Openfeign use step polling strategy and weight log4j configuration of openfeign interceptor

Call component Feign（openFeign）

JAVA  How to implement interface call in project ？ 1）Httpclient HttpClient  yes  Apache Jakarta Common  Sub projects under , To provide efficient 、 Abreast of the times 、 Rich in functions   Support for  Http  Client programming toolkit for protocol , And it supports  HTTP  The latest version of the agreement and recommendations .HttpClient  Compared with tradition  JDK  Self contained  URLConnection, Improved ease of use and flexibility , Make the client send  HTTP  It's easier to ask , Improved development efficiency . 2）Okhttp  An open source project to handle network requests , It's the most popular lightweight framework in Android , from  Square  The company contributed , Used in substitution HttpUrlConnection  and  Apache HttpClient.OkHttp  Have a simple  API、 Efficient performance , And support a variety of protocols （HTTP/2  and  SPDY）. 3）HttpURLConnection HttpURLConnection  yes  Java  Standard class , It is inherited from  URLConnection, Can be used to send GET  request 、POST  request .HttpURLConnection  It's complicated to use , Unlike  HttpClient  That's easy to use . 4）RestTemplate WebClient RestTemplate  yes  Spring  Provided for access  Rest  Client of service ,RestTemplate  Provides a variety of convenient remote access  HTTP  Method of service , Can greatly improve the writing efficiency of the client .  The above are the most common methods to call the interface , The method we're going to introduce next is simpler than the one above 、 convenient ,  It is  Feign.

What Well yes Feign ( This is especially for openFeign)

1.Feign yes Netflix Developed declarative 、 templated HTTP client , It's inspired by Retrofit、JAXRS-2.0 as well as WebSocket.Feign Can help us more convenient 、 Call... Gracefully HTTP API.
​
Feign Support multiple annotations , for example Feign Own notes or JAX-RS Annotations etc. .
​
#!!!!!!!!!!!!!!!!!!!!!
Spring Cloud openfeign Yes Feign Enhanced , To support Spring MVC annotation , In addition, it integrates Ribbon and Nacos, Thus making Feign It is more convenient to use 
​
 advantage 
Feign It can be used  HTTP  When requesting a remote service, it's like calling a local method , Developers don't realize it's a remote method , I don't even know it's a  HTTP  request . It looks like  Dubbo  equally ,consumer  Directly call the interface method  provider, It doesn't have to go through the regular  Http Client  Construct the request and parse the returned data . It solves the problem of allowing developers to call remote interfaces just like calling local methods , No need to pay attention to the details of the interaction with the remote , Let alone focus on distribution   Open environment development .

How do you use it? ？

linux Direct start nacos
# start-up 
startup.sh
# Open the browser 
192.168.64.200:8848/nacos/#/login

# Enter the address to execute the order   Inventory deduction 
http://localhost:12002/order-server/addorder

Use steps

First step Introduce dependencies

        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-openfeign</artifactId>
        </dependency>

Two steps Write call interface [email protected] annotation

@FeignClient(value = "stockserv",path = "/stock-server")
public interface StockFeignService {
    @RequestMapping("/reduced")
    public String reduced();
}
​

The third step The caller adds... On the startup class @EnableFeignClients annotation

@SpringBootApplication
@EnableFeignClients
public class OrderFeignApplication {
    public static void main(String[] args) {
        SpringApplication.run(OrderFeignApplication.class,args);
    }
}
​

Step four A call , Call the remote service as if it were local

@RestController
@RequestMapping("/order-server")
public class OrderCtrl {
    @Resource
    private StockFeignService stockFeignService;
​
    @Value("${dev.stock.baseurl}")
    private String baseUrl;
    @Value("${dev.stock.module.apiaddr[0]}")
    private String reduceStock;
​
    @GetMapping("/addorder")
    public  String adds(){
        return " Add order 111111111,"+stockFeignService.reduced();
    }
}

After configuring the self-contained polling （ Line up one by one ）

If you want to take the weight as follows 4 Ways of planting

among application in 2 Kind of

###application Class 
## To configure application
@SpringBootApplication
@EnableFeignClients
//@RibbonClients(value={
//        @RibbonClient(name="stockserv",configuration= RibbonRule.class)
//})
public class OrderFeignApplication {
    public static void main(String[] args) {
        SpringApplication.run(OrderFeignApplication.class,args);
    }
}
## To configure rules The weight of a class system 
@Configuration
public class RibbonRule {
    // Manual weights 
    @Bean
    public IRule iRule(){
//        return new NacosRule();
        // Auto weight 
        return new RandomRule();
    }
}
​
​
​
###application Class 
## To configure application
@SpringBootApplication
@EnableFeignClients
//@RibbonClients(value={
//        @RibbonClient(name="stockserv",configuration= MyNacosRule.class)
//})
public class OrderFeignApplication {
    public static void main(String[] args) {
        SpringApplication.run(OrderFeignApplication.class,args);
    }
}
## To configure rules Class custom weights 
public class MyNacosRule extends AbstractLoadBalancerRule {
    @Autowired
    private NacosDiscoveryProperties nacosDiscoveryProperties;
​
    @Override
    public Server choose(Object o) {
        // Get a list of dynamic services from the registry 
        DynamicServerListLoadBalancer lb= (DynamicServerListLoadBalancer)getLoadBalancer();
        // Get service name 
        String serverName = lb.getName();
        // Build service name instance 
        NamingService ns = nacosDiscoveryProperties.namingServiceInstance();
        //nacos Weight based algorithm 
        try {
            Instance instance = ns.selectOneHealthyInstance(serverName);
            // Put it into the server 
            return new NacosServer(instance);
        } catch (NacosException e) {
          e.printStackTrace();
        }
        // If something goes wrong   Then return the user null
        return null;
    }
​
    @Override
    public void initWithNiwsConfig(IClientConfig iClientConfig) {
​
    }
}

