Redis哨兵+keepalived高可用
redis哨兵高可用
基本环境
| 机器 | IP |
|---|---|
| db01 | 192.168.0.51(master) |
| db02 | 192.168.0.52(slave) |
| db03 | 192.168.0.53(slave) |
1：VIP随MASTER飘动，无需手动改
2：主从关系切换由sentinel管理
3：keepalived三个state全部设置为BACKUP，如果role:master的话，优先级+10（默认三个优先级全为100），不能开启nopreempt，否则只要keepalived运行，就不会释放VIP（即使这个节点已经变为redis-slave了）
systemd服务管理
Redis
[Unit]
Description=Redis
After=network.target
[Service]
Type=forking
PIDFile=/var/run/redis.pid
ExecStart=/opt/redis-6.2.1/src/redis-server /opt/redis-6.2.1/redis.conf
ExecReload=/bin/kill -s HUP $MAINPID
ExecStop=/opt/redis-6.2.1/src/redis-cli -a password shutdown
[Install]
WantedBy=multi-user.target
Sentinel
[Unit]
Description=Sentinel
After=network.target
[Service]
Type=forking
PIDFile=/var/run/sentinel.pid
ExecStart=/opt/redis-6.2.1/src/redis-sentinel /opt/redis-6.2.1/sentinel.conf
ExecReload=/bin/kill -s HUP $MAINPID
ExecStop=/bin/kill -s QUIT $MAINPID
PrivateTmp=true
[Install]
WantedBy=multi-user.target
Redis配置
初始时，db02,db03需要在配置文件中写slaveof db01，后续sentinel会自动去改
db01-redis
daemonize yes
bind 0.0.0.0
port 6379
timeout 300
loglevel notice
logfile "/opt/redis-6.2.1/redis.log"
pidfile "/var/run/redis.pid"
databases 16
save 900 1
save 300 10
save 60 10000
dbfilename "dump.rdb"
rdbcompression yes
dir "/opt/redis-6.2.1"
maxclients 20480
appendonly no
appendfsync no
requirepass "password"
masterauth "password"
db02-redis
daemonize yes
bind 0.0.0.0
port 6379
timeout 300
loglevel notice
logfile "/opt/redis-6.2.1/redis.log"
pidfile "/var/run/redis.pid"
databases 16
save 900 1
save 300 10
save 60 10000
dbfilename "dump.rdb"
rdbcompression yes
dir "/opt/redis-6.2.1"
maxclients 20480
appendonly no
appendfsync no
requirepass "password"
masterauth "password"
slaveof 192.168.0.51 6379
db03-redis
daemonize yes
bind 0.0.0.0
port 6379
timeout 300
loglevel notice
logfile "/opt/redis-6.2.1/redis.log"
pidfile "/var/run/redis.pid"
databases 16
save 900 1
save 300 10
save 60 10000
dbfilename "dump.rdb"
rdbcompression yes
dir "/opt/redis-6.2.1"
maxclients 20480
appendonly no
appendfsync no
requirepass "password"
masterauth "password"
slaveof 192.168.0.51 6379
sentinel配置
db01-sentinel
protected-mode no
port 26379
daemonize yes
logfile "/opt/redis-6.2.1/sentinel.log"
pidfile "/var/run/sentinel.pid"
dir "/tmp"
sentinel monitor mymaster 192.168.0.51 6379 1 #只要一个节点认为master有问题，即可发送failover
sentinel down-after-milliseconds mymaster 5000
sentinel auth-pass mymaster password
db02-sentinel
protected-mode no
port 26379
daemonize yes
logfile "/opt/redis-6.2.1/sentinel.log"
pidfile "/var/run/sentinel.pid"
dir "/tmp"
sentinel monitor mymaster 192.168.0.51 6379 1
sentinel down-after-milliseconds mymaster 5000
sentinel auth-pass mymaster password
db03-sentinel
protected-mode no
port 26379
daemonize yes
logfile "/opt/redis-6.2.1/sentinel.log"
pidfile "/var/run/sentinel.pid"
dir "/tmp"
sentinel monitor mymaster 192.168.0.51 6379 1
sentinel down-after-milliseconds mymaster 5000
sentinel auth-pass mymaster password
keepalived配置
将IP换了即可，三个节点全部设置为BACKUP，但是不能设置为nopreempt
db01-keepalived
! Configuration File for keepalived
global_defs {
router_id LVS_DEVEL
script_user root
enable_script_security
vrrp_skip_check_adv_addr
#vrrp_strict
vrrp_garp_interval 0
vrrp_gna_interval 0
}
vrrp_script sentinel_check {
script "/etc/keepalived/sentinel-check.sh 127.0.0.1 6379 password"
interval 2
weight 10
fall 3
rise 1
}
vrrp_instance VI_1 {
state BACKUP ##
interface ens33
virtual_router_id 51
priority 100
# nopreempt # 这里不要开nopreempt,只要keepalived在运行，会一直霸占VIP，我们要让VIP飘
advert_int 2
authentication {
auth_type PASS
auth_pass 1111
}
unicast_src_ip 192.168.0.51
unicast_peer {
192.168.0.52
192.168.0.53
virtual_ipaddress {
192.168.0.55/24
}
track_script {
sentinel_check
}
}
db02-keepalived
! Configuration File for keepalived
global_defs {
router_id LVS_DEVEL
script_user root
enable_script_security
vrrp_skip_check_adv_addr
#vrrp_strict
vrrp_garp_interval 0
vrrp_gna_interval 0
}
vrrp_script sentinel_check {
script "/etc/keepalived/sentinel-check.sh 127.0.0.1 6379 password"
interval 2
weight 10
fall 3
rise 1
}
vrrp_instance VI_1 {
state BACKUP ####
interface ens33
virtual_router_id 51
priority 100
# nopreempt
advert_int 2
authentication {
auth_type PASS
auth_pass 1111
}
unicast_src_ip 192.168.0.52
unicast_peer {
192.168.0.51
192.168.0.53
}
virtual_ipaddress {
192.168.0.55/24
}
track_script {
sentinel_check
}
}
db03-keepalived
! Configuration File for keepalived
global_defs {
router_id LVS_DEVEL
script_user root
enable_script_security
vrrp_skip_check_adv_addr
#vrrp_strict
vrrp_garp_interval 0
vrrp_gna_interval 0
}
vrrp_script sentinel_check {
script "/etc/keepalived/sentinel-check.sh 127.0.0.1 6379 password"
interval 2
weight 10
fall 3
rise 1
}
vrrp_instance VI_1 {
state BACKUP
interface ens33
virtual_router_id 51
priority 100
# nopreempt
advert_int 2
authentication {
auth_type PASS
auth_pass 1111
}
unicast_src_ip 192.168.0.53
unicast_peer {
192.168.0.52
192.168.0.51
}
virtual_ipaddress {
192.168.0.55/24
}
track_script {
sentinel_check
}
}
使用说明
1：三台节点启动redis
2：三台节点启动sentinel
3: 三台节点启动keepalived