最近公司重整架構,老闆給出十幾臺左右的服務器並且還要儘量節約成本我就谷歌了一下在幾種集羣以前進行比較最終採用了Keepalived+Nginx作負債均衡高可用。雖然以前也研究過集羣,看過不少集羣方面的原理和架構,但畢竟沒有真正操做過如下案例是在虛擬機中完成實驗其實對於高可用搭建來講只用給出Keepalived和Nginx的配置便可後面的一些安裝搭建徹底是本人項目須要能夠不用理睬僅供參考。javascript
本文只是實驗搭建記錄方便之後在服務器中實施搭建。 css
架構圖以下
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前提介紹本案例採用Centos7+Keepalived1.3.5+Tomcat9+Mysql5.6+Redis3.2.8+Rabbitmq3.6.10前端
1、集羣搭建DR模式
java
前端LVS採用主從模式,Nginx爲後端realserver負債均衡。node
服務器環境以下mysql
nginx+LVS_master | 192.168.23.14 |
nginx+LVS_backup | 192.168.23.15 |
VIP | 192.168.23.20 |
Tomcat | 192.168.23.16 ;192.168.23.17 ;192.168.23.18 |
redis | 192.168.23.21 |
Mysql | 192.168.23.22 |
一、安裝前調試以及優化linux
安裝centos7選擇默認最小化nginx
中止firewalld運行 c++
systemctl stop firewalld.service systemctl disable firewalld.service
內核優化vi/etc/sysctl.conf
##關閉ipv6 net.ipv6.conf.all.disable_ipv6 = 1 net.ipv6.conf.default.disable_ipv6 = 1 ##路由轉發n et.ipv4.ip_forward = 1 net.ipv4.conf.all.send_redirects = 0 net.ipv4.conf.default.send_redirects = 0
防火牆安裝iptables
yum -y install iptables-services iptables
修改selinux
vi/etc/selinux/config 修改selinux爲disabled
重啓
reboot
二、安裝master和backup
安裝前準備
yum -y install openssl openssl-devel popt popt-devel gcc* wget vim ipvsadm pcre pcre-devel
運行ipvsadm
查看內核模塊是否存在
lsmod|grep ip_vs
創建data目錄
makdir /data
下載安裝
wget tar zxfkeepalived-1.3.5.tar.gz -C /data ./configure --prefix=/usr/local/keepalived-1.3.5 make && make install
複製keepalived文件和腳本
cp/usr/local/keepalived-1.3.5/sbin/keepalived /usr/sbin/ cp/usr/local/keepalived/etc/keepalived/keepalived.conf /etc/keepalived/ cp/usr/local/keepalived/etc/sysconfig/keepalived /etc/sysconfig/ cp/data/keepalived-1.3.5/./keepalived/etc/init.d/keepalived /etc/init.d/ chmod 755/etc/init.d/keepalived mkdir/etc/keepalived/
配置lvs網卡設置下的vip
#!/bin/bash # description: Config realserver lo and apply noarp # chkconfig: 345 80 20 SNS_VIP0=192.168.23.20 . /etc/rc.d/init.d/functions case "$1" in start) /sbin/ifconfig ens37 down /sbin/ifconfig ens37 up echo "1" >/proc/sys/net/ipv4/conf/lo/arp_ignore echo "2" >/proc/sys/net/ipv4/conf/lo/arp_announce echo "1" >/proc/sys/net/ipv4/conf/all/arp_ignore echo "2" >/proc/sys/net/ipv4/conf/all/arp_announce ifconfig ens37:0 $SNS_VIP0 netmask 255.255.255.255 broadcast $SNS_VIP0 up /sbin/route add -host $SNS_VIP0 dev ens37:0 echo "RealServer Start OK" ;; stop) ifconfig ens37:0 down route del $SNS_VIP0 >/dev/null 2>&1 echo "0" >/proc/sys/net/ipv4/conf/lo/arp_ignore echo "0" >/proc/sys/net/ipv4/conf/lo/arp_announce echo "0" >/proc/sys/net/ipv4/conf/all/arp_ignore echo "0" >/proc/sys/net/ipv4/conf/all/arp_announce echo "RealServer Stoped" ;; *) echo "Usage: $0 {start|stop}" exit 1 esac exit 0
重啓網卡
systemctl restart network.service
設置開啓啓動
chkconfig --add keepalived chkconfig --level 345 keepalived on
設置master /etc/keepalived/文件
