Redis入门到高可用-6.Redis复制的原理与优化

1.概要

什么是主从复制
主从复制的配置
全量复制和部分复制
故障处理
开发运维的常见问题

2.什么是主从复制

Redis单机问题.png

Redis主从1.png

Redis主从2.png

Redis主从复制作用1.png

主从复制的作用.png

主从复制总结.png

3.主从复制的配置

slaveof

命令实现1.png

命令实现2.png
配置

修改配置.png

主从复制配置比较.png

4.实操

命令
配置
主从关系
主从数据

开启主从配置

vim redis-6379.conf

daemonize yes
pidfile /var/run/redis-6379.pid
logfile "6379.log"
#save 900 1
#save 300 10
#save 60 10000
dbfilename dump-6379.rdb
dir /opt/soft/redis/redis/data

vim redis-6380.conf

port 6380
daemonize yes
pidfile /var/run/redis-6380.pid
logfile "6380.log"
#save 900 1
#save 300 10
#save 60 10000
dbfilename dump-6380.rdb
dir /opt/soft/redis/redis/data
replicaof 127.0.0.1 6379

[root@master redis]# redis-server redis-6379.conf 
[root@master redis]# redis-cli
127.0.0.1:6379> info replication
# Replication
role:master
connected_slaves:0
master_replid:77c12844b3370cd33e5ec421891f6c400d12ee28
master_replid2:0000000000000000000000000000000000000000
master_repl_offset:0
second_repl_offset:-1
repl_backlog_active:0
repl_backlog_size:1048576
repl_backlog_first_byte_offset:0
repl_backlog_histlen:0
127.0.0.1:6379> exit
[root@master redis]# redis-server redis-6380.conf 
[root@master redis]# redis-cli -p 6380 info-replication
(error) ERR unknown command `info-replication`, with args beginning with: 
[root@master redis]# redis-cli -p 6380 info replication
# Replication
role:slave
master_host:127.0.0.1
master_port:6379
master_link_status:up
master_last_io_seconds_ago:10
master_sync_in_progress:0
slave_repl_offset:56
slave_priority:100
slave_read_only:1
connected_slaves:0
master_replid:e21d4f3793ad9495f4cf9ae6d23d3e426df72cb2
master_replid2:0000000000000000000000000000000000000000
master_repl_offset:56
second_repl_offset:-1
repl_backlog_active:1
repl_backlog_size:1048576
repl_backlog_first_byte_offset:1
repl_backlog_histlen:56
[root@master redis]# redis-cli
127.0.0.1:6379> set hello world
OK
127.0.0.1:6379> quit
[root@master redis]# redis-cli -p 6380 get hello
"world"

5.全量复制

[root@master redis]# redis-cli -p 6379 info server | grep run
run_id:26a8b09874078fda0a18b7a1f08c05ddb7ac8ab0
[root@master redis]# redis-cli -p 6380 info server | grep run
run_id:10858f81e4b3be96fefa9b07af1f9e87c31100ea
[root@master redis]# redis-cli -p 6380 info replication
# Replication
role:slave
master_host:127.0.0.1
master_port:6379
master_link_status:up
master_last_io_seconds_ago:4
master_sync_in_progress:0
slave_repl_offset:6218
slave_priority:100
slave_read_only:1
connected_slaves:0
master_replid:e21d4f3793ad9495f4cf9ae6d23d3e426df72cb2
master_replid2:0000000000000000000000000000000000000000
master_repl_offset:6218
second_repl_offset:-1
repl_backlog_active:1
repl_backlog_size:1048576
repl_backlog_first_byte_offset:1
repl_backlog_histlen:6218
[root@master redis]# redis-cli -p 6379 info replication
# Replication
role:master
connected_slaves:1
slave0:ip=127.0.0.1,port=6380,state=online,offset=6246,lag=0
master_replid:e21d4f3793ad9495f4cf9ae6d23d3e426df72cb2
master_replid2:0000000000000000000000000000000000000000
master_repl_offset:6246
second_repl_offset:-1
repl_backlog_active:1
repl_backlog_size:1048576
repl_backlog_first_byte_offset:1
repl_backlog_histlen:6246