yum One species

# To configure yum
stockserv:
  ribbon:
    NFLoadBalancerRuleClassName: com.kgc.rrules.MyNacosRule
    
## To configure rules Class custom weights 
public class MyNacosRule extends AbstractLoadBalancerRule {
    @Autowired
    private NacosDiscoveryProperties nacosDiscoveryProperties;
​
    @Override
    public Server choose(Object o) {
        // Get a list of dynamic services from the registry 
        DynamicServerListLoadBalancer lb= (DynamicServerListLoadBalancer)getLoadBalancer();
        // Get service name 
        String serverName = lb.getName();
        // Build service name instance 
        NamingService ns = nacosDiscoveryProperties.namingServiceInstance();
        //nacos Weight based algorithm 
        try {
            Instance instance = ns.selectOneHealthyInstance(serverName);
            // Put it into the server 
            return new NacosServer(instance);
        } catch (NacosException e) {
          e.printStackTrace();
        }
        // If something goes wrong   Then return the user null
        return null;
    }
​
    @Override
    public void initWithNiwsConfig(IClientConfig iClientConfig) {
​
    }
}    
    

log4j Use

debug--> Debugging use 
​
info--> In general use 
​
warn-->
​
error-->

The first one is Configure the log class

@Configuration
// Configure the log class 
public class LogConf {
    @Bean
    public  Logger.Level feignLoggerLevel(){
        return Logger.Level.FULL;
    }
    
}
​

The second kind To configure yum file

logging:
  level:
    com.kgc.mynacos.orderfeignserv.remoteserv: debug
feign:
  client:
    config:
      stockserv:
        loggerLevel: Full

1feign:
2client:
3config:
4mall‐order: # Corresponding to microservices 
5loggerLevel: FULL
6contract: feign.Contract.Default # Appoint Feign Native annotation contract configuration 

 

Custom interceptors implement authentication logic

First step

@Configuration
// Configure the log class   Interceptor 
public class LogConf {
//    @Bean
//    public  Logger.Level feignLoggerLevel(){
//        return Logger.Level.FULL;
//    }
​
    @Bean
    public AddTokenInterceptor addTokenInterceptor(){
        return new AddTokenInterceptor();
    }
}
​

The second step

# Configure interceptor entity class inheritance  openfign Built in interceptor requests 
public class AddTokenInterceptor implements RequestInterceptor {
    @Override
    public void apply(RequestTemplate requestTemplate) {
        // The consumer is requesting   Add an acquired... To the header of the post service TOKEN
        String token = UUID.randomUUID().toString();
        System.out.println(" The consumer interceptor starts , Add... To the head token："+token);
        requestTemplate.header("token",token);
    }
}

The third step

# To configure yum
server:
  port: 12002
spring:
  application:
    name: orderfeginserv
  cloud:
    nacos:
      discovery:
        server-addr: 192.168.64.200:8848
        username: nacos
        password: nacos
        namespace: public
#dev:
#  stock:
#    baseurl: http://stockserv/
#    module:
#      apiaddr:
#        - /stock-server/reduced
stockserv:
  ribbon:
    NFLoadBalancerRuleClassName: com.alibaba.cloud.nacos.ribbon.NacosRule
#logging:
#  level:
#    com.kgc.mynacos.orderfeignserv.remoteserv: debug
#feign:
#  client:
#    config:
#      stockserv:
#        loggerLevel: Full
#----------------------------------------- The following is a must 
feign:
  client:
    config:
      orderfeignserv:
        requestInterceptors:
          - com.kgc.mynacos.orderser.interceptor.AddTokenInterceptor
​

# Launch the browser

http://localhost:12002/order-server/addorder

 Request header ：
 Generally put the calibration parameters 
cookie
 Please go the way 
 state 
 Address 

Why? nginx Adopt multi process structure instead of multi thread structure ？

nginx Purpose ： Maintain high availability and reliability .
 If you use the multithreading model , Shared address space between threads , If a third-party module causes a segment error caused by the address space , When the address appears out of bounds , Will lead to the whole nginx All hang up . This problem does not occur with multiple processes .

Nginx Server load balancing strategies can be divided into two categories ： Built in policy and extended policy . The built-in policy mainly includes polling 、 Weighted polling and IP hash Three ; The extension strategy is mainly implemented through third-party modules , There are many kinds of them , Common are url hash、fair etc. .