DR模式
| 角色 | IP地址 | 备注 |
| LVS负载均衡器 | 192.168.119.132 | VIP：192.168.119.150 ipvsadm |
| http_Real server | 192.168.119.134 | apache |
| http_Real server | 192.168.119.135 | apache |
1、检查两台HTTP server是否正常
web01配置[root@web01 /]# hostnameweb01[root@web01 /]# yum -y install httpd[root@web01 /]# find / -name httpd.conf/etc/httpd/conf/httpd.conf[root@web01 /]# vim /etc/httpd/conf/httpd.confServerName www.web01.com:80[root@web01 /]# cd /var/www/html/[root@web01 html]# echo "web01_192.168.119.134" > index.html[root@web01 html]# lsindex.html[root@web01 html]# cat index.html web01_192.168.119.134[root@web01 html]# /etc/init.d/httpd startStarting httpd: [ OK ][root@web01 html]# curl localhostweb01_192.168.119.134web02配置[root@web02 /]# hostnameweb02[root@web02 /]# yum -y install httpd[root@web02 /]# vim /etc/httpd/conf/httpd.confServerName www.web02.com:80[root@web02 /]# echo "web02_192.168.119.135" > /var/www/html/index.html [root@web02 /]# cat /var/www/html/index.html web02_192.168.119.135[root@web02 /]# /etc/init.d/httpd startStarting httpd: [ OK ][root@web02 /]# curl localhostweb02_192.168.119.135
2、下载软件
[root@lvs /]# hostnamelvs[root@lvs /]# uname -r2.6.32-431.el6.x86_64
这里我们使用的2.6版本，并且注意内核是2.6版本的，如果你的版本是6.X版本的话，那么可以使用2.6版本
[root@lvs /]# wget http://www.linuxvirtualserver.org/software/kernel-2.6/ipvsadm-1.26.tar.gz
3、安装需要的依赖包
[root@lvs /]# yum -y install kernel-devel gcc gcc-c++ libnl* libpopt* popt-static
4、创建一个软链接，防止后面编译安装ipvsadm时找不到系统内核
[root@lvs /]# ln -s /usr/src/kernels/2.6.32-642.4.2.el6.x86_64/ /usr/src/linux
5、编译安装
[root@lvs /]# tar zxf ipvsadm-1.26.tar.gz [root@lvs /]# cd ipvsadm-1.26[root@lvs ipvsadm-1.26]# make[root@lvs ipvsadm-1.26]# make install[root@lvs ipvsadm-1.26]# lsmod | grep ip_vs把ipvs模块加载进系统，需要我们执行ipvsadm命令才会加载进去或者modprobe ip_vs。[root@lvs ipvsadm-1.26]# modprobe ip_vs [root@lvs ipvsadm-1.26]# lsmod | grep ip_vsip_vs 125220 0 libcrc32c 1246 1 ip_vsipv6 317340 142 ip_vs,ip6t_REJECT,nf_conntrack_ipv6,nf_defrag_ipv6
6、配置lvs
- 负载均衡器上配置VIP地址
[root@lvs ipvsadm-1.26]# ifconfig eth0:0 192.168.119.150/24[root@lvs ipvsadm-1.26]# route add -host 192.168.119.150 dev eth0
- 配置LVS、添加Real server节点
[root@lvs ipvsadm-1.26]# ipvsadm --helpipvsadm v1.26 2008/5/15 (compiled with popt and IPVS v1.2.1)Usage: ipvsadm -A|E -t|u|f service-address [-s scheduler] [-p [timeout]] [-M netmask] [--pe persistence_engine] ipvsadm -D -t|u|f service-address ipvsadm -C ipvsadm -R ipvsadm -S [-n] ipvsadm -a|e -t|u|f service-address -r server-address [options] ipvsadm -d -t|u|f service-address -r server-address ipvsadm -L|l [options] ipvsadm -Z [-t|u|f service-address] ipvsadm --set tcp tcpfin udp ipvsadm --start-daemon state [--mcast-interface interface] [--syncid sid] ipvsadm --stop-daemon state ipvsadm -hCommands:Either long or short options are allowed. --add-service -A add virtual service with options --edit-service -E edit virtual service with options --delete-service -D delete virtual service --clear -C clear the whole table --restore -R restore rules from stdin --save -S save rules to stdout --add-server -a add real server with options --edit-server -e edit real server with options --delete-server -d delete real server --list -L|-l list the table --zero -Z zero counters in a service or all services --set tcp tcpfin udp set connection timeout values --start-daemon start connection sync daemon --stop-daemon stop connection sync daemon --help -h display this help messageOptions: --tcp-service -t service-address service-address is host[:port] --udp-service -u service-address service-address is