nginx+tomcat+keepalived高可用负载均衡

前提-配置java环境变量

准备centos服务器或者虚拟机，以及JAVA环境，这个是必须的前提啊，我相信你可以的。

tomcat

下载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

• 解压tar -xvf apache-tomcat-8.5.31.tar.gz
• 启动./apache-tomcat-8.5.31/bin/startup.sh

nginx

下载及解压 相关的模块到/u01目录

• 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

编译安装nginx

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-1.0.2omake make install

如果有异常：./configure: error: C compiler cc is not found，则安装gcc等软件

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

配置并启动，最精简的nginx负载均衡配置，仅15行配置，直接覆盖conf文件夹下面的nginx.conf

nginx.conf全部内容

接下来就是通过keepalived实现nginx的高可用了

学习感言

这是我在学习下面这些高并发分布式技术时的笔记，不知道怎么发附件，需要配置文件的话我后续补上，或者你可以私信我。

高并发分布式技术学习课程

keepalived

下载安装相关相关的组件

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

下载安装keepalived

下载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
• 安装到/usr/local/keepalived目录./configure --prefix=/usr/local/keepalived --sysconf=/etc
• make && make install

配置文件存放地址

配置放在/etc/keepalived/，三份配置文件（一个nginx_monitor监控脚本，主备各一份keepalived配置）

nginx监控shell脚本 nginx_monitor.sh 文件

\创建nginx monitor 脚本，
并赋予可执行权限chmod +x /etc/keepalived/nginx_monitor.sh

• 测试一下脚本能不能执行执行命令：
  /etc/keepalived/nginx_monitor.sh 没报错即表示为成功

nginx_monitor.sh

keepalived配置（/etc/keepalived/目录下）

• master主机keepalived-nginx-master.conf
  放在备机- backup备机keepalived-nginx-backup.conf

keepalived-nginx-master.conf

keepalived-nginx-backup.conf

启动keepalived

• 启动master主机
  /usr/local/keepalived/sbin/keepalived -f /etc/keepalived/keepalived-nginx-master.conf
• 启动backup备机/usr/local/keepalived/sbin/keepalived -f /etc/keepalived/keepalived-nginx-backup.conf

停止

ps -ef | grep keepalivedkill -9 关闭相关的进程

测试高可用

1. 关掉备机，功能完全不受影响。2. 关掉主机，虚拟IP漂移到备机，备机开始工作。3. 关掉主机nginx，主机监控到无nginx后，自动切换