CentOS 6.4 Heartbeat+httpd+nfs实现高可用的web服务器
一、Heartbeat概念Heartbeat是Linux-HA项目中的一个组件，也是目前开源HA项目中最成功的一个例子, Linux-HA的全称是High-Availability Linux,这个开源项目的目标是：通过社区开发者的共同努力，提供一个增强linux可靠性（reliability)、可用性（availability）和可服务性（serviceability）（RAS）的群集解决方案.Heartbeat提供了所有 HA 软件所需要的基本功能，比如心跳检测和资源接管、监测群集中的系统服务、在群集中的节点间转移共享IP 地址的所有者等.
Heartbeat官方站点：
* http://www.linux-ha.org
* http://hg.linux-ha.org
二、准备工作
1、Heartbeat网络架构
2、操作系统
123CentOS 6.4 X86-64 最小化安装由于用源码编译安装heartbeat一直没有通过，所以没办法只能采用yum安装。heartbeat v3 3、地址规划
1234node1 192.168.0.101 255.255.255.0 192.168.0.1 node1.test.com eth1 Activenode2 192.168.0.102 255.255.255.0 192.168.0.1 node2.test.com eth1 Passivenode3 192.168.0.103 255.255.255.0 192.168.0.1 node3.test.com eth1 nfsvip 192.168.0.200 255.255.255.0 4、主机名解析
1234567# uname -nnode1.test.com# cat /etc/hosts127.0.0.1 localhost localhost.localdomain localhost4 localhost4.localdomain4::1 localhost localhost.localdomain localhost6 localhost6.localdomain6192.168.1.196 node1.test.com node1192.168.1.197 node2.test.com node21234567# uname -nnode2.test.com# cat /etc/hosts127.0.0.1 localhost localhost.localdomain localhost4 localhost4.localdomain4::1 localhost localhost.localdomain localhost6 localhost6.localdomain6192.168.1.196 node1.test.com node1192.168.1.197 node2.test.com node2 5、双机互信
123456789101112131415161718192021222324252627282930# ssh-keygen -t rsa -f ~/.ssh/id_rsa -P ''Generating public/private rsa key pair.Created directory '/root/.ssh'.Your identification has been saved in /root/.ssh/id_rsa.Your public key has been saved in /root/.ssh/id_rsa.pub.The key fingerprint is:ce:f3:d7:63:10:9b:d2:86:f8:8a:5a:ee:41:d8:d2:01 root@node1.test.comThe key's randomart image is:+--[ RSA 2048]----+| E || . || . || + . . || o + S. o + || o o. o * || o +. o o || o o o. . +|| .o+ .... . . |+-----------------+# ssh-copy-id -i .ssh/id_rsa.pub root@node2.test.comThe authenticity of host 'node2.test.com (192.168.0.102)' can't be established.RSA key fingerprint is 46:b9:7c:11:db:75:93:ad:f1:26:f0:a7:4d:00:40:20.Are you sure you want to continue connecting (yes/no)? yesWarning: Permanently added 'node2.test.com,192.168.0.102' (RSA) to the list of known hosts.root@node2.test.com's password: Now try logging into the machine, with "ssh 'root@node2.test.com'", and check in: .ssh/authorized_keys to make sure we haven't added extra keys that you weren't expecting.1234567891011121314151617181920212223242526272829# ssh-keygen -t rsa -f ~/.ssh/id_rsa -P ''Generating public/private rsa key pair.Your identification has been saved in /root/.ssh/id_rsa.Your public key has been saved in /root/.ssh/id_rsa.pub.The key fingerprint is:c4:e3:71:f8:82:09:f0:42:9c:e7:20:db:db:ce:dc:0b root@node2.test.comThe key's randomart image is:+--[ RSA 2048]----+| .o. ||..+o.. . || +.+o * . ||. .... = = || oo S . ||. . . || +E. || +.. || .. |+-----------------+# ssh-copy-id -i .ssh/id_rsa.pub root@node1.test.comThe authenticity of host 'node1.test.com (192.168.0.101)' can't be established.RSA key fingerprint is 46:b9:7c:11:db:75:93:ad:f1:26:f0:a7:4d:00:40:20.Are you sure you want to continue connecting (yes/no)? yesWarning: Permanently added 'node1.test.com,192.168.0.101' (RSA) to the list of known hosts.root@node1.test.com's password: Now try logging into the machine, with "ssh 'root@node1.test.com'", and check in: .ssh/authorized_keys to make sure we haven't added extra keys that you weren't expecting. 6、时间同步
