搭建哨兵集群

环境准备拉取镜像

搭建目标 ： 一主而从三哨兵集群

docker pull redis:6.2.6

创建文件夹及配置文件

我这里在/usr/local/docker/redis目录下

在 redis-master、redis-slave1、redis-slave2 下分别建立data、 redis.conf、 sentinel.conf

redis配置文件

在从节点上配置所属于哪个父集群（找爹行动）

• replicaof 39.106.53.30 6379（redis5.0之后）
• slaveof 39.106.53.30 6379（5.0之前的命令）

# master redis.conf
save 3600 1
save 300 100
save 60 10000

appendonly no

protected-mode no 
port 6379

# redis-slave1 redis.conf

save 3600 1
save 300 100

save 60 10000

appendonly no

bind 0.0.0.0

port 6380

protected-mode no 

replicaof 39.106.53.30 6379

# redis-slave2 redis.conf

save 3600 1
save 300 100

save 60 10000

appendonly no

bind 0.0.0.0

port 6381

protected-mode no 

replicaof 39.106.53.30 6379

 sentinel配置

# master 配置

port 26379
dir /tmp
sentinel monitor mymaster 39.106.53.30 6379 2
sentinel down-after-milliseconds mymaster 30000
sentinel failover-timeout mymaster 60000

# slave1 配置

port 26380
dir /tmp
sentinel monitor mymaster 39.106.53.30  6379 2
sentinel down-after-milliseconds mymaster 30000
sentinel failover-timeout mymaster 60000


# slave2 配置

port 26381
dir /tmp
sentinel monitor mymaster 39.106.53.30  6379 2
sentinel down-after-milliseconds mymaster 30000
sentinel failover-timeout mymaster 60000

 编写docker-compose.yml

version: '3'
services:
  master:
    image: redis:6.2.6       
    container_name: redis-master
    command: redis-server /etc/redis/redis.conf 
    ports:
      - 6379:6379
    volumes:
    - /usr/local/docker/redis/redis-master/data:/data
    - /usr/local/docker/redis/redis-master/redis.conf:/etc/redis/redis.conf
  slave1:
    image: redis:6.2.6                
    container_name: redis-slave1
    volumes:
    - /usr/local/docker/redis/redis-slave1/data:/data
    - /usr/local/docker/redis/redis-slave1/redis.conf:/etc/redis/redis.conf
    command: redis-server /etc/redis/redis.conf 
    ports:
      - 6380:6380
    depends_on:
    - master
  slave2:
    image: redis:6.2.6                
    container_name: redis-slave2
    volumes:
    - /usr/local/docker/redis/redis-slave2/data:/data
    - /usr/local/docker/redis/redis-slave2/redis.conf:/etc/redis/redis.conf
    command: redis-server /etc/redis/redis.conf 
    ports:
      - 6381:6381
    depends_on:
    - master
  sentinel1:
    image: redis:6.2.6      
    container_name: redis-sentinel1
    command: redis-sentinel /usr/local/etc/redis/sentinel.conf
    ports:
      - 26379:26379
    volumes:
    - /usr/local/docker/redis/redis-master/sentinel.conf:/usr/local/etc/redis/sentinel.conf
    depends_on:
    - master
    - slave1
    - slave2
  sentinel2:
    image: redis:6.2.6                
    container_name: redis-sentinel2          
    command: redis-sentinel /usr/local/etc/redis/sentinel.conf
    ports:
      - 26380:26380
    volumes:
    - /usr/local/docker/redis/redis-slave1/sentinel.conf:/usr/local/etc/redis/sentinel.conf
    depends_on:
    - master
    - slave1
    - slave2
  sentinel3:
    image: redis:6.2.6               
    container_name: redis-sentinel3          
    command: redis-sentinel /usr/local/etc/redis/sentinel.conf
    ports:
      - 26381:26381
    volumes:
    - /usr/local/docker/redis/redis-slave1/sentinel.conf:/usr/local/etc/redis/sentinel.conf
    depends_on:
    - master
    - slave1
    - slave2

 执行docker-compose

docker-compose up -d

查看集群信息 

 查看集群信息 info replication

测试数据同步

本次搭建的集群，在从节点是只读形式，只有主节点才能够写，在主节点写入 set test test 

set k v，查看所有从节点信息，在从节点中写，会提示只读副本

在主节点中写，发现在所有从节点中都存在数据，数据同步成功

主从集群同步原理

主从同步第一次同步是全量同步：

master如何判断slave是不是第一次来同步数据：

Replication ld: 简称replid，是数据集的标记，id一致则说明是同一数据集。每一个master都有唯一的replid,slave则会继承master节点的replid

ofset:偏移量，随着记录在repl_bak_log中的数据增多而逐渐增大。slave完成同步时也会记录当前同步的ofset如果slave的offset小于master的offset，说明slave数据落后于master，需要更新

