红帽集群套件RHCS四部曲（测试篇）
2013-09-26 15:45
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集群配置完成后，如何知道集群已经配置成功了呢，下面我们就分情况测试RHCS提供的高可用集群和存储集群功能。
一、 高可用集群测试
在前面的文章中，我们配置了四个节点的集群系统，每个节点的主机名分别是web1、web2、Mysql1、Mysql2，四个节点之间的关系是：web1和web2组成web集群，运行webserver服务，其中web1是主节点，正常状态下服务运行在此节点，web2是备用节 点；Mysql1和Mysql2组成Mysql集群，运行mysqlserver服务，其中，Mysql1是主节点，正常状态下服务运行在此节 点，Mysql2为备用节点。
下面分四种情况介绍当节点发生宕机时，集群是如何进行切换和工作的。
1 节点web2宕机时
宕机分为正常关机和异常宕机两种情况，下面分别说明。
（1） 节点web2正常关机
在节点web2上执行正常关机命令：
[root@web2 ~]#init 0
然后在web1节点查看/var/log/messages日志，输出信息如下：
Aug 24 00:57:09 web1 clurgmgrd[3321]: <notice> Member 1 shutting down
Aug 24 00:57:17 web1 qdiskd[2778]: <info> Node 1 shutdown
Aug 24 00:57:29 web1 openais[2755]: [TOTEM] The token was lost in theOPERATIONAL state.
Aug 24 00:57:29 web1 openais[2755]: [TOTEM] Receive multicast socket recvbuffer size (320000 bytes).
Aug 24 00:57:29 web1 openais[2755]: [TOTEM] Transmit multicast socket sendbuffer size (219136 bytes).
Aug 24 00:57:29 web1 openais[2755]: [TOTEM] entering GATHER state from 2.
Aug 24 00:57:49 web1 openais[2755]: [TOTEM] entering GATHER state from 0.
Aug 24 00:57:49 web1 openais[2755]: [TOTEM] Creating commit token because I amthe rep.
Aug 24 00:57:49 web1 openais[2755]: [TOTEM] Saving state aru 73 high seqreceived 73
Aug 24 00:57:49 web1 openais[2755]: [TOTEM] Storing new sequence id for ringbc8
Aug 24 00:57:49 web1 openais[2755]: [TOTEM] entering COMMIT state.
Aug 24 00:57:49 web1 openais[2755]: [TOTEM] entering RECOVERY state.
Aug 24 00:57:49 web1 openais[2755]: [TOTEM] position [0] member 192.168.12.230:
Aug 24 00:57:49 web1 openais[2755]: [TOTEM] previous ring seq 3012 rep192.168.12.230
Aug 24 00:57:49 web1 openais[2755]: [TOTEM] aru 73 high delivered 73 receivedflag 1
Aug 24 00:57:49 web1 openais[2755]: [TOTEM] position [1] member 192.168.12.231:
Aug 24 00:57:49 web1 openais[2755]: [TOTEM] previous ring seq 3012 rep192.168.12.230
Aug 24 00:57:49 web1 openais[2755]: [TOTEM] aru 73 high delivered 73 receivedflag 1
Aug 24 00:57:49 web1 openais[2755]: [TOTEM] position [2] member 192.168.12.232:
Aug 24 00:57:49 web1 openais[2755]: [TOTEM] previous ring seq 3012 rep192.168.12.230
Aug 24 00:57:49 web1 openais[2755]: [TOTEM] aru 73 high delivered 73 receivedflag 1
Aug 24 00:57:49 web1 openais[2755]: [TOTEM] Did not need to originate anymessages in recovery.
Aug 24 00:57:49 web1 openais[2755]: [TOTEM] Sending initial ORF token
Aug 24 00:57:49 web1 openais[2755]: [CLM ] CLM CONFIGURATION CHANGE
Aug 24 00:57:49 web1 openais[2755]: [CLM ] New Configuration:
Aug 24 00:57:49 web1 openais[2755]: [CLM ] r(0)ip(192.168.12.230)
Aug 24 00:57:49 web1 openais[2755]: [CLM ] r(0)ip(192.168.12.231)
Aug 24 00:57:49 web1 openais[2755]: [CLM ] r(0)ip(192.168.12.232)
Aug 24 00:57:49 web1 openais[2755]: [CLM ] Members Left:
Aug 24 00:57:49 web1 openais[2755]: [CLM ] r(0)ip(192.168.12.240)
Aug 24 00:57:49 web1 kernel: dlm: closing connection to node 1
Aug 24 00:57:49 web1 openais[2755]: [CLM ] Members Joined:
Aug 24 00:57:49 web1 openais[2755]: [CLM ] CLM CONFIGURATION CHANGE
Aug 24 00:57:49 web1 openais[2755]: [CLM ] New Configuration:
Aug 24 00:57:49 web1 openais[2755]: [CLM ] r(0)ip(192.168.12.230)
Aug 24 00:57:49 web1 openais[2755]: [CLM ] r(0)ip(192.168.12.231)
Aug 24 00:57:49 web1 openais[2755]: [CLM ] r(0)ip(192.168.12.232)
Aug 24 00:57:49 web1 openais[2755]: [CLM ] Members Left:
Aug 24 00:57:49 web1 openais[2755]: [CLM ] Members Joined:
Aug 24 00:57:49 web1 openais[2755]: [SYNC ] This node is within the primarycomponent and will provide service.
Aug 24 00:57:49 web1 openais[2755]: [TOTEM] entering OPERATIONAL state.
Aug 24 00:57:49 web1 openais[2755]: [CLM ] got nodejoin message192.168.12.230
Aug 24 00:57:49 web1 openais[2755]: [CLM ] got nodejoin message192.168.12.231
Aug 24 00:57:49 web1 openais[2755]: [CLM ] got nodejoin message192.168.12.232
Aug 24 00:57:49 web1 openais[2755]: [CPG ] got joinlist message from node3
Aug 24 00:57:49 web1 openais[2755]: [CPG ] got joinlist message from node4
Aug 24 00:57:49 web1 openais[2755]: [CPG ] got joinlist message from node2
从输出日志可以看出，当web2节点正常关机后，qdiskd进程立刻检测到web2节点已经关闭，然后dlm锁进程正常关闭了从web2的连接，由于是 正常关闭节点web2，所以RHCS认为整个集群系统没有发生异常，仅仅把节点web2从集群中隔离而已。请重点查看日志中斜体部分。
重新启动web2节点，然后在web1上继续观察日志信息：
Aug 24 01:10:50 web1 openais[2755]: [TOTEM] entering GATHER state from 11.
Aug 24 01:10:51 web1 openais[2755]: [TOTEM] Creating commit token because I amthe rep.
Aug 24 01:10:51 web1 openais[2755]: [TOTEM] Saving state aru 2b high seqreceived 2b
Aug 24 01:10:51 web1 openais[2755]: [TOTEM] Storing new sequence id for ringbcc
Aug 24 01:10:51 web1 openais[2755]: [TOTEM] entering COMMIT state.
Aug 24 01:10:51 web1 openais[2755]: [TOTEM] entering RECOVERY state.
Aug 24 01:10:51 web1 openais[2755]: [TOTEM] position [0] member 192.168.12.230:
Aug 24 01:10:51 web1 openais[2755]: [TOTEM] previous ring seq 3016 rep192.168.12.230
Aug 24 01:10:51 web1 openais[2755]: [TOTEM] aru 2b high delivered 2b receivedflag 1
Aug 24 01:10:51 web1 openais[2755]: [TOTEM] position [1] member 192.168.12.231:
Aug 24 01:10:51 web1 openais[2755]: [TOTEM] previous ring seq 3016 rep192.168.12.230
Aug 24 01:10:51 web1 openais[2755]: [TOTEM] aru 2b high delivered 2b receivedflag 1
Aug 24 01:10:51 web1 openais[2755]: [TOTEM] position [2] member 192.168.12.232:
Aug 24 01:10:51 web1 openais[2755]: [TOTEM] previous ring seq 3016 rep192.168.12.230
Aug 24 01:10:51 web1 openais[2755]: [TOTEM] aru 2b high delivered 2b receivedflag 1
Aug 24 01:10:51 web1 openais[2755]: [TOTEM] position [3] member 192.168.12.240:
Aug 24 01:10:51 web1 openais[2755]: [TOTEM] previous ring seq 3016 rep192.168.12.240
Aug 24 01:10:51 web1 openais[2755]: [TOTEM] aru c high delivered c receivedflag 1
Aug 24 01:10:51 web1 openais[2755]: [TOTEM] Did not need to originate anymessages in recovery.
Aug 24 01:10:51 web1 openais[2755]: [TOTEM] Sending initial ORF token
Aug 24 01:10:51 web1 openais[2755]: [CLM ] CLM CONFIGURATION CHANGE
Aug 24 01:10:51 web1 openais[2755]: [CLM ] New Configuration:
Aug 24 01:10:51 web1 openais[2755]: [CLM ] r(0)ip(192.168.12.230)
Aug 24 01:10:51 web1 openais[2755]: [CLM ] r(0)ip(192.168.12.231)
Aug 24 01:10:51 web1 openais[2755]: [CLM ] r(0)ip(192.168.12.232)
Aug 24 01:10:51 web1 openais[2755]: [CLM ] Members Left:
Aug 24 01:10:51 web1 openais[2755]: [CLM ] Members Joined:
Aug 24 01:10:51 web1 openais[2755]: [CLM ] CLM CONFIGURATION CHANGE
Aug 24 01:10:51 web1 openais[2755]: [CLM ] New Configuration:
Aug 24 01:10:51 web1 openais[2755]: [CLM ] r(0)ip(192.168.12.230)
Aug 24 01:10:51 web1 openais[2755]: [CLM ] r(0)ip(192.168.12.231)
Aug 24 01:10:51 web1 openais[2755]: [CLM ] r(0)ip(192.168.12.232)
Aug 24 01:10:51 web1 openais[2755]: [CLM ] r(0)ip(192.168.12.240)
Aug 24 01:10:51 web1 openais[2755]: [CLM ] Members Left:
Aug 24 01:10:51 web1 openais[2755]: [CLM ] Members Joined:
Aug 24 01:10:51 web1 openais[2755]: [CLM ] r(0)ip(192.168.12.240)
Aug 24 01:10:51 web1 openais[2755]: [SYNC ] This node is within theprimary component and will provide service.
Aug 24 01:10:51 web1 openais[2755]: [TOTEM] entering OPERATIONAL state.
