cluster(集群)模式-docker版 哈希槽分区进行亿级数据存储
1、场景
1~2亿条数据须要缓存，请问如何设计这个存储案例？
单机单台100%不可能，必定是分布式存储，用redis如何落地？
解决方案
1、哈希取余分区
2亿条记录就是2亿个k,v，咱们单机不行必须要分布式多机，假如有3台机器形成一个集群，用户每次读写操作都是依据公式：
hash(key) % N个机器台数，计算出哈希值，用来决定数据映射到哪一个节点上。
长处：
简略粗犷，间接无效，只须要预估好数据布局好节点，例如3台、8台、10台，就能保障一段时间的数据撑持。应用Hash算法让固定的一部分申请落到同一台服务器上，这样每台服务器固定解决一部分申请（并保护这些申请的信息），起到负载平衡+分而治之的作用。毛病：
原来布局好的节点，进行扩容或者缩容就比拟麻烦了额，不论扩缩，每次数据变动导致节点有变动，映射关系须要从新进行计算，在服务器个数固定不变时没有问题，如果须要弹性扩容或故障停机的状况下，原来的取模公式就会发生变化：Hash(key)/3会变成Hash(key) /?。此时地址通过取余运算的后果将产生很大变动，依据公式获取的服务器也会变得不可控。某个redis机器宕机了，因为台数数量变动，会导致hash取余全副数据从新洗牌。2、一致性哈希算法分区
一致性哈希算法在1997年由麻省理工学院中提出的，设计指标是为了解决分布式缓存数据变动和映射问题，某个机器宕机了，分母数量扭转了，天然取余数不OK了。
作用：
提出一致性Hash解决方案。目标是当服务器个数产生变动时，尽量减少影响客户端到服务器的映射关系
步骤：
算法构建一致性哈希环
一致性哈希环
一致性哈希算法必然有个hash函数并依照算法产生hash值，这个算法的所有可能哈希值会形成一个全量集，这个汇合能够成为一个hash空间[0,2^32-1]，这个是一个线性空间，然而在算法中，咱们通过适当的逻辑管制将它首尾相连(0 = 2^32),这样让它逻辑上造成了一个环形空间。
它也是依照应用取模的办法，后面笔记介绍的节点取模法是对节点（服务器）的数量进行取模。而一致性Hash算法是对2^32 取模，简略来说，一致性Hash算法将整个哈希值空间组织成一个虚构的圆环，如假如某哈希函数H的值空间为0-2^32-1 （即哈希值是一个32位无符号整形），整个哈希环如下图：整个空间按顺时针方向组织，圆环的正上方的点代表0，0点右侧的第一个点代表1，以此类推，2、3、4、……直到2^32-1 ，也就是说0点左侧的第一个点代表2^32-1， 0和2^32-1 在零点中方向重合，咱们把这个由2^32个点组成的圆环称为Hash环。
服务器IP节点映射
节点映射
将集群中各个IP节点映射到环上的某一个地位。
将各个服务器应用Hash进行一个哈希，具体能够抉择服务器的IP或主机名作为关键字进行哈希，这样每台机器就能确定其在哈希环上的地位。如果4个节点NodeA、B、C、D，通过IP地址的哈希函数计算(hash(ip))，应用IP地址哈希后在环空间的地位如下：
key落到服务器的落键规定
当咱们须要存储一个kv键值对时，首先计算key的hash值，hash(key)，将这个key应用雷同的函数Hash计算出哈希值并确定此数据在环上的地位，从此地位沿环顺时针“行走”，第一台遇到的服务器就是其应该定位到的服务器，并将该键值对存储在该节点上。
如咱们有Object A、Object B、Object C、Object D四个数据对象，通过哈希计算后，在环空间上的地位如下：依据一致性Hash算法，数据A会被定为到Node A上，B被定为到Node B上，C被定为到Node C上，D被定为到Node D上。
长处：
1.一致性哈希算法的容错性
容错性
假如Node C宕机，能够看到此时对象A、B、D不会受到影响，只有C对象被重定位到Node D。个别的，在一致性Hash算法中，如果一台服务器不可用，则受影响的数据仅仅是此服务器到其环空间中前一台服务器（即沿着逆时针方向行走遇到的第一台服务器）之间数据，其它不会受到影响。简略说，就是C挂了，受到影响的只是B、C之间的数据，并且这些数据会转移到D进行存储。
2.一致性哈希算法的扩展性
扩展性
数据量减少了，须要减少一台节点NodeX，X的地位在A和B之间，那收到影响的也就是A到X之间的数据，从新把A到X的数据录入到X上即可，不会导致hash取余全副数据从新洗牌。
毛病：
一致性哈希算法的数据歪斜问题
一致性Hash算法在服务节点太少时，容易因为节点散布不平均而造成数据歪斜（被缓存的对象大部分集中缓存在某一台服务器上）问题，
例如零碎中只有两台服务器：
总结：
为了在节点数目产生扭转时尽可能少的迁徙数据
将所有的存储节点排列在收尾相接的Hash环上，每个key在计算Hash后会顺时针找到邻近的存储节点寄存。
而当有节点退出或退出时仅影响该节点在Hash环上顺时针相邻的后续节点。长处 退出和删除节点只影响哈希环中顺时针方向的相邻的节点，对其余节点无影响。
毛病 数据的散布和节点的地位无关，因为这些节点不是平均的散布在哈希环上的，所以数据在进行存储时达不到均匀分布的成果。
3、哈希槽分区
哈希槽本质就是一个数组，数组[0,2^14 -1]造成hash slot空间。
作用：解决一致性哈希算法的数据歪斜问题
解决平均调配的问题，在数据和节点之间又退出了一层，把这层称为哈希槽（slot），用于治理数据和节点之间的关系，当初就相当于节点上放的是槽，槽里放的是数据。
槽解决的是粒度问题，相当于把粒度变大了，这样便于数据挪动。
哈希解决的是映射问题，应用key的哈希值来计算所在的槽，便于数据调配。
哈希槽的计算
Redis 集群中内置了 16384 个哈希槽，redis 会依据节点数量大抵均等的将哈希槽映射到不同的节点。当须要在 Redis 集群中搁置一个 key-value时，redis 先对 key 应用 crc16 算法算出一个后果，而后把后果对 16384 求余数，这样每个 key 都会对应一个编号在 0-16383 之间的哈希槽，也就是映射到某个节点上。如下代码，key之A 、B在Node2， key之C落在Node3上
2、3主3从集群配置
1、启动docker
systemctl start docker2、新建6个docker容器redis实例
docker run -d --name redis-node-1 --net host --privileged=true -v /data/redis/share/redis-node-1:/data redis --cluster-enabled yes --appendonly yes --port 6381 docker run -d --name redis-node-2 --net host --privileged=true -v /data/redis/share/redis-node-2:/data redis --cluster-enabled yes --appendonly yes --port 6382 docker run -d --name redis-node-3 --net host --privileged=true -v /data/redis/share/redis-node-3:/data redis --cluster-enabled yes --appendonly yes --port 6383 docker run -d --name redis-node-4 --net host --privileged=true -v /data/redis/share/redis-node-4:/data redis --cluster-enabled yes --appendonly yes --port 6384 docker run -d --name redis-node-5 --net host --privileged=true -v /data/redis/share/redis-node-5:/data redis --cluster-enabled yes --appendonly yes --port 6385 docker run -d --name redis-node-6 --net host --privileged=true -v /data/redis/share/redis-node-6:/data redis --cluster-enabled yes --appendonly yes --port 6386[root@docker ~]# docker psCONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMESd6fc3ef2855b redis "docker-entrypoint.s…" 3 seconds ago Up 2 seconds redis-node-69c8868d69a50 redis "docker-entrypoint.s…" 3 seconds ago Up 3 seconds redis-node-57fbb5345951a redis "docker-entrypoint.s…" 4 seconds ago Up 3 seconds redis-node-4d53b9d5af1ac redis "docker-entrypoint.s…" 4 seconds ago Up 4 seconds redis-node-3fe0e430cb940 redis "docker-entrypoint.s…" 6 seconds ago Up 4 seconds redis-node-2ee03a7ec212e redis "docker-entrypoint.s…" 8 seconds ago Up 6 seconds redis-node-1分步解释
docker run：创立并运行docker容器实例--name redis-node-6：容器名字--net host：应用宿主机的IP和端口，默认、--privileged=true：获取宿主机root用户权限-v /data/redis/share/redis-node-6:/data：容器卷，宿主机地址:docker外部地址redis：redis镜像和版本号--cluster-enabled yes：开启redis集群--appendonly yes：开启长久化--port 6386：redis端口号
3、进入容器redis-node-1并为6台机器构建集群关系
1、进入容器
docker exec -it redis-node-1 /bin/bash2、构建主从关系
PS：留神本人的实在IP地址
redis-cli --cluster create 192.168.130.132:6381 192.168.130.132:6382 192.168.130.132:6383 192.168.130.132:6384 192.168.130.132:6385 192.168.130.132:6386 --cluster-replicas 1--cluster-replicas 1：示意为每个master创立一个slave节点
[root@docker ~]# docker exec -it redis-node-1 /bin/bashroot@docker:/data# redis-cli --cluster create 192.168.130.132:6381 192.168.130.132:6382 192.168.130.132:6383 192.168.130.132:6384 192.168.130.132:6385 192.168.130.132:6386 --cluster-replicas 1>>> Performing hash slots allocation on 6 nodes...Master[0] -> Slots 0 - 5460Master[1] -> Slots 5461 - 10922Master[2] -> Slots 10923 - 16383Adding replica 192.168.130.132:6385 to 192.168.130.132:6381Adding replica 192.168.130.132:6386 to 192.168.130.132:6382Adding replica 192.168.130.132:6384 to 192.168.130.132:6383>>> Trying to optimize slaves allocation for anti-affinity[WARNING] Some slaves are in the same host as their masterM: 8335b5349d781c11745ee129f5dbae370dbd3394 192.168.130.132:6381 slots:[0-5460] (5461 slots) masterM: 60fa7e084483feca3af41f269de5a57b526c0ad7 192.168.130.132:6382 slots:[5461-10922] (5462 slots) masterM: 8dbe8b347410cf87d62933382b73693405535ba1 192.168.130.132:6383 slots:[10923-16383] (5461 slots) masterS: c366905ca5ec2472275bbea9b2ae9b642b92a737 192.168.130.132:6384 replicates 60fa7e084483feca3af41f269de5a57b526c0ad7S: b5fd469dd1f8b5a64cacd5ecaed9dd396e1b9217 192.168.130.132:6385 replicates 8dbe8b347410cf87d62933382b73693405535ba1S: 4051766aa375f0ed4533cb729afa8daf8649f5d2 192.168.130.132:6386 replicates 8335b5349d781c11745ee129f5dbae370dbd3394Can I set the above configuration? (type 'yes' to accept): yes>>> Nodes configuration updated>>> Assign a different config epoch to each node>>> Sending CLUSTER MEET messages to join the clusterWaiting for the cluster to join...