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

全量复制.png

6.全量复制开销

• bgsave时间
• RDB文件网络传输时间
• 从节点清空数据时间
• 从节点加载RDB的时间
• 可能的AOF重写时间

  部分复制.png

7.故障处理

故障转移.png

slave宕掉1.png

slave宕掉2.png

slave宕掉3.png

master宕掉1.png

master宕掉2.png

master宕掉3.png

master宕掉4.png

故障转移问题.png

7.主从复制开发与运维中的问题

• 读写分离

  Redis读写分离.png

• 主从配置不一致

  Redis配置不一致.png

• 规避全量复制

  Redis规避全量复制.png

• 规避复制风暴

  Redis规避复制风暴.png