host[:port] --fwmark-service -f fwmark fwmark is an integer greater than zero --ipv6 -6 fwmark entry uses IPv6 --scheduler -s scheduler one of rr|wrr|lc|wlc|lblc|lblcr|dh|sh|sed|nq, the default scheduler is wlc. --pe engine alternate persistence engine may be sip, not set by default. --persistent -p [timeout] persistent service --netmask -M netmask persistent granularity mask --real-server -r server-address server-address is host (and port) --gatewaying -g gatewaying (direct routing) (default) --ipip -i ipip encapsulation (tunneling) --masquerading -m masquerading (NAT) --weight -w weight capacity of real server --u-threshold -x uthreshold upper threshold of connections --l-threshold -y lthreshold lower threshold of connections --mcast-interface interface multicast interface for connection sync --syncid sid syncid for connection sync (default=255) --connection -c output of current IPVS connections --timeout output of timeout (tcp tcpfin udp) --daemon output of daemon information --stats output of statistics information --rate output of rate information --exact expand numbers (display exact values) --thresholds output of thresholds information --persistent-conn output of persistent connection info --nosort disable sorting output of service/server entries --sort does nothing, for backwards compatibility --ops -o one-packet scheduling --numeric -n numeric output of addresses and ports[root@lvs ipvsadm-1.26]# ipvsadm -C #清空原有配置[root@lvs ipvsadm-1.26]# ipvsadm -A -t 192.168.119.150:80 -s rr -p 20 #指定VIP[root@lvs ipvsadm-1.26]# ipvsadm -a -t 192.168.119.150:80 -r 192.168.119.134:80 -g -w 1 #rs节点[root@lvs ipvsadm-1.26]# ipvsadm -a -t 192.168.119.150:80 -r 192.168.119.135:80 -g -w 1 #rs节点[root@lvs ipvsadm-1.26]# ipvsadm -L -nIP Virtual Server version 1.2.1 (size=4096)Prot LocalAddress:Port Scheduler Flags -> RemoteAddress:Port Forward Weight ActiveConn InActConnTCP 192.168.119.150:80 rr persistent 20 -> 192.168.119.134:80 Route 10 0 0 -> 192.168.119.135:80 Route 10 0 0
7、real server节点配置
- 添加lo端口的VIP
[root@web01 /]# ifconfig lo 192.168.119.150/32 up[root@web01 /]# route add -host 192.168.119.150 dev lo
- ARP抑制
[root@web01 /]# ifconfig lo 192.168.119.150/32 up[root@web01 /]# route add -host 192.168.119.150 dev lo[root@web01 /]# echo "1">/proc/sys/net/ipv4/conf/lo/arp_ignore[root@web01 /]# echo "2">/proc/sys/net/ipv4/conf/lo/arp_announce [root@web01 /]# echo "1">/proc/sys/net/ipv4/conf/all/arp_announce[root@web01 /]# echo "2">/proc/sys/net/ipv4/conf/all/arp_announceweb02段配置[root@web02 /]# ifconfig lo 192.168.119.150/32 up[root@web02 /]# route add -host 192.168.119.150 dev lo[root@web02 /]# echo "1">/proc/sys/net/ipv4/conf/lo/arp_ignore[root@web02 /]# echo "2">/proc/sys/net/ipv4/conf/lo/arp_announce [root@web02 /]# echo "1">/proc/sys/net/ipv4/conf/all/arp_announce[root@web02 /]# echo "2">/proc/sys/net/ipv4/conf/all/arp_announce
arp抑制技术参数说明
arp_ignore
0-(默认值)：回应任何网络接口上对任何本地IP地址的ARP查询请求。
1-只回答目标IP地址是来访问网络接口笨的地址的ARP查询请求
2-只回答目标IP地址是来访问网络接口本地地址的ARP查询请求，且来访IP必须在该网络接口的子网段内。
3-不回应网络界面的ARP请求，而只对设置的唯一和连接地址做出回应。
4-7-保留未使用
8-不回应所有（本地地址）的ARP查询。
arp_announce
对网络接口上，本地IP地址的发出的，ARP回应，做出相应级别的限制：
确定不同程度的限制，宣布对来自本地源IP地址发出ARP请求的接口
0-（默认）在任意网络接口（eth0,eth1,lo）上的任何本地地址
1-尽量避免不在该网络接口子网段的本地地址做出ARP回应，当发起ARP请求的源IP地址是被设置应该经由路由达到此网络接口的时候很有用。此时会检查来访IP是否为所有接口上的子网段内IP之一。如果该来访IP不属于各个网络接口上的子网段内，那么将采用级别2的方式进行处理
2-对查询目标使用最适当的本地地址，在此模式下将忽略这个Ip数据包的源地址并尝试选择能与该地址通信的本地地址，首要是选择所有的网络接口的子网中外出访问子网中包含该目标IP地址的本地地址。如果没有合适的地址被发现，将选择当前的发送网络接口或其他的有可能接受到该ARP回应的网络接口来进行发送。限制了使用本地的VIP地址作为优先的网络接口。
8、测试
在前面加上watch可以动态的查看ipvsadm的会话分配。watch ipvsadm -L -n.
