linux 雙Redis + keepalived 主從複製+宕機自主切換
主要核心思想，如果master 和 salve 全部存活的情況，VIP就漂移到 master。讀寫都從master操作，如果master宕機，VIP就會漂移到salve,並將之前的salve切換為master,當宕機的master可以繼續服務的時候，首先會從salve同步資料，然後VIP漂移到master伺服器上面，持續提供服務。
環境準備：
master：ip 192.168.28.139；redis 19020；redis 19021；keepalived
slave ：ip 192.168.28.140；redis 19020；redis 19021；keepalived
keepalived VIP：192.168.28.99
1、下載Redis redis-5.0.5.tar.gz
解壓 tar xzf + Redis包（重複一下操作，改名可以配置2個redis）
mv redis-5.0.5 /usr/local/redis19020
進入 Redis檔案安裝
安裝依賴檔案
yum install gcc-c++
安裝
make
mv redis.conf redis.conf.back
重寫conf檔案
vim redis.conf
=======================================
daemonize yes
pidfile /var/run/redis19020.pid
#pidfile /var/run/redis19021.pid
port 19020 #19021
tcp-backlog 511
timeout 30
tcp-keepalive 60
loglevel warning
logfile /logs/redis/redis19020.log
#logfile /logs/redis/redis19021.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-5.0.5/ #redis安裝路徑
protected-mode no #關閉保護模式
requirepass test123 #主Redis 密碼
#masterauth test123 #從Redis 密碼（與主一致）
#slaveof 192.168.28.139 19021 #從Redis設定 Redis主從配置（主Redis ip 埠）
slave-serve-stale-data yes
slave-read-only yes
repl-diskless-sync no
repl-diskless-sync-delay 5
repl-disable-tcp-nodelay no
slave-priority 100
appendonly no
appendfilename "appendonly.aof"
appendfsync everysec
no-appendfsync-on-rewrite no
auto-aof-rewrite-percentage 100
auto-aof-rewrite-min-size 64mb
aof-load-truncated yes
lua-time-limit 5000
slowlog-log-slower-than 10000
slowlog-max-len 128
latency-monitor-threshold 0
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
hll-sparse-max-bytes 3000
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
==============================================
mkdir /logs/redis
touch /logs/redis/{redis19020.log,redis19021.log}
啟動redis服務，並指定啟動服務配置檔案
src/redis-server redis.conf
設定環境變數
將 Redis 新增到環境變數中：
# vi /etc/profile
在最後新增以下內容：
## Redis env
export PATH=$PATH:/usr/local/redis19020/src
export PATH=$PATH:/usr/local/redis19021/src
使配置生效：
# source /etc/profile
現在就可以直接使用 redis-cli 等 redis 命令了。
2、keepalived安裝
下載keepalived
官網: https://keepalived.org/download.html
上傳並解壓keepalived
/home
cd /home/
tar -zxvf keepalived-2.0.18.tar.gz -C /usr/local/src/
進入目錄/usr/local/src/keepalived-2.0.18
cd /usr/local/keepalived-2.0.18/
檢查安裝環境
./configure --prefix=/usr/local/keepalived
首次檢查
configure: error:
!!! OpenSSL is not properly installed on your system. !!!
!!! Can not inclu
de OpenSSL headers files. !!!
安裝openssl openssl-devel解決問題
yum -y install openssl openssl-devel
二次檢查
*** WARNING - this build will not support IPVS with IPv6. Please install libnl/libnl-3 dev libraries to support IPv6 with IPVS.
