Linux下安装lvs和keeplived实现负载均衡

前言

在生产工作中，后端服务器并不可能永远都处于正常运行状态，若服务器发生宕机，为了不影响正在进行的业务以及给用户更好的体验，我们可以通过keepalived监控后台服务器运行情况，当有服务器发生故障时，会从把该服务器剔除出LVS转发策略；等到服务器恢复正常后，keepalived也会重新把该服务器加入LVS转发策略中。

<code class="javascript">虚拟VIP：192.168.1.231​ip地址：192.168.1.244  【mac地址：00:16:3E:98:07:E8 ，以下简称D1】​ip地址：192.168.1.233  【mac地址：00:16:3E:3B:60:AA，以下简称D1】​系统： centos6</code>

<code class="javascript">D1,D2服务器都要安装keepalivedcd /data/software/rz 上传文件keepalived-1.2.13.tar.gz# tar -zvxf keepalived-1.2.13.tar.gz # cd keepalived-1.2.13# ./configure --sysconf=/data/conf/ --prefix=/data/apps/keepalived/ ​\# 如果报错!!! ​OpenSSL is not properly installed on your system. !!! ​则执行： ​# yum -y install openssl-devel</code>

<code class="javascript">makemake install​安装完成ln -s /data/apps/keepalived/sbin/keepalived /sbin/keepalivedcp /home/data/conf/rc.d/init.d/keepalived  /etc/rc.d/init.d/cp /home/data/conf/sysconfig/keepalived /etc/sysconfig/mkdir /etc/keepalivedcp /home/data/conf/keepalived/keepalived.conf /data/conf/ln -s /data/conf/keepalived.conf  /etc/keepalived/keepalived.confrm -rf  /data/conf/keepalived /data/conf/rc.d /data/conf/sysconfig          echo "1" >/proc/sys/net/ipv4/ip_forward             # 开启路由功能</code>

D1,D2服务器都要安装

检查kernel是否已经支持LVS的IPVS模块

<code class="javascript">modprobe -l | grep ipvs</code>

如果有类似上面的输出则说明内核已经支持

安装ipvs

<code class="javascript">yum -y install ipvsadm​ipvsadm --help  (看到参数信息则说明安装成功)</code>

<code class="javascript">iptables -F -t mangle       # 清空mangle中的规则​iptables -t mangle -I PREROUTING -d 192.168.1.231 -p tcp -m tcp --dport 80 -m mac ! --mac-source 00:16:3E:3B:60:AA -j MARK --set-mark 1 【192.168.1.244服务器配置】​iptables -t mangle -I PREROUTING -d 192.168.1.231 -p tcp -m tcp --dport 80 -m mac ! --mac-source 00:16:3E:98:07:E8 -j MARK --set-mark 1 【192.168.1.233服务器配置】​ ​\# 目标ip地址是192.168.1.231并且目标端口为80的数据标记为1（排除另外一台lvs调度器 所以是排除另外一台调度器的mac地址 两台lvs的set-mark 值不同 并且规则中都排除对端的mac地址）​service iptables save</code>

<code class="javascript">vi /etc/keepalived/keepalived.conf ​修改配置信息参考：​192.168.1.244的配置：​! Configuration File for keepalived​global_defs {    notification_email {        linmaogan@gmail.com # 故障通知邮件地址，可以多个地址        liuxing007xing@163.com    }    notification_email_from linmaogan@163.com # 故障发送人    smtp_server smtp.163.com # 由163.com发送邮件    smtp_connect_timeout 30​    #运行Keepalived服务器的一个标识    #发邮件时显示在邮件标题中的信息    router_id LVS_BACKUP  #BACKUP上修改为LVS_BACKUP，网上资料说这个值也需要修改，具体不详，之前我们线上的主备就一直是一样的 ^ ^还是修改一下吧！}​# 监测ipvsadm进程状态，每3秒执行一次vrrp_script chk_ipvsadm{    script "/data/conf/shell/chk_ipvsadm.sh"    interval 3    weight 3}​vrrp_instance VI_1 {    state MASTER    interface em1       【修改对应的网卡或eth0】    virtual_router_id 51    priority 100    advert_int 1    authentication {        auth_type PASS        auth_pass PZFKD2wSUJ3swnPN    }    virtual_ipaddress {        192.168.1.231    }}​virtual_server fwmark 80 {    delay_loop 6    lb_algo wlc    lb_kind DR    persistence_timeout 1    nat_mask 255.255.255.0   #网络掩码    persistence_timeout 50     protocol TCP    real_server 192.168.1.244 80 {        weight 5        TCP_CHECK {            connect_timeout 3            nb_get_retry 3            delay_before_retry 3            connect_port 80                #健康检查端口连接端口        }    }    real_server 192.168.1.233 80 {        weight 5        TCP_CHECK {            connect_timeout 3            nb_get_retry 3            delay_before_retry 3            connect_port 80                #健康检查端口连接端口        }    }}</code>