! Configuration File for keepalived global_defs { #lvs組設置 router_id LVS1 #id_惟一標識 } vrrp_instance VI_1 { #vrrp設置,VI_1自定義名稱 state MASTER #master設置,必須大寫 interface ens33 #網卡設置,綁定vip的子接口,lvs須要綁定在網卡上,realserver綁定在迴環口。區別:lvs對訪問爲外,realserver爲內不易暴露本機信息。 virtual_router_id 51 #router_id,vrrp惟一標識,一致 priority 100 #優先級,越大越優先 advert_int 1 #組播信息發送間隔,兩個節點設置必須同樣 authentication { #設置驗證信息,兩個節點必須一致 auth_type PASS auth_pass lmnginx } virtual_ipaddress { #設置vip 192.168.23.20 } } virtual_server 192.168.23.20 80 { #設置vip鏈接下的realserver delay_loop 1 #每1秒檢測迴環口 lb_algo rr #設置調度算法爲默認rr輪詢 lb_kind DR #設置lvs默認爲DR直接路由模式。建議lvs都是內網ip部署,最後vip用路由器映射到外網,最爲安全! protocol TCP #啓用TCP檢測模式 real_server 192.168.23.14 80 { #realserver的ip地址 weight 1 #權重,最大越高,lvs就越優先訪問。 TCP_CHECK { #TCP模式檢測後端鏈接 connect_timeout 3 #超時3秒 retry 2 #重連次數2次 delay_before_retry 3 #重連間隔時間3秒 connect_port 80 #檢測後端realserver的端口 } } real_server 192.168.23.15 80 { weight 1 TCP_CHECK { connect_timeout 3 retry 3 delay_before_retry 3 connect_port 80 } } }
設置backup /etc/keepalived/文件
! Configuration File for keepalived global_defs { router_id LVS2 } vrrp_instance VI_1 { state BACKUP interface ens33 virtual_router_id 51 priority 80 advert_int 1 authentication { auth_type PASS auth_pass lmnginx #與backup的認證密碼 } virtual_ipaddress { 192.168.23.20 } } virtual_server 192.168.23.20 80 { delay_loop 1 lb_algo rr lb_kind DR protocol TCP real_server 192.168.23.14 80 { weight 1 TCP_CHECK { connect_timeout 3 retry 2 delay_before_retry 3 connect_port 80 } } real_server 192.168.23.15 80 { weight 1 TCP_CHECK { connect_timeout 3 retry 3 delay_before_retry 3 connect_port 80 } } }
nginx監控腳本
#!/bin/bash ip=`ifconfig ens33 |grep "inet" |awk -F " " '{print $2}'` nginx=`ps -C nginx --no-header |wc -l` date=`date +%F-%r` while true do if [ $nginx -eq 0 ]; then killall keepalived echo "$date $ip nginx宕機" |/bin/mail -s "$ip" mynamelim@163.com >/dev/null 2>&1 fi sleep 1h done
sleep 1h 設置每小時發送一次while ture執行正確爲止後退出使用後臺運行
nohup ./nginx >/dev/null 2>&1 &
附mail設置
安裝mail
yum -y install mailx
設置mail文件
vim /etc/mail.rc set from=***@163.com你的郵箱名建議和帳號一致 smtp=smtp.163.com 郵箱的stmp服務器 set smtp-auth-user=***@163.com你的郵箱帳號 smtp-auth-password=password你的郵箱密碼這個密碼是stmp認證用戶的密碼不懂能夠百度 smtp-auth=login 肯定登錄
三、nginx編譯安裝
安裝依賴包
yum install -y vim wget lsof gcc gcc-c++ bzip2 net-tools bind-utilszlib-devel openssl-devel libxml2-devel libxslt-devel perl-devel perl-ExtUtils-Embed
建立nginx用戶
groupadd nginx useradd -s /sbin/nologin -g nginx -M nginx
安裝Pcre
下載 wget http://www.pcre.org/pcre-8.41.tar.gz
cd /data tar zxf pcre.tar.gz ./configure --prefix=/usr/local/pcre &&make && make install
安裝openssl
下載安裝
wget https://www.openssl.org/source/openssl-1.1.0f.tar.gz cd /data tar zxf openssl.tar.gz ./config --prefix=/usr/local/openssl &&make && make install
安裝zlib
下載安裝