Aug 24 01:10:51 web1 openais[2755]: [CLM ] got nodejoin message192.168.12.230
Aug 24 01:10:51 web1 openais[2755]: [CLM ] got nodejoin message192.168.12.231
Aug 24 01:10:51 web1 openais[2755]: [CLM ] got nodejoin message192.168.12.232
Aug 24 01:10:51 web1 openais[2755]: [CLM ] got nodejoin message192.168.12.240
Aug 24 01:10:51 web1 openais[2755]: [CPG ] got joinlist messagefrom node 3
Aug 24 01:10:51 web1 openais[2755]: [CPG ] got joinlist message from node4
Aug 24 01:10:51 web1 openais[2755]: [CPG ] got joinlist message from node2
Aug 24 01:10:55 web1 kernel: dlm: connecting to 1
从输出可知，重新启动节点web2后，openais底层通信进程检测到web2节点已经激活，并且将web2重新加入集群中，请重点查看日志中斜体部分。
（2） 节点web2异常宕机
在节点web2上执行如下命令，让内核崩溃：
[root@web2 ~]#echo c>/proc/sysrq-trigger
然后在节点Mysql1上查看/var/log/messages日志，信息如下：
Aug 24 02:26:16 Mysql1 openais[2649]: [TOTEM] entering GATHER state from 12.
Aug 24 02:26:28 Mysql1 qdiskd[2672]: <notice> Node 1 evicted
Aug 24 02:26:36 Mysql1 openais[2649]: [TOTEM] entering GATHER statefrom 11.
Aug 24 02:26:36 Mysql1 openais[2649]: [TOTEM] Saving state aru 78 high seqreceived 78
Aug 24 02:26:36 Mysql1 openais[2649]: [TOTEM] Storing new sequence id for ringbd0
Aug 24 02:26:36 Mysql1 openais[2649]: [TOTEM] entering COMMIT state.
Aug 24 02:26:36 Mysql1 openais[2649]: [TOTEM] entering RECOVERY state.
Aug 24 02:26:36 Mysql1 openais[2649]: [TOTEM] position [0] member192.168.12.230:
Aug 24 02:26:36 Mysql1 openais[2649]: [TOTEM] previous ring seq 3020 rep192.168.12.230
Aug 24 02:26:36 Mysql1 openais[2649]: [TOTEM] aru 78 high delivered 78 receivedflag 1
Aug 24 02:26:36 Mysql1 openais[2649]: [TOTEM] position [1] member192.168.12.231:
Aug 24 02:26:36 Mysql1 openais[2649]: [TOTEM] previous ring seq 3020 rep192.168.12.230
Aug 24 02:26:36 Mysql1 openais[2649]: [TOTEM] aru 78 high delivered 78 receivedflag 1
Aug 24 02:26:36 Mysql1 openais[2649]: [TOTEM] position [2] member192.168.12.232:
Aug 24 02:26:36 Mysql1 openais[2649]: [TOTEM] previous ring seq 3020 rep192.168.12.230
Aug 24 02:26:36 Mysql1 openais[2649]: [TOTEM] aru 78 high delivered 78 receivedflag 1
Aug 24 02:26:36 Mysql1 openais[2649]: [TOTEM] Did not need to originate anymessages in recovery.
Aug 24 02:26:36 Mysql1 openais[2649]: [CLM ] CLM CONFIGURATION CHANGE
Aug 24 02:26:36 Mysql1 openais[2649]: [CLM ] New Configuration:
Aug 24 02:26:36 Mysql1 kernel: dlm: closing connection to node 1
Aug 24 02:26:36 Mysql1 openais[2649]: [CLM ] r(0)ip(192.168.12.230)
Aug 24 02:26:36 Mysql1 openais[2649]: [CLM ] r(0)ip(192.168.12.231)
Aug 24 02:26:36 Mysql1 openais[2649]: [CLM ] r(0) ip(192.168.12.232)
Aug 24 02:26:36 Mysql1 openais[2649]: [CLM ] Members Left:
Aug 24 02:26:36 Mysql1 openais[2649]: [CLM ] r(0)ip(192.168.12.240)
Aug 24 02:26:36 Mysql1 openais[2649]: [CLM ] Members Joined:
Aug 24 02:26:36 Mysql1 openais[2649]: [CLM ] CLM CONFIGURATION CHANGE
Aug 24 02:26:36 Mysql1 openais[2649]: [CLM ] New Configuration:
Aug 24 02:26:36 Mysql1 openais[2649]: [CLM ] r(0)ip(192.168.12.230)
Aug 24 02:26:36 Mysql1 openais[2649]: [CLM ] r(0)ip(192.168.12.231)
Aug 24 02:26:36 Mysql1 openais[2649]: [CLM ] r(0)ip(192.168.12.232)
Aug 24 02:26:36 Mysql1 openais[2649]: [CLM ] Members Left:
Aug 24 02:26:36 Mysql1 openais[2649]: [CLM ] Members Joined:
Aug 24 02:26:36 Mysql1 openais[2649]: [SYNC ] This node is within the primarycomponent and will provide service.
Aug 24 02:26:36 Mysql1 fenced[2688]: web2 not a cluster member after 0 secpost_fail_delay
Aug 24 02:26:36 Mysql1 openais[2649]: [TOTEM] entering OPERATIONAL state.
Aug 24 02:26:36 Mysql1 fenced[2688]: fencing node "web2"
Aug 24 02:26:36 Mysql1 openais[2649]: [CLM ] got nodejoin message192.168.12.230
Aug 24 02:26:36 Mysql1 openais[2649]: [CLM ] got nodejoin message192.168.12.231
Aug 24 02:26:36 Mysql1 openais[2649]: [CLM ] got nodejoin message192.168.12.232
Aug 24 02:26:36 Mysql1 openais[2649]: [CPG ] got joinlist message fromnode 3
Aug 24 02:26:36 Mysql1 openais[2649]: [CPG ] got joinlist message fromnode 4
Aug 24 02:26:36 Mysql1 openais[2649]: [CPG ] got joinlist message fromnode 2
Aug 24 02:26:45 Mysql1 fenced[2688]: fence "web2" success
Aug 24 02:26:45 Mysql1 kernel: GFS2: fsid=mycluster:my-gfs2.2: jid=3: Trying toacquire journal lock...
Aug 24 02:26:45 Mysql1 kernel: GFS2: fsid=mycluster:my-gfs2.2: jid=3: Lookingat journal...
Aug 24 02:26:45 Mysql1 kernel: GFS2: fsid=mycluster:my-gfs2.2: jid=3: Done
从输出信息可知，qdiskd首先检测到web2出现异常，然后将它从集群中隔离，由于是异常宕机，所以RHCS为了保证集群资源的唯一性，必须重置 web2节点，于是fenced进程启动， 在fenced进程没有返回成功信息之前，所有节点挂载的GFS2共享分区将无法使用，处于hung住的状态。直到fence成功。
此时，在节点web1上查看web2的集群状态：
[root@web1 ~]#clustat -m web2
Member Name ID Status
------ ---- ---- ------
web2 1 Offline
由输出可知，web2已经处于offline状态了。
2 节点Mysql2宕机时
节点Mysql2在正常关机和异常宕机时，RHCS的切换状态与上面讲述的web2节点情况一模一样，这么不在重复讲述。
3 节点web1宕机时
（1） 节点web1正常关机
[root@web1 ~]# init 0
然后在节点web2上查看/var/log/messages日志，信息如下：
Aug 24 02:06:13 web2 last message repeated 3 times
Aug 24 02:14:58 web2 clurgmgrd[3239]: <notice> Member 4 shutting down
Aug 24 02:15:03 web2 clurgmgrd[3239]: <notice> Starting stopped serviceservice:webserver
Aug 24 02:15:05 web2 avahi-daemon[3110]: Registering new address record for192.168.12.233 on eth0.
Aug 24 02:15:06 web2 in.rdiscd[4451]: setsockopt (IP_ADD_MEMBERSHIP): Addressalready in use
Aug 24 02:15:06 web2 in.rdiscd[4451]: Failed joining addresses
Aug 24 02:15:07 web2 clurgmgrd[3239]: <notice> Service service:webserverstarted
Aug 24 02:15:08 web2 qdiskd[2712]: <info> Node 4 shutdown
Aug 24 02:15:21 web2 openais[2689]: [TOTEM] entering GATHER state from 12.
Aug 24 02:15:41 web2 openais[2689]: [TOTEM] entering GATHER state from 11.
Aug 24 02:15:41 web2 openais[2689]: [TOTEM] Saving state aru b7 high seqreceived b7
Aug 24 02:15:41 web2 openais[2689]: [TOTEM] Storing new sequence id for ringbd8
Aug 24 02:15:41 web2 openais[2689]: [TOTEM] entering COMMIT state.
Aug 24 02:15:41 web2 openais[2689]: [TOTEM] entering RECOVERY state.
Aug 24 02:15:41 web2 openais[2689]: [TOTEM] position [0] member 192.168.12.231:
Aug 24 02:15:41 web2 openais[2689]: [TOTEM] previous ring seq 3028 rep192.168.12.230
Aug 24 02:15:41 web2 openais[2689]: [TOTEM] aru b7 high delivered b7 receivedflag 1
Aug 24 02:15:41 web2 openais[2689]: [TOTEM] position [1] member 192.168.12.232:
Aug 24 02:15:41 web2 openais[2689]: [TOTEM] previous ring seq 3028 rep192.168.12.230
Aug 24 02:15:41 web2 openais[2689]: [TOTEM] aru b7 high delivered b7 receivedflag 1
Aug 24 02:15:41 web2 openais[2689]: [TOTEM] position [2] member 192.168.12.240:
Aug 24 02:15:41 web2 openais[2689]: [TOTEM] previous ring seq 3028 rep192.168.12.230
Aug 24 02:15:41 web2 openais[2689]: [TOTEM] aru b7 high delivered b7 receivedflag 1
Aug 24 02:15:41 web2 openais[2689]: [TOTEM] Did not need to originate anymessages in recovery.
Aug 24 02:15:41 web2 openais[2689]: [CLM ] CLM CONFIGURATION CHANGE
Aug 24 02:15:41 web2 openais[2689]: [CLM ] New Configuration:
Aug 24 02:15:41 web2 openais[2689]: [CLM ] r(0)ip(192.168.12.231)
Aug 24 02:15:41 web2 openais[2689]: [CLM ] r(0)ip(192.168.12.232)
Aug 24 02:15:41 web2 openais[2689]: [CLM ] r(0)ip(192.168.12.240)
Aug 24 02:15:41 web2 openais[2689]: [CLM ] Members Left:
Aug 24 02:15:41 web2 kernel: dlm: closing connection to node 4
Aug 24 02:15:41 web2 openais[2689]: [CLM ] r(0)ip(192.168.12.230)
Aug 24 02:15:41 web2 openais[2689]: [CLM ] Members Joined:
Aug 24 02:15:41 web2 openais[2689]: [CLM ] CLM CONFIGURATION CHANGE
Aug 24 02:15:41 web2 openais[2689]: [CLM ] New Configuration:
Aug 24 02:15:41 web2 openais[2689]: [CLM ] r(0)ip(192.168.12.231)
Aug 24 02:15:41 web2 openais[2689]: [CLM ] r(0)ip(192.168.12.232)
Aug 24 02:15:41 web2 openais[2689]: [CLM ] r(0)ip(192.168.12.240)
Aug 24 02:15:41 web2 openais[2689]: [CLM ] Members Left:
Aug 24 02:15:41 web2 openais[2689]: [CLM ] Members Joined:
Aug 24 02:15:41 web2 openais[2689]: [SYNC ] This node is within the primarycomponent and will provide service.