关闭所有主机的防火墙或开放相应的端口
[root@lvs ipvsadm-1.26]# /etc/init.d/iptables stopiptables: Setting chains to policy ACCEPT: filter [ OK ]iptables: Flushing firewall rules: [ OK ]iptables: Unloading modules: [ OK ][root@web01 /]# /etc/init.d/iptables stopiptables: Setting chains to policy ACCEPT: filter [ OK ]iptables: Flushing firewall rules: [ OK ]iptables: Unloading modules: [ OK ][root@web02 /]# /etc/init.d/iptables stopiptables: Setting chains to policy ACCEPT: filter [ OK ]iptables: Flushing firewall rules: [ OK ]iptables: Unloading modules: [ OK ]
使用多个不同的主机访问192.168.119.150 使用watch ipvsadm -L -n查看ipvsadm的会话分配[root@lvs ipvsadm-1.26]# watch ipvsadm -L -n
上面的配置 重启服务器后会失效 可写成脚本方便管理
LVS 负载均衡器脚本
[root@lvs /]# vim /usr/local/sbin/ipvs #!/bin/bashPORT=80VIP=192.168.119.150RIP=(192.168.119.134192.168.119.135)start(){ifconfig eth0:0 $VIP/24 uproute add -host $VIP dev eth0ipvsadm -Cipvsadm -A -t $VIP:$PORT -s rr -p 20for ((i=0;i<${#RIP[*]};i++))doipvsadm -a -t $VIP:$PORT -r ${RIP[$i]}:$PORT -g -w 1done}stop(){ ipvsadm -C ifconfig eth0:0 down route del -host $VIP dev eth0}case "$1" in start) start echo "ipvs is start" ;; stop) stop echo "ipvs is stop" ;; restart) stop echo "ipvs is stop" start echo "ipvs is start" ;; *) echo "usage:$0 {start|stop|restart}"esac 测试脚本[root@lvs /]# ipvs stopipvs is stop[root@lvs /]# ifconfig eth0:0eth0:0 Link encap:Ethernet HWaddr 00:0C:29:21:BC:27 UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1[root@lvs /]# ipvsadm -L -nIP Virtual Server version 1.2.1 (size=4096)Prot LocalAddress:Port Scheduler Flags -> RemoteAddress:Port Forward Weight ActiveConn InActConn[root@lvs /]# ipvs startipvs is start[root@lvs /]# ipvsadm -L -nIP Virtual Server version 1.2.1 (size=4096)Prot LocalAddress:Port Scheduler Flags -> RemoteAddress:Port Forward Weight ActiveConn InActConnTCP 192.168.119.150:80 rr persistent 20 -> 192.168.119.134:80 Route 1 0 0 -> 192.168.119.135:80 Route 1 0 0 [root@lvs /]# ifconfig eth0:0eth0:0 Link encap:Ethernet HWaddr 00:0C:29:21:BC:27 inet addr:192.168.119.150 Bcast:192.168.119.255 Mask:255.255.255.0 UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
Real Server脚本
#!/bin/bashVIP=192.168.119.150PORT=80case "$1" in start) ifconfig eth0:0 $VIP/32 up route add -host $VIP dev eth0 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_announce echo "2">/proc/sys/net/ipv4/conf/all/arp_announce echo "start LVS of REALServer IP" ;; stop) ifconfig eth0:0 $VIP/32 down route del -host $VIP dev eth0 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_announce echo "0">/proc/sys/net/ipv4/conf/all/arp_announce echo "stop LVS OF REALServer" ;;*) echo "Usage: $0 {start|stop}"esac测试脚本[root@web02 /]# ipvs_client.sh startstart LVS of REALServer IP[root@web02 /]# ipvs_client.sh stopstop LVS OF REALServer[root@web02 /]# ifconfig eth0:0eth0:0 Link encap:Ethernet HWaddr 00:0C:29:09:8E:31 UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1[root@web02 /]# ipvs_client.sh startstart LVS of REALServer IP[root@web02 /]# ifconfig eth0:0eth0:0 Link encap:Ethernet HWaddr 00:0C:29:09:8E:31 inet addr:192.168.119.150 Bcast:255.255.255.255 Mask:0.0.0.0 UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1