LVS+Keepalived负载均衡配置部署

骑猪看日落 2022-07-19 00:26 147阅读 0赞

**一、准备工作**  
1. 服务器、操作系统`（当前CentOS6.6 x86_64）`、网络环境`（服务期间网络互通）` ；

# 操作系统：CentOS6.6 x86_64
    # 服务器 （LVS主备各1台，WEB服务器3台，图片服务器2台）
    WEBServer负载虚拟IP：192.168.0.20
    IMGServer负载虚拟IP：192.168.0.30
    LVS主：192.168.0.11
    LVS备：192.168.0.12
    WebServer1： 192.168.0.21
    WebServer2： 192.168.0.22
    WebServer3： 192.168.0.23
    IMGServer1： 192.168.0.31
    IMGServer2： 192.168.0.32

2. 关闭SELinux`(改完需重启服务器)`；

# 关闭SELinux
    sed -i 's#^SELINUX=.*#SELINUX=disabled#' /etc/sysconfig/selinux   
    # 重启服务器
    reboot

3. Iptables开启需要端口，如80；

# Iptables 开启相应端口
    iptables -A INPUT -p tcp -s 0/0 --dport 80 -j ACCEPT   
    iptables -A OUTPUT  -p tcp --sport 80 -m state --state ESTABLISHED -j ACCEPT

**二、LVS主机安装Keepalived，ipvsadm**  
1. 安装依赖包

yum -y install wget popt popt-devel popt-static libnl libnl-devel kernel-devel;  
    ln -s /usr/src/kernels/$(uname -r)/ /usr/src/linux;

2. 安装 Keepalived，ipvsadm（YUM安装或TarBall安装）

# YUM安装 Keepalived，ipvsadm
    yum -y install  keepalived ipvsadm;
    
    # TarBall安装Keepalived
    wget http://www.keepalived.org/software/keepalived-1.2.15.tar.gz;
    tar xvf keepalived-1.2.15.tar.gz -C /usr/local/src/;
    cd /usr/local/src/keepalived-1.2.15/;
    ./configure \
    --bindir=/usr/bin \
    --sbindir=/usr/sbin \
    --sysconf=/etc \
    --with-kernel-dir=/usr/src/kernels/$(uname -r)/;
    make;
    make install;
    # TarBall安装ipvsadm
    wget http://www.linuxvirtualserver.org/software/kernel-2.6/ipvsadm-1.26.tar.gz;  
    tar xvf ipvsadm-1.26.tar.gz -C /usr/local/src/;
    cd /usr/local/src/ipvsadm-1.26/;
    make;
    make install;

3. 创建ipvsadm配置文件，启动并加入开机启动

/etc/init.d/ipvsadm save;  
    /etc/init.d/ipvsadm start;
    chkconfig ipvsadm on;

4. 配置并启动keepalived

# 备份keepalived配置文件
    cd /etc/keepalived/;
    [ -f "keepalived.conf" -a ! -f "keepalived.conf.default" ] && mv /etc/keepalived/keepalived.conf /etc/keepalived/keepalived.conf.default;
    [ -f "keepalived.conf" ] && mv keepalived.conf keepalived.conf.$(date +%F_%T);
    
    # 创建 Keepalived 配置文件（需先修改 virtual_ipaddress，virtual_server，real_server 配置的IP）
    cat >> /etc/keepalived/keepalived.conf <<KEEPALIVED
    ! Configuration File for keepalived
    
    global_defs {
        
        notification_email {
        
            mr@mruse.cn
        }
        notification_email_from xxx@163.com
        smtp_server smtp@163.com
        smtp_connect_timeout 30
        router_id LVS_1
    }
    
    vrrp_instance VI_1 {
        
        state MASTER
        interface eth0
        virtual_router_id 60
        priority 100
        advert_int 1
        authentication {
        
            auth_type PASS
            auth_pass MrUse
        }
        virtual_ipaddress {
        
            192.168.0.20
            192.168.0.30
        }
    }
    
    virtual_server 192.168.0.21 80 {
        
        delay_loop 3
        lb_algo rr
        lb_kind DR
        persistence_timeout 3
        protocol TCP
    
        real_server 192.168.0.22 80 {
        
            weight 3
            TCP_CHECK {
        
                connect_timeout 10
                nb_get_retry 3
                delay_before_retry 3
                connect_port 80
            }
        }
    
        real_server 192.168.0.23 80 {
        
            weight 3
            TCP_CHECK {
        
                connect_timeout 10
                nb_get_retry 3
                delay_before_retry 3
                connect_port 80
            }
        }
    }
    
