redis主从

redis主从
host1: master
192.168.40.130
host2: slave 
192.168.40.132
https://download.redis.io/releases/redis-6.2.6.tar.gz

编译：
mkdir -p /usr/local/redis-6.2.6


make install PREFIX=/usr/local/redis-6.2.6

cp redis.conf /usr/local/redis-6.2.6/bin/
 cd  /usr/local/redis-6.2.6/bin/
vim redis.conf
#bind 127.0.0.1 -::1
daemonize yes
requirepass lzjasdqq
./redis-server redis.conf 
./redis-cli 

pkill -9 redis 




vim  /usr/lib/systemd/system/redis.service
[Unit]
Description=redis-server
After=network.target

[Service]
Type=forking
# ExecStart需要按照实际情况修改成自己的地址
ExecStart=/usr/local/redis-6.2.6/bin/redis-server /usr/local/redis-6.2.6/bin/redis.conf
PrivateTmp=true

[Install]
WantedBy=multi-user.target

useradd -r redis -s /sbin/nologin         
systemctl daemon-reload         
systemctl start redis 



启动复制功能：
1、使用用户端启用：
在slave上:
    > SLAVAOF MASTER_IP MASTER_PORT
例：
    127.0.0.1:6379> slaveof 192.168.1.64 6379        //成为从库
    OK

2、使用配置配置（在从库上操作）：
# vim /etc/redis.conf
    # slaveof <masterip> <masterport>    //修改此项如下
    slaveof 192.168.1.63 6379
            
            
            
            
[root@host3 bin]# ./redis-cli 
127.0.0.1:6379> auth lzjasdqq
OK

127.0.0.1:6379> help slaveof

  SLAVEOF host port
  summary: Make the server a replica of another instance, or promote it as master. Deprecated starting with Redis 5. Use REPLICAOF instead.
  since: 1.0.0
  group: server

127.0.0.1:6379> SLAVEOF 192.168.40.130 6379 
OK
127.0.0.1:6379> info 
# Server
redis_version:6.2.6
redis_git_sha1:00000000
# Replication
role:slave
master_host:192.168.40.130
master_port:6379
master_link_status:down
master_last_io_seconds_ago:-1
master_sync_in_progress:1



master_link_status:down

sysctl vm.overcommit_memory=1



replicaof 192.168.40.130 5379

# If the master is password protected (using the "requirepass" configuration
# directive below) it is possible to tell the replica to authenticate before
# starting the replication synchronization process, otherwise the master will
# refuse the replica request.
#
masterauth  lzjasdqq


info 
# Replication
role:slave
master_host:192.168.40.130
master_port:6379
master_link_status:up

主：
127.0.0.1:6379> keys * 
(empty array)
127.0.0.1:6379> set a 1 
OK
127.0.0.1:6379> set b 2 
OK
127.0.0.1:6379> INCR b
(integer) 3
127.0.0.1:6379> get a 
"1"
127.0.0.1:6379> get b
"3"

127.0.0.1:6379> del b 
(integer) 1


从
127.0.0.1:6379> keys * 
1) "a"
2) "b"
127.0.0.1:6379> get a 
"1"
127.0.0.1:6379> get b 
"3"
127.0.0.1:6379> keys * 
1) "a"
2) "b"
127.0.0.1:6379> del b 
(error) READONLY You can't write against a read only replica.
127.0.0.1:6379> keys * 
1) "a"


从redis只能读，主redis可以读也可以写