nginx+keepalived实现双主负载均衡

xuanxi

测试环境如下：
系统：Ceentos 6.4 64位
nginx服务器     no1：172.16.4.7   vip：172.16.4.55
nginx服务器     no2：172.16.4.11  vip：172.16.4.56











No1、no2双机互信
    #vim /etc/hosts
172.16.4.7  no1.test.com  no1
172.16.4.11  no2.test.com  no2




No1:
    #ssh-keygen -t rsa -P ‘’
    #ssh-copy-id -i .ssh/id_rsa.pub root@no2.test.com
No2:
    #ssh-keygen -t rsa -P ‘’
    #ssh-copy-id -i .ssh/id_rsa.pub root@no1.test.com
还要确保两个节点时间同步
一、Nginx+keepalived 安装
nginx-1.4.2.tar.gz
    #yum -y install keepalived
1、安装编译所依赖的包pcre-devel openssl-devel
    # yum -y install pcre-devel openssl-devel
2、解压并添加用户nginx，以nginx的身份运行服务
    #tar xf nginx-1.4.2.tar.gz -C /usr/local/
    #cd /usr/local/nginx-1.4.2
    # groupadd -r nginx
    # useradd -r -g nginx nginx
3、编译和安装
    # ./configure \
    --prefix=/usr \
    --sbin-path=/usr/sbin/nginx \
    --conf-path=/etc/nginx/nginx.conf \
    --error-log-path=/var/log/nginx/error.log \--http-log-path=/var/log/nginx/access.log \
    --pid-path=/var/run/nginx/nginx.pid \
    --lock-path=/var/lock/nginx.lock \
    --user=nginx \
    --group=nginx \
    --with-http_ssl_module \
    --with-http_flv_module \
    --with-http_stub_status_module \
    --with-http_gzip_static_module \
    --http-client-body-temp-path=/var/tmp/nginx/client/ \
    --http-proxy-temp-path=/var/tmp/nginx/proxy/ \
    --http-fastcgi-temp-path=/var/tmp/nginx/fcgi/ \
    --http-uwsgi-temp-path=/var/tmp/nginx/uwsgi \
    --http-scgi-temp-path=/var/tmp/nginx/scgi \
    --with-pcre
编译过程中如果提示我们还需要依赖某个包时，我们要安装对应的devel包
    # make && make install

4、为nginx提供SysV init脚本
脚本存放位置/etc/rc.d/init.d/nginx
#!/bin/sh
#
# nginx - this script starts and stops the nginx daemon
#
# chkconfig:  - 85 15
# description: Nginx is an HTTP(S) server, HTTP(S) reverse \
#        proxy and IMAP/POP3 proxy server
# processname: nginx
# config:   /etc/nginx/nginx.conf
# config:   /etc/sysconfig/nginx
# pidfile:   /var/run/nginx.pid

# Source function library.
. /etc/rc.d/init.d/functions
# Source networking configuration.
. /etc/sysconfig/network
# Check that networking is up.
[ "$NETWORKING" = "no" ] && exit 0
nginx="/usr/sbin/nginx"
prog=$(basename $nginx)
NGINX_CONF_FILE="/etc/nginx/nginx.conf"
[ -f /etc/sysconfig/nginx ] && . /etc/sysconfig/nginx
lockfile=/var/lock/subsys/nginx
make_dirs() {
  # make required directories
  user=`nginx -V 2>&1 | grep "configure arguments:" | sed 's/[^*]*--user=\([^ ]*\).*/\1/g' -`
  options=`$nginx -V 2>&1 | grep 'configure arguments:'`
  for opt in $options; do
    if [ `echo $opt | grep '.*-temp-path'` ]; then
      value=`echo $opt | cut -d "=" -f 2`
      if [ ! -d "$value" ]; then
        # echo "creating" $value
        mkdir -p $value && chown -R $user $value
      fi
    fi
  done
}

start() {
  [ -x $nginx ] || exit 5
  [ -f $NGINX_CONF_FILE ] || exit 6
  make_dirs
  echo -n $"Starting $prog: "
  daemon $nginx -c $NGINX_CONF_FILE
  retval=$?
  echo
  [ $retval -eq 0 ] && touch $lockfile
  return $retval
}