    virtual_server 172.16.100.130 80 {
        
        delay_loop 3
        lb_algo rr
        lb_kind DR
        persistence_timeout 3
        protocol TCP
    
        real_server 192.168.0.31 80 {
        
            weight 3
            TCP_CHECK {
        
                connect_timeout 10
                nb_get_retry 3
                delay_before_retry 3
                connect_port 80
            }
        }
    
        real_server 192.168.0.32 80 {
        
            weight 3
            TCP_CHECK {
        
                connect_timeout 10
                nb_get_retry 3
                delay_before_retry 3
                connect_port 80
            }
        }
    }
    KEEPALIVED
    
    # 启动Keepalived并加入开机启动
    /etc/init.d/keepalived restart;
    chkconfig keepalived on;

5. 记录Keepalived日志

# 注释Keepalived默认配置
    grep ^KEEPALIVED_OPTIONS /etc/sysconfig/keepalived && sed -i 's#^KEEPALIVED_OPTIONS#\#KEEPALIVED_OPTIONS#g' /etc/sysconfig/keepalived;
    
    # 更新keepalived配置
    echo 'KEEPALIVED_OPTIONS="-D -d -S 0"' >> /etc/sysconfig/keepalived;
    /etc/init.d/keepalived restart
    grep "# CmsTop Keepalived" /etc/rsyslog.conf||cat >> /etc/rsyslog.conf <<SYSLOG
    # CmsTop Keepalived $(date +%F)
    # keepalived -D -d -S 0
    local0.*                    /var/log/keepalived.log
    SYSLOG
    /etc/init.d/rsyslog restart

6. 为真实服务器 WebServer, IMGServe创建配置启动脚本（需修改IP地址）

[ -f "/etc/init.d/lvsr" ] && mv /etc/init.d/lvsr /etc/init.d/lvsr.$(date +%F_%T)
    cat >> /etc/init.d/lvsr <<LVSR
    #!/bin/bash
    
    SNS_VIP=172.16.100.120
    
    /etc/rc.d/init.d/functions
    
    start()
    {
        
        /sbin/ifconfig lo:0 \$SNS_VIP netmask 255.255.255.255 broadcast \$SNS_VIP up
        /sbin/route add -host \$SNS_VIP dev lo:0
        echo "1" >/proc/sys/net/ipv4/conf/lo/arp_ignore
        echo "2" >/proc/sys/net/ipv4/conf/lo/arp_announce
        echo "1" >/proc/sys/net/ipv4/conf/all/arp_ignore
        echo "2" >/proc/sys/net/ipv4/conf/all/arp_announce
        sysctl -p >/dev/null 2>&1
        echo "LVS RealServer Start OK"
    }
    stop()
    {
        
        /sbin/ifconfig lo:0 down
        /sbin/route del \$SNS_VIP >/dev/null 2>&1
        echo "0" >/proc/sys/net/ipv4/conf/lo/arp_ignore
        echo "0" >/proc/sys/net/ipv4/conf/lo/arp_announce
        echo "0" >/proc/sys/net/ipv4/conf/all/arp_ignore
        echo "0" >/proc/sys/net/ipv4/conf/all/arp_announce
        echo "LVS RealServer Stoped"
    }
    
    case "\$1" in
        start)
            start;
        ;;
        stop)
            stop;
        ;;
        restart)
            stop;
            start;
        ;;
        status)
            /sbin/ifconfig|tail -5
        ;;
        *)
            echo "Usage: \$0 {start|stop|restart|status}"
            exit 1
    esac
    
    exit 0
    LVSR
    
    # 修改依赖文件及启动脚本权限并启动
    chmod +x /etc/init.d/lvsr;
    chmod +x /etc/rc.d/init.d/functions;
    /etc/init.d/lvsr start
    
    # 加入开机启动
    grep ^/etc/init.d/lvsr /etc/rc.local || echo '/etc/init.d/lvsr start' >> /etc/rc.local

**三、查看状态、测试排错**  
1. 重启Keepalived，在LVS服务器上查看状态

/etc/init.d/keepalived restart;
    /etc/init.d/ipvsadm status;

2. 测试排查思路

# 查看配置文件，查看ip
    # 查看Iptables是否开启相应端口
    # 查看网络，服务器间及与虚拟IP是否可以通信
    # 查看Keepalived，ipvsadm是否正常启动
    # 查看错误日志