apache+tomcat+keepalived jsp网站高可用（主备切换）
1、 测试环境
服务器：
master：centos 5.5 x86_64
10.10.0.38
backup: centos 5.5 x86_64
10.10.0.39
vip： 10.10.0.40
软件：
httpd-2.2.6.tar.gz
jdk-6u4-linux-x64.bin
apache-tomcat-6.0.36.tar.gz
tomcat-connectors-1.2.37-src
keepalived-1.1.15.tar.gz
2、整合apche tomcat（省略、见jsp网站部署）
echo "10.10.0.38" > apache主目录/ROOT/index.jsp
echo "10.10.0.39" > apache主目录/ROOT/index.jsp
以上测试主备切换时用到
3、安装keepalived（主、备机上）
#tar zxvf keepalived-1.1.15.tar.gz
#cd keepalived-1.1.15
#./configure --prefix=/usr/local/keepalived
#make
#make install
#cp /usr/local/keepalived/sbin/keepalived /usr/sbin/
#cp /usr/local/keepalived/etc/sysconfig/keepalived /etc/sysconfig/
#cp /usr/local/keepalived/etc/rc.d/init.d/keepalived /etc/init.d/
4、配置keepalived
1）主服务器：master
#mkdir /etc/keepalived
#vim /etc/keepalived/keepalived.conf
! Configuration File for keepalived
global_defs {
notification_email {
[email protected] #邮件通知地址
}
notification_email_from [email protected]
smtp_server 127.0.0.1
smtp_connect_timeout 30
router_id LVS_DEVEL
}
vrrp_script chk_http_port {
script "/etc/keepalived/http.sh" #监控脚本
# script "/etc/keepalived/http1.sh"
interval 2 #监控时间
weight 2
}
vrrp_instance VI_1 {
state MASTER #设置为主服务器
interface eth0 #监测网络接口
virtual_router_id 51 #主、备必须一样
mcast_src_ip 10.10.0.38 #(多播的源IP，设置为本机外网IP，与VIP同一网卡)此项可不设置
priority 100 #(主、备机取不同的优先级，主机值较大，备份机值较小,值越大优先级越高)
advert_int 1 #VRRP Multicast广播周期秒数
authentication {
auth_type PASS #VRRP认证方式，主备必须一致
auth_pass 1111 #(密码)
}
track_script {
chk_http_port #调用http进程监控脚本
}
virtual_ipaddress {
10.10.0.40 #VRRP HA虚拟地址
}
2）备份服务器：BACKUP
只需要将主服务器配置做如下修改即可：
state BACKUP
priority 90
5、编写监控脚本（主备机）
#vim /etc/keepalived/http.sh (监控apache)
#!/bin/sh
A=`ps -C httpd --no-header |wc -l`
if [ $A -eq 0 ];then
/usr/local/apache/bin/apachectl start
sleep 3
if [ `ps -C httpd --no-header |wc -l` -eq 0 ];then
killall keepalived
fi
fi
B=`ps aux | grep tomcat |wc -l`
if [ $B -eq 0 ];then
/usr/local/tomcat/bin/startup.sh
sleep 3
if [ `ps aux | grep tomcat |wc -l` -eq 0 ];then
killall keepalived
fi
fi
编写监控脚本的原因：
当apache或tomcat服务不能正常运行，而keepalived或机器正常，则主备不会自动切换。
6、启动服务
分别在主备机上启动apache tomcat nginx
#/usr/local/apache/bin/apachectl start
#/usr/locat/tomcat/bin/startup.sh
#service keepalived start
主服务器上keepalived日志：
#tail -f /var/log/message
Dec 21 14:49:09 monthplan Keepalived: Starting Keepalived v1.1.15 (12/21,2012)
Dec 21 14:49:09 monthplan Keepalived_vrrp: Using MII-BMSR NIC polling thread...
Dec 21 14:49:09 monthplan Keepalived_vrrp: Registering Kernel netlink reflector
Dec 21 14:49:09 monthplan Keepalived_vrrp: Registering Kernel netlink command channel
Dec 21 14:49:09 monthplan Keepalived_vrrp: Registering gratutious ARP shared channel
Dec 21 14:49:09 monthplan Keepalived: Starting VRRP child process, pid=1301
Dec 21 14:49:09 monthplan Keepalived_vrrp: Opening file '/etc/keepalived/keepalived.conf'.
