系统
两台Nginx：CentOS6.5 x86_64
两台tomcat：CentOS6.5 x86_64
拓扑
机器IP |
安装软件 |
角色 |
虚拟ip |
描述 |
192.168.15.132 |
Nginx、keepalived |
Nginx主机 |
192.168.15.135 |
反向代理到tomcat1和tomcat2 |
192.168.15.133 |
Nginx、keepalived |
Nginx备机 |
主机挂了切换虚拟ip 192.168.15.135 |
反向代理到tomcat1和tomcat2 |
192.168.15.128 |
Tomcat |
Tomcat1 |
无 |
|
192.168.15.30 |
Tomcat |
Tomcat2 |
无 |
|
IP地址
nginx(主LB):192.168.15.132
nginx(备LB):192.168.15.133
VIP地址:192.168.15.135
Real1的IP:192.168.15.128
Real2的IP:192.168.15.30
一．修改启动web服务器
在192.168.15.128和192.168.15.30上分别解压修改tomcat的index页面：
vi webapps/ROOT/index.jsp
修改页面html部分
<html> <head> </head> <body> SessionID:<%=session.getId()%> <br/> SessionIP:<%=request.getServerName()%> <br/> <h1>tomcat1 page</h1> </body> </html>1. <html> 2. 3. <head> 4. 5. </head> 6. 7. 8. 9. <body> 10. 11. SessionID:<%=session.getId()%> 12. 13. <br/> 14. 15. SessionIP:<%=request.getServerName()%> 16. 17. <br/> 18. 19. <h1>tomcat1 page</h1> 20. 21. </body> 22. 23. </html>
这样可以通过访问index来判断访问是不是轮询的
二．安装配置nginx
1.安装GCC编译器等工具：
yum install -y gcc gcc-c++ autoconf automake libtool make openssl openssl-devel pcre pcre-devel
2.下载安装Nginx:
wget http://nginx.org/download/nginx-1.6.3.tar.gz
注：这里也可以下载tengine压缩包，比一般nginx多一些功能
tar -zxvf nginx-1.6.3.tar.gz
cd nginx-1.6.3/
./configure --prefix=/usr/local/nginx
--sbin-path=/usr/local/nginx/sbin/nginx
--conf-path=/usr/local/nginx/conf/nginx.conf
--pid-path=/usr/local/nginx/logs/nginx.pid \
--with-http_ssl_module \
--with-http_stub_status_module \
--with-http_gzip_static_module \
make && make install
注：查询"./configure --help"相关模块，按需求指定启用
3.配置Nginx.conf
配置文件，二个nginx负载均衡器的文件一样
user nobody; worker_processes 1; error_log /usr/local/nginx/logs/error.log notice; pid /usr/local/nginx/logs/nginx.pid; worker_rlimit_nofile 51200; events { use epoll; worker_connections 51200; } 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; server_names_hash_bucket_size 128; client_header_buffer_size 32k; large_client_header_buffers 4 32k; client_max_body_size 8m; sendfile on; tcp_nopush on; server_tokens off; keepalive_timeout 60; fastcgi_connect_timeout 300; fastcgi_send_timeout 300; fastcgi_read_timeout 300; fastcgi_buffer_size 64k; fastcgi_buffers 4 64k; fastcgi_busy_buffers_size 128k; fastcgi_temp_file_write_size 128k; gzip on; upstream backend { server 192.168.15.128; server 192.168.15.130; } server { listen 80; server_name 192.168.15.135; location / { root html; index index.php index.html index.htm; proxy_redirect off; proxy_set_header Host $host; proxy_set_header X-Real-IP $remote_addr; #后端的Web服务器可以通过X-Forwarded-For获取用户真实IP proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for; proxy_pass http://backend; } error_page 500 502 503 504 /50x.html; location = /50x.html { root html; }
