Centos配置Keepalived 做双机热备切换分类：网站架构2009-07-25 13:53 7823人阅读评论(0) 收藏举报centosserverdelayauthenticationsnscompilerKeepalived系统环境：************************************************************两台服务器都装了CentOS-5.2-x86_64系统Virtual IP： 192.168.30.20Squid1+Real Server 1：网卡地址(eth0):192.168.30.12Squid2+Real Server 2：网卡地址(eth0):192.168.30.13************************************************************软件列表：keepalived/software/keepalived-1.1.17.tar.gzopenssl-develyum -y install openssl-devel***************************************************************配置：配置基于高可用keepalived,确定LVS使用DR模式1.安装配置keepalived1.1安装依赖软件如果系统为基本文本安装,需要安装一下软件# yum -y install ipvsadm# yum -y install kernel kernel-devel# reboot 重启系统切换内核# yum -y install openssl-devel ；安装keepalived依赖软件#ln -s /usr/src/kernels/`uname -r`-`uname -m`/ /usr/src/linux；建立内核链接，编译keepalived支持lvs时需要注意建立链接的内核名和当前运行的内核一致,否则导致安装失败#tar zxvf keepalived-1.1.17.tar.gz#cd keepalived-1.1.17#./configure --prefix=/usr --sysconf=/etcKeepalived configuration------------------------Keepalived version : 1.1.17Compiler : gccCompiler flags : -g -O2Extra Lib : -lpopt -lssl -lcryptoUse IPVS Framework : Yes ;注意编译时一定要支持lvsIPVS sync daemon support : YesUse VRRP Framework : YesUse LinkWatch : NoUse Debug flags : No#make#make install1.2编辑keepalived配置文件#Vi /etc/keepalived/keepalived.confglobal_defs {notification_email {test@}notification_email_from root@localhostsmtp_server 127.0.0.1smtp_connect_timeout 30router_id LVS_DEVEL}vrrp_instance VI_1 {state MASTER #备份服务器上将MASTER改为BACKUPinterface eth0 # HA 监测网络接口virtual_router_id 51 #主、备机的virtual_router_id必须相同priority 100 #主、备机取不同的优先级，主机值较大，备份机值较小 advert_int 2 # VRRP Multicast 广播周期秒数authentication {auth_type PASS #VRRP 认证方式auth_pass 1111 #VRRP 口令字}virtual_ipaddress {192.168.30.20 # VRRP HA 虚拟地址如果有多个VIP，继续换行填写 }}virtual_server 192.168.30.20 80 {delay_loop 2 #每隔6秒查询realserver状态lb_algo rr #lvs 算法lb_kind DR #Direct Routepersistence_timeout 50 #同一IP 的连接60 秒内被分配到同一台realserverprotocol TCP #用TCP协议检查realserver状态real_server 192.168.30.12 80 {weight 3 #(权重)TCP_CHECK {connect_timeout 10 #(10秒无响应超时)nb_get_retry 3delay_before_retry 3connect_port 80}}real_server 192.168.30.13 80 {weight 3 #(权重)TCP_CHECK {connect_timeout 10 #(10秒无响应超时)nb_get_retry 3delay_before_retry 3connect_port 80}}}1.3BACKUP服务器同上配置，先安装lvs再按装keepalived,仍后配置/etc/keepalived/keepalived.conf，只需将红色标示的部分改一下即可.global_defs {notification_email {test@}notification_email_from root@localhostsmtp_server 127.0.0.1smtp_connect_timeout 30router_id LVS_DEVEL}vrrp_instance VI_1 {state BACKUP #备份服务器上将MASTER改为BACKUPinterface eth0 # HA 监测网络接口virtual_router_id 51 #主、备机的virtual_router_id必须相同priority 