如何使用Heartbeat，组建一个高可用性的Apache集群？
一、原理
Heartbeat提供了诸多集群基础架构服务，比如集群之间的消息传递、节点成员身份、IP地址分配和迁移，以及服务的开启和停止。Heartbeat 可以用来为Apache、Samba和Squid等企业应用系统构建几乎任何一种高可用性的集群。此外，它可以结合负载均衡软件使用，那样入站请求就可以 由所有集群节点来分担。
二、配置网络
Server6节点：
[root@server6 network-scripts]# ip addr show ##eth0为本机的ip地址，eth1为心跳的ip地址
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 16436 qdisc noqueue state UNKNOWN
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
inet 127.0.0.1/8 scope host lo
inet6 ::1/128 scope host
valid_lft forever preferred_lft forever
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
link/ether 52:54:00:86:4c:9a brd ff:ff:ff:ff:ff:ff
inet 172.25.60.16/24 brd 172.25.60.255 scope global eth0
inet6 fe80::5054:ff:fe86:4c9a/64 scope link
valid_lft forever preferred_lft forever
3: eth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
link/ether 52:54:00:5d:65:8f brd ff:ff:ff:ff:ff:ff
inet 10.0.0.1/24 brd 10.0.0.255 scope global eth1
inet6 fe80::5054:ff:fe5d:658f/64 scope link
valid_lft forever preferred_lft forever
[root@server6 network-scripts]# route -n ##网关
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
172.25.60.0 0.0.0.0 255.255.255.0 U 0 0 0 eth0
10.0.0.0 0.0.0.0 255.255.255.0 U 0 0 0 eth1
169.254.0.0 0.0.0.0 255.255.0.0 U 1002 0 0 eth0
169.254.0.0 0.0.0.0 255.255.0.0 U 1003 0 0 eth1
0.0.0.0 172.25.60.1 0.0.0.0 UG 0 0 0 eth0
[root@server7 network-scripts]# ip addr show ##eth0为本机的ip地址，eth1为心跳的ip地址
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 16436 qdisc noqueue state UNKNOWN
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
inet 127.0.0.1/8 scope host lo
inet6 ::1/128 scope host
valid_lft forever preferred_lft forever
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
link/ether 52:54:00:02:a0:76 brd ff:ff:ff:ff:ff:ff
inet 172.25.60.17/24 brd 172.25.60.255 scope global eth0
inet6 fe80::5054:ff:fe02:a076/64 scope link
valid_lft forever preferred_lft forever
3: eth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
link/ether 52:54:00:50:32:32 brd ff:ff:ff:ff:ff:ff
inet 10.0.0.2/24 brd 10.0.0.255 scope global eth1
inet6 fe80::5054:ff:fe50:3232/64 scope link
valid_lft forever preferred_lft forever
[root@server7 network-scripts]# route -n
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
172.25.60.0 0.0.0.0 255.255.255.0 U 0 0 0 eth0
10.0.0.0 0.0.0.0 255.255.255.0 U 0 0 0 eth1
169.254.0.0 0.0.0.0 255.255.0.0 U 1002 0 0 eth0
169.254.0.0 0.0.0.0 255.255.0.0 U 1003 0 0 eth1
0.0.0.0 172.25.60.1 0.0.0.0 UG 0 0 0 eth0
[root@server7 network-scripts]# ping server6 ##检查两台服务器是否ping通
PING server6 (172.25.60.16) 56(84) bytes of data.
64 bytes from server6 (172.25.60.16): icmp_seq=1 ttl=64 time=0.224 ms
64 bytes from server6 (172.25.60.16): icmp_seq=2 ttl=64 time=0.157 ms
^C
--- server6 ping statistics ---
2 packets transmitted, 2 received, 0% packet loss, time 1917ms
rtt min/avg/max/mdev = 0.157/0.190/0.224/0.036 ms
三、安装heartbeat软件
Server6节点：
[root@server6 ~]# ls
heartbeat-3.0.4-2.el6.x86_64.rpm heartbeat-libs-3.0.4-2.el6.x86_64.rpm
heartbeat-devel-3.0.4-2.el6.x86_64.rpm libnet-1.1.6-7.el6.x86_64.rpm
[root@server6 ~]# rpm -ivh libnet-1.1.6-7.el6.x86_64.rpm
[root@server6 ~]# rpm -ivh heartbeat-*
Server7 节点同上
四、在两个节点安装apache服务测试
Server6节点：
[root@server6 ~]# /etc/init.d/httpd stop
停止 httpd： [失败]
[root@server6 ~]# /etc/init.d/httpd status
httpd 已停
[root@server6 ~]# chkconfig httpd off
Server7节点：
[root@server7 ~]# /etc/init.d/httpd status
httpd 已停
[root@server7 ~]# chkconfig httpd off
[root@server7 ~]# echo "node2" > /var/www/html/index.html
五、配置HeartBeat集群软件
Server6节点：
