1) 在172.16.60.208服务器上安装LVS (安装方式如上)
[root@lvs-208 ~]# yum install -y libnl* popt*
[root@lvs-208 ~]# cd /usr/local/src/
[root@lvs-208 src]# unlink /usr/src/linux
[root@lvs-208 src]# ln -s /usr/src/kernels/2.6.32-431.5.1.el6.x86_64/ /usr/src/linux
[root@lvs-208 src]# wget
[root@lvs-208 src]# tar -zvxf ipvsadm-1.26.tar.gz
[root@lvs-208 src]# cd ipvsadm-1.26
[root@lvs-208 ipvsadm-1.26]# make && make install
[root@lvs-208 ipvsadm-1.26]# ipvsadm -Ln
IP Virtual Server version 1.2.1 (size=4096)
Prot LocalAddress:Port Scheduler Flags
-> RemoteAddress:Port Forward Weight ActiveConn InActConn
2) 在后端两个web节点(realserver)上配置vip (连个realserver节点操作一样)
[root@rs-205 ~]# vim /etc/init.d/realserver
#!/bin/sh
VIP=172.16.60.119
. /etc/rc.d/init.d/functions
case "$1" in
# 禁用本地的ARP请求、绑定本地回环地址
start)
/sbin/ifconfig lo down
/sbin/ifconfig lo up
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
/sbin/sysctl -p >/dev/null 2>&1
/sbin/ifconfig lo:0 $VIP netmask 255.255.255.255 up
/sbin/route add -host $VIP dev lo:0
echo "LVS-DR real server starts successfully.\n"
;;
stop)
/sbin/ifconfig lo:0 down
/sbin/route del $VIP >/dev/null 2>&1
echo "1" >/proc/sys/net/ipv4/conf/lo/arp_ignore
echo "2" >/proc/sys/net/ipv4/conf/lo/arp_announce
echo "1" >/proc/sys/net/ipv4/conf/all/arp_ignore
echo "2" >/proc/sys/net/ipv4/conf/all/arp_announce
echo "LVS-DR real server stopped.\n"
;;
status)
isLoOn=`/sbin/ifconfig lo:0 | grep "$VIP"`
isRoOn=`/bin/netstat -rn | grep "$VIP"`
if [ "$isLoON" == "" -a "$isRoOn" == "" ]; then
echo "LVS-DR real server has run yet."
else
echo "LVS-DR real server is running."
fi
exit 3
;;
*)
echo "Usage: $0 {start|stop|status}"
exit 1
esac
exit 0
执行脚本
[root@rs-205 ~]# chmod 755 /etc/init.d/realserver
[root@rs-205 ~]# /etc/init.d/realserver start
LVS-DR real server starts successfully.\n
[root@rs-205 ~]# ifconfig
......
lo:0 Link encap:Local Loopback
inet addr:172.16.60.119 Mask:255.255.255.255
UP LOOPBACK RUNNING MTU:65536 Metric:1
后端两个web节点的80端口为nginx, nginx安装配置这里省略
[root@rs-205 ~]# ps -ef|grep nginx
root 24154 1 0 Dec25 ? 00:00:00 nginx: master process /usr/sbin/nginx -c /etc/nginx/nginx.conf
nginx 24155 24154 0 Dec25 ? 00:00:02 nginx: worker process
root 24556 23313 0 01:14 pts/1 00:00:00 grep nginx
[root@rs-205 ~]# lsof -i:80
COMMAND PID USER FD TYPE DEVICE SIZE/OFF NODE NAME
nginx 24154 root 7u IPv4 85119 0t0 TCP *:http (LISTEN)
nginx 24155 nginx 7u IPv4 85119 0t0 TCP *:http (LISTEN)
3) 在172.16.60.208服务器上管理LVS
添加LVS集群服务, vip为172.16.60.119
接着添加后面两个realserver，指定传输模式为DR
[root@lvs-208~]# /sbin/iptables -F
[root@lvs-208~]# /sbin/iptables -Z
[root@lvs-208~]# /sbin/ipvsadm -C
[root@lvs-208~]# /sbin/ipvsadm --set 30 5 60
[root@lvs-208~]# /sbin/ifconfig eth0:0 172.16.60.119 broadcast 172.16.60.119 netmask 255.255.255.255 up
[root@lvs-208~]# /sbin/route add -host 172.16.60.119 dev eth0:0
[root@lvs-208~]# /sbin/ipvsadm -A -t 172.16.60.119:80 -s wlc -p 600
[root@lvs-208~]# /sbin/ipvsadm -a -t 172.16.60.119:80 -r 172.16.60.205:80 -g
[root@lvs-208~]# /sbin/ipvsadm -a -t 172.16.60.119:80 -r 172.16.60.206:80 -g
[root@lvs-208~]# touch /var/lock/subsys/ipvsadm >/dev/null 2>&1
[root@lvs-208~]# /sbin/arping -I eth0 -c 5 -s 172.16.60.119 172.16.60.1 >/dev/null 2>&1
查看vip
[root@lvs-208~]# ifconfig
......
eth0:0 Link encap:Ethernet HWaddr 00:50:56:AC:5B:56
inet addr:172.16.60.119 Bcast:172.16.60.119 Mask:255.255.255.255
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
查看lvs集群转发情况
[root@lvs-208~]# ipvsadm -Ln
IP Virtual Server version 1.2.1 (size=4096)
Prot LocalAddress:Port Scheduler Flags
-> RemoteAddress:Port Forward Weight ActiveConn InActConn
TCP 172.16.60.119:80 wlc persistent 600
-> 172.16.60.205:80 Route 1 0 0
-> 172.16.60.206:80 Route 1 0 10
访问, 就可以负载到两个realserver的80端口了
由于配置了持久化, 则600秒内的客户端请求将会转发到同一个realserver节点上.
