Nacos

1. The common points of Nacos and Eureka

1. Data support service registration and service pull pull
2. The provider of the service center provider does a health check in the heartbeat method

2. The difference between Nacos and Eureka

1. NACOS support server active detection provider status: temporary instance adopts a heartbeat mode, non -temporary instances use active detection mode
2. Temporary instances will be removed normally, and non -temporary instances will not be removed
3. NACOS support service list change message push mode push, service list update is more timely
4. NACOS cluster uses an AP method by default. When there is a non -temporary example in the cluster, the CP mode is adopted; the Eureka talent AP method

Environmental isolation

NACOS environmental isolation

1. namespace is used for environmental isolation
2. Every namespace has unique ID
3. The services under different namespace are not visible

NACOS load balancing strategy

Nacosrule load balancing strategy

1. Prefer to choose the list of the same cluster service list
2. The local chicken group can not find the provider, take other clusters to find, and report to warn
3. After determining the available example list, then use a random load balancing example
   

Nacos configuration management

Unified configuration management

Fill in the configuration content:

1. Core configuration
2. Switch configuration, such as True/False
3. There will be changes in the future

All information with NACOS address and configuration file is placed in the bootstrap file

1. Introducing NACOS configuration management customer dependencies

<!-Nacos configuration management dependence->
<dependency>
	<groupId>com.alibaba.cloud</groupId>
    <artifactId>spring-cloud-starter-alibaba-nacos-config</artifactId>
</dependency>

2. Add a bootstrap.yml file to the Resource directory in service. This file is a guidance file, which is higher than the Application.yml:

spring:
	application:
		name: userservice #service name
	profiles:
		active: dev #Development environment, here is DEV
	cloud:
		nacos:
			server-addr: localhost:2010 #Nacos address
			config:
				file-extension: yaml #File suffix name

3. Inject the Pattern.dateFormat attribute in the service

@RestController
@RequestMapping("/*")
public class Controller {
    // Inject the configuration attribute in Nacos
    @Value("${pattern.dateformat}")
    privatet String dateformat;
    
    // Write Controller, format the current time by formatting the date formatter and return
    @GetMapping("now")
    public String now(){
        return LocalDate.now().format(
        	DateTimeFoematter.ofPattern(dateformat, Local.CHINA)
        );
    }
    //  ...slightly
}

Summary: The steps to hand over the configuration to NACOS management

1. Add configuration file to NACOS
2. Introduction to NACOS's config dependencies in microservices
3. Add bootstrap.yml to microservices, configure NACOS address, current environment, service name, file suffix name. These determine which file does the program go to NACOS when the program starts

NACOS configuration hot update

After the configuration file in NACOS is changed, microservices can be perceived without restarting. However, you need to implement the two configurations of the wire surface:

• Method 1: Add annotation @Refreshscope

@Slf4j
@RequestMapping("/user")
@RestController
@RefreshScope
public class UserController {
    @Value("${pattern.dateformat}")
    private String dateformat;
    ......
}

• Method two: Use @ConfigurationProperties annotation

@Component
@Data
@ConfigurationProperties(prefix = "pattern")
public class PatternProperties {
    private String dateformat;
    ......
}

Precautions

The configuration is not suitable for the configuration center, which is more troublesome to maintain.

It is recommended to put some key parameters that need to be adjusted at the NACOS configuration center, which is generally custom configuration.

Multi -environment configuration sharing

Micro -service reads multiple configuration files from NACOS when starting:

• [spring.application.name]-[spring.prfiles.active] .yaml, for example
• [Spring.application, name] .yaml, for example: UserSerrvice.yaml

Regardless of how profile changes, [spring.appliaction.name] .yaml this file will definitely be loaded, so many environmental sharing configurations can be written to this file.

Priority of multiple configurations:

Nacos cluster built

In the NACOS production environment, it must be a cluster deployment

Cluster structure map:

Cluster building steps:

1. Build the MySQL cluster and initialize the database table

2. Download decompression NACOS

3. Modify cluster configuration (node ​​branch), database configuration

   Enter the Conf directory of nacos, modify the configuration file cluster.conf.example, renamed unwanted without cluster.conf;

   Modify the content as

   127.0.0.1:8845
   127.0.0.1.8846
   127.0.0.1.8847
   

   Modify Application.properties

   spring.datasource.platform=mysql
   db.num=1
   db.url=jdbc:mysql//127.0.0.1:3306/nacos_config?charactorEncoding=utf8&connectTimeout=1000&socketTimeout=3000&autoReconnect=true&useUnicode=true&useSSL=false&serverTimezone=UTC
   db.user.0=root
   db.password.0=123456
   

4. Start multiple NACOS nodes separately

   Copy the NACOS folder three copies of three copies and name them: NACOS1, NACOS2, NACOS3

   Then modify the Application.properties of the three folders, respectively,

   nacos1:

   server.port=8845
   

   nacos2:

   server.port=8846
   

   nacos3:

   server.port=8847
   

5. nginx reverse proxy