Slot

版权声明 本站原创文章 由 萌叔 发表 转载请注明 萌叔 | http://vearne.cc 1.前言 在前面的文章中， 《REDIS-CLUSTER集群创建内部细节详解》 萌叔创建一个Redis集群。 这篇文章，我会为集群添加2个节点，并介绍slot的迁移过程。 2.集群扩容 添加主节点127.0.0.1:7006 redis-cli --cluster add-node 127.0.0.1:7006 127.0.0.1:7000 添加从节点127.0.0.1:7007(并指定其Master节点） redis-cli --cluster add-node 127.0.0.1:7007 127.0.0.1:7000 --cluster-slave --cluster-master-id 86f3cb72813a2d07711b56b3143ff727911f4e1e 新添加的节点上并没有slot分布，需要通过命令让slot重新分布 root@BJ-02:~/cluster-test/7007# redis-cli --cluster reshard 127.0.0.1:7000 >>> Performing Cluster Check (using node 127.0.0.1:7000) S: 7eb7ceb4d886580c6d122e7fd92e436594cc105e 127.0.0.1:7000 slots: (0 slots) slave replicates be905740b96469fc6f20339fc9898e153c06d497 M: 86f3cb72813a2d07711b56b3143ff727911f4e1e 127.0.0.1:7006 slots: (0 slots) master 1 additional replica(s) M: be905740b96469fc6f20339fc9898e153c06d497 127.0.0.1:7005 slots:[0-5460] (5461 slots) master 1 additional replica(s) S: 9e29dd4b2a7318e0e29a48ae4b37a7bd5ea0a828 127.0.0.1:7007 slots: (0 slots) slave replicates 86f3cb72813a2d07711b56b3143ff727911f4e1e S: 603a8a403536f625f53467881f5f78def9bd46e5 127.0.0.1:7003 slots: (0 slots) slave replicates 784fa4b720213b0e2b51a4542469f5e318e8658b M: 4e0e4be1b4afd2cd1d10166a6788449dd812a4c0 127.0.0.1:7002 slots:[10923-16383] (5461 slots) master 1 additional replica(s) S: 585c7df69fb267941a40611bbd8ed90349b49175 127.0.0.1:7004 slots: (0 slots) slave replicates 4e0e4be1b4afd2cd1d10166a6788449dd812a4c0 M: 784fa4b720213b0e2b51a4542469f5e318e8658b 127.0.0.1:7001 slots:[5461-10922] (5462 slots) master 1 additional replica(s) [OK] All nodes agree about slots configuration. >>> Check for open slots... >>> Check slots coverage... [OK] All 16384 slots covered. How many slots do you want to move (from 1 to 16384)? 0 How many slots do you want to move (from 1 to 16384)? 1 What is the receiving node ID? 86f3cb72813a2d07711b56b3143ff727911f4e1e Please enter all the source node IDs. Type 'all' to use all the nodes as source nodes for the hash slots. Type 'done' once you entered all the source nodes IDs. Source node #1: all Ready to move 1 slots. Source nodes: M: be905740b96469fc6f20339fc9898e153c06d497 127.0.0.1:7005 slots:[0-5460] (5461 slots) master 1 additional replica(s) M: 4e0e4be1b4afd2cd1d10166a6788449dd812a4c0 127.0.0.1:7002 slots:[10923-16383] (5461 slots) master 1 additional replica(s) M: 784fa4b720213b0e2b51a4542469f5e318e8658b 127.0.0.1:7001 slots:[5461-10922] (5462 slots) master 1 additional replica(s) Destination node: M: 86f3cb72813a2d07711b56b3143ff727911f4e1e 127.0.0.1:7006 slots: (0 slots) master 1 additional replica(s) Resharding plan: Moving slot 5461 from 784fa4b720213b0e2b51a4542469f5e318e8658b Do you want to proceed with the proposed reshard plan (yes/no)? yes Moving slot 5461 from 127.0.0.1:7001 to 127.0.0.1:7006: 3. Slot迁移过程 迁移过程在clusterManagerMoveSlot() 中 ...