Aug 24 02:15:41 web2 openais[2689]: [TOTEM] entering OPERATIONAL state.
Aug 24 02:15:41 web2 openais[2689]: [CLM ] got nodejoin message192.168.12.231
Aug 24 02:15:41 web2 openais[2689]: [CLM ] got nodejoin message192.168.12.232
Aug 24 02:15:41 web2 openais[2689]: [CLM ] got nodejoin message192.168.12.240
Aug 24 02:15:41 web2 openais[2689]: [CPG ] got joinlist message from node2
Aug 24 02:15:41 web2 openais[2689]: [CPG ] got joinlist message from node3
Aug 24 02:15:41 web2 openais[2689]: [CPG ] got joinlist message from node1
从输出日志可知，节点web1正常关机后，节点web1的服务和IP资源自动切换到了节点web2上，然后由qdiskd进程将节点web1从集群系统中隔离。由于web1节点是正常关闭，所以集群中GFS2共享文件系统可以正常读写，不受web1关闭的影响。
此时，在web2查看节点web1的状态：
[root@web2 ~]# clustat -m web1
Member Name ID Status
---------- ---- ------
web1 4 Offline
从输出可知，web1节点已经处于offline状态了。
接着，登录到节点web2，查看集群服务和IP资源是否正常切换，操作如下：
[root@web2 ~]# clustat -s webserver
Service Name Owner(Last) State
------- ---- ----------- -----
service:webserver web2 started
[root@web2 ~]# ip addr show|grep eth0
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast qlen1000
inet 192.168.12.240/24 brd 192.168.12.255 scope global eth0
inet 192.168.12.233/24 scope global secondary eth0
从输出可知，集群服务和IP地址已经成功切换到web2节点。
最后，重新启动节点web1，然后在节点web2查看/var/log/messages日志，信息如下：
Aug 24 02:42:36 web2 openais[2689]: [TOTEM] entering GATHER state from 11.
Aug 24 02:42:36 web2 openais[2689]: [TOTEM] Saving state aru 2b high seqreceived 2b
Aug 24 02:42:36 web2 openais[2689]: [TOTEM] Storing new sequence id for ringbdc
Aug 24 02:42:36 web2 openais[2689]: [TOTEM] entering COMMIT state.
Aug 24 02:42:36 web2 openais[2689]: [TOTEM] entering RECOVERY state.
Aug 24 02:42:36 web2 openais[2689]: [TOTEM] position [0] member 192.168.12.230:
Aug 24 02:42:36 web2 openais[2689]: [TOTEM] previous ring seq 3028 rep192.168.12.230
Aug 24 02:42:36 web2 openais[2689]: [TOTEM] aru 0 high delivered 0 receivedflag 1
Aug 24 02:42:36 web2 openais[2689]: [TOTEM] position [1] member 192.168.12.231:
Aug 24 02:42:36 web2 openais[2689]: [TOTEM] previous ring seq 3032 rep192.168.12.231
Aug 24 02:42:36 web2 openais[2689]: [TOTEM] aru 2b high delivered 2b receivedflag 1
Aug 24 02:42:36 web2 openais[2689]: [TOTEM] position [2] member 192.168.12.232:
Aug 24 02:42:36 web2 openais[2689]: [TOTEM] previous ring seq 3032 rep192.168.12.231
Aug 24 02:42:36 web2 openais[2689]: [TOTEM] aru 2b high delivered 2b receivedflag 1
Aug 24 02:42:36 web2 openais[2689]: [TOTEM] position [3] member 192.168.12.240:
Aug 24 02:42:36 web2 openais[2689]: [TOTEM] previous ring seq 3032 rep192.168.12.231
Aug 24 02:42:36 web2 openais[2689]: [TOTEM] aru 2b high delivered 2b receivedflag 1
Aug 24 02:42:36 web2 openais[2689]: [TOTEM] Did not need to originate anymessages in recovery.
Aug 24 02:42:36 web2 openais[2689]: [CLM ] CLM CONFIGURATION CHANGE
Aug 24 02:42:36 web2 openais[2689]: [CLM ] New Configuration:
Aug 24 02:42:36 web2 openais[2689]: [CLM ] r(0)ip(192.168.12.231)
Aug 24 02:42:36 web2 openais[2689]: [CLM ] r(0)ip(192.168.12.232)
Aug 24 02:42:36 web2 openais[2689]: [CLM ] r(0)ip(192.168.12.240)
Aug 24 02:42:36 web2 openais[2689]: [CLM ] Members Left:
Aug 24 02:42:36 web2 openais[2689]: [CLM ] Members Joined:
Aug 24 02:42:36 web2 openais[2689]: [CLM ] CLM CONFIGURATION CHANGE
Aug 24 02:42:36 web2 openais[2689]: [CLM ] New Configuration:
Aug 24 02:42:36 web2 openais[2689]: [CLM ] r(0)ip(192.168.12.230)
Aug 24 02:42:36 web2 openais[2689]: [CLM ] r(0)ip(192.168.12.231)
Aug 24 02:42:36 web2 openais[2689]: [CLM ] r(0)ip(192.168.12.232)
Aug 24 02:42:36 web2 openais[2689]: [CLM ] r(0)ip(192.168.12.240)
Aug 24 02:42:36 web2 openais[2689]: [CLM ] Members Left:
Aug 24 02:42:36 web2 openais[2689]: [CLM ] Members Joined:
Aug 24 02:42:36 web2 openais[2689]: [CLM ] r(0)ip(192.168.12.230)
Aug 24 02:42:36 web2 openais[2689]: [SYNC ] This node is within theprimary component and will provide service.
Aug 24 02:42:36 web2 openais[2689]: [TOTEM] entering OPERATIONAL state.
Aug 24 02:42:36 web2 openais[2689]: [CLM ] got nodejoin message192.168.12.230
Aug 24 02:42:36 web2 openais[2689]: [CLM ] got nodejoin message192.168.12.231
Aug 24 02:42:36 web2 openais[2689]: [CLM ] got nodejoin message192.168.12.232
Aug 24 02:42:36 web2 openais[2689]: [CLM ] got nodejoin message192.168.12.240
Aug 24 02:42:36 web2 openais[2689]: [CPG ] got joinlist message from node3
Aug 24 02:42:36 web2 openais[2689]: [CPG ] got joinlist message from node1
Aug 24 02:42:36 web2 openais[2689]: [CPG ] got joinlist message from node2
Aug 24 02:42:40 web2 kernel: dlm: got connection from 4
Aug 24 02:43:06 web2 clurgmgrd[3239]: <notice> Relocatingservice:webserver to better node web1
Aug 24 02:43:06 web2 clurgmgrd[3239]: <notice> Stopping serviceservice:webserver
Aug 24 02:43:07 web2 avahi-daemon[3110]: Withdrawing address record for192.168.12.233 on eth0.
Aug 24 02:43:17 web2 clurgmgrd[3239]: <notice> Service service:webserveris stopped
从输出可知，节点web1在重新启动后，再次被加入到集群系统中，同时停止自身的服务以及释放IP资源。这个切换方式跟集群 设置的Failover Domain策略有关，在创建的的失败转移域webserver-Failover中，没有加入“Do not fail backservices in this domain”一项功能，也就是主节点在重新启动后，自动将服务切换回来。
此时在节点web1查看/var/log/messages日志，信息如下：
Aug 24 02:43:19 web1 clurgmgrd[3252]: <notice> stop on script"mysqlscript" returned 5 (program not installed)
Aug 24 02:43:35 web1 clurgmgrd[3252]: <notice> Starting stoppedservice service:webserver
Aug 24 02:43:37 web1 avahi-daemon[3126]: Registering new address record for192.168.12.233 on eth0.
Aug 24 02:43:38 web1 in.rdiscd[4075]: setsockopt (IP_ADD_MEMBERSHIP): Addressalready in use
Aug 24 02:43:38 web1 in.rdiscd[4075]: Failed joining addresses
Aug 24 02:43:39 web1 clurgmgrd[3252]: <notice> Service service:webserverstarted
这个输出表明，web1在重启后，自动将集群服务和IP资源切换回来。
（2） 节点web1异常宕机
在节点web1上执行如下命令，让系统内核崩溃：
[root@web2 ~]#echo c>/proc/sysrq-trigger
然后在节点web2上查看/var/log/messages日志，信息如下：
Aug 24 02:59:57 web2 openais[2689]: [TOTEM] entering GATHER state from 12.
Aug 24 03:00:10 web2 qdiskd[2712]: <notice> Node 4 evicted
Aug 24 03:00:17 web2 openais[2689]: [TOTEM] entering GATHER state from 11.
Aug 24 03:00:17 web2 openais[2689]: [TOTEM] Saving state aru 92 high seqreceived 92
Aug 24 03:00:17 web2 openais[2689]: [TOTEM] Storing new sequence id for ringbe0
Aug 24 03:00:17 web2 openais[2689]: [TOTEM] entering COMMIT state.
Aug 24 03:00:17 web2 openais[2689]: [TOTEM] entering RECOVERY state.
Aug 24 03:00:17 web2 openais[2689]: [TOTEM] position [0] member 192.168.12.231:
Aug 24 03:00:17 web2 openais[2689]: [TOTEM] previous ring seq 3036 rep192.168.12.230
Aug 24 03:00:17 web2 openais[2689]: [TOTEM] aru 92 high delivered 92 receivedflag 1
Aug 24 03:00:17 web2 openais[2689]: [TOTEM] position [1] member 192.168.12.232:
Aug 24 03:00:17 web2 openais[2689]: [TOTEM] previous ring seq 3036 rep192.168.12.230
Aug 24 03:00:17 web2 openais[2689]: [TOTEM] aru 92 high delivered 92 receivedflag 1
Aug 24 03:00:17 web2 openais[2689]: [TOTEM] position [2] member 192.168.12.240:
Aug 24 03:00:17 web2 openais[2689]: [TOTEM] previous ring seq 3036 rep192.168.12.230
Aug 24 03:00:17 web2 openais[2689]: [TOTEM] aru 92 high delivered 92 receivedflag 1
Aug 24 03:00:17 web2 openais[2689]: [TOTEM] Did not need to originate anymessages in recovery.
