怎样搭建Redis群集

前言

Redis 集群是一个分布式（distributed）、容错（fault-tolerant）的 Redis 实现， 集群可以使用的功能是普通单机 Redis 所能使用的功能的一个子集（subset）。

Redis 集群中不存在中心（central）节点或者代理（proxy）节点， 集群的其中一个主要设计目标是达到线性可扩展性（linear scalability）。

Redis 集群提供了一种运行 Redis 的方式，其中数据在多个 Redis 节点间自动分区。Redis 集群还在分区期间提供一定程度的可用性，即在实际情况下能够在某些节点发生故障或无法通信时继续运行。但是，如果发生较大故障（例如，大多数主站不可用时），集群会停止运行。

实验环境

实验步骤

第一步:安装Redis

#安装编译环境[root@localhost ~]# yum install gcc gcc-c++ make -y#远程挂载源码包[root@localhost ~]# mount.cifs //192.168.142.1/redis /mntPassword for root@//192.168.142.1/redis:  #解压源码包[root@localhost ~]# cd /mnt[root@localhost mnt]# tar zxvf redis-5.0.7.tar.gz -C /opt#编译与安装[root@localhost mnt]# cd /opt/redis-5.0.7/[root@localhost redis-5.0.7]# make[root@localhost redis-5.0.7]# make PREFIX=/usr/local/redis/ install#建立服务命令软链接到系统[root@localhost redis-5.0.7]# ln -s /usr/redis/bin/* /usr/local/bin/#切入utils目录[root@localhost redis-5.0.7]# cd /opt/redis-5.0.7/utils/#执行启动脚本[root@localhost utils]# ./install_server.sh#以下内容,默认回车即可Welcome to the redis service installerThis script will help you easily set up a running redis serverPlease select the redis port for this instance: [6379] Selecting default: 6379Please select the redis config file name [/etc/redis/6379.conf] Selected default - /etc/redis/6379.confPlease select the redis log file name [/var/log/redis_6379.log] Selected default - /var/log/redis_6379.logPlease select the data directory for this instance [/var/lib/redis/6379] Selected default - /var/lib/redis/6379Please select the redis executable path [] /usr/local/redis/bin/redis-server#此处需手动指定扩展目录路径/usr/local/redis/bin/redis-server#使用进程控制启动服务[root@localhost utils]# /etc/init.d/redis_6379 startStarting Redis server...#配置redis的6379.conf文件,追加监听地址[root@localhost utils]# vim /etc/redis/6379.conf #注释第70行的监听127地址,已监听所有地址#bind 127.0.0.1 #去掉第89行注释关闭安全保护protected-mode no#去掉第93行注释,开启端口6379port 6379#去掉第137行注释,以独立进程启动daemonize yes#去掉第833行注释,开启群集功能cluster-enabled yes#去掉第841行注释,群集名称文件设置cluster-config-file nodes-6379.conf#去掉第847行注释,群集超时时间设置cluster-node-timeout 15000#去掉第700行注释,开启aof持久化appendonly yes#重启服务[root@localhost utils]# /etc/init.d/redis_6379 restartStopping ...Redis stoppedStarting Redis server...

第二步:主服务器安装rvm组件

#导入key文件[root@localhost utils]# gpg --keyserver hkp://keys.gnupg.net --recv-keys 409B6B1796C275462A1703113804BB82D39DC0E3#安装rvm[root@localhost utils]# curl -sSL https://get.rvm.io | bash -s stable#执行环境变量[root@localhost utils]# source /etc/profile.d/rvm.sh#列出ruby可以安装的版本[root@localhost utils]# rvm list known#安装2.4.1 版本[root@localhost utils]# rvm install 2.4.1#使用rubyruby2.4.1 版本[root@localhost utils]# rvm use 2.4.1Using /usr/local/rvm/gems/ruby-2.4.1#查看当前ruby2.4.1 版本[root@localhost utils]# ruby -vruby 2.4.1p111 (2017-03-22 revision 58053) [x86_64-linux]#再次安装Redis[root@localhost utils]# gem install redis

第三步:创建Redis集群

#加入所有节点地址,并加6379端口号[root@localhost utils]# redis-cli --cluster create 192.168.142.130:6379 192.168.142.145:6379 192.168.142.146:6379 192.168.142.143:6379 192.168.142.147:6379 192.168.142.148:6379 --cluster-replicas 1 >>> Performing hash slots allocation on 6 nodes...Master[0] -> Slots 0 - 5460Master[1] -> Slots 5461 - 10922Master[2] -> Slots 10923 - 16383Adding replica 192.168.142.147:6379 to 192.168.142.130:6379Adding replica 192.168.142.148:6379 to 192.168.142.145:6379Adding replica 192.168.142.143:6379 to 192.168.142.146:6379M: a27b43ec695099b36a5c79beae70cb0364f27338 192.168.142.130:6379   slots:[0-5460] (5461 slots) masterM: a27b43ec695099b36a5c79beae70cb0364f27338 192.168.142.145:6379   slots:[5461-10922] (5462 slots) masterM: a27b43ec695099b36a5c79beae70cb0364f27338 192.168.142.146:6379   slots:[10923-16383] (5461 slots) masterS: b6d317c5f192bf84e8f464ffbf6481529cd0708a 192.168.142.143:6379   replicates a27b43ec695099b36a5c79beae70cb0364f27338S: b6d317c5f192bf84e8f464ffbf6481529cd0708a 192.168.142.147:6379   replicates a27b43ec695099b36a5c79beae70cb0364f27338S: b6d317c5f192bf84e8f464ffbf6481529cd0708a 192.168.142.148:6379   replicates a27b43ec695099b36a5c79beae70cb0364f27338Can 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 192.168.142.130:6379)M: a27b43ec695099b36a5c79beae70cb0364f27338 192.168.142.130:6379   slots:[0-16383] (16384 slots) master   1 additional replica(s)S: b6d317c5f192bf84e8f464ffbf6481529cd0708a 192.168.142.148:6379   slots: (0 slots) slave   replicates a27b43ec695099b36a5c79beae70cb0364f27338[OK] All nodes agree about slots configuration.>>> Check for open slots...>>> Check slots coverage...[OK] All 16384 slots covered.

第四步:验证群集读写

#从主节点计入数据库写数据[root@localhost ~]# redis-cli -h 192.168.142.130 -p 6379192.168.142.130:6379> set name yangjiaOK192.168.142.130:6379> get name"yangjia"#从另一节点查看数据信息[root@localhost ~]# redis-cli -h 192.168.142.146 -p 6379192.168.142.146:6379> keys *1) "name"192.168.142.146:6379> get name"yangjia"#在从节点无法查看数据,提示切换主节点服务器地址[root@localhost ~]# redis-cli -h 192.168.142.143 -p 6379192.168.142.143:6379> keys *1) "name"192.168.142.143:6379> get name(error) MOVED 5798 192.168.142.146:6379