Solve the problem of unable to connect to command metric stream and related problems in the hystrix dashboard

solve hystrix dashboard Error reported in Unable to connect to Command Metric Stream And related questions

In practice spring cloud hystrix dashboard when , Summarize the three problems encountered .
Premise ：
On the provider client ( The port number is 8001) Be dependent ：

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-actuator</artifactId>
</dependency>

On the consumer client ( The port number is 9001) Be dependent ：

<dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-starter-netflix-hystrix</artifactId>
</dependency>
<dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-starter-netflix-hystrix-dashboard</artifactId>
</dependency>

1. visit http://localhost:8001/actuator/hystrix.stream, Page blank .

The situation is as follows ：

The problem is solved ： We will add... In the main startup class of the provider client ServletRegistrationBean Component can solve the problem of blank pages .

@Bean
public ServletRegistrationBean hystrixMetricsStreamServlet(){
    
    ServletRegistrationBean registrationBean = new ServletRegistrationBean(new HystrixMetricsStreamServlet());
    registrationBean.addUrlMappings("/actuator/hystrix.stream");
    return registrationBean;
}

2. visit http://localhost:8001/actuator/hystrix.stream, Page always ping.

The situation is as follows ：

The problem is solved ： First, we need to add a circuit breaker mechanism to the control class of the provider client

@RestController
public class DeptController {
    

    @Autowired
    private DeptService deptService;

    @RequestMapping(value = "/dept/get/{id}", method = RequestMethod.GET)
    @HystrixCommand(fallbackMethod = "processHystrix_Get")
    public Dept get(@PathVariable("id") Long id) {
    
        Dept dept = deptService.get(id);
        if (dept == null) {
    
            throw new RuntimeException(" The ID: " + id + "  There is no corresponding information ");
        }
        return dept;
    }

    public Dept processHystrix_Get(@PathVariable("id") Long id) {
    
        return new Dept().setDeptno(id)
                .setDname(" The ID: " + id + "  There is no corresponding information ,[email protected]")
                .setDb_source("no this database in MySQL");
    }
}

Secondly, add a pair in the main startup class of the provider client Hystrix The support of fuse mechanism

@EnableCircuitBreaker

restart eureka、 Provider client and consumer client services , Finally, request the method in the control class several times before accessing http://localhost:8001/actuator/hystrix.stream, will ping Produce results , as follows ：

3. The graphical interface of fuse monitoring reports an error Unable to connect to Command Metric Stream

The situation is as follows ：

Problem solving ： On the consumer client yml Add the following code to the file to solve

hystrix:
  dashboard:
    proxy-stream-allow-list: "*"

restart eureka、 Provider client and consumer client services , After sending several requests, refresh the graphic page of fuse monitoring , The final results are as follows ：