安裝libnl libnl-devel解決問題
yum -y install libnl libnl-devel
其他問題
configure: error: libnfnetlink headers missing
安裝libnfnetlink-devel解決問題
yum -y install libnfnetlink-devel
編譯並安裝
make && make install
將keepalived新增到系統服務中
拷貝執行檔案
cp /usr/local/keepalived/sbin/keepalived /usr/sbin/
將init.d檔案拷貝到etc下,加入開機啟動項
cp /usr/local/src/keepalived-2.0.18/keepalived/etc/init.d/keepalived /etc/init.d/keepalived
將keepalived檔案拷貝到etc下
cp /usr/local/src/keepalived-2.0.18/keepalived/etc/sysconfig/keepalived /etc/sysconfig/
建立keepalived資料夾
mkdir -p /etc/keepalived
將keepalived配置檔案拷貝到etc下
cp /usr/local/src/keepalived-2.0.18/keepalived/etc/keepalived/keepalived.conf /etc/keepalived/keepalived.conf
新增keepalived到開機啟動
chkconfig --add keepalived
新增可執行許可權
chmod +x /etc/init.d/keepalived
二、部署keepalived雙擊自主切換（以下配置檔案和指令碼，兩臺機器都要重新布）
備份keepalived配置檔案
cp keepalived.conf keepalived.conf.back
重新編輯配置檔案
vim keepalived.conf
配置檔案
================================================
! COnfiguration File for keepalived
global_defs {
router_id MASTER-HA #主機標識
#router_id BACKUP #備機標識
script_user root
enable_script_security
}
vrrp_script chk_redis {
script "/etc/keepalived/scripts/redis_check.sh" #指令碼地址和名字，此處呼叫改指令碼
interval 2
weight -5
fall 2
rise 1
}
vrrp_instance VI_1 {
state MASTER #主機MASTER、備機BACKUP
interface eth0 #本機的網絡卡
virtual_router_id 51
priority 101 #主機101，備機小於101便可
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
192.168.28.99 #新的IP地址，需要在同機網段內
}
track_script {
chk_redis
}
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/redis_stop.sh
}
================================================
新建資料夾scripts
mkdir scripts
新建指令碼資料夾
touch {redis_check.sh,redis_master.sh,redis_backup.sh,redis_fault.sh,redis_stop.sh}
編寫指令碼
vim redis_check.sh（共用指令碼）
#!/bin/bash
#This scripts is check for Redis Slave status
#19020
counter=$(netstat -na|grep "LISTEN"|grep "19020"|wc -l)
#查詢本機Redis是否存活，如果不存在，則執行以下指令碼
if [ "${counter}" -eq 0 ]; then
/etc/init.d/keepalived keepalived stop
killall keepalived
fi
ping 192.168.28.139 -w1 -c1 &>/dev/null #（本機IP）
#查詢本機ip是否存活，不存活則執行以下指令碼
if [ $? -ne 0 ]
then
/etc/init.d/keepalived keepalived stop
killall keepalived
fi
#19021
counterB=$(netstat -na|grep "LISTEN"|grep "19021"|wc -l)
#查詢本機Redis是否存活，如果不存在，則執行以下指令碼
if [ "${counterB}" -eq 0 ]; then
/etc/init.d/keepalived keepalived stop
killall keepalived
fi
ping 192.168.28.139 -w1 -c1 &>/dev/null #（本機IP）
#查詢本機ip是否存活，不存活則執行以下指令碼
if [ $? -ne 0 ]
then
/etc/init.d/keepalived keepalived stop
killall keepalived
fi
主reids指令碼
vim redis_master.sh
#!/bin/bash
REDISCLI="/usr/local/redis19020/src/redis-cli -a test123 -p 19020"
LOGFILE="/var/log/keepalived-redis-state.log" #需要新建日誌檔案
REDISCLIA="/usr/local/redis19021/src/redis-cli -a test123 -p 19021"
LOGFILEA="/var/log/keepalived-redis-stateA.log" #需要新建日誌檔案
#19020
sleep 5
echo "[master]" >> $LOGFILE
date >> $LOGFILE
echo "Being master...." >>$LOGFILE 2>&1
echo "Run SLAVEOF cmd ...">> $LOGFILE
$REDISCLI SLAVEOF 192.168.28.140 19020 >>$LOGFILE 2>&1 #主庫IP
if [ $? -ne 0 ];then
echo "data rsync fail." >>$LOGFILE 2>&1
else
echo "data rsync OK." >> $LOGFILE 2>&1
fi
sleep 5 #延遲10秒以後待資料同步完成後再取消同步狀態
echo "Run SLAVEOF NO ONE cmd ...">> $LOGFILE
$REDISCLI SLAVEOF NO ONE >> $LOGFILE 2>&1
if [ $? -ne 0 ];then
echo "Run SLAVEOF NO ONE cmd fail." >>$LOGFILE 2>&1
else
echo "Run SLAVEOF NO ONE cmd OK." >> $LOGFILE 2>&1
fi
#19021
sleep 5
echo "[master2]" >> $LOGFILEA
date >> $LOGFILEA
echo "Being master...." >>$LOGFILEA 2>&1
echo "Run SLAVEOF cmd ...">> $LOGFILEA