因此slave做数据同步，必须向master声明自己的replication id 和offset，master才可以判断到底需要同步哪些数据

但如果slave重启后同步，则执行增量同步

repl_bak_log大小有上限，写满后会覆盖最早的数据。如果slave断开时间过久，导致尚未备份的数据被覆盖，则无法基于log做增量同步，只能再次全量同步

 全量同步流程

增量同步流程 

spring boot整合集群并配置读写分离

引入依赖

<dependency>
  <groupId>org.springframework.boot</groupId>
  <artifactId>spring-boot-starter-data-redis</artifactId>
</dependency>

配置集群

由于哨兵模式的节点不固定，所以配置哨兵集群，监听的redis集群由哨兵去找

server:
  port: 9000
spring:
  redis:
    sentinel:
      master: mymaster
      nodes:
        - 39.106.53.30:26379
        - 39.106.53.30:26380
        - 39.106.53.30:26381

测试集群同步

这里的ReadFrom是配置Redis的读取策略：

• MASTER:从主节点读取.
• MASTER PREFERRED:优先从master节点读取，master不可用才读取replica
• REPLICA: 从slave (replica)节点读取
• REPLICA PREFERRED: 优先从slave (replica)节点读取，所有的slave都不可用才读取master

package com.test.cluster.rediscluster;

import io.lettuce.core.ReadFrom;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.autoconfigure.data.redis.LettuceClientConfigurationBuilderCustomizer;
import org.springframework.context.annotation.Bean;

@SpringBootApplication
public class RedisClusterApplication {

    public static void main(String[] args) {
        SpringApplication.run(RedisClusterApplication.class, args);
    }

    @Bean
    public LettuceClientConfigurationBuilderCustomizer clientConfigurationBuilderCustomizer(){
        return clientConfigurationBuilder -> clientConfigurationBuilder.readFrom(ReadFrom.REPLICA_PREFERRED);
    }

}

 编写controller

package com.test.cluster.rediscluster.controller;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

/**
 * @Author sl
 */
@RestController
public class TestRedisSentinelController {

    @Autowired
    private StringRedisTemplate redisTemplate;

    @RequestMapping("/get/{key}")
    public String getKey(@PathVariable("key") String key){
        String s = redisTemplate.opsForValue().get(key);
        if(s!= null){
            return "获取"+  s  + "成功";
        }
        return "获取"+  key  + "失败";
    }

    @RequestMapping("set/{key}/{value}")
    public String setValue(@PathVariable("key")String key,@PathVariable("value") String value){
        redisTemplate.opsForValue().set(key,value);
        return "set" +  key  + "success";
    }


}

设置key http://localhost:9000/set/china/yyds ，在80和81中，可以查到china的值

搭建分片集群

redis 哨兵模式虽然提供了 redis⾼可⽤、高并发读的解决方案，但是在海量数据应用场景下，仍然存在海量数据存储问题和高并发写的问题。当只有⼀个 Master 对外提供服务时，如果数据量特别⼤，内存占⽤问题严重，数据的高并发写、数据备份和恢复都会⼤⼤降低效率，针对这些问题，redis 推出 Cluster 集群架构，该结构具有如下特点：

Redis Cluster 采用的去中心化的网络拓扑架构，没有中心节点，所有节点既是数据存储节点，也是控制节点

引入槽(slot)的概念，通过 CRC+hashslot 算法支持多个主节点（分片），每个主节点分别负责存储一部分数据，这样理论上可以支持无限主节点的水平扩容以便支持海量吞吐量

在 Cluster 集群里设置了 16384 个哈希槽（hash slot），在 master 节点上写键值对数据时，redis 先对每个键（key），用CRC16 算法对 key 进行运算，然后用 16384 对运算结果取模，余数作为插槽，每个槽在不同的节点下，形成了分片

