CentOS7下搭建Nginx实现负载均衡
基本前提条件：安装好jdk，配置JAVA_HOME，CentOS7下再安装了gcc之后便可安装Nginx了。过程非常简单。
下面记录开始：
1.创建目录nginx，将nginx安装包上传至该文件夹
mkdir /usr/local/nginx2.解压安装包
tar -zxvf nginx-1.12.2.tar.gz3.进入解压后的安装包中运行configure命令(该命令后面可以指定参数，详见 --help)
cd /usr/local/nginx/nginx-1.12.2/
./configure4.默认不指定参数的话在/usr/local/nginx/目录下生成如下目录结构
5.在nginx目录下即可启动nginx
./sbin/nginx6.在防火墙关闭的情况下，windows访问虚拟机即可看到nginx启动成功页面
systemctl stop firewalld.service #停止firewall
systemctl disable firewalld.service #禁止firewall开机启动
下面再在CentOS7中装两个或者两个以上的tomcat（我这里装了4个），修改tomcat解压目录下的server.xml中的3个端口号，保证不冲突就行 apache-tomcat-7.0.81.tar.gz
启动4个tomcat，脚本如下：
startAll.sh
/usr/local/tomcat/tomcat01/apache-tomcat-7.0.81/bin/startup.sh
/usr/local/tomcat/tomcat02/apache-tomcat-7.0.81/bin/startup.sh
/usr/local/tomcat/tomcat03/apache-tomcat-7.0.81/bin/startup.sh
/usr/local/tomcat/tomcat04/apache-tomcat-7.0.81/bin/startup.sh再编辑nginx的配置文件(本例中配置文件在 /usr/local/nginx/conf/ 下)
vi /usr/local/nginx/conf/nginx.conf也用ssh工具编辑器编辑，内容如下：
#user nobody;
worker_processes 1;
#error_log logs/error.log;
#error_log logs/error.log notice;
#error_log logs/error.log info;
#pid logs/nginx.pid;
events {
worker_connections 1024;
}
http {
include mime.types;
default_type application/octet-stream;
#log_format main '$remote_addr - $remote_user [$time_local] "$request" '
# '$status $body_bytes_sent "$http_referer" '
# '"$http_user_agent" "$http_x_forwarded_for"';
#access_log logs/access.log main;
sendfile on;
#tcp_nopush on;
#keepalive_timeout 0;
keepalive_timeout 65;
#gzip on;
#server {
# listen 80;
# server_name localhost;
# #charset koi8-r;
# #access_log logs/host.access.log main;
# location / {
# root html;
# index index.html index.htm;
# }
#error_page 404 /404.html;
# redirect server error pages to the static page /50x.html
#
# error_page 500 502 503 504 /50x.html;
# location = /50x.html {
# root html;
# }
# proxy the PHP scripts to Apache listening on 127.0.0.1:80
#
#location ~ \.php$ {
# proxy_pass http://127.0.0.1;
#}
# pass the PHP scripts to FastCGI server listening on 127.0.0.1:9000
#
#location ~ \.php$ {
# root html;
# fastcgi_pass 127.0.0.1:9000;
# fastcgi_index index.php;
# fastcgi_param SCRIPT_FILENAME /scripts$fastcgi_script_name;
# include fastcgi_params;
#}
# deny access to .htaccess files, if Apache's document root
# concurs with nginx's one
#
#location ~ /\.ht {
# deny all;
#}
#}
server {
listen 80;
server_name 192.168.56.101;
location / {
root html;
index index.html index.htm;
}
error_page 404 /404.html;
error_page 500 502 503 504 /50x.html;
location = /50x.html {
root html;
}
}
server {
listen 9090; #通过端口号来区分
server_name 192.168.56.101;
location / {
root /web1;
index index.html index.htm;
}
error_page 404 /404.html;
error_page 500 502 503 504 /50x.html;
location = /50x.html {
root html;
}
}
server {
listen 9091; #通过端口号来区分
server_name 192.168.56.101;
location / {
root /web2;
index index.html index.htm;
}
error_page 404 /404.html;
location = /50x.html {
root html;
}
}
server {
listen 6060;
server_name www.web1.com; #通过域名来区分
location / {
root /web1;
index index.html index.htm;
}
error_page 404 /404.html;
error_page 500 502 503 504 /50x.html;
location = /50x.html {
root html;
}
}
server {
listen 6060;
server_name www.web2.com; #通过域名来区分
location / {
root /web2;
index index.html index.htm;
}
error_page 404 /404.html;
location = /50x.html {
root html;
}
}
#设置轮询或者权重来访问服务器
upstream tomcat01{
server 192.168.56.101:8080 weight=2; #权重默认都是1（默认状态是轮询）
server 192.168.56.101:8082 weight=2;
server 192.168.56.101:8083 weight=5;
}
upstream tomcat02{
server 192.168.56.101:8081 weight=2;
server 192.168.56.101:8082 weight=2;
server 192.168.56.101:8083 weight=5;
}
server {
listen 80;
server_name www.web1.com;
location / {
proxy_pass http://tomcat01;
index index.html index.htm;
}
error_page 404 /404.html;
error_page 500 502 503 504 /50x.html;
location = /50x.html {
root html;
}
}
server {
listen 80;
server_name www.web2.com;
location / {
proxy_pass http://tomcat02;
index index.html index.htm;
}
error_page 404 /404.html;
error_page 500 502 503 504 /50x.html;
location = /50x.html {
root html;
}
}
# another virtual host using mix of IP-, name-, and port-based configuration
#
#server {
# listen 8080;
# server_name localhost;
# location / {
# root /web1;
# index index.html index.htm;
# }
#}
#server {
# listen 8080;
# server_name localhost;
# location / {
# root /web2;
# index index.html index.htm;
# }
#}
# HTTPS server
#
#server {
# listen 443 ssl;
# server_name localhost;
# ssl_certificate cert.pem;
# ssl_certificate_key cert.key;
# ssl_session_cache shared:SSL:1m;
# ssl_session_timeout 5m;
# ssl_ciphers HIGH:!aNULL:!MD5;
# ssl_prefer_server_ciphers on;
# location / {
# root html;
# index index.html index.htm;
# }
#}
}
具体参数含义可自行百度
然后可以在不停nginx的情况下重新加载配置文件
/usr/local/nginx/sbin/nginx -s reload然后创建目录和文件来测试
[root@centos7-vm nginx]# mkdir /web1
[root@centos7-vm nginx]# mkdir /web2
[root@centos7-vm nginx]# echo "192.168.56.101--web1" > /web1/index.html
[root@centos7-vm nginx]# echo "192.168.56.101--web2" > /web2/index.html在windows下分别访问9090和9091端口
在windows的hosts文件中新增
192.168.56.101 www.web1.com
192.168.56.101 www.web2.com再访问www.web1.com
8082
8080
8083
访问www.web2.com，一样交替访问配置文件中配置的3个不同的server。
到此，安装nginx实现负载均衡的实例已完成。