Aug 24 03:00:17 web2 openais[2689]: [CLM ] CLM CONFIGURATION CHANGE
Aug 24 03:00:17 web2 openais[2689]: [CLM ] New Configuration:
Aug 24 03:00:17 web2 openais[2689]: [CLM ] r(0)ip(192.168.12.231)
Aug 24 03:00:17 web2 openais[2689]: [CLM ] r(0)ip(192.168.12.232)
Aug 24 03:00:17 web2 openais[2689]: [CLM ] r(0)ip(192.168.12.240)
Aug 24 03:00:17 web2 openais[2689]: [CLM ] Members Left:
Aug 24 03:00:17 web2 openais[2689]: [CLM ] r(0)ip(192.168.12.230)
Aug 24 03:00:17 web2 kernel: dlm: closing connection to node 4
Aug 24 03:00:17 web2 openais[2689]: [CLM ] Members Joined:
Aug 24 03:00:17 web2 openais[2689]: [CLM ] CLM CONFIGURATION CHANGE
Aug 24 03:00:17 web2 openais[2689]: [CLM ] New Configuration:
Aug 24 03:00:17 web2 openais[2689]: [CLM ] r(0)ip(192.168.12.231)
Aug 24 03:00:17 web2 openais[2689]: [CLM ] r(0)ip(192.168.12.232)
Aug 24 03:00:17 web2 openais[2689]: [CLM ] r(0)ip(192.168.12.240)
Aug 24 03:00:17 web2 openais[2689]: [CLM ] Members Left:
Aug 24 03:00:17 web2 openais[2689]: [CLM ] Members Joined:
Aug 24 03:00:17 web2 openais[2689]: [SYNC ] This node is within the primarycomponent and will provide service.
Aug 24 03:00:17 web2 openais[2689]: [TOTEM] entering OPERATIONAL state.
Aug 24 03:00:17 web2 openais[2689]: [CLM ] got nodejoin message192.168.12.231
Aug 24 03:00:17 web2 openais[2689]: [CLM ] got nodejoin message192.168.12.232
Aug 24 03:00:17 web2 openais[2689]: [CLM ] got nodejoin message192.168.12.240
Aug 24 03:00:17 web2 openais[2689]: [CPG ] got joinlist message from node2
Aug 24 03:00:17 web2 fenced[2728]: web1 not a cluster member after 0 secpost_fail_delay
Aug 24 03:00:17 web2 openais[2689]: [CPG ] got joinlist message from node3
Aug 24 03:00:17 web2 fenced[2728]: fencing node "web1"
Aug 24 03:00:17 web2 openais[2689]: [CPG ] got joinlist message from node1
Aug 24 03:00:55 web2 fenced[2728]: fence "web1" success
Aug 24 03:00:55 web2 kernel: GFS2: fsid=mycluster:my-gfs2.3: jid=0: Trying toacquire journal lock...
Aug 24 03:00:55 web2 kernel: GFS2: fsid=mycluster:my-gfs2.3: jid=0: Looking atjournal...
Aug 24 03:00:55 web2 kernel: GFS2: fsid=mycluster:my-gfs2.3: jid=0: Done
Aug 24 03:00:55 web2 clurgmgrd[3239]: <notice> Taking over serviceservice:webserver from down member web1
Aug 24 03:00:55 web2 avahi-daemon[3110]: Registering new address record for192.168.12.233 on eth0.
Aug 24 03:00:55 web2 clurgmgrd[3239]: <notice> Service service:webserverstarted
从输出日志可以看出，web1在异常宕机后，首先由qdiskd进程将失败节点从集群中隔离，然后qdiskd进程将结果返 回给cman进程，cman进程接着去调用Fence进程，最后Fence进程根据事先设置好的Fence agent调用Fence设备将web1成功Fence掉，clurgmgrd进程在接到成功Fence的信息后，web2开始接管web1的服务和IP 资源，同时释放dlm锁，GFS2文件系统可以正常读写。
4 节点Mysql1宕机时
节点Mysql1在正常关机和异常宕机时，RHCS的切换状态与上面讲述的web1节点宕机情况一模一样，这么不在重复演示。
5 四个节点任意三个宕机
这里将web1、Mysql2、Mysql1依次异常宕机，然后在web2节点查看RHCS是如何进行切换动作的。
首先停止web1节点，查看/var/log/messages日志，信息如下：
Aug 24 18:57:55 web2 openais[2691]: [TOTEM] entering GATHER state from 12.
Aug 24 18:58:14 web2 qdiskd[2714]: <notice> Writing eviction notice fornode 4
Aug 24 18:58:15 web2 openais[2691]: [TOTEM] entering GATHER state from 0.
Aug 24 18:58:15 web2 openais[2691]: [TOTEM] Saving state aru 8e high seqreceived 8e
Aug 24 18:58:15 web2 openais[2691]: [TOTEM] Storing new sequence id for ringc14
Aug 24 18:58:15 web2 openais[2691]: [TOTEM] entering COMMIT state.
Aug 24 18:58:15 web2 openais[2691]: [TOTEM] entering RECOVERY state.
Aug 24 18:58:15 web2 openais[2691]: [TOTEM] position [0] member 192.168.12.231:
Aug 24 18:58:15 web2 openais[2691]: [TOTEM] previous ring seq 3088 rep192.168.12.230
Aug 24 18:58:15 web2 openais[2691]: [TOTEM] aru 8e high delivered 8e receivedflag 1
Aug 24 18:58:15 web2 openais[2691]: [TOTEM] position [1] member 192.168.12.232:
Aug 24 18:58:15 web2 openais[2691]: [TOTEM] previous ring seq 3088 rep192.168.12.230
Aug 24 18:58:15 web2 openais[2691]: [TOTEM] aru 8e high delivered 8e receivedflag 1
Aug 24 18:58:15 web2 openais[2691]: [TOTEM] position [2] member 192.168.12.240:
Aug 24 18:58:15 web2 openais[2691]: [TOTEM] previous ring seq 3088 rep192.168.12.230
Aug 24 18:58:15 web2 openais[2691]: [TOTEM] aru 8e high delivered 8e receivedflag 1
Aug 24 18:58:15 web2 openais[2691]: [TOTEM] Did not need to originate anymessages in recovery.
Aug 24 18:58:15 web2 openais[2691]: [CLM ] CLM CONFIGURATION CHANGE
Aug 24 18:58:15 web2 openais[2691]: [CLM ] New Configuration:
Aug 24 18:58:15 web2 openais[2691]: [CLM ] r(0)ip(192.168.12.231)
Aug 24 18:58:15 web2 openais[2691]: [CLM ] r(0)ip(192.168.12.232)
Aug 24 18:58:15 web2 openais[2691]: [CLM ] r(0)ip(192.168.12.240)
Aug 24 18:58:15 web2 kernel: dlm: closing connection to node 4
Aug 24 18:58:15 web2 openais[2691]: [CLM ] Members Left:
Aug 24 18:58:15 web2 openais[2691]: [CLM ] r(0)ip(192.168.12.230)
Aug 24 18:58:15 web2 openais[2691]: [CLM ] Members Joined:
Aug 24 18:58:15 web2 openais[2691]: [CLM ] CLM CONFIGURATION CHANGE
Aug 24 18:58:15 web2 openais[2691]: [CLM ] New Configuration:
Aug 24 18:58:15 web2 openais[2691]: [CLM ] r(0)ip(192.168.12.231)
Aug 24 18:58:15 web2 openais[2691]: [CLM ] r(0)ip(192.168.12.232)
Aug 24 18:58:15 web2 openais[2691]: [CLM ] r(0) ip(192.168.12.240)
Aug 24 18:58:15 web2 openais[2691]: [CLM ] Members Left:
Aug 24 18:58:15 web2 openais[2691]: [CLM ] Members Joined:
Aug 24 18:58:15 web2 openais[2691]: [SYNC ] This node is within the primarycomponent and will provide service.
Aug 24 18:58:15 web2 openais[2691]: [TOTEM] entering OPERATIONAL state.
Aug 24 18:58:15 web2 openais[2691]: [CLM ] got nodejoin message192.168.12.231
Aug 24 18:58:15 web2 openais[2691]: [CLM ] got nodejoin message192.168.12.232
Aug 24 18:58:15 web2 openais[2691]: [CLM ] got nodejoin message192.168.12.240
Aug 24 18:58:15 web2 fenced[2730]: web1 not a cluster member after 0 secpost_fail_delay
Aug 24 18:58:15 web2 openais[2691]: [CPG ] got joinlist messagefrom node 3
Aug 24 18:58:15 web2 fenced[2730]: fencing node "web1"
Aug 24 18:58:15 web2 openais[2691]: [CPG ] got joinlist message from node1
Aug 24 18:58:15 web2 openais[2691]: [CPG ] got joinlist message from node2
Aug 24 18:58:17 web2 qdiskd[2714]: <notice> Node 4 evicted
Aug 24 18:58:29 web2 fenced[2730]: fence "web1" success
Aug 24 18:58:29 web2 kernel: GFS2: fsid=mycluster:my-gfs2.1: jid=3: Trying toacquire journal lock...
Aug 24 18:58:29 web2 kernel: GFS2: fsid=mycluster:my-gfs2.1: jid=3:Looking at journal...
Aug 24 18:58:29 web2 kernel: GFS2: fsid=mycluster:my-gfs2.1: jid=3: Done
Aug 24 18:58:30 web2 clurgmgrd[3300]: <notice> Taking over serviceservice:webserver from down member web1
Aug 24 18:58:32 web2 avahi-daemon[3174]: Registering new address record for192.168.12.233 on eth0.