[root@server6 doc]# cp authkeys /etc/ha.d/
[root@server6 doc]# cp haresources /etc/ha.d/
[root@server6 doc]# cp ha.cf /etc/ha.d/
[root@server6 doc]# cd /etc/ha.d/
[root@server6 ha.d]# ls
authkeys ha.cf haresources
[root@server6 ha.d]# vim authkeys ##修改认证信息
auth 3 ##添加这两行
3 md5 1111
[root@server6 ha.d]# chmod 600 authkeys ##修改权限
[root@server6 ha.d]# vim ha
ha.cf haresources
[root@server6 ha.d]# vim ha.cf
debugfile /var/log/ha-debug --去年前面的#号,开启调试日志
logfile /var/log/ha-log --去年前面的#号,开启运行和访问日志
keepalive 2 --去年前面的#号,心跳探测为2秒
deadtime 30 --去年前面的#号,死亡时间
warntime 10 --去年前面的#号,等待时间10秒
initdead 120 --去年前面的#号,确定死亡时间
udpport 694 --监听的端口
bcast eth1 --添加这行,组播地址绑定在哪个网卡(bcast--广播 mcast--多播或者组播 ucast--单播)
auto_failback on --如果主节点正常就恢复到主节点上
node server6 --添加这行,写上两台服务器的主机名
node server7
ping_group 172.25.60.16 172.25.60.17 172.25.60.1 --检查主机是否宕机
compression bz2 --压缩集群事物信息
compression_threshold 2 --大于2K就压缩
[root@server6 ha.d]# vim haresources ##定义资源
Server6 192.168.1.105/24/eth1:0 httpd ##--添加这行,server6主服务器的主机名,192.168.1.105虚拟IP，24子网掩码,eth1:0是vip的网络接口,httpd是应用服务
[root@server6 ha.d]# scp * server7:/etc/ha.d/ ##将三个配置文件复制到server7中
The authenticity of host 'server7 (172.25.60.17)' can't be established.
RSA key fingerprint is f7:67:1d:fd:81:8d:57:a4:cd:90:ed:de:3c:74:44:b5.
Are you sure you want to continue connecting (yes/no)? yes
Warning: Permanently added 'server7,172.25.60.17' (RSA) to the list of known hosts.
root@server7's password:
authkeys 100% 663 0.7KB/s 00:00
ha.cf 100% 10KB 10.3KB/s 00:00
haresources 100% 5943 5.8KB/s 00:00
六、启动服务，测试是否正常
Server6节点：
[root@server6 ha.d]# /etc/init.d/heartbeat start
Starting High-Availability services: INFO: Resource is stopped
Done.
[root@server6 ha.d]# netstat -antlpe
Active Internet connections (servers and established)
Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program name
tcp 0 0 0.0.0.0:22 0.0.0.0:* LISTEN 958/sshd
tcp 0 0 127.0.0.1:25 0.0.0.0:* LISTEN 1178/master
tcp 0 52
tcp 0 0 :::80 :::* LISTEN 7720/httpd
tcp 0 0 :::22 :::* LISTEN 958/sshd
tcp 0 0 ::1:25 :::* LISTEN 1178/master
udp 0 0 0.0.0.0:34964 0.0.0.0:* 7271/heartbeat: wri
udp 0 0 0.0.0.0:694 0.0.0.0:* 7271/heartbeat: wri
[root@server6 ha.d]# ifconfig eth1:0 --server6节点的vip启动
eth1:0 Link encap:Ethernet HWaddr 08:00:27:06:79:47
inet addr:192.168.1.105 Bcast:0.0.0.0 Mask:255.255.255.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
Server7节点:
[root@server7 ha.d]# /etc/init.d/heartbeat start
Starting High-Availability services: INFO: Resource is stopped
Done.
[root@server7 ha.d]# netstat -antlpe
Active Internet connections (servers and established)
Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program name
tcp 0 0 0.0.0.0:22 0.0.0.0:* LISTEN 956/sshd
tcp 0 0 127.0.0.1:25 0.0.0.0:* LISTEN 1176/master
tcp 0 52
tcp 0 0 :::22 :::* LISTEN 956/sshd
tcp 0 0 ::1:25 :::* LISTEN 1176/master
udp 0 0 0.0.0.0:42151 0.0.0.0:* 4581/heartbeat: wri
udp 0 0 0.0.0.0:694 0.0.0.0:* 4581/heartbeat: wri
测试访问：
测试故障转移:
Server6节点:
[root@server6 ha.d]# /etc/init.d/httpd stop
Stopping httpd: [ OK ]
Server7节点:
[root@server7 ha.d]# netstat -antlpe --关闭server6的httpd服务后,server7的httpd就自动启动了
Active Internet connections (servers and established)
Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program name
tcp 0 0 0.0.0.0:22 0.0.0.0:* LISTEN 956/sshd
tcp 0 0 127.0.0.1:25 0.0.0.0:* LISTEN 1176/master
tcp 0 52
tcp 0 0 :::80 :::* LISTEN 4918/httpd
tcp 0 0 :::22 :::* LISTEN 956/sshd
tcp 0 0 ::1:25 :::* LISTEN 1176/master
udp 0 0 0.0.0.0:42151 0.0.0.0:* 4581/heartbeat: wri
udp 0 0 0.0.0.0:694 0.0.0.0:* 4581/heartbeat: wri
测试:
