redis集群模式

文档

1. redis单机安装
2. redis常用的五种数据类型
3. redis数据类型-位图bitmap
4. redis数据类型-基数统计HyperLogLog
5. redis数据类型-地理空间GEO
6. redis数据类型-流Stream
7. redis数据类型-位域bitfield
8. redis持久化-RDB
9. redis持久化-AOF
10. redis持久化-RDB+AOF混合模式
11. redis持久化-纯缓存模式
12. redis事务
13. redis管道 -redis pipeline -redis pipelining
14. redis发布订阅
15. redis主从复制
16. redis哨兵模式
17. redis集群模式 -分区算法
18. redis集群模式 -集群搭建

官方文档

1. 官网操作命令指南页面：https://redis.io/docs/latest/commands/?name=get&group=string
2. Redis cluster specification

说明

1. redis版本：7.0.0

redis集群模式-节点故障

主节点故障

1. 主节点故障，该主节点对应的从节点会升级为主节点

2. 模拟主节点故障

   1. 查看当前集群节点信息：cluster nodes

      127.0.0.1:6379> cluster nodes
      a05bb419996d657b23d7fa405b17f85b7191391b 192.168.145.133:6380@16380 master - 0 1755183700000 3 connected 5461-10922
      b15ba2a55dec014b8f75bece670d436fa6e21c00 192.168.145.133:6383@16383 slave 40dc7e1b9489a63c945f35037fbdc782e55fc163 0 1755183700000 1 connected
      8ed3140019b6dcc2540488c6a29e49d260c09e57 192.168.145.134:6381@16381 slave b0837bac5c46ce3fcc6d89fc3220cbf03b8d71a9 0 1755183701000 7 connected
      b0837bac5c46ce3fcc6d89fc3220cbf03b8d71a9 192.168.145.132:6382@16382 master - 0 1755183701000 7 connected 10923-16383
      47b66a60fb4c0882cfd6da3040bcb5c237ace417 192.168.145.134:6384@16384 slave a05bb419996d657b23d7fa405b17f85b7191391b 0 1755183700973 3 connected
      40dc7e1b9489a63c945f35037fbdc782e55fc163 192.168.145.132:6379@16379 myself,master - 0 1755183700000 1 connected 0-5460
      

   2. 实际节点的主从关系

      master：192.168.145.132:6379，slave：192.168.145.133:6383

      master：192.168.145.133:6380，slave：192.168.145.134:6384

      master：192.168.145.132:6382，slave：192.168.145.134:6381

   3. 找到其中一个主节点，以192.168.145.132:6382为例，执行下线操作

      127.0.0.1:6382> shutdown
      

   4. 查看主从关系，会发现，192.168.145.132:6382节点被标记为fail，同时，原来该节点的从节点192.168.145.134:6381升级为主节点

      127.0.0.1:6379> cluster nodes
      a05bb419996d657b23d7fa405b17f85b7191391b 192.168.145.133:6380@16380 master - 0 1755184492733 3 connected 5461-10922
      b15ba2a55dec014b8f75bece670d436fa6e21c00 192.168.145.133:6383@16383 slave 40dc7e1b9489a63c945f35037fbdc782e55fc163 0 1755184491597 1 connected
      8ed3140019b6dcc2540488c6a29e49d260c09e57 192.168.145.134:6381@16381 master - 0 1755184492000 8 connected 10923-16383
      b0837bac5c46ce3fcc6d89fc3220cbf03b8d71a9 192.168.145.132:6382@16382 master,fail - 1755184482439 1755184480579 7 disconnected
      47b66a60fb4c0882cfd6da3040bcb5c237ace417 192.168.145.134:6384@16384 slave a05bb419996d657b23d7fa405b17f85b7191391b 0 1755184492217 3 connected
      40dc7e1b9489a63c945f35037fbdc782e55fc163 192.168.145.132:6379@16379 myself,master - 0 1755184491000 1 connected 0-5460
      

节点恢复

1. 当主节点下线后，原来该主节点对应的从节点会升级为主节点，下线的主节点恢复后，会变为从节点

2. 模拟节点恢复

   1. 原来shutdown的主节点192.168.145.132:6382，重新启动，恢复服务

      ./redis-server /opt/module/redis/myredis-cluster-6382/redis-cluster-6382.conf
      

   2. 查看主从关系，会发现，当前节点192.168.145.132:6382成为了192.168.145.134:6381节点的从节点

      127.0.0.1:6382> cluster nodes
      a05bb419996d657b23d7fa405b17f85b7191391b 192.168.145.133:6380@16380 master - 0 1755184934428 3 connected 5461-10922
      8ed3140019b6dcc2540488c6a29e49d260c09e57 192.168.145.134:6381@16381 master - 0 1755184935457 8 connected 10923-16383
      47b66a60fb4c0882cfd6da3040bcb5c237ace417 192.168.145.134:6384@16384 slave a05bb419996d657b23d7fa405b17f85b7191391b 0 1755184933000 3 connected
      b0837bac5c46ce3fcc6d89fc3220cbf03b8d71a9 192.168.145.132:6382@16382 myself,slave 8ed3140019b6dcc2540488c6a29e49d260c09e57 0 1755184934000 8 connected
      b15ba2a55dec014b8f75bece670d436fa6e21c00 192.168.145.133:6383@16383 slave 40dc7e1b9489a63c945f35037fbdc782e55fc163 0 1755184934121 1 connected
      40dc7e1b9489a63c945f35037fbdc782e55fc163 192.168.145.132:6379@16379 master - 0 1755184933396 1 connected 0-5460
      

节点主从调整

1. 当主节点下线后，原来该主节点对应的从节点会升级为主节点，下线的主节点再次上线后，会变为从节点

2. 主节点下线后再次恢复，会改变主从节点的角色，如果要恢复最原始状态，可以在原来的主节点192.168.145.132:6382，也就是现在的从节点上，执行下面的命令

   127.0.0.1:6382> cluster failover
   OK
   

3. 查看主从关系，会发现，主从节点已经调换过来

   127.0.0.1:6382> cluster nodes
   a05bb419996d657b23d7fa405b17f85b7191391b 192.168.145.133:6380@16380 master - 0 1755185672569 3 connected 5461-10922
   8ed3140019b6dcc2540488c6a29e49d260c09e57 192.168.145.134:6381@16381 slave b0837bac5c46ce3fcc6d89fc3220cbf03b8d71a9 0 1755185671032 9 connected
   47b66a60fb4c0882cfd6da3040bcb5c237ace417 192.168.145.134:6384@16384 slave a05bb419996d657b23d7fa405b17f85b7191391b 0 1755185671000 3 connected
   b0837bac5c46ce3fcc6d89fc3220cbf03b8d71a9 192.168.145.132:6382@16382 myself,master - 0 1755185672000 9 connected 10923-16383
   b15ba2a55dec014b8f75bece670d436fa6e21c00 192.168.145.133:6383@16383 slave 40dc7e1b9489a63c945f35037fbdc782e55fc163 0 1755185673077 1 connected
   40dc7e1b9489a63c945f35037fbdc782e55fc163 192.168.145.132:6379@16379 master - 0 1755185672057 1 connected 0-5460