redis主从redis主从配置：
原理(增量同步)：
从服务器-------发送sync到 ------>
主服务器----BGSAVE--->
主服务器将保存的RDB文件发送给从服务器
从服务器收到RDB文件后，重载到从服务器的内存中，
一次同步完成
在同一台机器上启两个进程
修改配置文件：
[root@node120 redis326]# ls
6379.conf 6380.conf
[root@node120 redis326]# pwd
/etc/redis326
在配置文件6380.conf中将6379修改成6380
[root@node120 redis326]# diff 6380.conf 6379.conf
83c83
< # Accept connections on the specified port, defaultis 6380 (IANA #815344).
---
> # Accept connections on the specified port, defaultis 6379 (IANA #815344).
85c85
< port 6380
---
> port 6379
152c152
< pidfile /var/run/redis_6380.pid
---
> pidfile /var/run/redis_6379.pid
239c239
< dbfilename dump_6380.rdb
---
> dbfilename dump_6379.rdb
600c600
< appendfilename "appendonly_6380.aof"
---
> appendfilename "appendonly_6379.aof"
732c732
< # cluster-config-file nodes-6380.conf
---
> # cluster-config-file nodes-6379.conf
手动启动redis:
[root@node120 redis326]#/usr/local/redis326/bin/redis-server 6379.conf
[root@node120 redis326]#/usr/local/redis326/bin/redis-server 6380.conf
[root@node120 redis326]# pwd
/etc/redis326
[root@node120 redis326]# ps -ef | grep redis
root 7244 1 0 15:15 ? 00:00:00/usr/local/redis326/bin/redis-server 192.168.2.120:6379
root 7248 1 0 15:15 ? 00:00:00 /usr/local/redis326/bin/redis-server192.168.2.120:6380
root 7252 6687 0 15:16 pts/1 00:00:00 grep --color=auto redis
将6380作为6379的从数据库：
192.168.2.120:6380> slaveof 192.168.2.120 6379 #也可以将这个配置写入配置文件中
OK
192.168.2.120:6380> info
# Replication
role:slave
master_host:192.168.2.120
master_port:6379
master_link_status:up
master_last_io_seconds_ago:7
master_sync_in_progress:0
slave_repl_offset:57
slave_priority:100
slave_read_only:1
connected_slaves:0
master_repl_offset:0
repl_backlog_active:0
repl_backlog_size:1048576
repl_backlog_first_byte_offset:0
repl_backlog_histlen:0
192.168.2.120:6379> info
# Replication
role:master
connected_slaves:1
slave0:ip=192.168.2.120,port=6380,state=online,offset=127,lag=0
master_repl_offset:127
repl_backlog_active:1
repl_backlog_size:1048576
repl_backlog_first_byte_offset:2
repl_backlog_histlen:126
测试：
master:
192.168.2.120:6379> keys *
(empty list or set)
192.168.2.120:6379> set key1 rscpass
OK
192.168.2.120:6379> keys *
1) "key1"
slave:
192.168.2.120:6380> keys *
1) "key1"
从服务器是只读的，不能写入数据：
192.168.2.120:6380> set key1 12
(error) READONLY You can't write against a read onlyslave.
