Redis Cluster 集群

一. 介绍

  Redis集群搭建的方式有多种，例如使用zookeeper等，但从redis 3.0之后版本支持redis-cluster集群，Redis-Cluster采用无中心结构，每个节点保存数据和整个集群状态,每个节点都和其他所有 节点连接。redis cluster自动master + slave复制和读写分离，master+slave高可用和主备切换，支持多个master的hash slot支持数据分布式存储。

二. Redis Cluster配置属性

cluster-enabled <yes/no>

cluster-config-file <filename>：这是指定一个文件，供cluster模式下的redis实例将集群状态保存在那里，包括集群中其他机器的信息，比如节点的上线和下限，故障转移，不是我们去维护的，给它指定一个文件，让redis自己去维护的

cluster-node-timeout <milliseconds>：节点存活超时时长，超过一定时长，认为节点宕机，master宕机的话就会触发主备切换，slave宕机就不会提供服务

三. 创建和配置

3.1 创建目录

/etc/redis（存放redis的配置文件）
/var/redis/6379（存放redis的持久化文件）

mkdir -p /etc/redis-cluster
mkdir -p /var/log/redis
mkdir -p /var/redis/7001

3.2 修改配置文件

（redis.conf 重命名 7001.conf）

port 7001
cluster-enabled yes
cluster-config-file /etc/redis-cluster/node-7001.conf
cluster-node-timeout 15000
daemonize yes
pidfile /var/run/redis_7001.pid
dir /var/redis/7001
logfile /var/log/redis/7001.log
bind 192.168.0.5
appendonly yes

存放路径如图所示：

将上面的配置文件(注意修改配置属性)，在各虚拟机/etc/redis下依次放2个，分别为:

192.168.0.5: 7001.conf 7002.conf
192.168.0.6: 7003.conf 7004.conf
192.168.0.7: 7005.conf 7006.conf

3.3 启动脚本配置

cp /usr/local/redis-3.2.8/utils/redis_init_script /etc/init.d/redis_7001
vi /etc/init.d/redis_7001

#!/bin/sh
#
# Simple Redis init.d script conceived to work on Linux systems
# as it does use of the /proc filesystem.
# chkconfig:   2345 90 10

# description:  Redis is a persistent key-value database

# 每个启动脚本内，都修改对应的端口号
REDISPORT=7001
EXEC=/usr/local/bin/redis-server
CLIEXEC=/usr/local/bin/redis-cli

PIDFILE=/var/run/redis_${REDISPORT}.pid

case "$1" in
    start)
        if [ -f $PIDFILE ]
        then
                echo "$PIDFILE exists, process is already running or crashed"
        else
                echo "Starting Redis server..."
                $EXEC $CONF
        fi
        ;;
    stop)
        if [ ! -f $PIDFILE ]
        then
                echo "$PIDFILE does not exist, process is not running"
        else
                PID=$(cat $PIDFILE)
                echo "Stopping ..."
                $CLIEXEC -p $REDISPORT shutdown
                while [ -x /proc/${PID} ]
                do
                    echo "Waiting for Redis to shutdown ..."
                    sleep 1
                done
                echo "Redis stopped"
        fi
        ;;
    *)
        echo "Please use start or stop as first argument"
        ;;
esac

分别在每个虚拟机/etc/init.d下，放6个启动脚本，分别为:

• 192.168.0.5: redis_7001 redis_7002
• 192.168.0.6: redis_7003 redis_7004
• 192.168.0.7: redis_7005 redis_7006

然后分别在3台机器上，启动6个redis实例

[root@sw01 utils]# cd /etc/init.d/
[root@sw01 utils]# ./redis_7001 start
[root@sw01 utils]# ps -ef | grep redis
root     26227  1  0 Jan21 ?  00:03:23 /usr/local/bin/redis-server 192.168.0.5:7002 [cluster]
root     26355  1  0 Jan21 ?  00:03:08 /usr/local/bin/redis-server 192.168.0.5:7001 [cluster]
root     26659 26254  0 04:44 pts/0    00:00:00 grep redis

四. 安装ruby创建集群

只需要在一台服务器安装即可

3.1 下载安装

[root@sw01 utils]# wget https://cache.ruby-lang.org/pub/ruby/2.3/ruby-2.3.1.tar.gz
[root@sw01 utils]# tar -zxvf ruby-2.3.1.tar.gz
[root@sw01 utils]# ./configure -prefix=/usr/local/ruby
[root@sw01 utils]# make && make install
[root@sw01 utils]# cd /usr/local/ruby
[root@sw01 utils]# cp bin/ruby /usr/local/bin
[root@sw01 utils]# cp bin/gem /usr/local/bin

3.2 centos安装较高版本ruby2.2+（RVM 安装）

centos安装较高版本ruby2.2+（RVM 安装）

3.3 Redis配置集群遇到问题及解决方法

Redis配置集群遇到问题及解决方法

3.4 创建集群

[root@sw01 utils]# cp /usr/local/redis-3.2.8/src/redis-trib.rb /usr/local/bin
[root@sw01 utils]# redis-trib.rb create --replicas 1 192.168.0.5:7001 192.168.0.5:7002 192.168.0.6:7003 192.168.0.6:7004 192.168.0.7:7005 192.168.0.7:7006
输入：yes
[root@sw01 utils]# redis-trib.rb check 192.168.0.5:7001
>>> Performing Cluster Check (using node 192.168.0.5:7001)
S: bcb8d971ed0875c173f50af950f6b7590b79510d 192.168.0.5:7001
   slots: (0 slots) slave
   replicates dedb9de54b51aa09106c772d743456b31e5d884f
M: 9617ff44c32b9afe9414724057cfdbeb65b492ab 192.168.0.7:7006
   slots:10923-16383 (5461 slots) master
   1 additional replica(s)
M: bb4313206fbacf94992f3b1de33e82373f9eb769 192.168.0.6:7003
   slots:5461-10922 (5462 slots) master
   1 additional replica(s)
S: 1aa3316590a71b6f788a31cebc109a76b654c5fb 192.168.0.7:7005
   slots: (0 slots) slave
   replicates 9617ff44c32b9afe9414724057cfdbeb65b492ab
S: f5648903d98526ee798b7aa7dfcc3f747652a229 192.168.0.5:7002
   slots: (0 slots) slave
   replicates bb4313206fbacf94992f3b1de33e82373f9eb769
M: dedb9de54b51aa09106c772d743456b31e5d884f 192.168.0.6:7004
   slots:0-5460 (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.

配置完成