wget www.zlib.net/zlib-1.2.11.tar.gz cd /data tar zxf zlib.tar.gz ./configure --prefix=/usr/local/zlib &&make && make install
建立目錄
mkdir -p /var/tmp/nginx/{client,proxy,fastcgi,uwsgi,scgi} mkdir /var/log/nginx mkdir /etc/nginx
安裝nginx
下載安裝
wget ./configure --prefix=/usr/local/nginx--sbin-path=/usr/sbin/nginx --conf-path=/etc/nginx/nginx.conf --error-log-path=/var/log/nginx/error.log --http-log-path=/var/log/nginx/access.log --lock-path=/var/lock/nginx.lock--user=nginx --group=nginx --with-http_ssl_module --with-http_dav_module --with-http_flv_module --with-http_realip_module --with-http_addition_module --with-http_xslt_module --with-http_stub_status_module --with-http_sub_module --with-http_random_index_module --with-http_degradation_module --with-http_secure_link_module --with-http_gzip_static_module --with-http_perl_module --with-http_v2_module --with-threads --with-stream--with-stream_ssl_module --with-pcre=/data/pcre=8.41.n"sp; --with-zlib=/data/zlib-1.2.11 --with-openssl=/data/openssl-1.1.0f --with-file-aio --with-mail --with-mail_ssl_module --http-client-body-temp-path=/var/tmp/nginx/client_body --http-proxy-temp-path=/var/tmp/nginx/proxy --http-fastcgi-temp-path=/var/tmp/nginx/fastcgi --http-uwsgi-temp-path=/var/tmp/nginx/uwsgi --http-scgi-temp-path=/var/tmp/nginx/scgi --with-ld-opt="-Wl,-E" make && make install
配置realserver迴環口下的的vip
#!/bin/bash # description: Config realserver lo and apply noarp # chkconfig: 345 80 20 SNS_VIP0=192.168.23.20 . /etc/rc.d/init.d/functions case "$1" in start) /sbin/ifconfig lo down /sbin/ifconfig lo up echo "1" >/proc/sys/net/ipv4/conf/lo/arp_ignore echo "2" >/proc/sys/net/ipv4/conf/lo/arp_announce echo "1" >/proc/sys/net/ipv4/conf/all/arp_ignore echo "2" >/proc/sys/net/ipv4/conf/all/arp_announce ifconfig lo:0 $SNS_VIP0 netmask 255.255.255.255 broadcast $SNS_VIP0 up /sbin/route add -host $SNS_VIP0 dev lo:0 echo "RealServer Start OK" ;; stop) ifconfig lo:0 down route del $SNS_VIP0 >/dev/null 2>&1 echo "0" >/proc/sys/net/ipv4/conf/lo/arp_ignore echo "0" >/proc/sys/net/ipv4/conf/lo/arp_announce echo "0" >/proc/sys/net/ipv4/conf/all/arp_ignore echo "0" >/proc/sys/net/ipv4/conf/all/arp_announce echo "RealServer Stoped" ;; *) echo "Usage: $0 {start|stop}" exit 1 esac exit 0
配置nginx
實現靜動分離和負債均衡
user nginx; worker_processes auto; events { worker_connections 65535; #使用epoll模塊加強性能 use epoll; #打開文件描述符(緩存有用) multi_accept on; } http { #隱藏nginx版本號 server_tokens off; #指定nginx配置的軟連接 include mime.types; include conf.d/*; #默認文件類型 default_type text/html; #日誌格式默認 log_format main '$remote_addr - $remote_user [$time_local] "$request" ' '$status $body_bytes_sent "$http_referer" ' '"$http_user_agent" "$http_x_forwarded_for" "$request_time"'; #開啓高效的文件傳輸模式 sendfile on; #鏈接超時後重置鏈接,減小等待 reset_timedout_connection