Aug 24 18:58:33 web2 clurgmgrd[3300]: <notice> Service service:webserverstarted
通过观察日志可以发现，qdiskd进程会首先将节点web1从集群隔离，然后由fenced进程将web1成功fence掉，最后，web2才接管了web1的服务和IP资源。这里有个先后问题，也就是说，只有Fence成功，集群资源切换才会进行。
如果fenced进程没有成功将web1节点fence掉，那么RHCS会进入等待状态，此时集群系统GFS2共享存储也将变得不可读写，直到Fence进程返回成功信息，集群才开始进行资源切换，同时GFS2文件系统也将恢复读写。
此时，在web2节点通过cman_tool查看集群状态，信息如下：
[root@web2 ~]# cman_tool status
Version: 6.2.0
Config Version: 40
Cluster Name: mycluster
Cluster Id: 56756
Cluster Member: Yes
Cluster Generation: 3092
Membership state: Cluster-Member
Nodes: 3
Expected votes: 6
Quorum device votes: 2
Total votes: 5
Quorum: 3
Active subsystems: 9
Flags: Dirty
Ports Bound: 0 177
Node name: web2
Node ID: 1
Multicast addresses: 239.192.221.146
Node addresses: 192.168.12.240
从输出可知，集群节点数变为3，同时Quorum值也有原来的4变为3，Quorum值是通过N/2整除加一得到的，其中N为所有集群节点的投票数加上表决磁盘投票值。其实也就在这里的“Total votes”值。
接着陆续将Mysql2、Mysql1异常宕机，宕机完成，在web2节点通过cman_tool查看集群状态，信息如下：
[root@web2 ~]# cman_tool status
Version: 6.2.0
Config Version: 40
Cluster Name: mycluster
Cluster Id: 56756
Cluster Member: Yes
Cluster Generation: 3100
Membership state: Cluster-Member
Nodes: 1
Expected votes: 6
Quorum device votes: 2
Total votes: 3
Quorum: 2
Active subsystems: 9
Flags: Dirty
Ports Bound: 0 177
Node name: web2
Node ID: 1
Multicast addresses: 239.192.221.146
Node addresses: 192.168.12.240
从输出可知，整个集群系统节点数已经变为一个，但是集群系统仍然可用，GFS2仍然可以正常读写，这些都是Qdisk的功能，一个RHCS集群中，如果没有表决磁盘的话，
仅剩一个节点的集群是不能工作的。
二、存储集群测试
GFS2文件系统是RHCS集群中的共享存储，在集群各个节点挂载GFS2共享文件系统，然后在任意节点对共享分区进行数据的读写操作，例如：
在节点web2上创建一个文件ixdba：
[root@web2 gfs2]# echo "This is GFS2 Files test" >/gfs2/ixdba
然后在节点web1查看此文件
[root@web1 gfs2]# more /gfs2/ixdba
This is GFS2 Files test
可以看到，写操作正常。
接着测试同时读写文件，首先在节点web1上编辑文件ixdba，然后同时在节点web2也编辑ixdba，此时会提示该文件locked。
到这里为止，RHCS所有功能点都已经测试完成了，在测试集群功能时，观察日志信息是很有必要的，通过观察日志输出，可以知道RHCS更加详细的切换过程，如果切换失败，也会在日志中输出，然后根据错误信息，就可以很容易的定位问题。
目前，RHCS已经广泛应用在企业的各个领域，与其它HA软件相比，RHCS可能显得比较复杂，管理和维护会比较困难，但是RHCS的可靠性和稳定性是毋庸置疑的，随着人们对业务实时性和稳定性需求的不断提升，RHCS的应用毕将越来越广泛。
（待续）
一、 高可用集群测试
在前面的文章中，我们配置了四个节点的集群系统，每个节点的主机名分别是web1、web2、Mysql1、Mysql2，四个节点之间的关系是：web1和web2组成web集群，运行webserver服务，其中web1是主节点，正常状态下服务运行在此节点，web2是备用节 点；Mysql1和Mysql2组成Mysql集群，运行mysqlserver服务，其中，Mysql1是主节点，正常状态下服务运行在此节 点，Mysql2为备用节点。
下面分四种情况介绍当节点发生宕机时，集群是如何进行切换和工作的。
1 节点web2宕机时
宕机分为正常关机和异常宕机两种情况，下面分别说明。
（1） 节点web2正常关机
在节点web2上执行正常关机命令：
[root@web2 ~]#init 0
然后在web1节点查看/var/log/messages日志，输出信息如下：
Aug 24 00:57:09 web1 clurgmgrd[3321]: <notice> Member 1 shutting down
Aug 24 00:57:17 web1 qdiskd[2778]: <info> Node 1 shutdown
Aug 24 00:57:29 web1 openais[2755]: [TOTEM] The token was lost in theOPERATIONAL state.
Aug 24 00:57:29 web1 openais[2755]: [TOTEM] Receive multicast socket recvbuffer size (320000 bytes).
Aug 24 00:57:29 web1 openais[2755]: [TOTEM] Transmit multicast socket sendbuffer size (219136 bytes).
Aug 24 00:57:29 web1 openais[2755]: [TOTEM] entering GATHER state from 2.
Aug 24 00:57:49 web1 openais[2755]: [TOTEM] entering GATHER state from 0.
Aug 24 00:57:49 web1 openais[2755]: [TOTEM] Creating commit token because I amthe rep.
Aug 24 00:57:49 web1 openais[2755]: [TOTEM] Saving state aru 73 high seqreceived 73
Aug 24 00:57:49 web1 openais[2755]: [TOTEM] Storing new sequence id for ringbc8
Aug 24 00:57:49 web1 openais[2755]: [TOTEM] entering COMMIT state.
Aug 24 00:57:49 web1 openais[2755]: [TOTEM] entering RECOVERY state.
Aug 24 00:57:49 web1 openais[2755]: [TOTEM] position [0] member 192.168.12.230:
Aug 24 00:57:49 web1 openais[2755]: [TOTEM] previous ring seq 3012 rep192.168.12.230
Aug 24 00:57:49 web1 openais[2755]: [TOTEM] aru 73 high delivered 73 receivedflag 1
Aug 24 00:57:49 web1 openais[2755]: [TOTEM] position [1] member 192.168.12.231:
Aug 24 00:57:49 web1 openais[2755]: [TOTEM] previous ring seq 3012 rep192.168.12.230
Aug 24 00:57:49 web1 openais[2755]: [TOTEM] aru 73 high delivered 73 receivedflag 1
Aug 24 00:57:49 web1 openais[2755]: [TOTEM] position [2] member 192.168.12.232:
Aug 24 00:57:49 web1 openais[2755]: [TOTEM] previous ring seq 3012 rep192.168.12.230
Aug 24 00:57:49 web1 openais[2755]: [TOTEM] aru 73 high delivered 73 receivedflag 1
Aug 24 00:57:49 web1 openais[2755]: [TOTEM] Did not need to originate anymessages in recovery.
Aug 24 00:57:49 web1 openais[2755]: [TOTEM] Sending initial ORF token
Aug 24 00:57:49 web1 openais[2755]: [CLM ] CLM CONFIGURATION CHANGE
Aug 24 00:57:49 web1 openais[2755]: [CLM ] New Configuration:
Aug 24 00:57:49 web1 openais[2755]: [CLM ] r(0)ip(192.168.12.230)
Aug 24 00:57:49 web1 openais[2755]: [CLM ] r(0)ip(192.168.12.231)
Aug 24 00:57:49 web1 openais[2755]: [CLM ] r(0)ip(192.168.12.232)
Aug 24 00:57:49 web1 openais[2755]: [CLM ] Members Left:
Aug 24 00:57:49 web1 openais[2755]: [CLM ] r(0)ip(192.168.12.240)
Aug 24 00:57:49 web1 kernel: dlm: closing connection to node 1
Aug 24 00:57:49 web1 openais[2755]: [CLM ] Members Joined:
Aug 24 00:57:49 web1 openais[2755]: [CLM ] CLM CONFIGURATION CHANGE
Aug 24 00:57:49 web1 openais[2755]: [CLM ] New Configuration:
Aug 24 00:57:49 web1 openais[2755]: [CLM ] r(0)ip(192.168.12.230)
Aug 24 00:57:49 web1 openais[2755]: [CLM ] r(0)ip(192.168.12.231)
Aug 24 00:57:49 web1 openais[2755]: [CLM ] r(0)ip(192.168.12.232)
Aug 24 00:57:49 web1 openais[2755]: [CLM ] Members Left:
Aug 24 00:57:49 web1 openais[2755]: [CLM ] Members Joined:
Aug 24 00:57:49 web1 openais[2755]: [SYNC ] This node is within the primarycomponent and will provide service.
Aug 24 00:57:49 web1 openais[2755]: [TOTEM] entering OPERATIONAL state.
Aug 24 00:57:49 web1 openais[2755]: [CLM ] got nodejoin message192.168.12.230
Aug 24 00:57:49 web1 openais[2755]: [CLM ] got nodejoin message192.168.12.231
Aug 24 00:57:49 web1 openais[2755]: [CLM ] got nodejoin message192.168.12.232
Aug 24 00:57:49 web1 openais[2755]: [CPG ] got joinlist message from node3
Aug 24 00:57:49 web1 openais[2755]: [CPG ] got joinlist message from node4
Aug 24 00:57:49 web1 openais[2755]: [CPG ] got joinlist message from node2
从输出日志可以看出，当web2节点正常关机后，qdiskd进程立刻检测到web2节点已经关闭，然后dlm锁进程正常关闭了从web2的连接，由于是 正常关闭节点web2，所以RHCS认为整个集群系统没有发生异常，仅仅把节点web2从集群中隔离而已。请重点查看日志中斜体部分。
重新启动web2节点，然后在web1上继续观察日志信息：
Aug 24 01:10:50 web1 openais[2755]: [TOTEM] entering GATHER state from 11.
Aug 24 01:10:51 web1 openais[2755]: [TOTEM] Creating commit token because I amthe rep.
Aug 24 01:10:51 web1 openais[2755]: [TOTEM] Saving state aru 2b high seqreceived 2b
Aug 24 01:10:51 web1 openais[2755]: [TOTEM] Storing new sequence id for ringbcc
Aug 24 01:10:51 web1 openais[2755]: [TOTEM] entering COMMIT state.
Aug 24 01:10:51 web1 openais[2755]: [TOTEM] entering RECOVERY state.
Aug 24 01:10:51 web1 openais[2755]: [TOTEM] position [0] member 192.168.12.230:
Aug 24 01:10:51 web1 openais[2755]: [TOTEM] previous ring seq 3016 rep192.168.12.230
Aug 24 01:10:51 web1 openais[2755]: [TOTEM] aru 2b high delivered 2b receivedflag 1
Aug 24 01:10:51 web1 openais[2755]: [TOTEM] position [1] member 192.168.12.231:
Aug 24 01:10:51 web1 openais[2755]: [TOTEM] previous ring seq 3016 rep192.168.12.230
Aug 24 01:10:51 web1 openais[2755]: [TOTEM] aru 2b high delivered 2b receivedflag 1
Aug 24 01:10:51 web1 openais[2755]: [TOTEM] position [2] member 192.168.12.232:
Aug 24 01:10:51 web1 openais[2755]: [TOTEM] previous ring seq 3016 rep192.168.12.230
Aug 24 01:10:51 web1 openais[2755]: [TOTEM] aru 2b high delivered 2b receivedflag 1
Aug 24 01:10:51 web1 openais[2755]: [TOTEM] position [3] member 192.168.12.240:
Aug 24 01:10:51 web1 openais[2755]: [TOTEM] previous ring seq 3016 rep192.168.12.240
Aug 24 01:10:51 web1 openais[2755]: [TOTEM] aru c high delivered c receivedflag 1
Aug 24 01:10:51 web1 openais[2755]: [TOTEM] Did not need to originate anymessages in recovery.