>>> Performing Cluster Check (using node 192.168.130.132:6381)M: 8335b5349d781c11745ee129f5dbae370dbd3394 192.168.130.132:6381 slots:[0-5460] (5461 slots) master 1 additional replica(s)S: b5fd469dd1f8b5a64cacd5ecaed9dd396e1b9217 192.168.130.132:6385 slots: (0 slots) slave replicates 8dbe8b347410cf87d62933382b73693405535ba1M: 8dbe8b347410cf87d62933382b73693405535ba1 192.168.130.132:6383 slots:[10923-16383] (5461 slots) master 1 additional replica(s)S: c366905ca5ec2472275bbea9b2ae9b642b92a737 192.168.130.132:6384 slots: (0 slots) slave replicates 60fa7e084483feca3af41f269de5a57b526c0ad7M: 60fa7e084483feca3af41f269de5a57b526c0ad7 192.168.130.132:6382 slots:[5461-10922] (5462 slots) master 1 additional replica(s)S: 4051766aa375f0ed4533cb729afa8daf8649f5d2 192.168.130.132:6386 slots: (0 slots) slave replicates 8335b5349d781c11745ee129f5dbae370dbd3394[OK] All nodes agree about slots configuration.>>> Check for open slots...>>> Check slots coverage...[OK] All 16384 slots covered.root@docker:/data# 到这里，3主3从就构建实现了。
4、链接进入6381作为切入点，查看集群状态
root@docker:/data# redis-cli -p 6381127.0.0.1:6381> cluster infocluster_state:okcluster_slots_assigned:16384cluster_slots_ok:16384cluster_slots_pfail:0cluster_slots_fail:0cluster_known_nodes:6cluster_size:3cluster_current_epoch:6cluster_my_epoch:1cluster_stats_messages_ping_sent:663cluster_stats_messages_pong_sent:671cluster_stats_messages_sent:1334cluster_stats_messages_ping_received:666cluster_stats_messages_pong_received:663cluster_stats_messages_meet_received:5cluster_stats_messages_received:1334127.0.0.1:6381> cluster nodesb5fd469dd1f8b5a64cacd5ecaed9dd396e1b9217 192.168.130.132:6385@16385 slave 8dbe8b347410cf87d62933382b73693405535ba1 0 1651152474000 3 connected8335b5349d781c11745ee129f5dbae370dbd3394 192.168.130.132:6381@16381 myself,master - 0 1651152472000 1 connected 0-54608dbe8b347410cf87d62933382b73693405535ba1 192.168.130.132:6383@16383 master - 0 1651152474000 3 connected 10923-16383c366905ca5ec2472275bbea9b2ae9b642b92a737 192.168.130.132:6384@16384 slave 60fa7e084483feca3af41f269de5a57b526c0ad7 0 1651152476585 2 connected60fa7e084483feca3af41f269de5a57b526c0ad7 192.168.130.132:6382@16382 master - 0 1651152475573 2 connected 5461-109224051766aa375f0ed4533cb729afa8daf8649f5d2 192.168.130.132:6386@16386 slave 8335b5349d781c11745ee129f5dbae370dbd3394 0 1651152474566 1 connected127.0.0.1:6381> 1、cluster info：查看集群状态
127.0.0.1:6381> cluster infocluster_state:okcluster_slots_assigned:16384cluster_slots_ok:16384cluster_slots_pfail:0cluster_slots_fail:0cluster_known_nodes:6cluster_size:3cluster_current_epoch:6cluster_my_epoch:1cluster_stats_messages_ping_sent:663cluster_stats_messages_pong_sent:671cluster_stats_messages_sent:1334cluster_stats_messages_ping_received:666cluster_stats_messages_pong_received:663cluster_stats_messages_meet_received:5cluster_stats_messages_received:1334cluster_state:ok状态示意集群能够失常承受查问申请。fail状态示意，至多有一个哈希槽没有被绑定（阐明有哈希槽没有被绑定到任意一个节点），或者在谬误的状态（节点能够提供服务然而带有FAIL 标记），或者该节点无奈分割到少数master节点。.cluster_slots_assigned: 已调配到集群节点的哈希槽数量（不是没有被绑定的数量）。16384个哈希槽全副被调配到集群节点是集群失常运行的必要条件.cluster_slots_ok: 哈希槽状态不是FAIL和PFAIL的数量.cluster_slots_pfail: 哈希槽状态是PFAIL的数量。只有哈希槽状态没有被降级到FAIL状态，这些哈希槽依然能够被失常解决。PFAIL状态示意咱们以后不能和节点进行交互，但这种状态只是长期的谬误状态。cluster_slots_fail: 哈希槽状态是FAIL的数量。如果值不是0，那么集群节点将无奈提供查问服务，除非cluster-require-full-coverage被设置为no.cluster_known_nodes: 集群中节点数量，包含处于握手状态还没有成为集群正式成员的节点.cluster_size: 至多蕴含一个哈希槽且可能提供服务的master节点数量.cluster_current_epoch: 集群本地Current Epoch变量的值。这个值在节点故障转移过程时有用，它总是递增和惟一的。cluster_my_epoch: 以后正在应用的节点的Config Epoch值. 这个是关联在本节点的版本值.cluster_stats_messages_sent: 通过node-to-node二进制总线发送的音讯数量.cluster_stats_messages_received: 通过node-to-node二进制总线接管的音讯数量.