off; #限制鏈接,zone自定義 limit_conn_zone $binary_remote_addr zone=addr:5m; #限制鏈接數每一個用戶最大打開100次 limit_conn addr 100; #默認一個一個發,這裏爲發送因此頭部文件 tcp_nopush on; #不緩存數據 tcp_nodelay on; #字符集 charset UTF-8; #鏈接超時(秒) keepalive_timeout 65; #開啓壓縮 gzip on; gzip_proxied any; gzip_min_length 1000; gzip_comp_level 4; gzip_types text/plain text/css application/json application/x-javascript text/xml application/xml application/xml+rss text/javascript; #設置訪問頭部 proxy_redirect off; proxy_set_header Host $host; proxy_set_header X-Real-IP $remote_addr; proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for; #設置緩存 client_max_body_size 10m; client_body_buffer_size 128k; proxy_connect_timeout 75; proxy_read_timeout 300; proxy_send_timeout 300; proxy_buffer_size 16k; proxy_buffers 4 64k; proxy_busy_buffers_size 128k; proxy_temp_file_write_size 128k; proxy_temp_path /data/temp_path; proxy_cache_path /data/cache_path levels=1:2 keys_zone=cache_one:200m inactive=5d max_size=30g; #設置負債均衡 upstream www.limeng.com { server 192.168.23.16; server 192.168.23.17; server 192.168.23.18; #設置nginx鏈接tomcat之間得鏈接爲長鏈接。此設置默認關閉,致使nginx與tomcat得time_wait短暫,形成資源浪費,keepalive默認單位秒,官方建議16不可大不可小。 keepalive 16 } server { listen 80; server_name limeng; index index.html index.htm index.jsp index.do; #默認代理本機默認頁面 location / { proxy_pass http://www.limeng.com; } #設置緩存策略 location ~ .*\.(html|htm|gif|jpg|jpeg|bmp|png|ico|txt|js|css)$ { root /usr/local/nginx/ROOT; if (-f $request_filename) { expires 1d; break; } proxy_cache_key '$host:$server_port$request_uri';#緩存服務和路徑 proxy_redirect off; proxy_cache cache_one;#緩存的zone名 proxy_cache_valid 200 302 1h; #緩存200和302時間1小時 proxy_cache_valid 301 1d;#緩存301時間爲1天 proxy_cache_valid any 1m; #其餘緩存爲1個月 expires 7d; } #設置其餘未緩存策略 location ~ .*$(jsp|do) { #設置長鏈接策略,nginx默認爲http1.0,而tomcat默認爲http1.1 。 proxy_http_version 1.1; proxy_set_header Connection ""; proxy_pass http://www.limeng.com if (-f $request_filename) { expires 1d; break; } } #禁止nginx訪問tomcat的關鍵目錄 location ~ ^/(WEB-INF|META-INF)/{ deny all; } #默認的訪問代碼 error_page 500 502 503 504 /50x.html; location = /50x.html { root html; } }
注倆臺nginx配置同樣
nginx啓動腳本自行谷歌
chmod 755 /etc/init.d/nginx
啓動nginx
/etc/init.d/nginx start
Nginx安裝完成
四、後端web服務器Tomcat安裝
jdk安裝
安裝前準備
yum -y install gcc*wget vim
檢查命令
java -version java -version
卸載
rpm -e --nodeps jdk
解壓安裝
wget http://download.oracle.com/otn-pub/java/jdk/8u144-b01/090f390dda5b47b9b721c7dfaa008135/jdk-8u144-linux-x64.tar.gz?AuthParam=1502180263_4da80e17ef2af74cdbd6c02a779d1db6 tar -zxvf jdk-8u144-linux-x64.tar.gz
移動目錄
mv ./jdk1.8.0_121/usr/local/java/
最後再刪除安裝文件
rm -rf jdk-8u144-linux-x64.gz
配置環境變量
vi /etc/profile加入如下變量 exportJAVA_HOME=/usr/local/java/ exportCLASSPATH=.:$JAVA_HOME/jre/lib/rt.jar:$JAVA_HOME/lib/dt.jar:$JAVA_HOME/lib/tools.jar exportPATH=$PATH:$JAVA_HOME/bin
