectj</ artifactId > < version >1.5.1</ version > </ dependency > < dependency > < groupId >com.alibaba.csp</ groupId > < artifactId >sentinel-datasource-zookeeper</ artifactId > < version >1.5.1</ version > < exclusions > < exclusion > < artifactId >zookeeper</ artifactId > < groupId >org.apache.zookeeper</ groupId > </ exclusion > </ exclusions > </ dependency > <!-- https://mvnrepository.com/artifact/com.alibaba.csp/sentinel-dubbo-adapter --> < dependency > < groupId >com.alibaba.csp</ groupId > < artifactId >sentinel-dubbo-adapter</ artifactId > < version >1.5.1</ version > </ dependency > <!--sentinel end-->

2、添加配置

添加配置： cloud: sentinel: transport: port:  8731 dashboard: http: //127.0.0.1:9001 datasource: ds: zk: path: / serverAddr: zookeeper: 2181 groupId: SENTINEL_GROUP dataId: ${spring.application.name}-flow-rules ruleType: FLOW ds1: zk: path: / serverAddr: zookeeper: 2181 groupId: SENTINEL_GROUP dataId: ${spring.application.name}-degrade-rules ruleType: DEGRADE

3、添加统一异常

API统一异常

@Configuration public class MyFallbackAPIConfig { private static volatile UrlBlockHandler urlBlockHandler =  new DefaultUrlBlockHandler(); static { WebCallbackManager.setUrlBlockHandler(urlBlockHandler); } public static class DefaultUrlBlockHandler  implements UrlBlockHandler { private static void writeDefaultBlockedPage(HttpServletResponse response)  throws IOException { response.setCharacterEncoding( "UTF-8" ); response.setHeader( "Content-Type" ,  "application/json; charset=utf-8" ); Map<String, Object> responseObject =  new HashMap<>( 3 ); responseObject.put( "code" , 10001 ); responseObject.put( "message" , "系统繁忙，请稍后再试！" ); responseObject.put( "body" , new Object()); JSONObject responseJSONObject = (JSONObject)JSONObject.toJSON(responseObject); PrintWriter out = response.getWriter(); out.write(responseJSONObject.toString()); out.flush(); out.close(); } @Override public void blocked(HttpServletRequest request, HttpServletResponse response, BlockException ex) throws IOException { // Directly redirect to the default flow control (blocked) page or customized block page. blockRequest(request, response); } public static void blockRequest(HttpServletRequest request, HttpServletResponse response)  throws IOException { StringBuffer url = request.getRequestURL(); if ( "GET" .equals(request.getMethod()) && StringUtil.isNotBlank(request.getQueryString())) { url.append( "?" ).append(request.getQueryString()); } if (StringUtil.isBlank(WebServletConfig.getBlockPage())) { writeDefaultBlockedPage(response); }  else { String redirectUrl = WebServletConfig.getBlockPage() +  "?http_referer=" + url.toString(); // Redirect to the customized block page. response.sendRedirect(redirectUrl); } } } }

dubbo统一异常

@Component public class MyFallbackDubboConfig  { private static volatile DefaultDubboBlockHandler dubboFallback =  new DefaultDubboBlockHandler(); static { DubboFallbackRegistry.setConsumerFallback(dubboFallback); } public static class DefaultDubboBlockHandler  implements DubboFallback { @Override public Result handle(Invoker<?> invoker, Invocation invocation, BlockException e) { return new RpcResult( null ); } } }