2、cluster nodes：提供了以后连贯节点所属集群的配置信息，信息格式和Redis集群在磁盘上存储应用的序列化格局齐全一样（在磁盘存储信息的结尾还存储了一些额定信息）
127.0.0.1:6381> cluster nodesb5fd469dd1f8b5a64cacd5ecaed9dd396e1b9217 192.168.130.132:6385@16385 slave 8dbe8b347410cf87d62933382b73693405535ba1 0 1651152474000 3 connected8335b5349d781c11745ee129f5dbae370dbd3394 192.168.130.132:6381@16381 myself,master - 0 1651152472000 1 connected 0-54608dbe8b347410cf87d62933382b73693405535ba1 192.168.130.132:6383@16383 master - 0 1651152474000 3 connected 10923-16383c366905ca5ec2472275bbea9b2ae9b642b92a737 192.168.130.132:6384@16384 slave 60fa7e084483feca3af41f269de5a57b526c0ad7 0 1651152476585 2 connected60fa7e084483feca3af41f269de5a57b526c0ad7 192.168.130.132:6382@16382 master - 0 1651152475573 2 connected 5461-109224051766aa375f0ed4533cb729afa8daf8649f5d2 192.168.130.132:6386@16386 slave 8335b5349d781c11745ee129f5dbae370dbd3394 0 1651152474566 1 connected127.0.0.1:6381> 主从关系图：
每行的组成：
<id> <ip:port> <flags> <master> <ping-sent> <pong-recv> <config-epoch> <link-state> <slot> <slot> ... <slot>
id: 节点ID,是一个40字节的随机字符串，这个值在节点启动的时候创立，并且永远不会扭转（除非应用CLUSTER RESET HARD命令）。ip:port: 客户端与节点通信应用的地址.flags: 逗号宰割的标记位，可能的值有:myself,master,slave,fail?,fail,handshake,noaddr,noflags. 下一部分将具体介绍这些标记.myself: 以后连贯的节点.master: 节点是master.slave: 节点是slave.fail?: 节点处于PFAIL状态。 以后节点无奈分割，但逻辑上是可达的 (非FAIL状态).fail: 节点处于FAIL状态. 大部分节点都无奈与其取得联系将会将改节点由PFAIL状态降级至FAIL状态。handshake: 还未获得信赖的节点，以后正在与其进行握手.noaddr: 没有地址的节点（No address known for this node）.noflags: 连个标记都没有（No flags at all）.
master: 如果节点是slave，并且已知master节点，则这里列出master节点ID,否则的话这里列出”-“。ping-sent: 最近一次发送ping的工夫，这个工夫是一个unix毫秒工夫戳，0代表没有发送过.pong-recv: 最近一次收到pong的工夫，应用unix工夫戳示意.config-epoch: 节点的epoch值（or of the current master if the node is a slave）。每当节点产生失败切换时，都会创立一个新的，独特的，递增的epoch。如果多个节点竞争同一个哈希槽时，epoch值更高的节点会抢夺到。link-state: node-to-node集群总线应用的链接的状态，咱们应用这个链接与集群中其余节点进行通信.值能够是connected和disconnected.slot: 哈希槽值或者一个哈希槽范畴. 从第9个参数开始，前面最多可能有16384个 数(limit never reached)。代表以后节点能够提供服务的所有哈希槽值。如果只是一个值,那就是只有一个槽会被应用。如果是一个范畴，这个值示意为起始槽-完结槽，节点将解决包含起始槽和完结槽在内的所有哈希槽。
官网地址：http://www.redis.cn/commands/...
3、主从容错切换迁徙案例
1、数据读写存储
1、启动6机构成的集群并通过exec进入
root@docker:/data# redis-cli -p 6381127.0.0.1:6381> set k1 v1(error) MOVED 12706 192.168.130.132:6383127.0.0.1:6381> set k2 v2\OK127.0.0.1:6381> set k3 v3OK127.0.0.1:6381> set k4 v4(error) MOVED 8455 192.168.130.132:6382127.0.0.1:6381> 显示k1和k4没有存储进去
(error) MOVED 12706 192.168.130.132:6383：请转到6383的redis进行存储
2、避免路由生效加参数-c并新增两个key
root@docker:/data# redis-cli -p 6381 -c127.0.0.1:6381> set k1 v1-> Redirected to slot [12706] located at 192.168.130.132:6383OK192.168.130.132:6383> set k4 v4-> Redirected to slot [8455] located at 192.168.130.132:6382OK192.168.130.132:6382> get k4"v4"192.168.130.132:6382> Redirected to slot [8455] located at 192.168.130.132:6382：重定向到6382
3、查看集群状态
redis-cli --cluster check 192.168.130.132:6381root@docker:/data# redis-cli --cluster check 192.168.130.132:6381192.168.130.132:6381 (8335b534...) -> 2 keys | 5461 slots | 1 slaves.192.168.130.132:6383 (8dbe8b34...) -> 1 keys | 5461 slots | 1 slaves.192.168.130.132:6382 (60fa7e08...) -> 1 keys | 5462 slots | 1 slaves.[OK] 4 keys in 3 masters.0.00 keys per slot on average.>>> Performing Cluster Check (using node 192.168.130.132:6381)M: 8335b5349d781c11745ee129f5dbae370dbd3394 192.168.130.132:6381 slots:[0-5460] (5461 slots) master 1 additional replica(s)S: b5fd469dd1f8b5a64cacd5ecaed9dd396e1b9217 192.168.130.132:6385 slots: (0 slots) slave replicates 8dbe8b347410cf87d62933382b73693405535ba1M: 8dbe8b347410cf87d62933382b73693405535ba1 192.168.130.132:6383 slots:[10923-16383] (5461 slots) master 1 additional replica(s)S: c366905ca5ec2472275bbea9b2ae9b642b92a737 192.168.130.132:6384 slots: (0 slots) slave replicates 60fa7e084483feca3af41f269de5a57b526c0ad7M: 60fa7e084483feca3af41f269de5a57b526c0ad7 192.168.130.132:6382 slots:[5461-10922] (5462 slots) master 1 additional replica(s)S: 4051766aa375f0ed4533cb729afa8daf8649f5d2 192.168.130.132:6386 slots: (0 slots) slave replicates 8335b5349d781c11745ee129f5dbae370dbd3394[OK] All nodes agree about slots configuration.>>> Check for open slots...>>> Check slots coverage...[OK] All 16384 slots covered.root@docker:/data# 2、容错切换迁徙