192.168.1.233的配置：

<code class="javascript">! Configuration File for keepalived​global_defs {    notification_email {        linmaogan@gmail.com # 故障通知邮件地址，可以多个地址        liuxing007xing@163.com    }    notification_email_from linmaogan@163.com # 故障发送人    smtp_server smtp.163.com # 由163.com发送邮件    smtp_connect_timeout 30​    #运行Keepalived服务器的一个标识    #发邮件时显示在邮件标题中的信息    router_id LVS_BACKUP  #BACKUP上修改为LVS_BACKUP，网上资料说这个值也需要修改，具体不详，之前我们线上的主备就一直是一样的 ^ ^还是修改一下吧！}​# 监测ipvsadm进程状态，每3秒执行一次vrrp_script chk_ipvsadm{    script "/data/conf/shell/chk_ipvsadm.sh"    interval 3    weight 3}​vrrp_instance VI_1 {    state BACKUP    interface em1           【修改对应的网卡或eth0】    virtual_router_id 51    priority 80    advert_int 1    authentication {        auth_type PASS        auth_pass PZFKD2wSUJ3swnPN    }    virtual_ipaddress {        192.168.1.231    }}​virtual_server fwmark 80 {    delay_loop 6    lb_algo wlc    lb_kind DR    persistence_timeout 1    nat_mask 255.255.255.0   #网络掩码    persistence_timeout 50     protocol TCP    real_server 192.168.1.244 80 {        weight 5        TCP_CHECK {            connect_timeout 3            nb_get_retry 3            delay_before_retry 3            connect_port 80                #健康检查端口连接端口        }    }    real_server 192.168.1.233 80 {        weight 5        TCP_CHECK {            connect_timeout 3            nb_get_retry 3            delay_before_retry 3            connect_port 80                #健康检查端口连接端口        }    }}</code>

D2上配值和D1基本相同只是state MASTER改成state BACKUP,priority 100 改成 priority 80

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<code class="javascript">vi /data/conf/shell/chk_ipvsadm.sh​插入配置信息#!/bin/bash# 定时查看ipvsadm是否存在，如果不存在则启动ipvsadm，# 如果启动失败，则停止keepalivedstatus=$(ps aux|grep ipvsadm | grep -v grep | grep -v bash | wc -l)if [ "${status}" = "0" ]; then    service ipvsadm start    status2=$(ps aux|grep ipvsadm | grep -v grep | grep -v bash |wc -l)    if [ "${status2}" = "0"  ]; then    /etc/init.d/keepalived stop     fifi</code>

在LVS的DR模式下，用户的访问请求到达Real Server 后，是直接返回给用户的，不再经过前端的Director Server,因此，需要在每个Real server节点上增加虚拟的VIP地址，这样数据才能直接返回给用户

<code class="javascript">chmod 777 /etc/rc.d/init.d/functions ​vi /etc/init.d/lvsrs#!/bin/bash#把以下内容保存成:lvsrs#并放置在/etc/init.d目录下#如果想启动LVS Server执行:/etc/init.d/lvsrs start#如果想停止LVS Server执行:/etc/init.d/lvsrs stopVIP=192.168.1.231  #虚拟IP，视具体情况而变. /etc/rc.d/init.d/functions   # 如果提示权限不够，那么先在命令行执行: chmod 777 /etc/rc.d/init.d/functions​case "$1" instart)    ifconfig lo:0 $VIP netmask 255.255.255.255 broadcast $VIP    /sbin/route add -host $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 "RealServer Start OK"    ;;stop)    ifconfig lo:0 down    route del $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 "RealServer Stoped"    ;;    *)    echo "Usage: $0 {start|stop}"    exit 1esacexit 0</code>

<code class="javascript">chmod 755 /etc/init.d/lvsrs​service lvsrs start</code>

以下D1,D2上都执行

1）启动lvs调度器

<code class="javascript">service keepalived start                            # 开启路由功能echo "1" >/proc/sys/net/ipv4/ip_forward</code>

2） 关闭lvs调度器

<code class="javascript">service keepalived stopecho "0" >/proc/sys/net/ipv4/ip_forward</code>

<code class="javascript">chkconfig --add keepalivedchkconfig keepalived on​vi /etc/rc.d/rc.local/etc/init.d/lvsrs start  # 添加这一行到末尾</code>

ip a 查询