stop() {
  echo -n $"Stopping $prog: "
  killproc $prog -QUIT
  retval=$?
  echo
  [ $retval -eq 0 ] && rm -f $lockfile
  return $retval
}
restart() {
  configtest || return $?
  stop
  sleep 1
  start
}
reload() {
  configtest || return $?
  echo -n $"Reloading $prog: "
  killproc $nginx -HUP
  RETVAL=$?
  echo
}
force_reload() {
  restart
}
configtest() {
$nginx -t -c $NGINX_CONF_FILE
}
rh_status() {
  status $prog
}
rh_status_q() {
  rh_status >/dev/null 2>&1
}
case "$1" in
  start)
    rh_status_q && exit 0
    $1
    ;;
  stop)
    rh_status_q || exit 0
    $1
    ;;
  restart|configtest)
    $1
    ;;
  reload)
    rh_status_q || exit 7
    $1
    ;;
  force-reload)
    force_reload
    ;;
  status)
    rh_status
    ;;
  condrestart|try-restart)
    rh_status_q || exit 0
      ;;
  *)
    echo $"Usage: $0 {start|stop|status|restart|condrestart|try-restart|reload|force-reload|configtest}"
    exit 2
esac

而后为此脚本赋予执行权限：
    # chmod +x /etc/rc.d/init.d/nginx

添加至服务管理列表，并让其开机自动启动：
    # chkconfig --add nginx
    # chkconfig nginx on

而后就可以启动服务并测试了：
    # service nginx start

二、no1 配置
    # mkdir -p /web/htdocs
    # echo "172.16.4.7" > /web/htdocs/index.html
    #vim /etc/nginx/nginx.conf
server {
    listen    80;
    server_name localhost;

    location / {
      root  /web/htdocs;
      index index.html index.htm;
    }
配置完成后重新加载服务
    #service nginx reload

测试使用curl命令请求或在浏览器访问
    # curl 172.16.4.7
172.16.4.7

三、no1的Keepalived配置
    # vim /etc/keepalived/keepalived.conf

! Configuration File for keepalived
global_defs {
  notification_email {
    root@localhost
  }
  notification_email_from keepadmin@localhost
  smtp_server 127.0.0.1
  smtp_connect_timeout 30
  router_id LVS_DEVEL
}
vrrp_script chk_nginx {
script "killall -0 nginx"
interval 2
weight -2
}

vrrp_instance VI_1 {
  state MASTER
  interface eth0
  virtual_router_id 55
  priority 100
  advert_int 1
  authentication {
    auth_type PASS
    auth_pass 1111
  }
  virtual_ipaddress {
    172.16.4.55
}
track_script {
chk_nginx
}

}
vrrp_instance VI_2 {
  state BACKUP
  interface eth0
  virtual_router_id 56
  priority 99
  advert_int 1
  authentication {
    auth_type PASS
    auth_pass 1111
  }
  virtual_ipaddress {
    172.16.4.56
}
track_script {
chk_nginx
}

}

四、no2的nginx配置以及keepalived配置
可以将no1的配置发送到no2上
    #cd /etc/keepalived
    #scp keepalived.conf no2:/etc/keepalived/
然后在其keepalived配置中修改下面选项：
vrrp_instance VI_1 {
  state BACKUP
  interface eth0
  virtual_router_id 55
  priority 99
  advert_int 1
  authentication {
    auth_type PASS
    auth_pass 1111
  }
  virtual_ipaddress {
    172.16.4.55
}
track_script {
chk_nginx
}

}
vrrp_instance VI_2 {
  state MASTER
  interface eth0
  virtual_router_id 56
  priority100
  advert_int 1
  authentication {
    auth_type PASS
    auth_pass 1111
  }
  virtual_ipaddress {
    172.16.4.56
}
track_script {
chk_nginx
}

}

五、测试
分别在2台nginx上重启启动nginx和keepalived服务，然后停掉其中一台的服务，查看资源能否转移到另一台nginx上,
查看方式：
    #ip addr show
    #ip a
查看no1：
        

查看no2：
        

将no1节点服务停掉，然后查看资源转移情况

再将no1的服务开启查看资源转移
        

    #tail /var/log/messages
    #tail -f /var/log/messages  #实时查看，不会退出日志
或者在浏览器访问我们定义的vip查看，这里我们就不演示了