12# yum -y install ntpdate# ntpdate asia.pool.ntp.org 7、关闭防火墙
1234# getenforceDisabled# /etc/init.d/iptables statusiptables：未运行防火墙。
三、安装heartbeat包
1、node1和node2节点安装epel源
123# wget http://dl.fedoraproject.org/pub/epel/6/x86_64/epel-release-6-8.noarch.rpm # wget http://rpms.famillecollet.com/enterprise/remi-release-6.rpm # rpm -Uvh remi-release-6*.rpm epel-release-6*.rpm 2、修改epel源的配置文件
12# sed -i 's/#baseurl/baseurl/g' /etc/yum.repos.d/epel.repo # sed -i 's/mirrorlist/#mirrorlist/' /etc/yum.repos.d/epel.repo 3、安装heartbeat包
1# yum install heartbeat heartbeat-libs 4、查看heartbeat所依赖的包
四、配置Heartbeat服务
1、heartbeat配置文件的介绍
1234heartbeat3个配置文件 authkeys #节点之间认证的秘钥key文件，权限为600 ha.cf #heartbeat服务核心配置文件 aresources #集群资源管理配置文件(haresource | crm) 2、拷贝heartbeat初始配置文件
1# cp /usr/share/doc/heartbeat-3.0.4/{ha.cf,authkeys,haresources} /etc/ha.d/ 3、编辑authkeys文件
12345678910# dd if=/dev/random bs=512 count=1 | openssl md5#生成密钥随机数记录了0+1 的读入记录了0+1 的写出72字节(72 B)已复制，4.8467e-05 秒，1.5 MB/秒(stdin)= acf7401e6b20d4cec482ba1160eb8efe# vim /etc/ha.d/authkeys#注释：末尾添加以下两行auth 11 md5 acf7401e6b20d4cec482ba1160eb8efe# chmod 600 /etc/ha.d/authkeys 4、编辑ha.cf主配置文件
1234567# grep -v '^#' ha.cf |sed '/^$/d'注释：主要修改两处，其它的都可以默认logfacility local0mcast eth1 225.100.100.100 694 1 0 #修改心跳信息的传播方式|组播auto_failback onnode node1.test.com #配置集群中的节点数node node2.test.com #配置集群中的节点数 5、编辑haresources配置文件
12# grep -v '^#' /etc/ha.d/haresources node1.test.com IPaddr::192.168.0.200/24/eth1 httpd 6、拷贝配置文件到node2节点
1# scp /etc/ha.d/{ha.cf,haresources,authkeys} root@node2.test.com:/etc/ha.d/
五、节点提供httpd服务
1、安装httpd包
1# yum -y install httpd 2、提供测试页面
1# echo "<h1>node1.test.com</h1>" > /var/www/html/index.html 3、启动httpd服务
1# service httpd start 4、浏览器访问web页面
注释：测试完成后关闭服务，并让其开机不启动，httpd由heartbeat管理
5、停止httpd服务，设置开机不启动httpd服务
12345# service httpd stop停止 httpd： [确定]# chkconfig httpd off# chkconfig --list httpdhttpd 0:关闭 1:关闭 2:关闭 3:关闭 4:关闭 5:关闭 6:关闭 6、节点2同上操作
12345# yum -y install httpd# echo "<h1>node2.test.com</h1>" > /var/www/html/index.html# service httpd start# service httpd stop# chkconfig httpd off 7、访问节点2的httpd服务测试页面
六、启动heartbeat服务
1、启动heartbeat服务
1234567# /etc/init.d/heartbeat start Starting High-Availability services: INFO:Resource is stoppedDone. # ssh node2 "/etc/init.d/heartbeat start"Starting High-Availability services: 2014/12/25_21:09:12 INFO:Resource is stoppedDone. 2、查看heartbeat日志
1# tail -f /var/log/message 3、查看vip信息
123456789101112# ip addr1: 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 forever2: eth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000 link/ether 00:0c:29:c7:14:97 brd ff:ff:ff:ff:ff:ff inet 192.168.0.101/24 brd 192.168.0.255 scope global eth1 inet 192.168.0.200/24 scope global eth1 #vip已经成功绑定在eth1的网卡上 inet6 fe80::20c:29ff:fec7:1497/64 scope link valid_lft forever preferred_lft forever 4、查看httpd服务是否被heartbeat接管
