Part1Redis 6.X Cluster 集群搭建
码哥带大家完成在 CentOS 7 中安装 Redis 6.x 教程。在学习 Redis Cluster 集群之前，我们需要先搭建一套集群环境。机器有限，实现目标是一台机器上搭建 6 个节点，构成一个三主三从集群模式。
1下载解压
可直接到 Redis 官网下载最新稳定包，地址：https://redis.io/download。或者使用 命令：sudo wget http://download.redis.io/releases/redis-6.0.9.tar.gz 下载安装包.。
- 码哥统一把软件包放在
/opt/soft目录下，并创建目录mkdir redisCluster用于放置集群配置文件。在 redisCluster 目录下执行mkdir 7000 7001 7002 7003 7004 7005创建 6 个目录分别对应每个节点 redis.conf 配置模板。 tar -zxf redis-6.0.9.tar.gz -C redisCluster解压到 redisCluster 目录中。
2make 编译
在编译之前我们需要确认 gcc 版本，自 redis 6.0.0 之后，编译 redis 需要支持 C11 特性，C11 特性在 4.9 中被引入。Centos 7 默认 gcc 版本为 4.8.5，所以需要升级gcc版本。
编译错误
否则在编译过程中会遇到如下错误日志：
In file included from server.c:31:0: server.c:4999:59: error: ‘struct redisServer’ has no member named ‘cluster’ (server.cluster_enabled && nodeIsMaster(server.cluster->myself))); ^ cluster.h:58:27: note: in definition of macro ‘nodeIsMaster’ #define nodeIsMaster(n) ((n)->flags & CLUSTER_NODE_MASTER) ^ server.c: In function ‘main’: server.c:5047:11: error: ‘struct redisServer’ has no member named ‘sentinel_mode’ server.sentinel_mode = checkForSentinelMode(argc,argv); ^ server.c:5064:15: error: ‘struct redisServer’ has no member named ‘sentinel_mode’ if (server.sentinel_mode) { ^ server.c:5131:19: error: ‘struct redisServer’ has no member named ‘sentinel_mode’ if (server.sentinel_mode && configfile && *configfile == '-') { ^ server.c:5153:168: error: ‘struct redisServer’ has no member named ‘sentinel_mode’ serverLog(LL_WARNING, "Warning: no config file specified, using the default config. In order to specify a config file use %s /path/to/%s.conf", argv[0], server.sentinel_mode ? "sentinel" : "redis"); ^ server.c:5158:11: error: ‘struct redisServer’ has no member named ‘supervised’ server.supervised = redisIsSupervised(server.supervised_mode); ^ server.c:5158:49: error: ‘struct redisServer’ has no member named ‘supervised_mode’ server.supervised = redisIsSupervised(server.supervised_mode); ^ server.c:5159:28: error: ‘struct redisServer’ has no member named ‘daemonize’ int background = server.daemonize && !server.supervised; ^ server.c:5159:49: error: ‘struct redisServer’ has no member named ‘supervised’ int background = server.daemonize && !server.supervised; ^ server.c:5163:29: error: ‘struct redisServer’ has no member named ‘pidfile’ if (background || server.pidfile) createPidFile(); ^ server.c:5168:16: error: ‘struct redisServer’ has no member named ‘sentinel_mode’ if (!server.sentinel_mode) { ^ server.c:5178:19: error: ‘struct redisServer’ has no member named ‘cluster_enabled’ if (server.cluster_enabled) { ^ server.c:5186:19: error: ‘struct redisServer’ has no member named ‘ipfd_count’ if (server.ipfd_count > 0 || server.tlsfd_count > 0) ^ server.c:5186:44: error: ‘struct redisServer’ has no member named ‘tlsfd_count’ if (server.ipfd_count > 0 || server.tlsfd_count > 0) ^ server.c:5188:19: error: ‘struct redisServer’ has no member named ‘sofd’ if (server.sofd > 0) ^ server.c:5189:94: error: ‘struct redisServer’ has no member named ‘unixsocket’ serverLog(LL_NOTICE,"The server is now ready to accept connections at %s", server.unixsocket); ^ server.c:5190:19: error: ‘struct redisServer’ has no member named ‘supervised_mode’ if (server.supervised_mode == SUPERVISED_SYSTEMD) { ^ server.c:5191:24: error: ‘struct redisServer’ has no member named ‘masterhost’ if (!server.masterhost) { ^ server.c:5201:19: error: ‘struct redisServer’ has no member named ‘supervised_mode’ if (server.supervised_mode == SUPERVISED_SYSTEMD) { ^ server.c:5208:15: error: ‘struct redisServer’ has no member named ‘maxmemory’ if (server.maxmemory > 0 && server.maxmemory < 1024*1024) { ^ server.c:5208:39: error: ‘struct redisServer’ has no member named ‘maxmemory’ if (server.maxmemory > 0 && server.maxmemory < 1024*1024) { ^ server.c:5209:176: error: ‘struct redisServer’ has no member named ‘maxmemory’ serverLog(LL_WARNING,"WARNING: You specified a maxmemory value that is less than 1MB (current value is %llu bytes). Are you sure this is what you really want?", server.maxmemory); ^ server.c:5212:31: error: ‘struct redisServer’ has no member named ‘server_cpulist’ redisSetCpuAffinity(server.server_cpulist); ^ server.c: In function ‘hasActiveChildProcess’: server.c:1480:1: warning: control reaches end of non-void function [-Wreturn-type] } ^ server.c: In function ‘allPersistenceDisabled’: server.c:1486:1: warning: control reaches end of non-void function [-Wreturn-type] } ^ server.c: In function ‘writeCommandsDeniedByDiskError’: server.c:3826:1: warning: control reaches end of non-void function [-Wreturn-type] } ^ server.c: In function ‘iAmMaster’: server.c:5000:1: warning: control reaches end of non-void function [-Wreturn-type] } ^ ....
解决方式
yum -y install gcc gcc-c++ make tcl yum -y install centos-release-scl yum -y install devtoolset-9-gcc devtoolset-9-gcc-c++ devtoolset-9-binutils scl enable devtoolset-9 bash
升级之后便可解决 make 报错问题。
注意：scl命令启用只是临时的，退出xshell或者重启就会恢复到原来的gcc版本。如果要长期生效的话，执行如下 sudo echo "source /opt/rh/devtoolset-9/enable" >>/etc/profile。
cd /opt/soft/redisCluster/redis-6.0.9 切换到目录执行 make 。
编译完成使用 make install 对 redis 进行安装 ，命令：sudo make install。
3修改配置文件
cd /opt/soft/redisCluster/redis-6.0.9 将 redis.conf 分别复制到 7000 7001 7002 7003 7004 目录中。
分别修改 6 个 redis.conf
## 7000-7005端口 port 7000 ## 后台启动 daemonize yes ## 如果是在单机模拟集群必须指定bind的IP，如果不修改ip的话使用程序连接集群会报错 bind 192.168.221.150 ## 开启redis-cluster集群 cluster-enabled yes ## 每个实例还包含存储此节点配置的文件的路径，默认情况下为nodes.conf，自动创建 cluster-config-file nodes_7000.conf ## 超时 cluster-node-timeout 500 ## 开启aof appendonly yes #注释cluster集群下不允许复制。 #replicaof 127.0.0.1 9000 #关闭保护模式,如果开启需要设置密码，比较繁琐，可根据自己的需求来 protected-mode no
每个配置文件只需要修改 port 和 cluster-config-file 就可以了。
4启动节点并创建集群
启动节点
进入 redisCluster 目录，执行指令依次启动每个节点。redis-6.0.9/src/redis-server 700x/redis.conf 注意指定每个节点配置文件，如果不指定配置文件会默认使用src下的配置。
创建集群
