摘要：前提配置環(huán)境變量準(zhǔn)備服務(wù)器或者虛擬機(jī)，以及環(huán)境，這個(gè)是必須的前提啊，我相信你可以的。關(guān)掉主機(jī)，主機(jī)監(jiān)控到無(wú)后，自動(dòng)切換

準(zhǔn)備centos服務(wù)器或者虛擬機(jī)，以及JAVA環(huán)境，這個(gè)是必須的前提啊，我相信你可以的。

# 下載
curl "http://mirror.bit.edu.cn/apache/tomcat/tomcat-8/v8.5.31/bin/apache-tomcat-8.5.31.tar.gz" -o apache-tomcat-8.5.31.tar.gz

# 解壓
tar -xvf apache-tomcat-8.5.31.tar.gz 

# 啟動(dòng)
./apache-tomcat-8.5.31/bin/startup.sh

curl "http://nginx.org/download/nginx-1.14.0.tar.gz" -o nginx-1.14.0.tar.gz
tar -xvf nginx-1.14.0.tar.gz

curl "http://www.zlib.net/zlib-1.2.11.tar.gz" -o zlib-1.2.11.tar.gz
tar -xvf zlib-1.2.11.tar.gz

curl "https://jaist.dl.sourceforge.net/project/pcre/pcre/8.41/pcre-8.41.tar.gz" -o pcre-8.41.tar.gz
tar -xvf pcre-8.41.tar.gz

curl "https://www.openssl.org/source/openssl-1.0.2o.tar.gz" -o openssl-1.0.2o.tar.gz
tar -xvf openssl-1.0.2o.tar.gz

cd nginx-1.14.0

./configure  --prefix=/usr/local/nginx --with-http_ssl_module --with-pcre=../pcre-8.41 --with-zlib=../zlib-1.2.11 --with-openssl=../openssl-1.0.2o

make 

make install

如果有異常：./configure: error: C compiler cc is not found，則安裝gcc等軟件

yum -y install gcc gcc-c++ autoconf automake make

# 最精簡(jiǎn)的nginx負(fù)載均衡配置，僅15行配置
events {
    # 并發(fā)連接數(shù)
    worker_connections  1024;
}
http {
    # Tomcat服務(wù)器集群
    upstream tomcat_servers {
        server 192.168.100.1:8081;
        server 192.168.100.1:8080;
    }
    server {
        # 監(jiān)聽(tīng)80端口
        listen    80;
        
        # 將所有請(qǐng)求交給Tomcat集群去處理
        location / {
            proxy_pass http://tomcat_servers;
        }
    }
}

# 執(zhí)行命令 /usr/local/nginx/sbin/nginx 就可以啟動(dòng)啦

接下來(lái)就是通過(guò)keepalived實(shí)現(xiàn)nginx的高可用了

這是我在學(xué)習(xí)下面這些高并發(fā)分布式技術(shù)時(shí)的筆記，不知道怎么發(fā)附件，需要配置文件的話我后續(xù)補(bǔ)上，或者你可以私信我。

yum -y install openssl-devel 
yum -y install libnl libnl-devel
yum install -y libnfnetlink-devel

# 下載
curl "http://www.keepalived.org/software/keepalived-1.4.4.tar.gz" -o keepalived-1.4.4.tar.gz
tar -xvf keepalived-1.4.4.tar.gz

cd keepalived-1.4.4  

# 安裝到/usr/local/keepalived目錄
./configure --prefix=/usr/local/keepalived --sysconf=/etc  
make && make install

配置放在/etc/keepalived/，三份配置文件（一個(gè)nginx_monitor監(jiān)控腳本，主備各一份keepalived配置）

# 創(chuàng)建nginx monitor 腳本，并賦予可執(zhí)行權(quán)限
chmod +x /etc/keepalived/nginx_monitor.sh
# 測(cè)試一下腳本能不能執(zhí)行
執(zhí)行命令：/etc/keepalived/nginx_monitor.sh 
沒(méi)報(bào)錯(cuò)即表示為成功

#  - master主機(jī)
keepalived-nginx-master.conf
#  - backup備機(jī)
keepalived-nginx-backup.conf

# 啟動(dòng)master主機(jī)
/usr/local/keepalived/sbin/keepalived -f /etc/keepalived/keepalived-nginx-master.conf
# 啟動(dòng)backup備機(jī)
/usr/local/keepalived/sbin/keepalived -f /etc/keepalived/keepalived-nginx-backup.conf

ps -ef | grep keepalived
kill -9  關(guān)閉相關(guān)的進(jìn)程

1. 關(guān)掉備機(jī)，功能完全不受影響。
2. 關(guān)掉主機(jī)，虛擬IP漂移到備機(jī)，備機(jī)開(kāi)始工作。
3. 關(guān)掉主機(jī)nginx，主機(jī)監(jiān)控到無(wú)nginx后，自動(dòng)切換