1、主6381和从机切换，先进行主机6381
[root@docker ~]# docker stop redis-node-1redis-node-1[root@docker ~]# docker psCONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMESd6fc3ef2855b redis "docker-entrypoint.s…" 47 hours ago Up 47 hours redis-node-69c8868d69a50 redis "docker-entrypoint.s…" 47 hours ago Up 47 hours redis-node-57fbb5345951a redis "docker-entrypoint.s…" 47 hours ago Up 47 hours redis-node-4d53b9d5af1ac redis "docker-entrypoint.s…" 47 hours ago Up 47 hours redis-node-3fe0e430cb940 redis "docker-entrypoint.s…" 47 hours ago Up 47 hours redis-node-2[root@docker ~]# 6381主机停了，对应的实在从机上位，也就是6号机变成了主机器
2、查看集群状况
127.0.0.1:6382> cluster nodes4051766aa375f0ed4533cb729afa8daf8649f5d2 192.168.130.132:6386@16386 master - 0 1651158299456 7 connected 0-5460c366905ca5ec2472275bbea9b2ae9b642b92a737 192.168.130.132:6384@16384 slave 60fa7e084483feca3af41f269de5a57b526c0ad7 0 1651158300472 2 connected60fa7e084483feca3af41f269de5a57b526c0ad7 192.168.130.132:6382@16382 myself,master - 0 1651158298000 2 connected 5461-109228dbe8b347410cf87d62933382b73693405535ba1 192.168.130.132:6383@16383 master - 0 1651158298444 3 connected 10923-163838335b5349d781c11745ee129f5dbae370dbd3394 192.168.130.132:6381@16381 master,fail - 1651154146064 1651154140969 1 disconnectedb5fd469dd1f8b5a64cacd5ecaed9dd396e1b9217 192.168.130.132:6385@16385 slave 8dbe8b347410cf87d62933382b73693405535ba1 0 1651158297000 3 connected127.0.0.1:6382> 3、复原3主3从
重新启动1号机之后，6号机还是主机，1号机器从之前的主机变成了从机
docker start redis-node-1停掉6号机，再启动6号机
docker stop redis-node-6docker start redis-node-6查看集群状态
root@docker:/data# redis-cli --cluster check 192.168.130.132:6381192.168.130.132:6381 (8335b534...) -> 2 keys | 5461 slots | 1 slaves.192.168.130.132:6382 (60fa7e08...) -> 1 keys | 5462 slots | 1 slaves.192.168.130.132:6383 (8dbe8b34...) -> 1 keys | 5461 slots | 1 slaves.[OK] 4 keys in 3 masters.0.00 keys per slot on average.>>> Performing Cluster Check (using node 192.168.130.132:6381)M: 8335b5349d781c11745ee129f5dbae370dbd3394 192.168.130.132:6381 slots:[0-5460] (5461 slots) master 1 additional replica(s)S: c366905ca5ec2472275bbea9b2ae9b642b92a737 192.168.130.132:6384 slots: (0 slots) slave replicates 60fa7e084483feca3af41f269de5a57b526c0ad7S: 4051766aa375f0ed4533cb729afa8daf8649f5d2 192.168.130.132:6386 slots: (0 slots) slave replicates 8335b5349d781c11745ee129f5dbae370dbd3394M: 60fa7e084483feca3af41f269de5a57b526c0ad7 192.168.130.132:6382 slots:[5461-10922] (5462 slots) master 1 additional replica(s)M: 8dbe8b347410cf87d62933382b73693405535ba1 192.168.130.132:6383 slots:[10923-16383] (5461 slots) master 1 additional replica(s)S: b5fd469dd1f8b5a64cacd5ecaed9dd396e1b9217 192.168.130.132:6385 slots: (0 slots) slave replicates 8dbe8b347410cf87d62933382b73693405535ba1[OK] All nodes agree about slots configuration.>>> Check for open slots...>>> Check slots coverage...[OK] All 16384 slots covered.root@docker:/data# 4、主从扩容案例
1、新建6387、6388两个节点+新建后启动+查看是否8节点
docker run -d --name redis-node-7 --net host --privileged=true -v /data/redis/share/redis-node-7:/data redis --cluster-enabled yes --appendonly yes --port 6387docker run -d --name redis-node-8 --net host --privileged=true -v /data/redis/share/redis-node-8:/data redis --cluster-enabled yes --appendonly yes --port 63882、进入6387容器实例外部
docker exec -it redis-node-7 /bin/bash3、将新增的6387节点(空槽号)作为master节点退出原集群
将新增的6387作为master节点退出集群
redis-cli --cluster add-node 本人理论IP地址:6387 本人理论IP地址:6381
6387 就是将要作为master新增节点
6381 就是原来集群节点外面的领路人，相当于6387拜拜6381的码头从而找到组织退出集群