12# netstat -tnlpu |grep httpdtcp 0 0 :::80 :::* LISTEN 2140/httpd 5、浏览器访问测试
6、将node1节点由Active切换成Passive
12# sh /usr/share/heartbeat/hb_standbyGoing standby . 7、查看node1节点的日志信息
123456789101112131415# tail -f /var/log/messages Dec 25 21:36:11 node1 heartbeat: : info: node1.test.com wants to go standby Dec 25 21:36:11 node1 heartbeat: : info: standby: node2.test.com can take our all resourcesDec 25 21:36:11 node1 heartbeat: : info: give up all HA resources (standby).Dec 25 21:36:11 node1 ResourceManager(default): info: Releasing resource group: node1.test.com IPaddr::192.168.0.200/24/eth1 httpdDec 25 21:36:11 node1 ResourceManager(default): info: Running /etc/init.d/httpdstopDec 25 21:36:11 node1 ResourceManager(default): info: Running /etc/ha.d/resource.d/IPaddr 192.168.0.200/24/eth1 stopDec 25 21:36:11 node1 IPaddr(IPaddr_192.168.0.200): INFO: IP status = ok, IP_CIP=Dec 25 21:36:11 node1 /usr/lib/ocf/resource.d//heartbeat/IPaddr(IPaddr_192.168.0.200): INFO:SuccessDec 25 21:36:11 node1 heartbeat: : info: all HA resource release completed (standby).Dec 25 21:36:11 node1 heartbeat: : info: Local standby process completed .Dec 25 21:36:12 node1 heartbeat: : WARN: 1 lost packet(s) for Dec 25 21:36:12 node1 heartbeat: : info: remote resource transition completed.Dec 25 21:36:12 node1 heartbeat: : info: No pkts missing from node2.test.com!Dec 25 21:36:12 node1 heartbeat: : info: Other node completed standby takeover of all resources. 8、注释说明
1node1节点由Active切换到Passive后，httpd服务停止，vip有node1转移到node2上 9、查看node2节点
1234567891011121314# ip addr1: 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 forever2: eth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000 link/ether 00:0c:29:ad:9f:36 brd ff:ff:ff:ff:ff:ff inet 192.168.0.102/24 brd 192.168.0.255 scope global eth1 inet 192.168.0.200/24 brd 192.168.0.255 scope global secondary eth1 inet6 fe80::20c:29ff:fead:9f36/64 scope link valid_lft forever preferred_lft forever# netstat -tnlp |grep httpdtcp 0 0 :::80 :::* LISTEN 2709/httpd 10、vip转移后再次访问
到此处，最基本最简单的heartbeat服务的高可用就完成了。
七、Heartbeat的共享存储
1、配置node3的NFS服务
12345678910# yum -y install nfs-utils rpcbind# mkdir /web/htdocs -p # cat /etc/exports /web/htdocs 192.168.0.0/24(ro)# /etc/init.d/rpcbind start# /etc/init.d/nfs start# showmount -e '192.168.0.103'Export list for 192.168.0.103:/web/htdocs 192.168.0.0/24# echo "<h1>node3 nfs server</h1>" > /web/htdocs/index.html 2、节点挂载测试
node1
123456789101112131415# mount -t nfs 192.168.0.103:/web/htdocs /mnt/# ll /mnt/总用量 4-rw-r--r-- 1 nobody nobody 26 12月 25 21:53 index.html# cat /mnt/index.html <h1>node3 nfs server</h1># df文件系统 1K-块 已用 可用 已用% 挂载点/dev/mapper/VolGroup-lv_root 16134560 13957401391921210% /tmpfs 247208 0 247208 0% /dev/shm/dev/sda1 495844 32418 437826 7% /boot192.168.0.103:/web/htdocs 16134560 130252814012416 9% /mnt# umount /mnt/ node2
123456789101112131415# mount -t nfs 192.168.0.103:/web/htdocs /mnt/# ll /mnt/总用量 4-rw-r--r-- 1 nobody nobody 26 12月 25 21:53 index.html# cat /mnt/index.html <h1>node3 nfs server</h1># df文件系统 1K-块 已用 可用 已用% 挂载点/dev/mapper/VolGroup-lv_root 16134560 14167961389815610% /tmpfs 247208 0 247208 0% /dev/shm/dev/sda1 495844 32418 437826 7% /boot192.168.0.103:/web/htdocs 16134560 130252814012416 9% /mnt# umount /mnt/ 3、停止node1和node2节点的heartbeat服务
