linux中搭建高可用及负载均衡的REDIS

作者：袖梨 2022-06-29

项目决定数据存储使用Redis为主，Mysql只保存日志信息。需要对Redis的高可用及负载均衡做一个部署测试。测试使用虚拟机用。

测试环境

机器

母机：Ubuntu 4核 16G

虚拟机:centos6.5-64 单核 1G 独立ip 3个

虚拟机使用virtual box,centos为64位6.5.具体信息如下

192.168.0.231 Redis-master

192.168.0.231 Redis-slave

192.168.0.239 Virtual IP
软件

Reidis
Keepalived
安装前配置

虚拟机最小化安装，更新系统及安装必须组件

$ yum install -y openssl openssl-devel kernel kernel-devel gcc wget tcl libnl-devel

$ yum upgrade

$ reboot //重启系统
安装Keepalived

安装keepalived 下载地址:http://www.keepalived.org/software/keepalived-1.2.13.tar.gz 安装：

$ wget http://www.keepalived.org/software/keepalived-1.2.13.tar.gz

$ tar -zxvf keepalived-1.2.13.tar.gz

$ cd keepalived-1.2.13

$ ln -s /usr/src/kernels/`uname -r`-`uname -m`/ /usr/src/linux

$ ./configure --prefix=/usr/local/keepalived --sysconf=/etc

$ chkconfig --add keepalived

//查看是否成功

$ service keepalived status
安装redis

下载Redis,目前Redis的稳定版本是2.8.17，下载地址Redis-2.8.17

$ wget http://download.redis.io/releases/redis-2.8.17.tar.gz

$ tar -zxvf redis-2.8.17.tar.gz

$ cd redis-2.8.17

$ make && make test

$ mkdir -p /usr/local/redis/{bin,var,etc}

$ cp ./src/{redis-benchmark,redis-cli,redis-server,redis-check-dump,redis-check-aof} /usr/local/redis/bin/

$ cp /usr/local/redis/bin/* /usr/local/bin/
配置

Master配置

先配置好Redis，主从复制成功之后再行配置Keepalived。

Master-Redis配置

$ vim /usr/local/redis/etc/redis.conf
修改如下值

daemonize yes
pidfile /var/run/redis.pid
port 6379
tcp-backlog 511
timeout 0
tcp-keepalive 0
loglevel notice
logfile "/usr/local/redis/log/redis.log"
databases 16
save 900 1
save 300 10
save 60 10000
stop-writes-on-bgsave-error yes
rdbcompression yes
rdbchecksum yes
dbfilename dump.rdb
dir /usr/local/redis/data
slave-serve-stale-data yes
slave-read-only no
repl-disable-tcp-nodelay no
slave-priority 100
appendonly yes
appendfilename "appendonly.aof"
appendfsync everysec
no-appendfsync-on-rewrite no
auto-aof-rewrite-percentage 100
auto-aof-rewrite-min-size 64mb
lua-time-limit 5000
slowlog-log-slower-than 10000
slowlog-max-len 128
notify-keyspace-events ""
hash-max-ziplist-entries 512
hash-max-ziplist-value 64
list-max-ziplist-entries 512
list-max-ziplist-value 64
set-max-intset-entries 512
zset-max-ziplist-entries 128
zset-max-ziplist-value 64
activerehashing yes
client-output-buffer-limit normal 0 0 0
client-output-buffer-limit slave 256mb 64mb 60
client-output-buffer-limit pubsub 32mb 8mb 60
hz 10
aof-rewrite-incremental-fsync yes
Master-Keepalived配置

global_defs {
    router_id redis
}
vrrp_script chk_redis {
    script "/etc/keepalived/scripts/redis_check.sh"   ###监控脚本
    interval 2                  ###监控时间
    timeout 2                                  ###超时时间
    fall     3                  ###重试次数
}
vrrp_instance redis {
state MASTER                  ###设置为MASTER
interface eth0              ###监控网卡
virtual_router_id 52
priority 101              ###权重值
authentication {
         auth_type PASS          ###加密
         auth_pass redis        ###密码
}
track_script {
    chk_redis              ###执行上面定义的chk_redis
}
virtual_ipaddress {
       192.168.0.239            ###VIP
}
notify_master /etc/keepalived/scripts/redis_master.sh
notify_backup /etc/keepalived/scripts/redis_backup.sh
notify_fault /etc/keepalived/scripts/redis_fault.sh
notify_stop   /etc/keepalived/scripts/redsi_stop.sh
}
也可在本地编辑好后使用scp上传到服务器。 Master-keepalived脚本redis_master.sh:

#!/bin/bash
REDISCLI="/usr/local/redis/bin/redis-cli"
LOGFILE="/usr/local/redis/var/keepalived-redis-state.log"
echo "[master]" >> $LOGFILE
date >> $LOGFILE
echo "Being master...." >> $LOGFILE 2>&1
echo "Run SLAVEOF cmd ..." >> $LOGFILE
$REDISCLI SLAVEOF 192.168.0.232 6379 >> $LOGFILE 2>&1
sleep 10 #延迟10秒以后待数据同步完成后再取消同步状态
echo "Run SLAVEOF NO ONE cmd ..." >> $LOGFILE
$REDISCLI SLAVEOF NO ONE >> $LOGFILE 2>&1
Master-keepalived脚本redis_backup.sh:

