Article directory
Overview
Nacos: Dynamic Naming and Configuration Service
Nacos = Eureka+Config +Bus
Nacos is a combination of registration center + configuration center,
a dynamic service discovery, configuration management and service management platform that makes it easier to build cloud native applications.
Official website
https://github.com/alibaba/Nacos
https://nacos.io/zh-cn/index.html
https://spring-cloud-alibaba-group.github.io/github-pages/greenwich/spring -cloud-alibaba.html#_spring_cloud_alibaba_nacos_discovery
Registration center
POM
parent module
<dependency>
<groupId>com.alibaba.cloud</groupId>
<artifactId>spring-cloud-alibaba-dependencies</artifactId>
<version>2.1.0.RELEASE</version>
<type>pom</type>
<scope>import</scope>
</dependency>
This module
<!--SpringCloud ailibaba nacos -->
<dependency>
<groupId>com.alibaba.cloud</groupId>
<artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
</dependency>
YML
server:
port: 9001
spring:
application:
name: nacos-payment-provider
cloud:
nacos:
discovery:
server-addr: localhost:8848 #配置Nacos地址
management:
endpoints:
web:
exposure:
include: '*'
Startup class
@EnableDiscoveryClient
CAP
C means that the data seen by all nodes at the same time is consistent; and the definition of A is that all requests will receive responses.
When do you choose which mode to use?
Generally speaking,
if there is no need to store service level information and the service instance is registered through nacos-client and can maintain heartbeat reporting, then you can choose AP mode. Current mainstream services such as Spring cloud and Dubbo services are all suitable for AP mode. AP mode weakens consistency for the sake of service possibility, so AP mode only supports registration of temporary instances.
If you need to edit or store configuration information at the service level, then CP is required, and K8S services and DNS services are suitable for CP mode.
CP mode supports the registration of persistent instances. At this time, the Raft protocol is used as the cluster operating mode. In this mode, the service must be registered before registering the instance. If the service does not exist, an error will be returned.
curl -X PUT '$NACOS_SERVER:8848/nacos/v1/ns/operator/switches?entry=serverMode&value=CP'
Configuration center
POM
<!--nacos-config-->
<dependency>
<groupId>com.alibaba.cloud</groupId>
<artifactId>spring-cloud-starter-alibaba-nacos-config</artifactId>
</dependency>
<!--nacos-discovery-->
<dependency>
<groupId>com.alibaba.cloud</groupId>
<artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
</dependency>
YML
Nacos is the same as springcloud-config. When initializing the project, you must first pull the configuration from the configuration center. Only
after pulling the configuration can the normal startup of the project be guaranteed.
There is a priority order for loading configuration files in springboot, bootstrap has higher priority than application
#bootstrap
# nacos配置
server:
port: 3377
spring:
application:
name: nacos-config-client
cloud:
nacos:
discovery:
server-addr: localhost:8848 #Nacos服务注册中心地址
config:
server-addr: localhost:8848 #Nacos作为配置中心地址
file-extension: yaml #指定yaml格式的配置
spring:
profiles:
active: dev # 表示开发环境
Startup class
@EnableDiscoveryClient
ConfigClientController
@RefreshScope //在控制器类加入@RefreshScope注解使当前类下的配置支持Nacos的动态刷新功能。
public class ConfigClientController
{
@Value("${config.info}")
private String configInfo;
@GetMapping("/config/info")
public String getConfigInfo() {
return configInfo;
}
}
Matching rules in Nacos
${
spring.application.name}-${
spring.profiles.active}.${
spring.cloud.nacos.config.file-extension}
Three options for loading configuration
- DataID scheme
- Group plan
- Namespace scheme
The relationship between the three
Example
bootstrap.yml
server:
port: 3377
spring:
application:
name: nacos-config-client
cloud:
nacos:
discovery:
server-addr: localhost:8848 #Nacos服务注册中心地址
config:
server-addr: localhost:8848 #Nacos作为配置中心地址
file-extension: yaml #指定yaml格式的配置
group: DEV_GROUP
namespace: 7d8f0f5a-6a53-4785-9686-dd460158e5d4
application.yml
spring:
profiles:
active: dev # 表示开发环境
#active: test # 表示测试环境
#active: info
Startup class
@EnableDiscoveryClient
@SpringBootApplication
public class NacosConfigClientMain3377
{
public static void main(String[] args) {
SpringApplication.run(NacosConfigClientMain3377.class, args);
}
}
Cluster deployment
Overview
Official website:
https://nacos.io/zh-cn/docs/cluster-mode-quick-start.html
Official website architecture diagram The actual mode
comes with the embedded database derby by default
https://github.com/alibaba/nacos /blob/develop/config/pom.xml
Deployment mode
- Standalone mode - for testing
- Cluster Mode - High Availability
- Multi-cluster mode - multiple data centers
Modify derby to mysql
spring.datasource.platform=mysql
db.num=1
db.url.0=jdbc:mysql://127.0.0.1:3306/nacos_config?characterEncoding=utf8&connectTimeout=1000&socketTimeout=3000&autoReconnect=true
db.user=root
db.password=123456
Configuration
cluster.conf
This IP cannot be written as 127.0.0.1, it must be an IP that can be recognized by the Linux command hostname -i
Edit Nacos startup script startup.sh so that it can accept different startup ports
./startup.sh -p 3333 means starting the nacos server instance with port number 3333, which is consistent with the cluster.conf configuration in the previous step.
Nginx configuration, using it as a load balancer
upstream cluster{
server 127.0.0.1:3333;
server 127.0.0.1:4444;
server 127.0.0.1:5555;
}
server {
listen 1111;
server_name localhost;
#charset koi8-r;
#access_log logs/host.access.log main;
location / {
#root html;
#index index.html index.htm;
proxy_pass http://cluster;
}
.......省略
As of now, 1 Nginx + 3 nacos registration centers + 1 mysql
test
yml
server:
port: 9002
spring:
application:
name: nacos-payment-provider
cloud:
nacos:
discovery:
#配置Nacos地址
#server-addr: localhost:8848
# 换成nginx的1111端口，做集群
server-addr: 192.168.111.144:1111
management:
endpoints:
web:
exposure:
include: '*'