如果当前请求转发到172.16.60.206节点上, 则关闭该节点的80端口, 则访问就失败了!
因为手动将该节点从lvs集群中踢出去,如下:
[root@lvs-208~]# ipvsadm -d -t 172.16.60.119:80 -r 172.16.60.206
[root@lvs-208~]# ipvsadm -Ln
IP Virtual Server version 1.2.1 (size=4096)
Prot LocalAddress:Port Scheduler Flags
-> RemoteAddress:Port Forward Weight ActiveConn InActConn
TCP 172.16.60.119:80 wlc persistent 600
-> 172.16.60.205:80 Route 1 0 0
然后访问 显示的就是172.16.60.205节点的80端口页面!
以上的LVS没有实现后端realserver节点健康检查机制, 如果要想对后端realserver节点进行健康检查,
则需要结合ldirectord软件, ldirectord配置里有参数可以实现:
realserver节点故障发生时自动踢出lvs集群;
realserver节点故障恢复后重新加入lvs集群;
======================================================
ldirectord部分的安装和配置可以参考: https://www.linuxidc.com/Linux/2019-01/156139.htm
[root@lvs-208src]# pwd
/usr/local/src
[root@lvs-208src]# ll ldirectord-3.9.5-3.1.x86_64.rpm
-rw-rw-r-- 1 root root 90140 Dec 24 15:54 ldirectord-3.9.5-3.1.x86_64.rpm
[root@lvs-208src]# yum install -y ldirectord-3.9.5-3.1.x86_64.rpm
[root@lvs-208src]# cat /etc/init.d/ldirectord |grep "config file"
# Using the config file /etc/ha.d/ldirectord.cf
# It uses the config file /etc/ha.d/ldirectord.cf.
如上查找可知, ldirectord的配置文件为/etc/ha.d/ldirectord.cf
[root@lvs-208src]# cd /usr/share/doc/ldirectord-3.9.5
[root@lvs-208ldirectord-3.9.5]# ll ldirectord.cf
-rw-r--r-- 1 root root 8301 Feb 7 2013 ldirectord.cf
[root@lvs-208ldirectord-3.9.5]# cp ldirectord.cf /etc/ha.d/
[root@lvs-208ldirectord-3.9.5]# cd /etc/ha.d/
[root@lvs-208ha.d]# ll
total 20
-rw-r--r-- 1 root root 8301 Dec 26 01:44 ldirectord.cf
drwxr-xr-x 2 root root 4096 Dec 26 01:40 resource.d
-rw-r--r-- 1 root root 2082 Mar 24 2017 shellfuncs
配置ldirectord.cf, 实现realserver节点的健康检查机制 (根据文件中的配置范例进行修改)
[root@lvs-208ha.d]# cp ldirectord.cf ldirectord.cf.bak
[root@lvs-208ha.d]# vim ldirectord.cf
checktimeout=3
checkinterval=1
autoreload=yes
logfile="/var/log/ldirectord.log"
quiescent=no #这个参数配置就实现了realserver的监控检查机制
virtual=172.16.60.119:80
real=172.16.60.205:80 gate
real=172.16.60.206:80 gate
fallback=127.0.0.1:80 gate #realserver都故障时, 转发请求到lvs本机的80端口
service=http
scheduler=rr
persistent=600
#netmask=255.255.255.255
protocol=tcp
checktype=negotiate
checkport=80
#request="index.html"
#receive="Test Page"
#virtualhost=www.x.y.z
重启ldirectord服务
[root@lvs-208ha.d]# /etc/init.d/ldirectord start
[root@lvs-208ha.d]# ps -ef|grep ldirectord
root 4399 1 0 01:48 ? 00:00:00 /usr/bin/perl -w /usr/sbin/ldirectord start
root 4428 3750 0 01:50 pts/0 00:00:00 grep ldirectord
这样, 后端的realserver就通过ldirectord配置实现了健康检查!
[root@lvs-208ha.d]# ipvsadm -Ln
IP Virtual Server version 1.2.1 (size=4096)
Prot LocalAddress:Port Scheduler Flags
-> RemoteAddress:Port Forward Weight ActiveConn InActConn
TCP 172.16.60.119:80 rr persistent 600
-> 172.16.60.205:80 Route 1 0 0
-> 172.16.60.206:80 Route 1 0 0
当172.16.60.205 和 172.16.60.206 中的任意一个节点故障时, 该节点就会自动从lvs集群中踢出来, 此时请求都转发至另一个节点上;
该故障节点恢复后, 该节点就会自动重新加入到lvs集群中; 整个过程对于前面的客户端访问来说是无感知.
如172.16.60.205节点的80端口挂了, 则lvs转发情况:
[root@lvs-208ha.d]# ipvsadm -ln
IP Virtual Server version 1.2.1 (size=4096)
Prot LocalAddress:Port Scheduler Flags
-> RemoteAddress:Port Forward Weight ActiveConn InActConn
TCP 172.16.60.119:80 rr persistent 600
-> 172.16.60.206:80 Route 1 0 0
当172.16.60.205节点的80端口恢复后, 则lvs转发情况
[root@lvs-208ha.d]# ipvsadm -Ln
IP Virtual Server version 1.2.1 (size=4096)
Prot LocalAddress:Port Scheduler Flags
-> RemoteAddress:Port Forward Weight ActiveConn InActConn
TCP 172.16.60.119:80 rr persistent 600
-> 172.16.60.205:80 Route 1 0 0
-> 172.16.60.206:80 Route 1 0 0
这就实现了realserver 层面的高可用了!!!
但是此时lvs层是单点, 如果还想实现lvs层的高可用, 就要利用keepalived 或 heartbeat了!
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