# 修改所有主從節(jié)點配置文件
[root@ubuntu2204 ~]#vim /apps/redis/etc/redis.conf
bind 0.0.0.0
masterauth 123456
requirepass 123456

# 修改所有從節(jié)點配置文件
[root@ubuntu2204 ~]#vim /apps/redis/etc/redis.conf
replicaof 10.0.0.100 6379

# 所有主從節(jié)點執(zhí)行 重啟redis服務(wù)
[root@ubuntu2204 ~]#systemctl restart redis

# 查看主從節(jié)點狀態(tài)
[root@ubuntu2204 ~]#redis-cli -a 123456 info replication

# 在源碼目錄有sentinel.conf，復(fù)制到安裝目錄即可
[root@ubuntu2204 ~]#cp /usr/local/src/redis-7.2.6/sentinel.conf /apps/redis/etc/
[root@ubuntu2204 ~]#ll /apps/redis/etc/

[root@ubuntu2204 ~]#chown redis.redis /apps/redis/etc/sentinel.conf 
[root@ubuntu2204 ~]#ll /apps/redis/etc/

# 修改配置文件
[root@ubuntu2204 ~]#vim /apps/redis/etc/sentinel.conf

protected-mode no
port 26379
daemonize no
pidfile /apps/redis/run/redis-sentinel.pid
logfile "/apps/redis/log/redis-sentinel.log"
dir /apps/redis/data/sentinel

#mymaster是集群的名稱，此行指定當前mymaster集群中master服務(wù)器的地址和端口
#2為法定人數(shù)限制(quorum)，即有幾個sentinel認為master down了就進行故障轉(zhuǎn)移，一般此值是所有sentinel節(jié)點(一般總數(shù)是>=3的 奇數(shù),如:3,5,7等)的一半以上的整數(shù)值，比如，總數(shù)是3，即3/2=1.5，取整為2,是master的ODOWN客觀下線的依據(jù)
sentinel monitor mymaster 10.0.0.100 6379 2

# mymaster集群中master的密碼，注意此行要在上面行的下面
sentinel auth-pass mymaster 123456

# 判斷mymaster集群中所有節(jié)點的主觀下線(SDOWN)的時間，單位：毫秒，建議3000
sentinel down-after-milliseconds mymaster 3000

# #發(fā)生故障轉(zhuǎn)移后，可以同時向新master同步數(shù)據(jù)的slave的數(shù)量，數(shù)字越小總同步時間越長，但可以減輕新master的負載壓力
sentinel parallel-syncs mymaster 1

# 所有slaves指向新的master所需的超時時間，單位：毫秒
sentinel failover-timeout mymaster 180000

acllog-max-len 128

# 禁止修改腳本
sentinel deny-scripts-reconfig yes

SENTINEL resolve-hostnames no

SENTINEL announce-hostnames no

# 修改一個節(jié)點，其他節(jié)點直接scp
[root@ubuntu2204 ~]#scp  /apps/redis/etc/sentinel.conf 10.0.0.101:/apps/redis/etc/

[root@ubuntu2204 ~]#scp  /apps/redis/etc/sentinel.conf 10.0.0.102:/apps/redis/etc/

# 修改scp后的兩個sentinel.conf文件的權(quán)限
[root@ubuntu2204 ~]#chown redis.redis /apps/redis/etc/sentinel.conf

# 驗證三個哨兵服務(wù)器的配置
[root@ubuntu2204 ~]#grep -Ev '^#|^$' /apps/redis/etc/sentinel.conf
protected-mode no
port 26379
daemonize no
pidfile /apps/redis/run/redis-sentinel.pid
loglevel notice
logfile "/apps/redis/log/redis-sentinel.log"
dir /apps/redis/data/sentinel
sentinel monitor mymaster 10.0.0.100 6379 2
sentinel auth-pass mymaster 123456
sentinel down-after-milliseconds mymaster 30000
acllog-max-len 128
sentinel parallel-syncs mymaster 1
sentinel failover-timeout mymaster 180000
sentinel deny-scripts-reconfig yes
SENTINEL resolve-hostnames no
SENTINEL announce-hostnames no
SENTINEL master-reboot-down-after-period mymaster 0