redis-cli --cluster add-node 192.168.130.132:6387 192.168.130.132:6381root@docker:/data# redis-cli --cluster add-node 192.168.130.132:6387 192.168.130.132:6381>>> Adding node 192.168.130.132:6387 to cluster 192.168.130.132:6381>>> Performing Cluster Check (using node 192.168.130.132:6381)M: 8335b5349d781c11745ee129f5dbae370dbd3394 192.168.130.132:6381 slots:[0-5460] (5461 slots) master 1 additional replica(s)S: c366905ca5ec2472275bbea9b2ae9b642b92a737 192.168.130.132:6384 slots: (0 slots) slave replicates 60fa7e084483feca3af41f269de5a57b526c0ad7S: 4051766aa375f0ed4533cb729afa8daf8649f5d2 192.168.130.132:6386 slots: (0 slots) slave replicates 8335b5349d781c11745ee129f5dbae370dbd3394M: 60fa7e084483feca3af41f269de5a57b526c0ad7 192.168.130.132:6382 slots:[5461-10922] (5462 slots) master 1 additional replica(s)M: 8dbe8b347410cf87d62933382b73693405535ba1 192.168.130.132:6383 slots:[10923-16383] (5461 slots) master 1 additional replica(s)S: b5fd469dd1f8b5a64cacd5ecaed9dd396e1b9217 192.168.130.132:6385 slots: (0 slots) slave replicates 8dbe8b347410cf87d62933382b73693405535ba1[OK] All nodes agree about slots configuration.>>> Check for open slots...>>> Check slots coverage...[OK] All 16384 slots covered.>>> Send CLUSTER MEET to node 192.168.130.132:6387 to make it join the cluster.[OK] New node added correctly.root@docker:/data# 4、查看集群状况
redis-cli --cluster check 192.168.130.132:6381root@docker:/data# redis-cli --cluster check 192.168.130.132:6381192.168.130.132:6381 (8335b534...) -> 2 keys | 5461 slots | 1 slaves.192.168.130.132:6382 (60fa7e08...) -> 1 keys | 5462 slots | 1 slaves.192.168.130.132:6383 (8dbe8b34...) -> 1 keys | 5461 slots | 1 slaves.192.168.130.132:6387 (34b689b7...) -> 0 keys | 0 slots | 0 slaves.很显著，6387没有槽号
5、重新分配槽号
从新分派槽号
命令：redis-cli --cluster reshard IP地址:端口号
redis-cli --cluster reshard 192.168.130.:6381输出须要迁徙的槽数量，此处咱们输出4096。
指标节点ID，只能指定一个，因为咱们须要迁徙到6387中，因而上面输出6387的ID。
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之后输出源节点的ID，redis会从这些源节点中均匀取出对应数量的槽，而后迁徙到6385中。最初要输出done示意完结。
最初输出yes即可。
6、查看集群状况
redis-cli --cluster check 192.168.130.132:6381root@docker:/data# redis-cli --cluster check 192.168.130.132:6381192.168.130.132:6381 (8335b534...) -> 1 keys | 4096 slots | 1 slaves.192.168.130.132:6382 (60fa7e08...) -> 1 keys | 4096 slots | 1 slaves.192.168.130.132:6383 (8dbe8b34...) -> 1 keys | 4096 slots | 1 slaves.192.168.130.132:6387 (34b689b7...) -> 1 keys | 4096 slots | 0 slaves.[OK] 4 keys in 4 masters.0.00 keys per slot on average.>>> Performing Cluster Check (using node 192.168.130.132:6381)M: 8335b5349d781c11745ee129f5dbae370dbd3394 192.168.130.132:6381 slots:[1365-5460] (4096 slots) master 1 additional replica(s)S: c366905ca5ec2472275bbea9b2ae9b642b92a737 192.168.130.132:6384 slots: (0 slots) slave replicates 60fa7e084483feca3af41f269de5a57b526c0ad7S: 4051766aa375f0ed4533cb729afa8daf8649f5d2 192.168.130.132:6386 slots: (0 slots) slave replicates 8335b5349d781c11745ee129f5dbae370dbd3394M: 60fa7e084483feca3af41f269de5a57b526c0ad7 192.168.130.132:6382 slots:[6827-10922] (4096 slots) master 1 additional replica(s)M: 8dbe8b347410cf87d62933382b73693405535ba1 192.168.130.132:6383 slots:[12288-16383] (4096 slots) master 1 additional replica(s)M: 34b689b791d9945a0b761349f1bc7b64f0be876f 192.168.130.132:6387 slots:[0-1364],[5461-6826],[10923-12287] (4096 slots) masterS: b5fd469dd1f8b5a64cacd5ecaed9dd396e1b9217 192.168.130.132:6385 slots: (0 slots) slave replicates 8dbe8b347410cf87d62933382b73693405535ba1[OK] All nodes agree about slots configuration.>>> Check for open slots...>>> Check slots coverage...[OK] All 16384 slots covered.root@docker:/data# \M: 34b689b791d9945a0b761349f1bc7b64f0be876f 192.168.130.132:6387 slots:[0-1364],[5461-6826],[10923-12287] (4096 slots) master为什么6387是3个新的区间，以前的还是间断？
重新分配老本太高，所以前3家各自匀出来一部分，从6381/6382/6383三个旧节点别离匀出1364个坑位给新节点6387
7、为主节点6387调配从节点6388
命令：redis-cli --cluster add-node ip:新slave端口 ip:新master端口 --cluster-slave --cluster-master-id 新主机节点IDredis-cli --cluster add-node 192.168.130.132:6388 192.168.130.132:6387 --cluster-slave --cluster-master-id 34b689b791d9945a0b761349f1bc7b64f0be876f8、查看集群状况