Dec 21 14:49:09 monthplan Keepalived_vrrp: Configuration is using : 65382 Bytes
Dec 21 14:49:09 monthplan Keepalived_vrrp: VRRP sockpool: [ifindex(2), proto(112), fd(7,8)]
Dec 21 14:49:09 monthplan Keepalived_vrrp: VRRP_Instance(VI_1) Transition to MASTER STATE
Dec 21 14:49:10 monthplan Keepalived_vrrp: VRRP_Instance(VI_1) Entering MASTER STATE
Dec 21 14:49:10 monthplan Keepalived_vrrp: VRRP_Instance(VI_1) setting protocol VIPs.
Dec 21 14:49:10 monthplan Keepalived_vrrp: VRRP_Instance(VI_1) Sending gratuitous ARPs on eth0 for 10.10.0.40
Dec 21 14:49:10 monthplan avahi-daemon[1829]: Registering new address record for 10.10.0.40 on eth0.
Dec 21 14:49:11 monthplan Keepalived_vrrp: VRRP_Script(chk_http_port) succeeded
Dec 21 14:49:15 monthplan Keepalived_vrrp: VRRP_Instance(VI_1) Sending gratuitous ARPs on eth0 for 10.10.0.40
备服务器上keepalived日志：
#tail -f /var/log/message
Dec 21 14:50:20 monthplan Keepalived: Starting Keepalived v1.1.15 (12/21,2012)
Dec 21 14:50:20 monthplan Keepalived_vrrp: Using MII-BMSR NIC polling thread...
Dec 21 14:50:20 monthplan Keepalived_vrrp: Registering Kernel netlink reflector
Dec 21 14:50:20 monthplan Keepalived_vrrp: Registering Kernel netlink command channel
Dec 21 14:50:20 monthplan Keepalived_vrrp: Registering gratutious ARP shared channel
Dec 21 14:50:20 monthplan Keepalived: Starting VRRP child process, pid=22788
Dec 21 14:50:20 monthplan Keepalived_vrrp: Opening file '/etc/keepalived/keepalived.conf'.
Dec 21 14:50:20 monthplan Keepalived_vrrp: Configuration is using : 65256 Bytes
Dec 21 14:50:20 monthplan Keepalived_vrrp: VRRP_Instance(VI_1) Entering BACKUP STATE
Dec 21 14:50:20 monthplan Keepalived_vrrp: VRRP sockpool: [ifindex(2), proto(112), fd(7,8)]
Dec 21 14:50:22 monthplan Keepalived_vrrp: VRRP_Script(chk_http_port) succeeded
从日志中可以看出主备服务正常启动
7、测试
1）停掉主服务器keepalived
主日志：
Dec 21 14:53:42 monthplan Keepalived: Stopping Keepalived v1.1.15 (12/21,2012)
Dec 21 14:53:42 monthplan Keepalived_vrrp: Terminating VRRP child process on signal
Dec 21 14:53:42 monthplan Keepalived_vrrp: VRRP_Instance(VI_1) removing protocol VIPs.
Dec 21 14:53:42 monthplan avahi-daemon[1829]: Withdrawing address record for 10.10.0.40 on eth0.
备日志：
Dec 21 14:53:46 monthplan Keepalived_vrrp: VRRP_Instance(VI_1) Transition to MASTER STATE
Dec 21 14:53:47 monthplan Keepalived_vrrp: VRRP_Instance(VI_1) Entering MASTER STATE
Dec 21 14:53:47 monthplan Keepalived_vrrp: VRRP_Instance(VI_1) setting protocol VIPs.
Dec 21 14:53:47 monthplan Keepalived_vrrp: VRRP_Instance(VI_1) Sending gratuitous ARPs on eth0 for 10.10.0.40
Dec 21 14:53:47 monthplan avahi-daemon[1812]: Registering new address record for 10.10.0.40 on eth0.
Dec 21 14:53:52 monthplan Keepalived_vrrp: VRRP_Instance(VI_1) Sending gratuitous ARPs on eth0 for 10.10.0.40
备份服务器已成功接管vip：10.10.0.40，同时访问网页也可以看出。
2)关闭任何服务器apache进程
日志：
Dec 21 14:59:41 monthplan Keepalived_vrrp: VRRP_Script(chk_http_port) succeeded
apache进程自动启动
3）掉主服务器，备份服务器成功接管vip