Springcloud Circuit Breaker Monitoring (Hystrix Dashboard) (ix)

Circuit Breaker

The circuit breaker model originates from Martin Fowler's circuit breaker. "Circuit Breaker" itself is a switch device, used in the circuit to protect the line overload, when the circuit has a short circuit, "circuit breaker" can timely cut off the fault circuit, to prevent the occurrence of overload, heat, and even fire serious consequences.

In a distributed architecture, the role of the circuit breaker pattern is similar, when a service unit fails (similar to a short-circuit with electrical appliances), through the fault monitoring of the circuit breaker (similar to a fuse fuse), to the caller returned an error response, rather than a long wait. This does not cause the thread to fail to be released for a long time because of the invocation of the fault service, thus avoiding the spread of the fault in the distributed system.

Circuit Breaker Monitoring

In the micro-service architecture, a circuit breaker model is presented to ensure the usability of the program and prevent the network from causing the error. The condition of the circuit breaker reflects the usability and robustness of a program, which is an important indicator. The Hystrix dashboard is a component of the circuit breaker State, providing data monitoring and a friendly graphical interface

Renovation Project

Copy the project spring-cloud-ribbon-consumer-hystrix , modify the name spring-cloud-ribbon-consumer-hystrix-dashboard on its basis to transform it. FeignThe transformation is the same as this.

The pom corresponding dependencies are introduced in the project file:

<dependency> <groupId></groupId> <artifactId> spring-cloud-starter-  </artifactId> </dependency> <dependency> <groupId></groupId> < Artifactid> Spring-boot-starter-</artifactId> </dependency>   <dependency > <groupId></groupId> <artifactId> spring-cloud-starter-hystrix-  </artifactId> </dependency>

Turn on HD

Modifying a RibbonConsumerApplication.java class

In the program's entry RibbonConsumerApplication class, plus @EnableHystrix annotations to open the circuit breaker, this is necessary, and you need to declare the break point in the program @HystrixCommand； @EnableHystrixDashboard annotated, open HystrixDashboard， You are welcome to study the relevant technology to understand the source of friends directly seeking exchange and sharing technology: 2147775633

Package Io.ymq.example.ribbon.consumer.hystrix;import Org.springframework.boot.springapplication;import Org.springframework.boot.autoconfigure.springbootapplication;import Org.springframework.cloud.client.discovery.enablediscoveryclient;import Org.springframework.cloud.client.loadbalancer.loadbalanced;import Org.springframework.cloud.netflix.hystrix.enablehystrix;import Org.springframework.cloud.netflix.hystrix.dashboard.enablehystrixdashboard;import Org.springframework.context.annotation.Bean, .... Import org.springframework.web.client.resttemplate;@ Enablehystrix@enablediscoveryclient@enablehystrixdashboard@springbootapplication Public classribbonconsumerapplication {@LoadBalanced @beanresttemplate resttemplate () {return Newresttemplate (); Public Static voidMain (string[] args) {Springapplication.run (ribbonconsumerapplication.class, args);

Declaring a break point

Declaring a break point@HystrixCommand(fallbackMethod="defaultStores")

Package Io.ymq.example.ribbon.consumer.hystrix; import Com.netflix.hystrix.contrib.javanica.annotation.HystrixCommand; Import org.springframework.beans.factory.annotation.Autowired; Import org.springframework.stereotype.Component; Import org.springframework.web.bind.annotation.GetMapping; Import Org.springframework.web.bind.annotation.RestController; Import Org.springframework.web.client.RestTemplate; *Description: Call the provider's ' home ' method*@author Yanpenglei @RestController Public classConsumercontroller {@AutowiredPrivateresttemplate resttemplate; @HystrixCommand (Fallbackmethod="Defaultstores") @GetMapping (value="/hello")     PublicString Hello () {returnResttemplate.getforentity ("http://eureka-provider/", String.class). GetBody ();  PublicString defaultstores () {return "feign + hystrix Dashboard, provider service hung up";

@HystrixCommandIndicates that the method is a hystrix package, can be dependent on the service to isolate, downgrade, rapid failure, quick retry, and so on hystrix related functions The annotation properties are many, the following explains several of them

fallbackMethodDowngrade method

commandPropertiesGeneral configuration properties that can be configured HystrixCommand , such as thread pool or semaphore isolation, fuse fuse rules, etc.

ignoreExceptionsIgnored exception, default does not HystrixBadRequestException count to failed

groupKey()Group name, using the class name by default

commandKeyCommand name, default use method name

More detailed source code reference: http://minglisoft.cn/honghu/technology.html

Springcloud Circuit Breaker Monitoring (Hystrix Dashboard) (ix)