$REDISCLIA SLAVEOF 192.168.28.140 19020 >>$LOGFILEA 2>&1 #主庫IP
if [ $? -ne 0 ];then
echo "data rsync fail." >>$LOGFILEA 2>&1
else
echo "data rsync OK." >> $LOGFILEA 2>&1
fi
sleep 10 #延遲10秒以後待資料同步完成後再取消同步狀態
echo "Run SLAVEOF NO ONE cmd ...">> $LOGFILEA
$REDISCLIA SLAVEOF NO ONE >> $LOGFILEA 2>&1
if [ $? -ne 0 ];then
echo "Run SLAVEOF NO ONE cmd fail." >>$LOGFILEA 2>&1
else
echo "Run SLAVEOF NO ONE cmd OK." >> $LOGFILEA 2>&1
redis_backup.sh
#!/bin/bash
REDISCLI="/usr/local/redis19020/src/redis-cli -a test123-p 19020"
REDISCLIA="/usr/local/redis19021/src/redis-cli -a test123 -p 19021"
LOGFILE="/var/log/keepalived-redis-state.log"
LOGFILEA="/var/log/keepalived-redis-stateA.log"
echo "[backup]" >> $LOGFILE
date >> $LOGFILE
echo "Being slave...." >>$LOGFILE 2>&1
sleep 15 #延遲15秒待資料被對方同步完成之後再切換主從角色
echo "Run SLAVEOF cmd ...">> $LOGFILE
$REDISCLI SLAVEOF 192.168.28.140 19020 >>$LOGFILE 2>&1 #主庫IP
#19021
echo "[backup2]" >> $LOGFILEA
date >> $LOGFILEA
echo "Being slave...." >>$LOGFILEA 2>&1
sleep 3 #延遲15秒待資料被對方同步完成之後再切換主從角色
echo "Run SLAVEOF cmd ...">> $LOGFILEA
$REDISCLIA SLAVEOF 192.168.28.140 19021 >>$LOGFILEA 2>&1 #從庫IP
從Redis指令碼
vim redis_master.sh
#!/bin/bash
REDISCLI="/usr/local/redis19020/src/redis-cli -a test123 -p 19020"
REDISCLIA="/usr/local/redis19021/src/redis-cli -a test123 -p 19021"
LOGFILE="/var/log/keepalived-redis-state.log" #需要新建日誌檔案
LOGFILEA="/var/log/keepalived-redis-stateA.log" #需要新建日誌檔案
sleep 15
echo "[master]" >> $LOGFILE
date >> $LOGFILE
echo "Being master...." >>$LOGFILE 2>&1
echo "Run SLAVEOF cmd ...">> $LOGFILE
$REDISCLI SLAVEOF 192.168.28.139 19020 >>$LOGFILE 2>&1 #主庫IP
sleep 10 #延遲10秒以後待資料同步完成後再取消同步狀態
echo "Run SLAVEOF NO ONE cmd ...">> $LOGFILE
$REDISCLI SLAVEOF NO ONE >> $LOGFILE 2>&1
#19021
sleep 15
echo "[masterA]" >> $LOGFILEA
date >> $LOGFILEA
echo "Being master...." >>$LOGFILEA 2>&1
echo "Run SLAVEOF cmd ...">> $LOGFILEA
$REDISCLIA SLAVEOF 192.168.28.139 19021 >>$LOGFILEA 2>&1 #主庫IP
sleep 10 #延遲10秒以後待資料同步完成後再取消同步狀態
echo "Run SLAVEOF NO ONE cmd ...">> $LOGFILEA
$REDISCLIA SLAVEOF NO ONE >> $LOGFILEA 2>&1
redis_backup.sh
#!/bin/bash
REDISCLI="/usr/local/redis19020/src/redis-cli -a test123 -p 19020"
REDISCLIA="/usr/local/redis19021/src/redis-cli -a test123 -p 19021"
LOGFILE="/var/log/keepalived-redis-state.log"
LOGFILEA="/var/log/keepalived-redis-stateA.log"
echo "[backup]" >> $LOGFILE
date >> $LOGFILE
echo "Being slave...." >>$LOGFILE 2>&1
sleep 15 #延遲15秒待資料被對方同步完成之後再切換主從角色
echo "Run SLAVEOF cmd ...">> $LOGFILE
$REDISCLI SLAVEOF 192.168.28.139 19020 >>$LOGFILE 2>&1 #主庫IP
#19021
echo "[backupA]" >> $LOGFILEA
date >> $LOGFILEA
echo "Being slave...." >>$LOGFILEA 2>&1
sleep 3 #延遲15秒待資料被對方同步完成之後再切換主從角色
echo "Run SLAVEOF cmd ...">> $LOGFILEA
$REDISCLIA SLAVEOF 192.168.28.139 19021 >>$LOGFILEA 2>&1 #主庫IP
共用指令碼
redis_fault.sh
#!/bin/bashLOGFILE=/var/log/keepalived-redis-state.log
LOGFILEA=/var/log/keepalived-redis-stateA.log
echo "[fault]" >> $LOGFILE
date >> $LOGFILE
echo "[fault]" >> $LOGFILEA
date >> $LOGFILEA
redis_stop.sh
#!/bin/bashLOGFILE=/var/log/keepalived-redis-state.log
LOGFILEA=/var/log/keepalived-redis-stateA.log
echo "[fault]" >> $LOGFILE
date >> $LOGFILE
echo "[fault]" >> $LOGFILEA
date >> $LOGFILEA
新增可執行許可權
chmod +x /etc/init.d/keepalived
顯示指令碼檔案為
啟動keepalived
/etc/init.d/keepalived start
檢視是否啟動成功
ps -ef | grep keepalived
啟動成功之後會生成一個新的伺服器IP地址，可通過新IP直接連線Redis，可以自由關閉其中一臺Redis服務，keepalived會自動切換到另外一臺Redis伺服器當中。
宕機後啟動順序為，先啟動Redis，在啟動keepalived即可，啟動後會自動同步兩臺Redis的資料。
&n