# 生成service文件
[root@ubuntu2204 ~]#vim /lib/systemd/system/redis-sentinel.service

[Unit]
Description=Redis Sentinel
After=network.target

[Service]
ExecStart=/apps/redis/bin/redis-sentinel /apps/redis/etc/sentinel.conf --supervised systemd
ExecStop=/bin/kill -s QUIT $MAINPID
Type=notify
User=redis
Group=redis
RuntimeDirectory=redis
RuntimeDirectoryMode=0755

[Install]
WantedBy=multi-user.target

[root@ubuntu2204 ~]#systemctl daemon-reload
[root@ubuntu2204 ~]#systemctl enable --now redis-sentinel.service
[root@ubuntu2204 ~]#systemctl status redis-sentinel.service

注意：
1. 確保權(quán)限是redis  
2. Redis Sentinel 配置 daemonize yes 與 --supervised systemd 沖突，導(dǎo)致 systemd 無法管理服務(wù)進程，應(yīng)將 daemonize 改為 no
3. --supervised systemd：表示 Redis Sentinel 由 systemd 管理進程生命周期，Redis 不能自己后臺運行

# 查看哨兵服務(wù)端口狀態(tài)
[root@ubuntu2204 run]#ss -nlt

# 查看哨兵日志
[root@ubuntu2204 ~]#tail -f /apps/redis/log/redis-sentinel.log

# 當前sentinel狀態(tài)
[root@ubuntu2204 ~]#redis-cli -p 26379  info sentinel
# 在sentinel狀態(tài)中尤其是最后一行，涉及到masterIP是多少，有幾個slave，有幾個sentinels，必須是符合全部服務(wù)器數(shù)量
# 兩個slave,三個sentinel服務(wù)器,如果sentinels值不符合,檢查myid可能沖突
master0:name=mymaster,status=ok,address=10.0.0.100:6379,slaves=2,sentinels=3

# 查看 Redis 各節(jié)點狀態(tài)
[root@ubuntu2204 ~]#redis-cli -a 123456  info replication

# 停止 Master 節(jié)點
[root@ubuntu2204 ~]#systemctl stop redis

# 變成101
[root@ubuntu2204 ~]#redis-cli -p 26379  info sentinel

master0:name=mymaster,status=ok,address=10.0.0.101:6379,slaves=2,sentinels=3

# 故障轉(zhuǎn)移后從節(jié)點redis.conf中的replicaof行的master IP會被修改
[root@ubuntu2204 ~]#grep replicaof /apps/redis/etc/redis.conf
# Master-Replica replication. Use replicaof to make a Redis instance a copy of
# replicaof <masterip> <masterport>
replicaof 10.0.0.101 6379

# 哨兵配置文件的sentinel monitor IP 同樣也會被修改
[root@ubuntu2204 ~]#grep 'sentinel monitor' /apps/redis/etc/sentinel.conf
# sentinel monitor <master-name> <ip> <redis-port> <quorum>
sentinel monitor mymaster 10.0.0.101 6379 2


# 驗證 Redis 各節(jié)點狀態(tài)
[root@ubuntu2204 ~]#redis-cli -a 123456  info replication
[root@ubuntu2204 ~]#redis-cli -p 26379  info sentinel

# 啟動redis
[root@ubuntu2204 ~]#systemctl start redis

# 觀察狀態(tài)
[root@ubuntu2204 ~]#grep replicaof /apps/redis/etc/redis.conf
[root@ubuntu2204 ~]#redis-cli -a 123456  info replication
[root@ubuntu2204 ~]#redis-cli -p 26379  info sentinel

[root@ubuntu2204 ~]#vim /apps/redis/etc/redis.conf
replica-priority 80

# 或者動態(tài)修改
[root@ubuntu2204 ~]#redis-cli -a 123456
127.0.0.1:6379> CONFIG GET replica-priority
127.0.0.1:6379> CONFIG SET replica-priority 60
127.0.0.1:6379> CONFIG GET replica-priority

# 原主節(jié)點自動變成從節(jié)點
[root@ubuntu2204 ~]#redis-cli -p 26379
127.0.0.1:26379> sentinel failover mymaster 
OK
127.0.0.1:26379>