内置类似哨兵的高可用机制，能够实现自动故障转移，保证每个主节点的高可用

创建文件和映射

创建6379-6384的文件夹，目录为data ，redis.conf

编写redis.conf

port 6379

daemonize no

cluster-enabled yes

# reids维护
cluster-config-file nodes_6379.conf

tcp-keepalive 300
timeout 0

appendonly yes

logfile "redis_6379.log"

bind 0.0.0.0

cluster-node-timeout 5000

protected-mode no 

cluster-announce-ip 39.106.53.30

cluster-announce-bus-port 16379

编写docker-compose

version: '3'
services:
  node1:
    image: redis:6.2.6
    container_name: redis-node1
    restart: always
    ports:
      - 6379:6379
      - 16379:16379
    volumes:
      - /usr/local/docker/redis/6379/data:/data
      - /usr/local/docker/redis/6379/redis.conf:/etc/redis/redis.conf
    command:
      redis-server /etc/redis/redis.conf

  node2:
    image: redis:6.2.6
    container_name: redis-node2
    restart: always
    ports:
      - 6380:6380
      - 16380:16380
    volumes:
      - /usr/local/docker/redis/6380/data:/data
      - /usr/local/docker/redis/6380/redis.conf:/etc/redis/redis.conf
    command:
      redis-server /etc/redis/redis.conf


  node3:
    image: redis:6.2.6
    container_name: redis-node3
    restart: always
    ports:
      - 6381:6381
      - 16381:16381
    volumes:
      - /usr/local/docker/redis/6381/data:/data
      - /usr/local/docker/redis/6381/redis.conf:/etc/redis/redis.conf
    command:
      redis-server /etc/redis/redis.conf

  node4:
    image: redis:6.2.6
    container_name: redis-node4
    restart: always
    ports:
      - 6382:6382
      - 16382:16382
    volumes:
      - /usr/local/docker/redis/6382/data:/data
      - /usr/local/docker/redis/6382/redis.conf:/etc/redis/redis.conf
    command:
      redis-server /etc/redis/redis.conf

  node5:
    image: redis:6.2.6
    container_name: redis-node5
    restart: always
    ports:
      - 6383:6383
      - 16383:16383
    volumes:
      - /usr/local/docker/redis/6383/data:/data
      - /usr/local/docker/redis/6383/redis.conf:/etc/redis/redis.conf
    command:
      redis-server /etc/redis/redis.conf

  node6:
    image: redis:6.2.6
    container_name: redis-node6
    restart: always
    ports:
      - 6384:6384
      - 16384:16384
    volumes:
      - /usr/local/docker/redis/6384/data:/data
      - /usr/local/docker/redis/6384/redis.conf:/etc/redis/redis.conf
    command:
      redis-server /etc/redis/redis.conf

执行docker-compose

docker-compose up -d

集群启动 

进入任意节点 docker exec -it redis-node1 /bin/bash

redis-cli --cluster create 39.106.53.30:6379 39.106.53.30:6380 39.106.53.30:6381 39.106.53.30:6382 39.106.53.30:6383 39.106.53.30:6384 --cluster-replicas 1

--cluster-replicas 或者 --replicas 1 表示集群中每个master的副本数为1，此时 节点总数/(replicas+1)得到的就是master的数量，因此节点中前n个是master节点 

查看集群信息 

连接集群

以cluster方式连接集群，并set test test 值 ，在其他节点中有相同的值

spring boot 整合分片集群

更改配置

server:
  port: 9000
# 哨兵集群
#spring:
#  redis:
#    sentinel:
#      master: mymaster
#      nodes:
#        - 39.106.53.30:26379
#        - 39.106.53.30:26380
#        - 39.106.53.30:26381
# 分片集群
spring:
  redis:
    cluster:
      nodes:
        - 39.106.53.30:6379
        - 39.106.53.30:6380
        - 39.106.53.30:6381
        - 39.106.53.30:6382
        - 39.106.53.30:6383
        - 39.106.53.30:6384

 测试controller

package com.test.cluster.rediscluster.controller;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

/**
 * @Author sl
 */
@RestController
public class TestRedisClusterController {

    @Autowired
    private StringRedisTemplate redisTemplate;

    @RequestMapping("/get/{key}")
    public String getKey(@PathVariable("key") String key){
        String s = redisTemplate.opsForValue().get(key);
        if(s!= null){
            return "获取"+  s  + "成功";
        }
        return "获取"+  key  + "失败";
    }

    @RequestMapping("set/{key}/{value}")
    public String setValue(@PathVariable("key")String key,@PathVariable("value") String value){
        redisTemplate.opsForValue().set(key,value);
        return "set" +  key  + "success";
    }


}

测试集群