加載變量
source /etc/profile
tomcat安裝
解壓
wget http://mirror.bit.edu.cn/apache/tomcat/tomcat-9/v9.0.0.M22/bin/apache-tomcat-9.0.0.M18.tar.gz tar -zxvf apache-tomcat-9.0.0.M18.tar.gz
解壓完整後刪除安裝包
rm -rf apache-tomcat-9.0.0.M18.tar.gz
移動目錄
mkdir /usr/local/tomcat/ mv ./apache-tomcat-9.0.0.M18//usr/local/tomcat/
首先咱們來配置一下tomcat的環境變量和內存設置進入tomcat的bin目錄後經過vim命令打開catalina.sh文件並在其中加入以下配置>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
xms:初始化內存。
xmx:最大內存,通常爲物理機的1/4。(和xms同樣爲了防止內存溢出)
xmn:tomcat最小內存,通常爲xmn的一半的值。
JAVA_OPTS="-Dfile.encoding=UTF-8 -server -Xms1024m -Xmx1024m -Xmn512m -XX:SurvivorRatio=10 -XX:MaxTenuringThreshold=15 -XX:NewRatio=2 -XX:+DisableExplicitGC" export TOMCAT_HOME=/tmp/tomcat/apache-tomcat-9.0.0.M18 export CATALINA_HOME=/tmp/tomcat/apache-tomcat-9.0.0.M18 export JRE_HOME=/tmp/java/jdk1.8.0_121 export JAVA_HOME=/tmp/java/jdk1.8.0_121
server.xml優化配置 >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
maxThreads:tomcat最大線程組。
minSpareThreads:tomcat初始線程值。
maxSpareThreads:tomcat空閒線程,超過這個線程將關閉無用線程值。
acceptCount:當全部可使用的處理請求的線程數都被使用時,能夠放處處理隊列中的請求數,超過這個數的請求將不予處理。
<Connector port="8080" protocol="HTTP/1.1" maxThreads="8000" minSpareThreads="2000" maxSpareThreads="1000" acceptCount="1000" URIEncoding="utf-8" server="Neo App Srv 1.0" connectionTimeout="20000" redirectPort="8443" />
啓動
./startup.sh
五、mysql安裝配置
安裝前準備
yum -y install makegcc cmake bison-devel ncurses-devel libaio libaio-devel per-Data-Dumpernet-tools gcc* wget vim autoconf
查看是否有mysql的rpm包
rpm -qa |grep mysql rpm -e --nodeps mysql
查看是否有mariadb-libs的rpm包
rpm -qa |grep mariadb-libs yum -y install mariadb-libs
解壓文件
wget https://www.mysql.com/downloads/mysql-5.6.23.tar.gz tar -zxf /data/mysql-5.6.23.tar.gz
編譯安裝
cmake -DCMAKE_INSTALL_PREFIX=/usr/local/mysql -DMYSQL_DATADIR=/usr/local/mysql/data -DSYSCONFDIR=/etc -DWITH_MYISAM_STORAGE_ENGINE=1 -DWITH_INNOBASE_STORAGE_ENGINE=1 -DWITH_MEMORY_STORAGE_ENGINE=1 -DWITH_READLINE=1 -DMYSQL_UNIX_ADDR=/var/lib/mysql/mysql.sock -DMYSQL_TCP_PORT=3306 -DENABLED_LOCAL_INFILE=1 -DWITH_PARTITION_STORAGE_ENGINE=1 -DEXTRA_CHARSETS=all -DDEFAULT_CHARSET=utf8 -DDEFAULT_COLLATION=utf8_general_ci make &&make install
創建用戶和組
groupadd mysql useradd mysql -s/sbin/nologin -g mysql
給權限
chown -Rmysql:mysql /usr/local/mysql/
mysql下的初始化
/usr/local/mysql/scripts/mysql_install_db--user=mysql --basedir=/usr/local/mysql/
拷貝配置文件my.cnf
cd support-files/ cp my-default.cnf /etc/my.cnf
配置mysql
