Redis Cluster
图解
1
每个节点主数据不同，是数据的子集
利用多台服务器构建集群提高超大规模数据处理能力
同时提供高可用支持
2
Redis Cluster 集群采用 Hash Slot（哈希槽）分配
Redis 集群预分好 16384 个槽，初始化集群时平均规划给每一台 Redis Master
为什么是 16384?
在 Redis 集群中槽分配的元数据会不间断的在 Redis 集群中分发，以保证所有节点都知晓槽的分配情况
16384=16k，在发送心跳包时使用 char 进行 bitmap 压缩后是 2k（2*8(8 bit) * 1024(1k)=16K）
通常我们不会部署超过10000个 Redis 主节点，因此16384就够用了
配置
cluster-master-0.conf
bind 127.0.0.1
port 6379
cluster-enabled yes
cluster-config-file nodes-6379.conf
cluster-node-timeout 15000
cluster-announce-port 6379
cluster-announce-bus-port 16379
cluster-master-1.conf
bind 127.0.0.1
port 6380
cluster-enabled yes
cluster-config-file nodes-6380.conf
cluster-node-timeout 15000
cluster-announce-port 6380
cluster-announce-bus-port 16380
cluster-master-2.conf
bind 127.0.0.1
port 6381
cluster-enabled yes
cluster-config-file nodes-6381.conf
cluster-node-timeout 15000
cluster-announce-port 6381
cluster-announce-bus-port 16381
cluster-slave-0.conf
bind 127.0.0.1
port 6479
cluster-enabled yes
cluster-config-file nodes-6479.conf
cluster-node-timeout 15000
cluster-announce-port 6479
cluster-announce-bus-port 16479
cluster-slave-1.conf
bind 127.0.0.1
port 6480
cluster-enabled yes
cluster-config-file nodes-6480.conf
cluster-node-timeout 15000
cluster-announce-port 6480
cluster-announce-bus-port 16480
cluster-slave-2.conf
注意
- 集群配置中不允许出现 replicaof 的配置项，否则就会报
F:\下载目录\Redis-x64-5.0.14.1>.\redis-server.exe .\config\cluster\redis-cluster0.conf [31444] 20 Feb 10:59:14.659 # *** FATAL CONFIG FILE ERROR *** [31444] 20 Feb 10:59:14.659 # Reading the configuration file, at line 1345 [31444] 20 Feb 10:59:14.660 # >>> 'replicaof 127.0.0.1 6380' [31444] 20 Feb 10:59:14.660 # replicaof directive not allowed in cluster mode
启动
master-0
F:\下载目录\Redis-x64-5.0.14.1>.\redis-server.exe .\config\cluster\cluster-master-0.conf
[21000] 20 Feb 11:05:53.729 # oO0OoO0OoO0Oo Redis is starting oO0OoO0OoO0Oo
[21000] 20 Feb 11:05:53.729 # Redis version=5.0.14.1, bits=64, commit=ec77f72d, modified=0, pid=21000, just started
[21000] 20 Feb 11:05:53.729 # Configuration loaded
[21000] 20 Feb 11:05:53.732 * No cluster configuration found, I'm 74168c6581ab94338a85097768ae4cb376ef3c75
……
[21000] 20 Feb 11:05:53.927 # I have keys for unassigned slot 9231. Taking responsibility for it.
[21000] 20 Feb 11:05:53.928 # I have keys for unassigned slot 15118. Taking responsibility for it.
[21000] 20 Feb 11:05:53.928 # I have keys for unassigned slot 15901. Taking responsibility for it.
[21000] 20 Feb 11:05:53.928 # I have keys for unassigned slot 16066. Taking responsibility for it.
[21000] 20 Feb 11:05:53.977 * Ready to accept connections