版权声明 本站原创文章 由 萌叔 发表 转载请注明 萌叔 | http://vearne.cc 本文基于redis 6.2.7 1.引言 Redis-Cluster集群的搭建非常简单。搭建过程见参考资料1。 执行 redis-cli --cluster create 127.0.0.1:7000 127.0.0.1:7001 \ 127.0.0.1:7002 127.0.0.1:7003 127.0.0.1:7004 127.0.0.1:7005 \ --cluster-replicas 1 root@BJ-02:~/cluster-test# redis-cli --cluster create 127.0.0.1:7000 127.0.0.1:7001 \ > 127.0.0.1:7002 127.0.0.1:7003 127.0.0.1:7004 127.0.0.1:7005 \ > --cluster-replicas 1 >>> Performing hash slots allocation on 6 nodes... Master[0] -> Slots 0 - 5460 Master[1] -> Slots 5461 - 10922 Master[2] -> Slots 10923 - 16383 Adding replica 127.0.0.1:7004 to 127.0.0.1:7000 Adding replica 127.0.0.1:7005 to 127.0.0.1:7001 Adding replica 127.0.0.1:7003 to 127.0.0.1:7002 >>> Trying to optimize slaves allocation for anti-affinity [WARNING] Some slaves are in the same host as their master M: 7eb7ceb4d886580c6d122e7fd92e436594cc105e 127.0.0.1:7000 slots:[0-5460] (5461 slots) master M: 784fa4b720213b0e2b51a4542469f5e318e8658b 127.0.0.1:7001 slots:[5461-10922] (5462 slots) master M: 4e0e4be1b4afd2cd1d10166a6788449dd812a4c0 127.0.0.1:7002 slots:[10923-16383] (5461 slots) master S: 603a8a403536f625f53467881f5f78def9bd46e5 127.0.0.1:7003 replicates 784fa4b720213b0e2b51a4542469f5e318e8658b S: 585c7df69fb267941a40611bbd8ed90349b49175 127.0.0.1:7004 replicates 4e0e4be1b4afd2cd1d10166a6788449dd812a4c0 S: be905740b96469fc6f20339fc9898e153c06d497 127.0.0.1:7005 replicates 7eb7ceb4d886580c6d122e7fd92e436594cc105e Can 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 cluster Waiting for the cluster to join .. >>> Performing Cluster Check (using node 127.0.0.1:7000) M: 7eb7ceb4d886580c6d122e7fd92e436594cc105e 127.0.0.1:7000 slots:[0-5460] (5461 slots) master 1 additional replica(s) M: 784fa4b720213b0e2b51a4542469f5e318e8658b 127.0.0.1:7001 slots:[5461-10922] (5462 slots) master 1 additional replica(s) M: 4e0e4be1b4afd2cd1d10166a6788449dd812a4c0 127.0.0.1:7002 slots:[10923-16383] (5461 slots) master 1 additional replica(s) S: 585c7df69fb267941a40611bbd8ed90349b49175 127.0.0.1:7004 slots: (0 slots) slave replicates 4e0e4be1b4afd2cd1d10166a6788449dd812a4c0 S: be905740b96469fc6f20339fc9898e153c06d497 127.0.0.1:7005 slots: (0 slots) slave replicates 7eb7ceb4d886580c6d122e7fd92e436594cc105e S: 603a8a403536f625f53467881f5f78def9bd46e5 127.0.0.1:7003 slots: (0 slots) slave replicates 784fa4b720213b0e2b51a4542469f5e318e8658b [OK] All nodes agree about slots configuration. >>> Check for open slots... >>> Check slots coverage... [OK] All 16384 slots covered. 验证 root@BJ-02:~# redis-cli -h 127.0.0.1 -p 7000 127.0.0.1:7000> cluster nodes 784fa4b720213b0e2b51a4542469f5e318e8658b 127.0.0.1:7001@17001 master - 0 1652672999293 2 connected 5461-10922 7eb7ceb4d886580c6d122e7fd92e436594cc105e 127.0.0.1:7000@17000 myself,master - 0 1652672998000 1 connected 0-5460 4e0e4be1b4afd2cd1d10166a6788449dd812a4c0 127.0.0.1:7002@17002 master - 0 1652673000333 3 connected 10923-16383 585c7df69fb267941a40611bbd8ed90349b49175 127.0.0.1:7004@17004 slave 4e0e4be1b4afd2cd1d10166a6788449dd812a4c0 0 1652673000126 3 connected be905740b96469fc6f20339fc9898e153c06d497 127.0.0.1:7005@17005 slave 7eb7ceb4d886580c6d122e7fd92e436594cc105e 0 1652673001373 1 connected 603a8a403536f625f53467881f5f78def9bd46e5 127.0.0.1:7003@17003 slave 784fa4b720213b0e2b51a4542469f5e318e8658b 0 1652673000000 2 connected 一行命令就完成了集群的部署，redis-cli --cluster create到底做了什么。这篇文章萌叔将带你探寻其中的秘密。 ...

版权声明 本站原创文章 由 萌叔 发表 转载请注明 萌叔 | http://vearne.cc 1. 引言 我们都知道在Redis-Cluster集群模式下，集群中有18634个slot，slot分布在集群多个实例上，当执行一个Command时，Redis客户端会提取Command中的key 根据下面的算法得出key所属的slot slot=CRC16（key）&16383 在根据客户端中的路由表，找到slot所在的Redis实例 这里的路由表存储的就是 slot -> redis-instance 那么问题来了redis客户端是如何得到这个路由表的呢？ 2. 分析 下面以go-redis/redis的代码为例,谈谈Redis客户端如何获取和维护slot路由信息。 2.1 存储结构 type clusterClient struct { opt *ClusterOptions nodes *clusterNodes state *clusterStateHolder // 在这里 cmdsInfoCache *cmdsInfoCache //nolint:structcheck } type clusterState struct { nodes *clusterNodes Masters []*clusterNode Slaves []*clusterNode slots []*clusterSlot // 路由信息存储在这里 generation uint32 createdAt time.Time } type clusterSlot struct { start, end int nodes []*clusterNode } 2.2 命令执行过程 1)通过key计算出对应slot 2)通过路由表查找到对应的node信息 3)向node发送CMD 其实第2步根据slot从clusterState中查询对应clusterNode ...