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LVS+Keepalived负载均衡主备
LVS+Keepalived 介绍
LVS
LVS是Linux Virtual Server的简写,意即Linux虚拟服务器,是一个虚拟的服务器集群系统。本项目在1998年5月由章文嵩博士成立,是中国国内最早出现的自由软件项目之一。目前有三种IP负载均衡技术(VS/NAT、VS/TUN和VS/DR);
十种调度算法(rrr|wrr|lc|wlc|lblc|lblcr|dh|sh|sed|nq)。
Keepalvied
Keepalived在这里主要用作RealServer的健康状态检查以及LoadBalance主机和BackUP主机之间failover的实现
一、LVS+Keepalived负载均衡主备架构
I. 网站负载均衡拓朴图
(略)
IP信息清单:
名称 IP
LVS-DR-Master 192.168.2.98
LVS-DR-Backup 192.168.2.99
LVS-DR-VIP 192.168.2.100
Realserver01 192.168.2.101
Realserver02 192.168.2.102
Realserver03 192.168.2.103
Realserver04 192.168.2.104
II.安装ipvsadm和keepalived软件包
ipvsadm: http://www.linuxvirtualserver.org/software/kernel-2.6/ipvsadm-1.24.tar.gz
keepalived:http://www.keepalived.org/software/keepalived-1.1.15.tar.gz
下载后建议统一放置在/usr/local/src/lvs
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 | #uname -r 2.6.18-53.el5PAE //查看内核版本 #ln -s /usr/src/kernels/2.6.18-53.el5PAE-i686/ /usr/src/linux //防止报错 #tar zxvf ipvsadm-1.24.tar.gz #cd ipvsadm-1.24 #make && make install #find / -name ipvsadm # 查看ipvsadm的位置 #tar zxvf keepalived-1.1.15.tar.gz #cd keepalived-1.1.15 #./configure && make && make install #find / -name keepalived # 查看keepalived位置 #cp /usr/local/etc/rc.d/init.d/keepalived /etc/rc.d/init.d/ #cp /usr/local/etc/sysconfig/keepalived /etc/sysconfig/ #mkdir /etc/keepalived #cp /usr/local/etc/keepalived/keepalived.conf /etc/keepalived/ #cp /usr/local/sbin/keepalived /usr/sbin/ #service keepalived start|stop #做成系统启动服务方便管理. |
III. 配置Realserver脚本
在4台Realserver主机上建立如下脚本,然后执行
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 | #!/bin/bash VIP=192.168.2.100 /etc/rc.d/init.d/functions case “$1″ in start) ifconfig lo:0 $VIP netmask 255.255.255.255 broadcast $VIP up /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 echo "RealServer Start OK" ;; stop) ifconfig lo:0 down route del $VIP 2>/dev/null 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 "RealServer Stoped" ;; *) echo "Usage: $0 {start|stop}" exit 1 esac exit 0 |
IV. 配置keepalived实现负载均衡和和高可用性
1.在LVS-DR-Master主机上编辑keepalived的配置文件 : vim /etc/keepalived/keepalived.conf
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 | ! Configuration File for keepalived
global_defs { notification_email { //此处填写你的邮件地址 } notification_email_from your email!
smtp_server smtp.**.com smtp_connect_timeout 30 router_id LVS_DEVEL } vrrp_instance VI_1 { state MASTER interface eth0 lvs_sync_daemon_inteface eth0 //如是同一个网卡,可省略 virtual_router_id 77 //标识ID,请务必保证内网唯一性,和备机必须一致! priority 100 //权重需比备机高 advert_int 2 //主备检测间隔 authentication { //主备通信密码,必须一致 auth_type PASS auth_pass 1111 } virtual_ipaddress { 192.168.2.100 VIP,多个请换行填写
} }
virtual_server 192.168.2.100 80 { delay_loop 6 //每隔6秒检测Realserver健康状况 lb_algo wlc //wlc算法,其他算法请参考ipvsadm十大算法 lb_kind DR // 采用DR模式,即直接路由,其他还有TUN和NAT两种模式。 persistence_timeout 1800 //设置超时未半小时 protocol TCP
real_server 192.168.2.101 80 { //第一个realserver,请注意80和后面{之间有个空格! weight 100 //权重 HTTP_GET { //通过检测网页来检查Realserver健康状态 url { path /XX/index.jsp //Realserver上的网页,如/model/index.jsp status_code 200 //正确的返回值,一般是200 } connect_timeout 3 //超时3秒,则失败 nb_get_retry 3 //失败重试次数 delay_before_retry 3 //重试间隔时间 } }
real_server 192.168.2.102 80 { weight 100 TCP_CHECK { //此范例为TCP检查方法,区别于HTTP方法,推荐使用HTTP方法。 connect_timeout 10 nb_get_retry 3 delay_before_retry 3 connect_port 80 } } }
real_server 192.168.2.103 80 { weight 100 HTTP_GET { url { path /XX/index.jsp status_code 200 } connect_timeout 3 nb_get_retry 3 delay_before_retry 3 } }
real_server 192.168.2.104 80 { weight 100 HTTP_GET { url { path /XX/index.jsp status_code 200 } connect_timeout 3 nb_get_retry 3 delay_before_retry 3 } } |
2.编辑LVS-DR-Backup上的keepalived配置文件(可拷贝Master上的),然后如下修改:
1 2 | state BACKUP //主机上则为Master priority 90 //权值小于主机 |
其余保持不变即可。
V. 启动LVS
Realserver脚本启动之后不需要操作,然后依次启动LVS主机上的keepalived服务即可: service keepalived start
本文出自 “XFICC” 博客,请务必保留此出处http://xficc.blog.51cto.com/1189288/1564395
LVS+Keepalived负载均衡主备