[client] port=3306 socket=/var/lib/mysql/mysql.sock #socket線程,建議設置,若是設置爲默認,意外重啓後可能會報錯。 [mysql] no-auto-rehash #啓動條件,優化啓動時間。 [mysqld] user=mysql port=3306 basedir=/usr/local/mysql #mysql主目錄 datadir=/var/lib/mysql #mysql數據目錄 open_files_limit=10240 #打開文件數 back_log=600 #TCP/IP鏈接監聽隊列大小,默認80 max_connections = 3000 #最大進程鏈接數,默認151 external-locking = FALSE #避免外部鎖定,默認開啓 max_allowed_packet = 32M #設置網絡傳輸一次消息的最大,默認爲4M thread_cache_size = 300 #配置服務器線程的緩存值,爲M key_buffer_size = 2048M #批定用於索引的緩衝區大小 read_rnd_buffer_size = 16M #MySql的隨機讀(查詢操做)緩衝區大小,儘可能適當設置該值,以免內存開銷過大 bulk_insert_buffer_size = 64M #批量插入數據緩存大小,默認爲8M innodb_buffer_pool_size = 2048M #這對Innodb表來講很是重要,設置它高達 70-80% 的可用內存。 skip-name-resolve #跳過域名 #skip-innodb #不使用innodb引擎,5.5默認使用innodb,性能優越。 # Disabling symbolic-links is recommended to prevent assorted security risks symbolic-links=0 # Settings user and group are ignored when systemd is used. # If&n`sp;xou need to run mysqld under a different user or group, # customize your systemd unit file for mariadb according to the # instructions in http://fedoraproject.org/wiki/Systemd [mysqld_safe] log-error=/var/log/mysql_error.log pid-file=/var/run/mysql/mysql.pid # # include all files from the config directory # !includedir /etc/my.cnf.d
添加變量
echo "exportPATH=$PATH:/usr/local/mysql/bin" >> /etc/profile source /etc/profile
添加開機啓動
cp/usr/local/mysql/./support-files/mysql.server /etc/rc.d/init.d/mysqld chmod +x/etc/init.d/mysqld chkconfig --addmysqld chkconfig mysqld on
啓動mysql
systemctl startmysqld.service
查看端口
netstat -anpt |grepmysql
編輯etc下的my.cnf文件
設置mysql密碼
mysqladmin -uroot password
6、redis安裝
解壓安裝
wget https://redis.io/download/redis-3.2.8.tar.gz tar -zxf /data/redis-3.2.8.tar.gz cd redis-3.2.8 make PREFIX=/usr/local/redis install
執行完進入目錄/usr/local/redis
創建文件夾並拷貝
mkdir /etc/redis cp -rf /data/redis-3.2.8/redis.conf /etc/6379.conf
編輯配置文件vim/etc/redis/6379.conf
daemonize yes bind 192.168.23.21 127.0.0.1 (連接ip和本地 logfile "/var/log/redis.log"(自定義) databases 16 (默認數據庫數量 dbfilename dump.rdb 默認存儲名 dir/tmp/redis/data/redisdata 默認數據存放目錄 requirepass password (本身設置redis的密碼)
啓動redis
./redis_server /usr/local/redis/redis.conf
7、rabbitmq安裝
安裝前準備
yum -y install makegcc gcc-c++ kernel-devel m4 ncurses-devel openssl-devel
解壓 zlang
tar -zxf /data/otp_src_19.3.tar.gz cd otp_src_19.3
編譯安裝
./configure --prefix=/usr/local/erlang --with-ssl -enable-threads -enable-smmp-support -enable-kernel-poll --enable-hipe --without -javac make && make install
安裝rtabbitmq
wget 鑤tp:o/wuw.rabbitmq.com/download.html/rabbitmq-server-generic-unix-3.6.10.tar.xz tar -xf rabbitmq-server-generic-unix-3.6.10.tar.xz
移動位置
mv rabbitmq_server-3.6.10/ /usr/local/rabbitmq-3.6.10/ cd rabbitmq-3.6.10/sbin
啓動rabbitmq
./rabbitmq-plugins enabler abbitmq_management ./rabbitmq-server -detached後臺啓動
中止
./rabbitmqctl stop
查看程序和端口運行狀態
ps aux |grep rabbitmq netstat -anpt |grep 15672
添加帳戶並設置爲管理員
./rabbitmqctl add_user admin password ./rabbitmq set_tagsadmin administrator
刪除默認用戶guest
./rabbitmqctl delete_user guest
查看設置用戶是否存在
./rabbitmqctl list_users
2、測試集羣
在界面打開瀏覽器測試訪問192.168.23.20以下
期間不斷的刷新會出現不一樣的後端web頁面。
關閉master測試訪問正常backup接替工做
systemctl stop keepalived