redis-cli --cluster check 192.168.130.132:6381root@docker:/data# redis-cli --cluster check 192.168.130.132:6381192.168.130.132:6381 (8335b534...) -> 1 keys | 4096 slots | 1 slaves.192.168.130.132:6382 (60fa7e08...) -> 1 keys | 4096 slots | 1 slaves.192.168.130.132:6383 (8dbe8b34...) -> 1 keys | 4096 slots | 1 slaves.192.168.130.132:6387 (34b689b7...) -> 1 keys | 4096 slots | 1 slaves.[OK] 4 keys in 4 masters.0.00 keys per slot on average.>>> Performing Cluster Check (using node 192.168.130.132:6381)M: 8335b5349d781c11745ee129f5dbae370dbd3394 192.168.130.132:6381 slots:[1365-5460] (4096 slots) master 1 additional replica(s)S: c366905ca5ec2472275bbea9b2ae9b642b92a737 192.168.130.132:6384 slots: (0 slots) slave replicates 60fa7e084483feca3af41f269de5a57b526c0ad7S: 4051766aa375f0ed4533cb729afa8daf8649f5d2 192.168.130.132:6386 slots: (0 slots) slave replicates 8335b5349d781c11745ee129f5dbae370dbd3394M: 60fa7e084483feca3af41f269de5a57b526c0ad7 192.168.130.132:6382 slots:[6827-10922] (4096 slots) master 1 additional replica(s)M: 8dbe8b347410cf87d62933382b73693405535ba1 192.168.130.132:6383 slots:[12288-16383] (4096 slots) master 1 additional replica(s)S: 4b4b4a8a4d50548e954b46e921ff8085ed555c39 192.168.130.132:6388 slots: (0 slots) slave replicates 34b689b791d9945a0b761349f1bc7b64f0be876fM: 34b689b791d9945a0b761349f1bc7b64f0be876f 192.168.130.132:6387 slots:[0-1364],[5461-6826],[10923-12287] (4096 slots) master 1 additional replica(s)S: b5fd469dd1f8b5a64cacd5ecaed9dd396e1b9217 192.168.130.132:6385 slots: (0 slots) slave replicates 8dbe8b347410cf87d62933382b73693405535ba1[OK] All nodes agree about slots configuration.>>> Check for open slots...>>> Check slots coverage...[OK] All 16384 slots covered.root@docker:/data# 6387存在一个子机器
5、主从缩容案例
目标：6387和6388下线
1、查看集群状况1取得6388的节点ID
redis-cli --cluster check 192.168.130.132:6382S: 4b4b4a8a4d50548e954b46e921ff8085ed555c39 192.168.130.132:6388 slots: (0 slots) slave replicates 34b689b791d9945a0b761349f1bc7b64f0be876fM: 34b689b791d9945a0b761349f1bc7b64f0be876f 192.168.130.132:6387 slots:[0-1364],[5461-6826],[10923-12287] (4096 slots) master 1 additional replica(s)S: b5fd469dd1f8b5a64cacd5ecaed9dd396e1b9217 192.168.130.132:6385 slots: (0 slots) slave replicates 8dbe8b347410cf87d62933382b73693405535ba1[OK] All nodes agree about slots configuration.>>> Check for open slots...>>> Check slots coverage...[OK] All 16384 slots covered.root@docker:/data# 节点ID为：4b4b4a8a4d50548e954b46e921ff8085ed555c39
2、从集群中将节点6388删除
命令：redis-cli --cluster del-node ip:从机端口 从机6388节点IDredis-cli --cluster del-node 192.168.130.132:6388 4b4b4a8a4d50548e954b46e921ff8085ed555c39oot@docker:/data# redis-cli --cluster del-node 192.168.130.132:6388 4b4b4a8a4d50548e954b46e921ff8085ed555c39>>> Removing node 4b4b4a8a4d50548e954b46e921ff8085ed555c39 from cluster 192.168.130.132:6388>>> Sending CLUSTER FORGET messages to the cluster...>>> Sending CLUSTER RESET SOFT to the deleted node.root@docker:/data# 查看集群状况
redis-cli --cluster check 192.168.130.132:6381root@docker:/data# redis-cli --cluster check 192.168.130.132:6381192.168.130.132:6381 (8335b534...) -> 1 keys | 4096 slots | 1 slaves.192.168.130.132:6382 (60fa7e08...) -> 1 keys | 4096 slots | 1 slaves.192.168.130.132:6383 (8dbe8b34...) -> 1 keys | 4096 slots | 1 slaves.192.168.130.132:6387 (34b689b7...) -> 1 keys | 4096 slots | 0 slaves.[OK] 4 keys in 4 masters.0.00 keys per slot on average.