哨兵基础认识

关于 Redis 哨兵的介绍：

• 一个哨兵就是一个 redis-sentinel 服务，默认使用 26379 端口。和 Redis 服务是分开的，可以理解为一个哨兵就是一台额外的服务器，用来监控 Redis 服务能不能正常运行。
• 多个哨兵就是多个 redis-sentinel 服务，每个可以部署在不同的机器上，甚至可以全部部署在同一台机器上，监听不同端口就行了，但这样就失去了多个哨兵的意义。
• 所有的哨兵都是监听同一个 Redis 服务的，就是 Master 服务，也就是说哨兵的数量和 Redis 服务的数量没有任何关系。
• 哨兵只需要监听 Redis Master 服务，因为 Slave 信息会注册在 Master 上，所有哨兵通过 Master 就可以知道所有的 Slave 服务信息了。
• 每个哨兵只需要知道当前的 Redis Master 服务是谁就行了，不需要知道其他哨兵的信息，因为他们会在 Master 上通过相互沟通得知当前其他哨兵的情况。

目录结构

sentinel/
├── docker-compose.yml
├── master
│   ├── data/
│   └── redis.conf
├── slave1
│   ├── data/
│   └── redis.conf
├── slave2
|   ├── data/
|   └── redis.conf
├── sentinel1
│   └── sentinel.conf
├── sentinel2
│   └── sentinel.conf
└── sentinel3
    └── sentinel.conf

docker-compose.yml

version: "3"

networks:
  redis-replication:
    driver: bridge
    ipam:
      config:
        - subnet: 172.25.0.0/24

services:
  master:
    image: redis
    container_name: redis-master
    ports:
      - "6380:6379"
    volumes:
      - "./master/redis.conf:/etc/redis.conf"
      - "./master/data:/data"
    command: ["redis-server", "/etc/redis.conf"]
    restart: always
    networks:
      redis-replication:
        ipv4_address: 172.25.0.101

  slave1:
    image: redis
    container_name: redis-slave-1
    ports:
      - "6381:6379"
    volumes:
      - "./slave1/redis.conf:/etc/redis.conf"
      - "./slave1/data:/data"
    command: ["redis-server", "/etc/redis.conf"]
    restart: always
    networks:
      redis-replication:
        ipv4_address: 172.25.0.102

  slave2:
    image: redis
    container_name: redis-slave-2
    ports:
      - "6382:6379"
    volumes:
      - "./slave2/redis.conf:/etc/redis.conf"
      - "./slave2/data:/data"
    command: ["redis-server", "/etc/redis.conf"]
    restart: always
    networks:
      redis-replication:
        ipv4_address: 172.25.0.103
  
  sentinel1:
    image: redis
    container_name: redis-sentinel-1
    ports:
      - "26380:26379"
    volumes: 
      - "./sentinel1/sentinel.conf:/etc/sentinel.conf"
    command: ["/bin/bash", "-c", "cp /etc/sentinel.conf /sentinel.conf && redis-sentinel /sentinel.conf"]
    restart: always
    networks:
      redis-replication:
        ipv4_address: 172.25.0.201

  sentinel2:
    image: redis
    container_name: redis-sentinel-2
    ports:
      - "26381:26379"
    volumes: 
      - "./sentinel2/sentinel.conf:/etc/sentinel.conf"
    command: ["/bin/bash", "-c", "cp /etc/sentinel.conf /sentinel.conf && redis-sentinel /sentinel.conf"]
    restart: always
    networks:
      redis-replication:
        ipv4_address: 172.25.0.202

  sentinel3:
    image: redis
    container_name: redis-sentinel-3
    ports:
      - "26382:26379"
    volumes: 
      - "./sentinel3/sentinel.conf:/etc/sentinel.conf"
    command: ["/bin/bash", "-c", "cp /etc/sentinel.conf /sentinel.conf && redis-sentinel /sentinel.conf"]
    restart: always
    networks:
      redis-replication:
        ipv4_address: 172.25.0.203

master

port 6379
pidfile /var/run/redis_6379.pid
protected-mode no
timeout 0
tcp-keepalive 300
loglevel notice

################################# REPLICATION #################################
slave-serve-stale-data yes
slave-read-only yes
repl-diskless-sync no
repl-diskless-sync-delay 5
repl-disable-tcp-nodelay no

##################################### RDB #####################################
dbfilename dump.rdb
save 900 1
save 300 10
save 60 10000
stop-writes-on-bgsave-error yes
rdbcompression yes
rdbchecksum yes
dir ./

##################################### AOF #####################################
appendonly yes
appendfilename "appendonly.aof"
appendfsync everysec
no-appendfsync-on-rewrite no
aof-load-truncated yes
aof-use-rdb-preamble no

slave1 & slave2

port 6379
pidfile /var/run/redis_6379.pid
protected-mode no
timeout 0
tcp-keepalive 300
loglevel notice

################################# REPLICATION #################################
slave-serve-stale-data yes
slave-read-only yes
repl-diskless-sync no
repl-diskless-sync-delay 5
repl-disable-tcp-nodelay no
#slaveof 172.25.0.101 6379
replicaof 172.25.0.101 6379

##################################### RDB #####################################
dbfilename dump.rdb
save 900 1
save 300 10
save 60 10000
stop-writes-on-bgsave-error yes
rdbcompression yes
rdbchecksum yes
dir ./

##################################### AOF #####################################
appendonly yes
appendfilename "appendonly.aof"
appendfsync everysec
no-appendfsync-on-rewrite no
aof-load-truncated yes
aof-use-rdb-preamble no

sentinel1 & sentinel2 & sentinel3

# 所有哨兵端口都一致，因为使用 Docker 桥接网络映射 
port 26379

# 哨兵设置，所有哨兵皆一致，都指向 Master
sentinel monitor mymaster 172.25.0.101 6379 2
sentinel parallel-syncs mymaster 1
sentinel down-after-milliseconds mymaster 30000
sentinel failover-timeout mymaster 180000

bind 0.0.0.0
protected-mode no
daemonize no
pidfile /var/run/redis-sentinel.pid
logfile ""
dir /tmp

启动服务

docker-compose up -d

停止容器

docker stop redis-master redis-slave-1 redis-slave-2 redis-sentinel-1 redis-sentinel-2 redis-sentinel-3

查看容器配置是否正常

docker logs --tail 100 redis-master