Aug 24 01:10:51 web1 openais[2755]: [TOTEM] Sending initial ORF token
Aug 24 01:10:51 web1 openais[2755]: [CLM ] CLM CONFIGURATION CHANGE
Aug 24 01:10:51 web1 openais[2755]: [CLM ] New Configuration:
Aug 24 01:10:51 web1 openais[2755]: [CLM ] r(0)ip(192.168.12.230)
Aug 24 01:10:51 web1 openais[2755]: [CLM ] r(0)ip(192.168.12.231)
Aug 24 01:10:51 web1 openais[2755]: [CLM ] r(0)ip(192.168.12.232)
Aug 24 01:10:51 web1 openais[2755]: [CLM ] Members Left:
Aug 24 01:10:51 web1 openais[2755]: [CLM ] Members Joined:
Aug 24 01:10:51 web1 openais[2755]: [CLM ] CLM CONFIGURATION CHANGE
Aug 24 01:10:51 web1 openais[2755]: [CLM ] New Configuration:
Aug 24 01:10:51 web1 openais[2755]: [CLM ] r(0)ip(192.168.12.230)
Aug 24 01:10:51 web1 openais[2755]: [CLM ] r(0)ip(192.168.12.231)
Aug 24 01:10:51 web1 openais[2755]: [CLM ] r(0)ip(192.168.12.232)
Aug 24 01:10:51 web1 openais[2755]: [CLM ] r(0)ip(192.168.12.240)
Aug 24 01:10:51 web1 openais[2755]: [CLM ] Members Left:
Aug 24 01:10:51 web1 openais[2755]: [CLM ] Members Joined:
Aug 24 01:10:51 web1 openais[2755]: [CLM ] r(0)ip(192.168.12.240)
Aug 24 01:10:51 web1 openais[2755]: [SYNC ] This node is within theprimary component and will provide service.
Aug 24 01:10:51 web1 openais[2755]: [TOTEM] entering OPERATIONAL state.
Aug 24 01:10:51 web1 openais[2755]: [CLM ] got nodejoin message192.168.12.230
Aug 24 01:10:51 web1 openais[2755]: [CLM ] got nodejoin message192.168.12.231
Aug 24 01:10:51 web1 openais[2755]: [CLM ] got nodejoin message192.168.12.232
Aug 24 01:10:51 web1 openais[2755]: [CLM ] got nodejoin message192.168.12.240
Aug 24 01:10:51 web1 openais[2755]: [CPG ] got joinlist messagefrom node 3
Aug 24 01:10:51 web1 openais[2755]: [CPG ] got joinlist message from node4
Aug 24 01:10:51 web1 openais[2755]: [CPG ] got joinlist message from node2
Aug 24 01:10:55 web1 kernel: dlm: connecting to 1
从输出可知，重新启动节点web2后，openais底层通信进程检测到web2节点已经激活，并且将web2重新加入集群中，请重点查看日志中斜体部分。
（2） 节点web2异常宕机
在节点web2上执行如下命令，让内核崩溃：
[root@web2 ~]#echo c>/proc/sysrq-trigger
然后在节点Mysql1上查看/var/log/messages日志，信息如下：
Aug 24 02:26:16 Mysql1 openais[2649]: [TOTEM] entering GATHER state from 12.
Aug 24 02:26:28 Mysql1 qdiskd[2672]: <notice> Node 1 evicted
Aug 24 02:26:36 Mysql1 openais[2649]: [TOTEM] entering GATHER statefrom 11.
Aug 24 02:26:36 Mysql1 openais[2649]: [TOTEM] Saving state aru 78 high seqreceived 78
Aug 24 02:26:36 Mysql1 openais[2649]: [TOTEM] Storing new sequence id for ringbd0
Aug 24 02:26:36 Mysql1 openais[2649]: [TOTEM] entering COMMIT state.
Aug 24 02:26:36 Mysql1 openais[2649]: [TOTEM] entering RECOVERY state.
Aug 24 02:26:36 Mysql1 openais[2649]: [TOTEM] position [0] member192.168.12.230:
Aug 24 02:26:36 Mysql1 openais[2649]: [TOTEM] previous ring seq 3020 rep192.168.12.230
Aug 24 02:26:36 Mysql1 openais[2649]: [TOTEM] aru 78 high delivered 78 receivedflag 1
Aug 24 02:26:36 Mysql1 openais[2649]: [TOTEM] position [1] member192.168.12.231:
Aug 24 02:26:36 Mysql1 openais[2649]: [TOTEM] previous ring seq 3020 rep192.168.12.230
Aug 24 02:26:36 Mysql1 openais[2649]: [TOTEM] aru 78 high delivered 78 receivedflag 1
Aug 24 02:26:36 Mysql1 openais[2649]: [TOTEM] position [2] member192.168.12.232:
Aug 24 02:26:36 Mysql1 openais[2649]: [TOTEM] previous ring seq 3020 rep192.168.12.230
Aug 24 02:26:36 Mysql1 openais[2649]: [TOTEM] aru 78 high delivered 78 receivedflag 1
Aug 24 02:26:36 Mysql1 openais[2649]: [TOTEM] Did not need to originate anymessages in recovery.
Aug 24 02:26:36 Mysql1 openais[2649]: [CLM ] CLM CONFIGURATION CHANGE
Aug 24 02:26:36 Mysql1 openais[2649]: [CLM ] New Configuration:
Aug 24 02:26:36 Mysql1 kernel: dlm: closing connection to node 1
Aug 24 02:26:36 Mysql1 openais[2649]: [CLM ] r(0)ip(192.168.12.230)
Aug 24 02:26:36 Mysql1 openais[2649]: [CLM ] r(0)ip(192.168.12.231)
Aug 24 02:26:36 Mysql1 openais[2649]: [CLM ] r(0) ip(192.168.12.232)
Aug 24 02:26:36 Mysql1 openais[2649]: [CLM ] Members Left:
Aug 24 02:26:36 Mysql1 openais[2649]: [CLM ] r(0)ip(192.168.12.240)
Aug 24 02:26:36 Mysql1 openais[2649]: [CLM ] Members Joined:
Aug 24 02:26:36 Mysql1 openais[2649]: [CLM ] CLM CONFIGURATION CHANGE
Aug 24 02:26:36 Mysql1 openais[2649]: [CLM ] New Configuration:
Aug 24 02:26:36 Mysql1 openais[2649]: [CLM ] r(0)ip(192.168.12.230)
Aug 24 02:26:36 Mysql1 openais[2649]: [CLM ] r(0)ip(192.168.12.231)
Aug 24 02:26:36 Mysql1 openais[2649]: [CLM ] r(0)ip(192.168.12.232)
Aug 24 02:26:36 Mysql1 openais[2649]: [CLM ] Members Left:
Aug 24 02:26:36 Mysql1 openais[2649]: [CLM ] Members Joined:
Aug 24 02:26:36 Mysql1 openais[2649]: [SYNC ] This node is within the primarycomponent and will provide service.
Aug 24 02:26:36 Mysql1 fenced[2688]: web2 not a cluster member after 0 secpost_fail_delay
Aug 24 02:26:36 Mysql1 openais[2649]: [TOTEM] entering OPERATIONAL state.
Aug 24 02:26:36 Mysql1 fenced[2688]: fencing node "web2"
Aug 24 02:26:36 Mysql1 openais[2649]: [CLM ] got nodejoin message192.168.12.230
Aug 24 02:26:36 Mysql1 openais[2649]: [CLM ] got nodejoin message192.168.12.231
Aug 24 02:26:36 Mysql1 openais[2649]: [CLM ] got nodejoin message192.168.12.232
Aug 24 02:26:36 Mysql1 openais[2649]: [CPG ] got joinlist message fromnode 3
Aug 24 02:26:36 Mysql1 openais[2649]: [CPG ] got joinlist message fromnode 4
Aug 24 02:26:36 Mysql1 openais[2649]: [CPG ] got joinlist message fromnode 2
Aug 24 02:26:45 Mysql1 fenced[2688]: fence "web2" success
Aug 24 02:26:45 Mysql1 kernel: GFS2: fsid=mycluster:my-gfs2.2: jid=3: Trying toacquire journal lock...
Aug 24 02:26:45 Mysql1 kernel: GFS2: fsid=mycluster:my-gfs2.2: jid=3: Lookingat journal...
Aug 24 02:26:45 Mysql1 kernel: GFS2: fsid=mycluster:my-gfs2.2: jid=3: Done
从输出信息可知，qdiskd首先检测到web2出现异常，然后将它从集群中隔离，由于是异常宕机，所以RHCS为了保证集群资源的唯一性，必须重置 web2节点，于是fenced进程启动， 在fenced进程没有返回成功信息之前，所有节点挂载的GFS2共享分区将无法使用，处于hung住的状态。直到fence成功。
此时，在节点web1上查看web2的集群状态：
[root@web1 ~]#clustat -m web2
Member Name ID Status
------ ---- ---- ------
web2 1 Offline
由输出可知，web2已经处于offline状态了。
2 节点Mysql2宕机时
节点Mysql2在正常关机和异常宕机时，RHCS的切换状态与上面讲述的web2节点情况一模一样，这么不在重复讲述。
3 节点web1宕机时
（1） 节点web1正常关机
[root@web1 ~]# init 0
然后在节点web2上查看/var/log/messages日志，信息如下：
Aug 24 02:06:13 web2 last message repeated 3 times
Aug 24 02:14:58 web2 clurgmgrd[3239]: <notice> Member 4 shutting down
Aug 24 02:15:03 web2 clurgmgrd[3239]: <notice> Starting stopped serviceservice:webserver
Aug 24 02:15:05 web2 avahi-daemon[3110]: Registering new address record for192.168.12.233 on eth0.
Aug 24 02:15:06 web2 in.rdiscd[4451]: setsockopt (IP_ADD_MEMBERSHIP): Addressalready in use
Aug 24 02:15:06 web2 in.rdiscd[4451]: Failed joining addresses
Aug 24 02:15:07 web2 clurgmgrd[3239]: <notice> Service service:webserverstarted
Aug 24 02:15:08 web2 qdiskd[2712]: <info> Node 4 shutdown
Aug 24 02:15:21 web2 openais[2689]: [TOTEM] entering GATHER state from 12.
Aug 24 02:15:41 web2 openais[2689]: [TOTEM] entering GATHER state from 11.
Aug 24 02:15:41 web2 openais[2689]: [TOTEM] Saving state aru b7 high seqreceived b7
Aug 24 02:15:41 web2 openais[2689]: [TOTEM] Storing new sequence id for ringbd8
Aug 24 02:15:41 web2 openais[2689]: [TOTEM] entering COMMIT state.
Aug 24 02:15:41 web2 openais[2689]: [TOTEM] entering RECOVERY state.