>>> Performing Cluster Check (using node 192.168.130.132:6381)M: 8335b5349d781c11745ee129f5dbae370dbd3394 192.168.130.132:6381 slots:[1365-5460] (4096 slots) master 1 additional replica(s)S: c366905ca5ec2472275bbea9b2ae9b642b92a737 192.168.130.132:6384 slots: (0 slots) slave replicates 60fa7e084483feca3af41f269de5a57b526c0ad7S: 4051766aa375f0ed4533cb729afa8daf8649f5d2 192.168.130.132:6386 slots: (0 slots) slave replicates 8335b5349d781c11745ee129f5dbae370dbd3394M: 60fa7e084483feca3af41f269de5a57b526c0ad7 192.168.130.132:6382 slots:[6827-10922] (4096 slots) master 1 additional replica(s)M: 8dbe8b347410cf87d62933382b73693405535ba1 192.168.130.132:6383 slots:[12288-16383] (4096 slots) master 1 additional replica(s)M: 34b689b791d9945a0b761349f1bc7b64f0be876f 192.168.130.132:6387 slots:[0-1364],[5461-6826],[10923-12287] (4096 slots) masterS: b5fd469dd1f8b5a64cacd5ecaed9dd396e1b9217 192.168.130.132:6385 slots: (0 slots) slave replicates 8dbe8b347410cf87d62933382b73693405535ba1[OK] All nodes agree about slots configuration.>>> Check for open slots...>>> Check slots coverage...[OK] All 16384 slots covered.root@docker:/data# 很显著，6387的从机器曾经被没了，6388机器也曾经被删除了，只剩下7台机器了。
3、将6387的槽号清空，重新分配，本例将清进去的槽号都给6381
redis-cli --cluster reshard 192.168.130.132:6381这里我没有截到图，以阳哥的截图步骤
4、查看集群状态
redis-cli --cluster check 192.168.130.132:6381root@docker:/data# redis-cli --cluster check 192.168.130.132:6381192.168.130.132:6381 (8335b534...) -> 2 keys | 8192 slots | 1 slaves.192.168.130.132:6382 (60fa7e08...) -> 1 keys | 4096 slots | 1 slaves.192.168.130.132:6383 (8dbe8b34...) -> 1 keys | 4096 slots | 1 slaves.192.168.130.132:6387 (34b689b7...) -> 0 keys | 0 slots | 0 slaves.[OK] 4 keys in 4 masters.0.00 keys per slot on average.>>> Performing Cluster Check (using node 192.168.130.132:6381)M: 8335b5349d781c11745ee129f5dbae370dbd3394 192.168.130.132:6381 slots:[0-6826],[10923-12287] (8192 slots) master 1 additional replica(s)S: c366905ca5ec2472275bbea9b2ae9b642b92a737 192.168.130.132:6384 slots: (0 slots) slave replicates 60fa7e084483feca3af41f269de5a57b526c0ad7S: 4051766aa375f0ed4533cb729afa8daf8649f5d2 192.168.130.132:6386 slots: (0 slots) slave replicates 8335b5349d781c11745ee129f5dbae370dbd3394M: 60fa7e084483feca3af41f269de5a57b526c0ad7 192.168.130.132:6382 slots:[6827-10922] (4096 slots) master 1 additional replica(s)M: 8dbe8b347410cf87d62933382b73693405535ba1 192.168.130.132:6383 slots:[12288-16383] (4096 slots) master 1 additional replica(s)M: 34b689b791d9945a0b761349f1bc7b64f0be876f 192.168.130.132:6387 slots: (0 slots) masterS: b5fd469dd1f8b5a64cacd5ecaed9dd396e1b9217 192.168.130.132:6385 slots: (0 slots) slave replicates 8dbe8b347410cf87d62933382b73693405535ba1[OK] All nodes agree about slots configuration.>>> Check for open slots...>>> Check slots coverage...[OK] All 16384 slots covered.6381领有8192个槽位
5、将6387删除
命令：redis-cli --cluster del-node ip:端口 6387节点IDredis-cli --cluster del-node 192.168.130.132:6387 34b689b791d9945a0b761349f1bc7b64f0be876f再次查看集群状况
redis-cli --cluster check 192.168.130.132:6381root@docker:/data# redis-cli --cluster check 192.168.130.132:6381192.168.130.132:6381 (8335b534...) -> 2 keys | 8192 slots | 1 slaves.192.168.130.132:6382 (60fa7e08...) -> 1 keys | 4096 slots | 1 slaves.192.168.130.132:6383 (8dbe8b34...) -> 1 keys | 4096 slots | 1 slaves.[OK] 4 keys in 3 masters.0.00 keys per slot on average.>>> Performing Cluster Check (using node 192.168.130.132:6381)M: 8335b5349d781c11745ee129f5dbae370dbd3394 192.168.130.132:6381 slots:[0-6826],[10923-12287] (8192 slots) master 1 additional replica(s)S: c366905ca5ec2472275bbea9b2ae9b642b92a737 192.168.130.132:6384 slots: (0 slots) slave replicates 60fa7e084483feca3af41f269de5a57b526c0ad7S: 4051766aa375f0ed4533cb729afa8daf8649f5d2 192.168.130.132:6386 slots: (0 slots) slave replicates 8335b5349d781c11745ee129f5dbae370dbd3394M: 60fa7e084483feca3af41f269de5a57b526c0ad7 192.168.130.132:6382 slots:[6827-10922] (4096 slots) master 1 additional replica(s)M: 8dbe8b347410cf87d62933382b73693405535ba1 192.168.130.132:6383 slots:[12288-16383] (4096 slots) master 1 additional replica(s)S: b5fd469dd1f8b5a64cacd5ecaed9dd396e1b9217 192.168.130.132:6385 slots: (0 slots) slave replicates 8dbe8b347410cf87d62933382b73693405535ba1[OK] All nodes agree about slots configuration.>>> Check for open slots...>>> Check slots coverage...[OK] All 16384 slots covered.root@docker:/data# 发现曾经删除了