Nacos认识和安装

nacos官网：

nacos.iohttp://nacos.io

父工程pom.xml

<properties>
    <project.build.sourceencoding>utf-8</project.build.sourceencoding>
    <maven.compiler.source>1.8</maven.compiler.source>
    <maven.compiler.target>1.8</maven.compiler.target>
    <junit.version>4.12</junit.version>
    <log4j.version>1.2.17</log4j.version>
    <lombok.version>1.16.18</lombok.version>
    <mysql.version>8.0.26</mysql.version>
    <druid.version>1.2.6</druid.version>
    <spring-cloud.version>hoxton.sr1</spring-cloud.version>
    <spring-cloud-alibaba.version>2.2.7.release</spring-cloud-alibaba.version>
    <hutool-all.version>5.7.22</hutool-all.version>
  </properties>
  <dependencymanagement>
    <dependencies>
      <dependency>
        <groupid>org.springframework.cloud</groupid>
        <artifactid>spring-cloud-dependencies</artifactid>
        <version>${spring-cloud.version}</version>
        <type>pom</type>
        <scope>import</scope>
      </dependency>
      <dependency>
        <groupid>org.springframework.boot</groupid>
        <artifactid>spring-boot-dependencies</artifactid>
        <version>2.2.2.release</version>
        <type>pom</type>
        <scope>import</scope>
      </dependency>
      <dependency>
        <groupid>com.alibaba.cloud</groupid>
        <artifactid>spring-cloud-alibaba-dependencies</artifactid>
        <version>${spring-cloud-alibaba.version}</version>
        <type>pom</type>
        <scope>import</scope>
      </dependency>
      <dependency>
        <groupid>mysql</groupid>
        <artifactid>mysql-connector-java</artifactid>
        <version>${mysql.version}</version>
      </dependency>
      <dependency>
        <groupid>cn.hutool</groupid>
        <artifactid>hutool-all</artifactid>
        <version>${hutool-all.version}</version>
      </dependency>
      <dependency>
        <groupid>com.alibaba</groupid>
        <artifactid>druid-spring-boot-starter</artifactid>
        <version>${druid.version}</version>
      </dependency>
      <dependency>
        <groupid>org.mybatis.spring.boot</groupid>
        <artifactid>mybatis-spring-boot-starter</artifactid>
        <version>2.2.0</version>
      </dependency>
    </dependencies>
  </dependencymanagement>

1.在cloud-demo父工程中添加spring-cloud-alilbaba的管理依赖：

<dependency>
    <groupid>com.alibaba.cloud</groupid>
    <artifactid>spring-cloud-alibaba-dependencies</artifactid>
    <version>2.2.7.release</version>
    <type>pom</type>
    <scope>import</scope>
</dependency>

2.注释掉order-service和user-service中原有的eureka依赖。

3.添加nacos的客户端依赖:

<dependency>
       <groupid>com.alibaba.cloud</groupid>
       <artifactid>spring-cloud-starter-alibaba-nacos-discovery</artifactid>
</dependency>

4.在application.yml中配置nacos服务

server:
  port: 8089
spring:
  datasource:
    druid:
      driver-class-name: com.mysql.cj.jdbc.driver
      username: root
      password: 123456
      url: jdbc:mysql:///cloud-user
  application:
    name: userservice #user服务名称
#===================================
  cloud:
    nacos:
      server-addr: localhost:8848 #nacos服务地址
#===================================
mybatis-plus:
  type-aliases-package: entity
  mapper-locations: classpath:*/mepper/*.xml
  configuration:
    log-impl: org.apache.ibatis.logging.stdout.stdoutimpl
#eureka:
#  client:
#    service-url:
#      defaultzone: http://127.0.0.1:10086/eureka

5.启动nacos，启动application服务。

1.nacos启动报错 error creating bean with name ‘authfilterregistration‘ defined in class path resource

原因：可能是startup.cmd文件中set mode = ""不恰当

set base_dir="%base_dir:~0,-5%"
 
set custom_search_locations=file:%base_dir%/conf/
 
set mode="cluster"
set function_mode="all"
set server=nacos-server
set mode_index=-1
set function_mode_index=-1
set server_index=-1
set embedded_storage_index=-1
set embedded_storage=""

解决方法：将set mode="cluster"改为set mode="standalone"即可 

6.启动报错。原因及解决方法。

原因： nacos客户端与服务的版本不一致

nacos2.0的服务端完全兼容1.x客户端。nacos2.0客户端由于使用了grpc，无法兼容nacos1.x服务端，请勿使用2.0以上版本客户端连接nacos1.x服务端。

我的依赖：

<dependency>
    <groupid>com.alibaba.cloud</groupid>
    <artifactid>spring-cloud-alibaba-dependencies</artifactid>
    <version>2.2.7.release</version>
    <type>pom</type>
    <scope>import</scope>
</dependency>

解决方法：降低依赖版本或者下载nacos高版本

7.登录nacos 默认账户和密码都是nacos

8.集群配置

1.在application.xml中添加

  cloud:
    nacos:
      server-addr: localhost:8848 #nacos服务地址
      discovery:
        cluster-name: hz #集群名称

2.nacos负载均衡

        nacosrule负载均衡策略：优先选择同集群服务实例列表，本地集群找不到提供者，才去其它集群寻找，并且会报警告，确定了可用实例列表后，再采用随机负载均衡挑选实例。

userservice:
  ribbon:
    nfloadbalancerruleclassname: com.alibaba.cloud.nacos.ribbon.nacosrule

3.环境隔离

        nacos中服务存储和数据存储的最外层都是一个名为namespace的东西，用来做最外层隔离。

4.命名空间

  cloud:
    nacos:
      discovery:
        server-addr: localhost:8848
        namespace: 44b98d0d-39ac-458f-8bcf-82c7f6e0283d #命名空间id

 5.设置非临时实例

  cloud:
    nacos:
      discovery:
        server-addr: localhost:8848
        namespace: 44b98d0d-39ac-458f-8bcf-82c7f6e0283d #命名空间id
        ephemeral: false #非临时实例