Aug 24 02:15:41 web2 openais[2689]: [TOTEM] position [0] member 192.168.12.231:
Aug 24 02:15:41 web2 openais[2689]: [TOTEM] previous ring seq 3028 rep192.168.12.230
Aug 24 02:15:41 web2 openais[2689]: [TOTEM] aru b7 high delivered b7 receivedflag 1
Aug 24 02:15:41 web2 openais[2689]: [TOTEM] position [1] member 192.168.12.232:
Aug 24 02:15:41 web2 openais[2689]: [TOTEM] previous ring seq 3028 rep192.168.12.230
Aug 24 02:15:41 web2 openais[2689]: [TOTEM] aru b7 high delivered b7 receivedflag 1
Aug 24 02:15:41 web2 openais[2689]: [TOTEM] position [2] member 192.168.12.240:
Aug 24 02:15:41 web2 openais[2689]: [TOTEM] previous ring seq 3028 rep192.168.12.230
Aug 24 02:15:41 web2 openais[2689]: [TOTEM] aru b7 high delivered b7 receivedflag 1
Aug 24 02:15:41 web2 openais[2689]: [TOTEM] Did not need to originate anymessages in recovery.
Aug 24 02:15:41 web2 openais[2689]: [CLM ] CLM CONFIGURATION CHANGE
Aug 24 02:15:41 web2 openais[2689]: [CLM ] New Configuration:
Aug 24 02:15:41 web2 openais[2689]: [CLM ] r(0)ip(192.168.12.231)
Aug 24 02:15:41 web2 openais[2689]: [CLM ] r(0)ip(192.168.12.232)
Aug 24 02:15:41 web2 openais[2689]: [CLM ] r(0)ip(192.168.12.240)
Aug 24 02:15:41 web2 openais[2689]: [CLM ] Members Left:
Aug 24 02:15:41 web2 kernel: dlm: closing connection to node 4
Aug 24 02:15:41 web2 openais[2689]: [CLM ] r(0)ip(192.168.12.230)
Aug 24 02:15:41 web2 openais[2689]: [CLM ] Members Joined:
Aug 24 02:15:41 web2 openais[2689]: [CLM ] CLM CONFIGURATION CHANGE
Aug 24 02:15:41 web2 openais[2689]: [CLM ] New Configuration:
Aug 24 02:15:41 web2 openais[2689]: [CLM ] r(0)ip(192.168.12.231)
Aug 24 02:15:41 web2 openais[2689]: [CLM ] r(0)ip(192.168.12.232)
Aug 24 02:15:41 web2 openais[2689]: [CLM ] r(0)ip(192.168.12.240)
Aug 24 02:15:41 web2 openais[2689]: [CLM ] Members Left:
Aug 24 02:15:41 web2 openais[2689]: [CLM ] Members Joined:
Aug 24 02:15:41 web2 openais[2689]: [SYNC ] This node is within the primarycomponent and will provide service.
Aug 24 02:15:41 web2 openais[2689]: [TOTEM] entering OPERATIONAL state.
Aug 24 02:15:41 web2 openais[2689]: [CLM ] got nodejoin message192.168.12.231
Aug 24 02:15:41 web2 openais[2689]: [CLM ] got nodejoin message192.168.12.232
Aug 24 02:15:41 web2 openais[2689]: [CLM ] got nodejoin message192.168.12.240
Aug 24 02:15:41 web2 openais[2689]: [CPG ] got joinlist message from node2
Aug 24 02:15:41 web2 openais[2689]: [CPG ] got joinlist message from node3
Aug 24 02:15:41 web2 openais[2689]: [CPG ] got joinlist message from node1
从输出日志可知，节点web1正常关机后，节点web1的服务和IP资源自动切换到了节点web2上，然后由qdiskd进程将节点web1从集群系统中隔离。由于web1节点是正常关闭，所以集群中GFS2共享文件系统可以正常读写，不受web1关闭的影响。
此时，在web2查看节点web1的状态：
[root@web2 ~]# clustat -m web1
Member Name ID Status
---------- ---- ------
web1 4 Offline
从输出可知，web1节点已经处于offline状态了。
接着，登录到节点web2，查看集群服务和IP资源是否正常切换，操作如下：
[root@web2 ~]# clustat -s webserver
Service Name Owner(Last) State
------- ---- ----------- -----
service:webserver web2 started
[root@web2 ~]# ip addr show|grep eth0
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast qlen1000
inet 192.168.12.240/24 brd 192.168.12.255 scope global eth0
inet 192.168.12.233/24 scope global secondary eth0
从输出可知，集群服务和IP地址已经成功切换到web2节点。
最后，重新启动节点web1，然后在节点web2查看/var/log/messages日志，信息如下：
Aug 24 02:42:36 web2 openais[2689]: [TOTEM] entering GATHER state from 11.
Aug 24 02:42:36 web2 openais[2689]: [TOTEM] Saving state aru 2b high seqreceived 2b
Aug 24 02:42:36 web2 openais[2689]: [TOTEM] Storing new sequence id for ringbdc
Aug 24 02:42:36 web2 openais[2689]: [TOTEM] entering COMMIT state.
Aug 24 02:42:36 web2 openais[2689]: [TOTEM] entering RECOVERY state.
Aug 24 02:42:36 web2 openais[2689]: [TOTEM] position [0] member 192.168.12.230:
Aug 24 02:42:36 web2 openais[2689]: [TOTEM] previous ring seq 3028 rep192.168.12.230
Aug 24 02:42:36 web2 openais[2689]: [TOTEM] aru 0 high delivered 0 receivedflag 1
Aug 24 02:42:36 web2 openais[2689]: [TOTEM] position [1] member 192.168.12.231:
Aug 24 02:42:36 web2 openais[2689]: [TOTEM] previous ring seq 3032 rep192.168.12.231
Aug 24 02:42:36 web2 openais[2689]: [TOTEM] aru 2b high delivered 2b receivedflag 1
Aug 24 02:42:36 web2 openais[2689]: [TOTEM] position [2] member 192.168.12.232:
Aug 24 02:42:36 web2 openais[2689]: [TOTEM] previous ring seq 3032 rep192.168.12.231
Aug 24 02:42:36 web2 openais[2689]: [TOTEM] aru 2b high delivered 2b receivedflag 1
Aug 24 02:42:36 web2 openais[2689]: [TOTEM] position [3] member 192.168.12.240:
Aug 24 02:42:36 web2 openais[2689]: [TOTEM] previous ring seq 3032 rep192.168.12.231
Aug 24 02:42:36 web2 openais[2689]: [TOTEM] aru 2b high delivered 2b receivedflag 1
Aug 24 02:42:36 web2 openais[2689]: [TOTEM] Did not need to originate anymessages in recovery.
Aug 24 02:42:36 web2 openais[2689]: [CLM ] CLM CONFIGURATION CHANGE
Aug 24 02:42:36 web2 openais[2689]: [CLM ] New Configuration:
Aug 24 02:42:36 web2 openais[2689]: [CLM ] r(0)ip(192.168.12.231)
Aug 24 02:42:36 web2 openais[2689]: [CLM ] r(0)ip(192.168.12.232)
Aug 24 02:42:36 web2 openais[2689]: [CLM ] r(0)ip(192.168.12.240)
Aug 24 02:42:36 web2 openais[2689]: [CLM ] Members Left:
Aug 24 02:42:36 web2 openais[2689]: [CLM ] Members Joined:
Aug 24 02:42:36 web2 openais[2689]: [CLM ] CLM CONFIGURATION CHANGE
Aug 24 02:42:36 web2 openais[2689]: [CLM ] New Configuration:
Aug 24 02:42:36 web2 openais[2689]: [CLM ] r(0)ip(192.168.12.230)
Aug 24 02:42:36 web2 openais[2689]: [CLM ] r(0)ip(192.168.12.231)
Aug 24 02:42:36 web2 openais[2689]: [CLM ] r(0)ip(192.168.12.232)
Aug 24 02:42:36 web2 openais[2689]: [CLM ] r(0)ip(192.168.12.240)
Aug 24 02:42:36 web2 openais[2689]: [CLM ] Members Left:
Aug 24 02:42:36 web2 openais[2689]: [CLM ] Members Joined:
Aug 24 02:42:36 web2 openais[2689]: [CLM ] r(0)ip(192.168.12.230)
Aug 24 02:42:36 web2 openais[2689]: [SYNC ] This node is within theprimary component and will provide service.
Aug 24 02:42:36 web2 openais[2689]: [TOTEM] entering OPERATIONAL state.
Aug 24 02:42:36 web2 openais[2689]: [CLM ] got nodejoin message192.168.12.230
Aug 24 02:42:36 web2 openais[2689]: [CLM ] got nodejoin message192.168.12.231
Aug 24 02:42:36 web2 openais[2689]: [CLM ] got nodejoin message192.168.12.232
Aug 24 02:42:36 web2 openais[2689]: [CLM ] got nodejoin message192.168.12.240
Aug 24 02:42:36 web2 openais[2689]: [CPG ] got joinlist message from node3
Aug 24 02:42:36 web2 openais[2689]: [CPG ] got joinlist message from node1
Aug 24 02:42:36 web2 openais[2689]: [CPG ] got joinlist message from node2
Aug 24 02:42:40 web2 kernel: dlm: got connection from 4
Aug 24 02:43:06 web2 clurgmgrd[3239]: <notice> Relocatingservice:webserver to better node web1
Aug 24 02:43:06 web2 clurgmgrd[3239]: <notice> Stopping serviceservice:webserver
Aug 24 02:43:07 web2 avahi-daemon[3110]: Withdrawing address record for192.168.12.233 on eth0.
Aug 24 02:43:17 web2 clurgmgrd[3239]: <notice> Service service:webserveris stopped
从输出可知，节点web1在重新启动后，再次被加入到集群系统中，同时停止自身的服务以及释放IP资源。这个切换方式跟集群 设置的Failover Domain策略有关，在创建的的失败转移域webserver-Failover中，没有加入“Do not fail backservices in this domain”一项功能，也就是主节点在重新启动后，自动将服务切换回来。
此时在节点web1查看/var/log/messages日志，信息如下：
Aug 24 02:43:19 web1 clurgmgrd[3252]: <notice> stop on script"mysqlscript" returned 5 (program not installed)
Aug 24 02:43:35 web1 clurgmgrd[3252]: <notice> Starting stoppedservice service:webserver
Aug 24 02:43:37 web1 avahi-daemon[3126]: Registering new address record for192.168.12.233 on eth0.
Aug 24 02:43:38 web1 in.rdiscd[4075]: setsockopt (IP_ADD_MEMBERSHIP): Addressalready in use
Aug 24 02:43:38 web1 in.rdiscd[4075]: Failed joining addresses
Aug 24 02:43:39 web1 clurgmgrd[3252]: <notice> Service service:webserverstarted
这个输出表明，web1在重启后，自动将集群服务和IP资源切换回来。
（2） 节点web1异常宕机
在节点web1上执行如下命令，让系统内核崩溃：
[root@web2 ~]#echo c>/proc/sysrq-trigger
然后在节点web2上查看/var/log/messages日志，信息如下：
Aug 24 02:59:57 web2 openais[2689]: [TOTEM] entering GATHER state from 12.
