[micro service ~sentinel] sentinel dashboard control panel

Here is 【 Microservices ~Sentinel】, Pay attention to me to learn micro services without getting lost
If it helps you , Give the blogger a free praise to show encouragement
You are welcome to comment on the collection ️

Column introduction

【 Microservices ~Sentinel】 At present, it mainly updates micro services , Learn together and progress together .

Introduction to this issue

This issue focuses on Sentinel And dashboard Control panel

List of articles

dashboard Control panel

summary

To configure dashboard

Set resource point ( Buried point )

Current limiting

Writing test classes

Current limiting method

Current limiting operation

Fusing the drop

Degradation method

test

Degraded operation

The difference between current limiting and degradation

dashboard Control panel

summary

Sentinel Dashboard It's an independent project ,sentinel-dashboard-1.8.4.jar, Need to use java -jar function

java -jar -Dserver.port=18080 sentinel-dashboard-1.8.4.jar

Download address

Releases · alibaba/Sentinel · GitHub

To configure dashboard

Add coordinates （ existing ）

<!--  Downgrade  -->
<dependency>
    <groupId>com.alibaba.cloud</groupId>
    <artifactId>spring-cloud-starter-alibaba-sentinel</artifactId>
</dependency>

To configure yml

#server.port=8071
#spring.application.name=service-consumer
#spring.cloud.nacos.discovery.server-addr=127.0.0.1:8848
#spring.cloud.sentinel.transport.dashboard=192.168.152.153:8080
# Port number 
server:
  port: 8071

spring:
  application:
    name: service-consumer          # service name 
  cloud:
    nacos:
      discovery:
        server-addr: 127.0.0.1:8848   #nacos Service address 
    sentinel:
      transport:
        dashboard: 127.0.0.1:18080
feign:
  sentinel:
    enabled: true

test

• Access resources first http://localhost:8071/feign/echo/123

• dashboard Sign in

Look at the control panel http://localhost:18080/

Set resource point ( Buried point )

adopt @SentinelResource annotation , Set monitoring point （ Define control resources 、 Configure the control policy ）

package com.czxy.nacos.controller;

import com.alibaba.csp.sentinel.annotation.SentinelResource;
import com.czxy.nacos.feign.TestFeign;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RestController;

import javax.annotation.Resource;


@RestController
@RequestMapping("/feign")
public class TestFeignController {
    @Resource
    private TestFeign testMyFeign;

    @RequestMapping(value = "/echo/{str}", method = RequestMethod.GET)
    @SentinelResource("/feign/echo")
    public String echo(@PathVariable String str) {
        return testMyFeign.echo(str);
    }
}

test

Current limiting

Writing test classes

package com.czxy.controller;

import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;


@RestController
@RequestMapping("/user")
public class UserController {

    @GetMapping("/login")
    public String login(String str) {
        return " Login successful " + str;
    }


    @GetMapping("/register")
    public String register(String str) {
        return " Registered successfully ";
    }
}

Current limiting method

• adopt @SentinelResource Annotated blockHandler Property specifies the current limiting handler

package com.czxy.nacos.controller;

import com.alibaba.csp.sentinel.annotation.SentinelResource;
import com.alibaba.csp.sentinel.slots.block.BlockException;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
@RequestMapping("/user")
public class UserController {

    @GetMapping("/login")
    //  Current limiting setting 
    @SentinelResource(value="login", blockHandler = "loginBlockHandler")
    public String login(String str) {
        return " Login successful " + str;
    }

    public String loginBlockHandler(String str , BlockException e) {
        return str + ":  Please try again later ";
    }

    @GetMapping("/register")
    public String register(String str) {
        return " Registered successfully ";
    }
}

Current limiting operation

• function sentinel-dashboard-1.8.4.jar

• Access test functions ：http://localhost:8071/user/login?str=1234

• adopt dashboard Set current limiting

Continuous fast 2 Access test function

Fusing the drop

Degradation method

• Use @SentinelResource Annotated fallback Property to specify the degraded method name

package com.czxy.controller;

import com.alibaba.csp.sentinel.annotation.SentinelResource;
import com.alibaba.csp.sentinel.slots.block.BlockException;
import org.apache.commons.lang.math.RandomUtils;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;


@RestController
@RequestMapping("/user")
public class UserController {

    @GetMapping("/login")
    //  Current limiting setting 
    @SentinelResource(value="login", blockHandler = "loginBlockHandler")
    public String login(String str) {
        return " Login successful " + str;
    }

    public String loginBlockHandler(String str , BlockException e) {
        return str + ":  Please try again later ";
    }


    @GetMapping("/register")
    //  Fusing the drop 
    @SentinelResource(value="register", fallback = "registerFallback")
    public String register(String str) {
        int r = RandomUtils.nextInt(10);
        if(r < 5) {
            int i = 1 / 0;
        }
        return " Registered successfully ";
    }

    public String registerFallback(String str) {
        return str + ":  Fusing the drop ";
    }
}

test

success

Fusing the drop

Degraded operation

• Slow call ratio ：

  • RT： Mean response time

  • Scale threshold ：

  • Duration of fusing ：

  • Minimum number of requests ：

• Abnormal proportion ： The ratio of the total number of exceptions per second to the throughput exceeds the threshold （DegradeRule Medium count） after , Resources go into a degraded state

• Number of abnormal ： When resources are near 1 After the number of exceptions exceeds the threshold, it will fuse

The difference between current limiting and degradation

• Current limiting is achieved by setting QPS( Query rate per second )/ Number of threads , Reject the part exceeding the threshold ;

• Service degradation is to monitor request response time 、 Response exception ratio 、 Number of exceptions ; Threshold exceeded , The service will be degraded and blown , Not available for a certain period of time ;