location /nginx_status { stub_status on; auth_basic "NginxStatus"; auth_basic_user_file /usr/local/nginx/htpasswd; #allow 127.0.0.1; #deny all; } location ~* \.(ini|docx|txt|doc|pdf)$ { #禁止访问文档性文件 root /usr/share/nginx/html; deny all; } location ~ .*\.(gif|jpg|jpeg|png|bmp|swf|js|html|htm|css)$ { root /home/image; proxy_store on; proxy_store_access user:rw group:rw all:rw; proxy_temp_path /home/image; if ( !-e $request_filename) { proxy_pass http://backend; } } } } 这里面配置较多，其中比较有用的已经标红了，可以直接将此部分配置在默认的nginx的配置文件里面即可 |
三．安装及配置keepalived
1.安装keepalived
在两台nginx服务器张安装keepalived：
wget http://www.keepalived.org/software/keepalived-1.2.15.tar.gz
tar -zxvf keepalived-1.2.15.tar.gz
cd keepalived-1.2.15
./configure --sysconf=/etc/ --with-kernel-dir=/usr/src/kernels/2.6.32-573.8.1.el6.x86_64
make && make install
ln -s /usr/local/sbin/keepalived /sbin/
#这一步很重要，不执行ln -s会报错“Starting keepalived: /bin/bash: keepalived: command not found”
service keepalived start
上述步骤也可以直接通过yum –y install keepalived 来代替，不同安装方式而已，不是重点
二台Nginx上keepalived.conf配置文件如下，配置完成后分别service keepalived start启动｡检验keepalived配置是否成功
两台keepalived的配置如下：可以看出两者之间的区别仅仅是主备的权重不同，主为100备为66，其余一些有作用的配置已经用红色标注
主：
global_defs { notification_email { test@163.com } notification_email_from keepalived@localhost smtp_server 127.0.0.1 smtp_connect_timeout 30 router_id LVS_MASTER } vrrp_script chk_http_port { script "/usr/local/src/check_nginx_pid.sh" interval 2 #（检测脚本执行的间隔） weight 2 } vrrp_instance VI_1 { #state MASTER state BACKUP nopreempt #设置非抢占模式时，修改“state MASTER”为“state BACKUP”，添加“nopreempt“ interface bond0 virtual_router_id 51 priority 100 advert_int 1 authentication { auth_type PASS auth_pass 1111 } track_script { chk_http_port #（调用检测脚本） } virtual_ipaddress { 192.168.15.135 } } |
备：
global_defs { notification_email { test@163.com } notification_email_from keepalived@localhost smtp_server 127.0.0.1 smtp_connect_timeout 30 router_id LVS_BACKUP } vrrp_script chk_http_port { script "/usr/local/src/check_nginx_pid.sh" interval 2 #（检测脚本执行的间隔） weight 2 } vrrp_instance VI_1 { state BACKUP interface bond0 virtual_router_id 51 priority 66 advert_int 1 authentication { auth_type PASS auth_pass 1111 } track_script { chk_http_port #（调用检测脚本） } virtual_ipaddress { 192.168.15.135 } } |
以下是针对nginx状态进行检测的脚本，第一次nginx服务死掉时，会重新启动，如果Nginx服务无法正常启动，则杀掉keepalived进程
vim /usr/local/src/check_nginx_pid.sh
#!/bin/bash A=`ps -C nginx --no-header |wc -l` if [ $A -eq 0 ];then /usr/local/nginx/sbin/nginx if [ `ps -C nginx --no-header |wc -l` -eq 0 ];then killall keepalived fi fi |
Ok，开始nginx负载均衡测试，停掉其中一台的任何服务，不影响整个系统的运作｡
四．测试
依次启动两个tomcat=》启动两个nginx=》启动两个keepalived，查看主机上是否有虚拟ip 192.168.15.135
通过虚拟ip访问nignx，看页面是不是轮询两个tomcat
将主机的nginx进程kill掉，看看vip是不是切换到备机器上了
访问虚拟ip是不是还能轮询访问tomcat