99 #主、备机取不同的优先级，主机值较大，备份机值较小 advert_int 2 # VRRP Multicast 广播周期秒数authentication {auth_type PASS #VRRP 认证方式auth_pass 1111 #VRRP 口令字}virtual_ipaddress {192.168.30.20 # VRRP HA 虚拟地址}}virtual_server 192.168.30.20 80 {delay_loop 2 #每隔6秒查询realserver状态lb_algo rr #lvs 算法lb_kind DR #Direct Routepersistence_timeout 50 #同一IP 的连接60 秒内被分配到同一台realserver protocol TCP #用TCP协议检查realserver状态real_server 192.168.30.12 80 {weight 3 #(权重)TCP_CHECK {connect_timeout 10 #(10秒无响应超时)nb_get_retry 3delay_before_retry 3connect_port 80}}real_server 192.168.30.13 80 {weight 3 #(权重)TCP_CHECK {connect_timeout 10 #(10秒无响应超时)nb_get_retry 3delay_before_retry 3connect_port 80}}}2. 配置lvs客户端脚本[c-sharp]view plaincopyprint?1.#vi /usr/local/sbin/realserver.sh2. #!/bin/bash3. # description: Config realserver lo and apply noarp4. #Written by :NetSeek 5.6. SNS_VIP=192.168.30.207.8. . /etc/rc.d/init.d/functions9.10.case"$1"in11. start)12. ifconfig lo:0 $SNS_VIP netmask 255.255.255.255 broadcast $SNS_VIP13. /sbin/route add -host $SNS_VIP dev lo:014. echo "1" >/proc/sys/net/ipv4/conf/lo/arp_ignore15. echo "2" >/proc/sys/net/ipv4/conf/lo/arp_announce16. echo "1" >/proc/sys/net/ipv4/conf/all/arp_ignore17. echo "2" >/proc/sys/net/ipv4/conf/all/arp_announce18. sysctl -p >/dev/null 2>&119. echo "RealServer Start OK"20.21. ;;22. stop)23. ifconfig lo:0 down24. route del $SNS_VIP >/dev/null 2>&125. echo "0" >/proc/sys/net/ipv4/conf/lo/arp_ignore26. echo "0" >/proc/sys/net/ipv4/conf/lo/arp_announce27. echo "0" >/proc/sys/net/ipv4/conf/all/arp_ignore28. echo "0" >/proc/sys/net/ipv4/conf/all/arp_announce29. echo "RealServer Stoped"30. ;;31. *)32. echo "Usage: $0 {start|stop}"33. exit 134. esac35.36. exit 0或者采用secondary ip address方式配置# vi /etc/sysctl.confnet.ipv4.conf.lo.arp_ignore = 1net.ipv4.conf.lo.arp_announce = 2net.ipv4.conf.all.arp_ignore = 1net.ipv4.conf.all.arp_announce = 2#sysctl -p#ip addr add 192.168.30.20/32 dev lo#ip add list 查看是否绑定3. 启动lvs-dr脚本和realserver启本，在DR上可以查看LVS当前状态: #watch ipvsadm -ln4. 启动keepalived 服务#service httpd start#/etc/init.d/keepalived start查看keepalived的安装位置：# find / -name keepalived将keepalived作为服务添加到chkconfig中，并设置开机启动# chkconfig --add keepalived# chkconfig --level 35 keepalived on# chkconfig --list keepalivedkeepalived 0:关闭 1:关闭 2:关闭 3:启用 4:关闭 5:启用 6:关闭“各等级”包括2、3、4、5等级等级0表示：表示关机等级1表示：单用户模式等级2表示：无网络连接的多用户命令行模式等级3表示：有网络连接的多用户命令行模式等级4表示：不可用等级5表示：带图形界面的多用户模式等级6表示：重新启动5. 测试lvs服务是否正常5.1通过浏览器访问http://192.168.30.20是否正常多次刷新浏览器，在主LVS上看连接数变化5.2停止主LVS上的keepalived 看看备份keepalived是否正常接管服务注：realserver如果为windows主机的话需要安装microsoft loopback,设置IP为VIP确认之后搜索注册表,关键字"VIP"把搜到结果的每项里面的subnet mask都改成255.255.255.255然后重启即可。