#!/bin/bash
REDISCLI="/usr/local/redis/bin/redis-cli"
LOGFILE="/usr/local/redis/log/keepalived-redis-state.log"
echo "[backup]" >> $LOGFILE
date >> $LOGFILE
echo "Being slave...." >> $LOGFILE 2>&1
sleep 15 #延迟15秒待数据被对方同步完成之后再切换主从角色
echo "Run SLAVEOF cmd ..." >> $LOGFILE
$REDISCLI SLAVEOF 192.168.0.232 6379 >> $LOGFILE 2>&1
Backup配置

同样先配置好Redis，主从复制成功之后再行配置Keepalived。

Backup-Redis配置

$ vim /usr/local/redis/etc/redis.conf
修改如下值

global_defs {
    router_id redis
}
vrrp_script chk_redis {
    script "/etc/keepalived/scripts/redis_check.sh"   ###监控脚本
    interval 2                  ###监控时间
    timeout 2                                  ###超时时间
    fall     3                  ###重试次数
}
vrrp_instance redis {
state BACKUP                  ###设置为MASTER
interface eth0              ###监控网卡
virtual_router_id 51
priority 100              ###权重值
authentication {
         auth_type PASS          ###加密
         auth_pass redis        ###密码
}
track_script {
    chk_redis              ###执行上面定义的chk_redis
}
virtual_ipaddress {
       192.168.0.239            ###VIP
}
notify_master /etc/keepalived/scripts/redis_master.sh
notify_backup /etc/keepalived/scripts/redis_backup.sh
notify_fault /etc/keepalived/scripts/redis_fault.sh
notify_stop   /etc/keepalived/scripts/redsi_stop.sh
}
也可在本地编辑好后使用scp上传到服务器。 Master-keepalived脚本redis_master.sh:

#!/bin/bash
REDISCLI="/usr/local/redis/bin/redis-cli"
LOGFILE="/usr/local/redis/var/keepalived-redis-state.log"
echo "[master]" >> $LOGFILE
date >> $LOGFILE
echo "Being master...." >> $LOGFILE 2>&1
echo "Run SLAVEOF cmd ..." >> $LOGFILE
$REDISCLI SLAVEOF 192.168.0.231 6379 >> $LOGFILE 2>&1
sleep 10 #延迟10秒以后待数据同步完成后再取消同步状态
echo "Run SLAVEOF NO ONE cmd ..." >> $LOGFILE
$REDISCLI SLAVEOF NO ONE >> $LOGFILE 2>&1
Master-keepalived脚本redis_backup.sh:

redis_chekc.sh

可以使用netcat来检测redis服务的状态.

安装nc，使用nc检测redis的服务而不是ping
$ wget http://sourceforge.net/projects/netcat/files/netcat/0.7.1/netcat-0.7.1.tar.gz
$ tar -zxvf netcat-0.7.1.tar.gz
$ ./configure
$ make && make install

建立脚本:

$ vim /etc/keepalived/scripts/redis_check.sh
脚本内容:

#!/bin/bash
ALIVE=`/usr/local/redis/bin/redis-cli PING`

if ["$ALIVE" == "PONG"] ;then
      echo $ALIVE
      exit 0
else
      echo $ALIVE
      exit 1
fi
redis_fault.sh

建立脚本:

$ vim /etc/keepalived/scripts/redis_fault.sh
脚本内容:

# !/bin/bash

LOGFILE=/usr/local/redis/var/keepalived-redis-state.log
echo "[faule]" >> $LOGFILE
date >> $LOGFILE
redis_stop.sh

建立脚本:

$ vim /etc/keepalived/scripts/redis_stop.sh
脚本内容:

# !/bin/bash

LOGFILE=/usr/local/redis/var/keepalived-redis-state.log
echo "[stop]" >> $LOGFILE
date >> $LOGFILE
测试

主从复制测试

先打开Master上的Redis，再打开Backup上的Redis，分别查看info

$ redis-cli info
Master的rule显示master为正常，slave会显示为192.168.0.232

在Master上写入数据，在Backup读取

$ redis-cli set a hello //Master 写入数据
$ redis-cli get a //Backup 读取数据
"hello"
主从复制正常。

主从切换测试
先后启动Master和Backup上的keepalived，在Master上查看vip

$ ip a
enter image description here

从图中可以看出vip已经绑定在Master上，现在通过vip来进行数据测试

$ redis-cli -h 192.168.0.239 set a test
$ redis-cli -h 192.168.0.239 get a //测试虚拟ip数据读取
//在主机和从机上分别进行数据读取
$ redis-cli get a
enter image description here

从图中可以看出测试无问题。

现在关闭Master上的redis，来看VIP能否正常漂移，并进行数据测试。

$ killall -9 redis-server
$ redis-cli -h 192.168.0.232 info
enter image description here

现在给redis写入数据，测试看Master恢复服务后能否正常恢复数据

$ redis-cli -h 192.168.0.239 set a nihao
恢复Master上的Redis，查看ip a

$ service redis-server start
$ ip a
$ redis-cli get a
enter image description here

数据恢复，VIP切换回Master，Redis高可用环境搭建成功.