进入任意一个节点，执行以下指令创建集群
指令如下：
redis-6.0.9/src/redis-cli --cluster create 172.16.90.152:7000 172.16.90.152:7001 172.16.90.152:7002 172.16.90.152:7003 172.16.90.152:7004 172.16.90.152:7005 --cluster-replicas 1
集群参数解释：
- cluster-replicas 1：表示希望为集群中的每个主节点创建一个从节点(一主一从)。
- cluster-replicas 2：表示希望为集群中的每个主节点创建两个从节点(一主二从)。
控制台响应：
>>> Performing hash slots allocation on 6 nodes... Master[0] -> Slots 0 - 5460 Master[1] -> Slots 5461 - 10922 Master[2] -> Slots 10923 - 16383 Adding replica 172.16.90.152:7004 to 172.16.90.152:7000 Adding replica 172.16.90.152:7005 to 172.16.90.152:7001 Adding replica 172.16.90.152:7003 to 172.16.90.152:7002 >>> Trying to optimize slaves allocation for anti-affinity [WARNING] Some slaves are in the same host as their master M: 06c56f5a6a4436108fae931be499465985141d39 172.16.90.152:7000 slots:[0-5460] (5461 slots) master M: 0ab7c9efd97319d94a8ea52452ec58f7708d812d 172.16.90.152:7001 slots:[5461-10922] (5462 slots) master M: 096f076d99363270c02785a2fb298e2ee65d3f07 172.16.90.152:7002 slots:[10923-16383] (5461 slots) master S: 69d621060295eb433af3e34e702142df0fd4d73d 172.16.90.152:7003 replicates 06c56f5a6a4436108fae931be499465985141d39 S: 1d37df0aa0e2310aedb5a380f95cc818256003f8 172.16.90.152:7004 replicates 0ab7c9efd97319d94a8ea52452ec58f7708d812d S: d9204f6da875a4b2522c5fa25d9e6c1f95cf51ea 172.16.90.152:7005 replicates 096f076d99363270c02785a2fb298e2ee65d3f07 Can I set the above configuration? (type 'yes' to accept):
Can I set the above configuration? (type 'yes' to accept): 询问是否确认节点 slots 分配方案， 我们输入 ‘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 172.16.90.152:7000) M: 06c56f5a6a4436108fae931be499465985141d39 172.16.90.152:7000 slots:[0-5460] (5461 slots) master 1 additional replica(s) S: 1d37df0aa0e2310aedb5a380f95cc818256003f8 172.16.90.152:7004 slots: (0 slots) slave replicates 0ab7c9efd97319d94a8ea52452ec58f7708d812d M: 0ab7c9efd97319d94a8ea52452ec58f7708d812d 172.16.90.152:7001 slots:[5461-10922] (5462 slots) master 1 additional replica(s) S: d9204f6da875a4b2522c5fa25d9e6c1f95cf51ea 172.16.90.152:7005 slots: (0 slots) slave replicates 096f076d99363270c02785a2fb298e2ee65d3f07 S: 69d621060295eb433af3e34e702142df0fd4d73d 172.16.90.152:7003 slots: (0 slots) slave replicates 06c56f5a6a4436108fae931be499465985141d39 M: 096f076d99363270c02785a2fb298e2ee65d3f07 172.16.90.152:7002 slots:[10923-16383] (5461 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.
[OK] All 16384 slots covered.
到此完成！
5查看集群状态
redis-6.0.9/src/redis-cli --cluster check 172.16.90.152:7000
6注意事项
当使用 redis-6.0.9/src/redis-cli --cluster create 172.16.90.152:7000 172.16.90.152:7001 172.16.90.152:7002 172.16.90.152:7003 172.16.90.152:7004 172.16.90.152:7005 --cluster-replicas 1 创建集群以后，一次创建，永久使用。之后直接启动每个节点即可构建集群。
结束命令：redis-6.0.9/src/redis-cli -c -h 192.168.124.23 -p 7004 shutdown
进入集群命令 redis-cli -c -h host -p prot 不带-c 参数进入的不是集群
搭建好集群后，期待下一篇「Redis 高可用篇：Cluster 能支持的数据有多大？」
