Nginx+Keepalived 负载均衡环境：
两台负载均衡服务器
nginx proxy 10.0.0.5 (keepalived +nginxproxy1)
nginx proxy 10.0.0.6 (keepalived +nginxproxy2)
两台后端RS服务器
RS1 10.0.0.3 nginx
RS2 10.0.0.4 nginx
下面nginx和keepalived都要在两台负载均衡服务器中安装
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1、安装nginx
#1.安装nginx依赖库
yum install openssl openssl-devel -y
yum install pcre-devel -y
#2.创建nginx用户：
useradd -s /sbin/nologin nginx
tail -1 /etc/passwd
#3 安装nginx
mkdir -p /home/lvnian/tools
cd /home/lvnian/tools
wget http://nginx.org/download/nginx-1.6.2.tar.gz
tar zxf nginx-1.6.2.tar.gz
cd nginx-1.6.2
./configure \
--user=nginx \
--group=nginx \
--prefix=/application/nginx-1.6.2 \
--with-http_stub_status_module \
--with-http_ssl_module \
--with-http_realip_module
make && make install
#4.制作软连接：
ln -s /application/nginx-1.6.2 /application/nginx
ll /application
#5 启动nginx
#/application/nginx/sbin/nginx -t
/application/nginx/sbin/nginx #（不用接参数，就是启动nginx）
######安装完成nginx
netstat -lnt |grep 80
ps -ef |grep nginx |grep -v grep
lsof -i :80
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2、安装keepalived
1.做相关内核软连接
安装keepalived之前要先做软连接
ls /usr/src/kernels/`uname -r` -ld
ln -s /usr/src/kernels/`uname -r` /usr/src/linux
ls /usr/src/ -l
2.下载并安装keepalived软件
[ ! -d /home/lvnian/tools ] && mkdir /home/lvnian/tools -p
cd /home/lvnian/tools
wget http://www.keepalived.org/software/keepalived-1.2.10.tar.gz
tar xf keepalived-1.2.10.tar.gz
cd keepalived-1.2.10
./configure
make && make install
3.配置启动规范
/bin/cp /usr/local/etc/rc.d/init.d/keepalived /etc/init.d/
/bin/cp /usr/local/etc/sysconfig/keepalived /etc/sysconfig/
mkdir /etc/keepalived
/bin/cp /usr/local/etc/keepalived/keepalived.conf /etc/keepalived/
/bin/cp /usr/local/sbin/keepalived /usr/sbin/
/etc/init.d/keepalived start
ps -ef |grep keepalived
安装完成keepalived服务
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3、配置Keepalived 服务
MASTER:
[root@KEEP1 keepalived]# cat keepalived.conf
! Configuration File for keepalived
global_defs {
notification_email {
759685538@qq.com
}
notification_email_from Alexandre.Cassen@firewall.loc
smtp_server 127.0.0.1
smtp_connect_timeout 30
router_id LVS_1
}
vrrp_instance VI_1 {
state MASTER
interface eth0
virtual_router_id 55
priority 150
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
10.0.0.100/24
}
}
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BACKUP:
[root@KEEP2 keepalived]# cat keepalived.conf
! Configuration File for keepalived
global_defs {
notification_email {
759685538@qq.com
}
notification_email_from Alexandre.Cassen@firewall.loc
smtp_server 127.0.0.1
smtp_connect_timeout 30
router_id LVS_2
}
vrrp_instance VI_1 {
state BACKUP
interface eth0
virtual_router_id 55
priority 100
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
10.0.0.100/24
}
}
[root@KEEP2 keepalived]#
配置成功Keepalived的标准是VIP可以随服务器是否正常进行漂移。这里用是否启动keepalived服务进行VIP漂移
正常情况下：
停止KEEP1
[root@KEEP1 ~]# /etc/init.d/keepalived stop
Stopping keepalived: [ OK ]
[root@KEEP1 ~]#
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4、配置nginx负载均衡功能
下面配置文件在两个负载均衡服务器上面配置相同
[root@KEEP1 conf]# cat nginx.conf
worker_processes 1;
events {
worker_connections 1024;
}
http {
include mime.types;
default_type application/octet-stream;
sendfile on;
keepalive_timeout 65;
upstream web_real_server{
# ip_hash; #用ip哈希算法保持会话
server 10.0.0.3:80 max_fails=3 fail_timeout=20s;
server 10.0.0.4:80 max_fails=3 fail_timeout=20s;
}
server {
listen 80;
server_name www.lvnian.com;
location / {
index index.php index.htm index.html;
proxy_redirect off;
proxy_set_header Host $host;
proxy_set_header X-Real-IP $remote_addr;
proxy_next_upstream http_500 http_502 http_503 error timeout invalid_header;
proxy_set_header X-Forwarded-For $remote_addr;
proxy_pass http://web_real_server;
}
}
}
[root@KEEP1 conf]#
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proxy_pass http://web_real_server;
用于指定反向代理的服务器池
proxy_set_header Host $host;
当后端web服务器上也配置有多个虚拟主机时，需要用改Header来区分反向代理那个主机名
proxy_set_header X-Forwarded-For $remote_addr;
如果后端Web服务器上的程序需要获取用户IP，从该Header头中获取
proxy_next_upstream http_500 http_502 http_503 error timeout invalid_header;
这个参数是用来定义故障转移策略的，当后端服务器节点返回500/502/503和执行超时等错误时，自动将请求转到upstream负载均衡中的另外一台服务器，实现故障转移
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2、配置调试用的nginx web服务器或者Apache(RS节点)操作（（RS）nginx的安装和上面的nginx安装一样）
RS1 10.0.0.3 nginx
RS210.0.0.4nginx
RS就把web服务配置成功即可
[root@RS1 ~]# curl 10.0.0.3
10.0.0.3
[root@RS1 ~]#
[root@RS2 ~]# curl 10.0.0.4
10.0.0.4
[root@RS2 ~]#
在实际的工作场景中。RS1和RS2提供的web服务应该是一样，在这里设置成不一样，主要是为了区分客户端访问的时候，是不同的服务器在提供服务。
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测试的客户端配置hosts文件
echo "10.0.0.100 www.lvnian.com">>/etc/hosts
上面的测试说明这个实验已经实现了负载均衡的功能了
部署完成
你还可以把其中一台RS服务挂起；或者把其中一台Nginx负载均衡服务器断开；设置可以把一台nginx负载均衡服务器断开以及一台RS同时断开；服务都可以已经对外正常提供，这就是Keepalived+Nginx的高可用性。在这就不一一做实验了。