12345# ssh node2 'service heartbeat stop'Stopping High-Availability services: Done. # service heartbeat stopStopping High-Availability services: Done. 4、修改haresource配置文件
12# vim /etc/ha.d/haresources node1.test.com IPaddr::192.168.0.200/24/eth1 Filesystem::192.168.0.103:/web/htdocs::/var/www/html::nfs httpd 5、拷贝修改后的haresource配置文件到node2
1# scp /etc/ha.d/haresources root@node2.test.com:/etc/ha.d/ 6、启动节点的heartbeat服务
1234567# service heartbeat startStarting High-Availability services: INFO:Resource is stoppedDone. # ssh node2 "service heartbeat start"Starting High-Availability services: 2014/12/25_22:01:40 INFO:Resource is stoppedDone. 7、浏览器测试访问
8、查看node1节点信息
123456789101112131415161718192021222324# ip addr1: 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 forever2: eth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000 link/ether 00:0c:29:c7:14:97 brd ff:ff:ff:ff:ff:ff inet 192.168.0.101/24 brd 192.168.0.255 scope global eth1 inet 192.168.0.200/24 brd 192.168.0.255 scope global secondary eth1 inet6 fe80::20c:29ff:fec7:1497/64 scope link valid_lft forever preferred_lft forever# netstat -tnlp |grep httpdtcp 0 0 :::80 :::* LISTEN 3301/httpd # df文件系统 1K-块 已用 可用 已用% 挂载点/dev/mapper/VolGroup-lv_root 16134560 13957561391919610% /tmpfs 247208 0 247208 0% /dev/shm/dev/sda1 495844 32418 437826 7% /boot192.168.0.103:/web/htdocs 16134560 130252814012416 9% /var/www/html# cat /var/www/html/index.html <h1>node3 nfs server</h1> 9、停止node1节点的heartbeat服务，进行切换，并查看vip信息，再次访问vip地址
123456789101112131415# service heartbeat stopStopping High-Availability services: Done. # ip addr1: 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 forever2: eth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000 link/ether 00:0c:29:c7:14:97 brd ff:ff:ff:ff:ff:ff inet 192.168.0.101/24 brd 192.168.0.255 scope global eth1 inet6 fe80::20c:29ff:fec7:1497/64 scope link valid_lft forever preferred_lft forever# netstat -tnlp |grep httpd
八、测试Heartbeat高可用
正常关闭和重启主节点的heartbeat服务 或者 脚本切换主节点为备用节点
123细节流程：正常关闭Heartbeat服务：/etc/init.d/heartbeat stop && service heartbeat stop脚本切换主节点为备用节点：sh /usr/share/heartbeat/hb_standby12345678910111213在主节点node1上关闭heartbeat服务执行“service heartbeat stop”，正常关闭主节点的heartbeat服务进程。此时主节点通过“ip addr”命令查看主节点的网卡信息，正常情况下，应该可以看到主节点已经释放了集群服务的ip(vip)地址，同时释放了挂载磁盘的共享分区，并且httpd服务处于停止状态。 然后登陆备用节点执行“ssh node2'”查看备用节点node2相关属性信息，在备用节点node2上用“ip addr”命令查看集群ip(vip)是否已经被接管，同时是否已经挂载上了共享磁盘分区，并且httpd服务是否已经启动;得出的结论就是备用节点已经接管了vip地址，共享磁盘分区已经被挂载，httpd服务已经启动。 在这个过程中，使用ping命令对集群服务ip(vip)进行测试，可以看到集群服务ip一直处于可通状态，并没有任何延迟和堵塞现象，也就是说在正常关闭主节点node1上的heartbeat服务的情况下，主备节点的切换时无缝的，HA对外提供的服务可以不间断运行。 接着，主节点的Heartbeat服务正常启动，那么备用节点的集群服务ip(vip)将被释放，同时卸载挂载的共享磁盘分区和停止httpd服务，反而主节点将再次接管集群服务ip(vip)和挂载共享磁盘分区，其实备用节点释放资源与主节点绑定资源是同步进行的。因而，这个过程也是一个无缝切换。 但是大家需要注意的是主节点重新上线后，在进行ping测试的过程中会有一次中断，不过是瞬间的 影响不是很大。
到此，heartbeat的web高可用就完成了。后续会继续补充Heartbeat的相关知识。
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