Aug 24 03:00:10 web2 qdiskd[2712]: <notice> Node 4 evicted
Aug 24 03:00:17 web2 openais[2689]: [TOTEM] entering GATHER state from 11.
Aug 24 03:00:17 web2 openais[2689]: [TOTEM] Saving state aru 92 high seqreceived 92
Aug 24 03:00:17 web2 openais[2689]: [TOTEM] Storing new sequence id for ringbe0
Aug 24 03:00:17 web2 openais[2689]: [TOTEM] entering COMMIT state.
Aug 24 03:00:17 web2 openais[2689]: [TOTEM] entering RECOVERY state.
Aug 24 03:00:17 web2 openais[2689]: [TOTEM] position [0] member 192.168.12.231:
Aug 24 03:00:17 web2 openais[2689]: [TOTEM] previous ring seq 3036 rep192.168.12.230
Aug 24 03:00:17 web2 openais[2689]: [TOTEM] aru 92 high delivered 92 receivedflag 1
Aug 24 03:00:17 web2 openais[2689]: [TOTEM] position [1] member 192.168.12.232:
Aug 24 03:00:17 web2 openais[2689]: [TOTEM] previous ring seq 3036 rep192.168.12.230
Aug 24 03:00:17 web2 openais[2689]: [TOTEM] aru 92 high delivered 92 receivedflag 1
Aug 24 03:00:17 web2 openais[2689]: [TOTEM] position [2] member 192.168.12.240:
Aug 24 03:00:17 web2 openais[2689]: [TOTEM] previous ring seq 3036 rep192.168.12.230
Aug 24 03:00:17 web2 openais[2689]: [TOTEM] aru 92 high delivered 92 receivedflag 1
Aug 24 03:00:17 web2 openais[2689]: [TOTEM] Did not need to originate anymessages in recovery.
Aug 24 03:00:17 web2 openais[2689]: [CLM ] CLM CONFIGURATION CHANGE
Aug 24 03:00:17 web2 openais[2689]: [CLM ] New Configuration:
Aug 24 03:00:17 web2 openais[2689]: [CLM ] r(0)ip(192.168.12.231)
Aug 24 03:00:17 web2 openais[2689]: [CLM ] r(0)ip(192.168.12.232)
Aug 24 03:00:17 web2 openais[2689]: [CLM ] r(0)ip(192.168.12.240)
Aug 24 03:00:17 web2 openais[2689]: [CLM ] Members Left:
Aug 24 03:00:17 web2 openais[2689]: [CLM ] r(0)ip(192.168.12.230)
Aug 24 03:00:17 web2 kernel: dlm: closing connection to node 4
Aug 24 03:00:17 web2 openais[2689]: [CLM ] Members Joined:
Aug 24 03:00:17 web2 openais[2689]: [CLM ] CLM CONFIGURATION CHANGE
Aug 24 03:00:17 web2 openais[2689]: [CLM ] New Configuration:
Aug 24 03:00:17 web2 openais[2689]: [CLM ] r(0)ip(192.168.12.231)
Aug 24 03:00:17 web2 openais[2689]: [CLM ] r(0)ip(192.168.12.232)
Aug 24 03:00:17 web2 openais[2689]: [CLM ] r(0)ip(192.168.12.240)
Aug 24 03:00:17 web2 openais[2689]: [CLM ] Members Left:
Aug 24 03:00:17 web2 openais[2689]: [CLM ] Members Joined:
Aug 24 03:00:17 web2 openais[2689]: [SYNC ] This node is within the primarycomponent and will provide service.
Aug 24 03:00:17 web2 openais[2689]: [TOTEM] entering OPERATIONAL state.
Aug 24 03:00:17 web2 openais[2689]: [CLM ] got nodejoin message192.168.12.231
Aug 24 03:00:17 web2 openais[2689]: [CLM ] got nodejoin message192.168.12.232
Aug 24 03:00:17 web2 openais[2689]: [CLM ] got nodejoin message192.168.12.240
Aug 24 03:00:17 web2 openais[2689]: [CPG ] got joinlist message from node2
Aug 24 03:00:17 web2 fenced[2728]: web1 not a cluster member after 0 secpost_fail_delay
Aug 24 03:00:17 web2 openais[2689]: [CPG ] got joinlist message from node3
Aug 24 03:00:17 web2 fenced[2728]: fencing node "web1"
Aug 24 03:00:17 web2 openais[2689]: [CPG ] got joinlist message from node1
Aug 24 03:00:55 web2 fenced[2728]: fence "web1" success
Aug 24 03:00:55 web2 kernel: GFS2: fsid=mycluster:my-gfs2.3: jid=0: Trying toacquire journal lock...
Aug 24 03:00:55 web2 kernel: GFS2: fsid=mycluster:my-gfs2.3: jid=0: Looking atjournal...
Aug 24 03:00:55 web2 kernel: GFS2: fsid=mycluster:my-gfs2.3: jid=0: Done
Aug 24 03:00:55 web2 clurgmgrd[3239]: <notice> Taking over serviceservice:webserver from down member web1
Aug 24 03:00:55 web2 avahi-daemon[3110]: Registering new address record for192.168.12.233 on eth0.
Aug 24 03:00:55 web2 clurgmgrd[3239]: <notice> Service service:webserverstarted
从输出日志可以看出，web1在异常宕机后，首先由qdiskd进程将失败节点从集群中隔离，然后qdiskd进程将结果返 回给cman进程，cman进程接着去调用Fence进程，最后Fence进程根据事先设置好的Fence agent调用Fence设备将web1成功Fence掉，clurgmgrd进程在接到成功Fence的信息后，web2开始接管web1的服务和IP 资源，同时释放dlm锁，GFS2文件系统可以正常读写。
4 节点Mysql1宕机时
节点Mysql1在正常关机和异常宕机时，RHCS的切换状态与上面讲述的web1节点宕机情况一模一样，这么不在重复演示。
5 四个节点任意三个宕机
这里将web1、Mysql2、Mysql1依次异常宕机，然后在web2节点查看RHCS是如何进行切换动作的。
首先停止web1节点，查看/var/log/messages日志，信息如下：
Aug 24 18:57:55 web2 openais[2691]: [TOTEM] entering GATHER state from 12.
Aug 24 18:58:14 web2 qdiskd[2714]: <notice> Writing eviction notice fornode 4
Aug 24 18:58:15 web2 openais[2691]: [TOTEM] entering GATHER state from 0.
Aug 24 18:58:15 web2 openais[2691]: [TOTEM] Saving state aru 8e high seqreceived 8e
Aug 24 18:58:15 web2 openais[2691]: [TOTEM] Storing new sequence id for ringc14
Aug 24 18:58:15 web2 openais[2691]: [TOTEM] entering COMMIT state.
Aug 24 18:58:15 web2 openais[2691]: [TOTEM] entering RECOVERY state.
Aug 24 18:58:15 web2 openais[2691]: [TOTEM] position [0] member 192.168.12.231:
Aug 24 18:58:15 web2 openais[2691]: [TOTEM] previous ring seq 3088 rep192.168.12.230
Aug 24 18:58:15 web2 openais[2691]: [TOTEM] aru 8e high delivered 8e receivedflag 1
Aug 24 18:58:15 web2 openais[2691]: [TOTEM] position [1] member 192.168.12.232:
Aug 24 18:58:15 web2 openais[2691]: [TOTEM] previous ring seq 3088 rep192.168.12.230
Aug 24 18:58:15 web2 openais[2691]: [TOTEM] aru 8e high delivered 8e receivedflag 1
Aug 24 18:58:15 web2 openais[2691]: [TOTEM] position [2] member 192.168.12.240:
Aug 24 18:58:15 web2 openais[2691]: [TOTEM] previous ring seq 3088 rep192.168.12.230
Aug 24 18:58:15 web2 openais[2691]: [TOTEM] aru 8e high delivered 8e receivedflag 1
Aug 24 18:58:15 web2 openais[2691]: [TOTEM] Did not need to originate anymessages in recovery.
Aug 24 18:58:15 web2 openais[2691]: [CLM ] CLM CONFIGURATION CHANGE
Aug 24 18:58:15 web2 openais[2691]: [CLM ] New Configuration:
Aug 24 18:58:15 web2 openais[2691]: [CLM ] r(0)ip(192.168.12.231)
Aug 24 18:58:15 web2 openais[2691]: [CLM ] r(0)ip(192.168.12.232)
Aug 24 18:58:15 web2 openais[2691]: [CLM ] r(0)ip(192.168.12.240)
Aug 24 18:58:15 web2 kernel: dlm: closing connection to node 4
Aug 24 18:58:15 web2 openais[2691]: [CLM ] Members Left:
Aug 24 18:58:15 web2 openais[2691]: [CLM ] r(0)ip(192.168.12.230)
Aug 24 18:58:15 web2 openais[2691]: [CLM ] Members Joined:
Aug 24 18:58:15 web2 openais[2691]: [CLM ] CLM CONFIGURATION CHANGE
Aug 24 18:58:15 web2 openais[2691]: [CLM ] New Configuration:
Aug 24 18:58:15 web2 openais[2691]: [CLM ] r(0)ip(192.168.12.231)
Aug 24 18:58:15 web2 openais[2691]: [CLM ] r(0)ip(192.168.12.232)
Aug 24 18:58:15 web2 openais[2691]: [CLM ] r(0) ip(192.168.12.240)
Aug 24 18:58:15 web2 openais[2691]: [CLM ] Members Left:
Aug 24 18:58:15 web2 openais[2691]: [CLM ] Members Joined:
Aug 24 18:58:15 web2 openais[2691]: [SYNC ] This node is within the primarycomponent and will provide service.
Aug 24 18:58:15 web2 openais[2691]: [TOTEM] entering OPERATIONAL state.
Aug 24 18:58:15 web2 openais[2691]: [CLM ] got nodejoin message192.168.12.231
Aug 24 18:58:15 web2 openais[2691]: [CLM ] got nodejoin message192.168.12.232
Aug 24 18:58:15 web2 openais[2691]: [CLM ] got nodejoin message192.168.12.240
Aug 24 18:58:15 web2 fenced[2730]: web1 not a cluster member after 0 secpost_fail_delay
Aug 24 18:58:15 web2 openais[2691]: [CPG ] got joinlist messagefrom node 3
Aug 24 18:58:15 web2 fenced[2730]: fencing node "web1"
Aug 24 18:58:15 web2 openais[2691]: [CPG ] got joinlist message from node1
Aug 24 18:58:15 web2 openais[2691]: [CPG ] got joinlist message from node2
Aug 24 18:58:17 web2 qdiskd[2714]: <notice> Node 4 evicted
Aug 24 18:58:29 web2 fenced[2730]: fence "web1" success
Aug 24 18:58:29 web2 kernel: GFS2: fsid=mycluster:my-gfs2.1: jid=3: Trying toacquire journal lock...
Aug 24 18:58:29 web2 kernel: GFS2: fsid=mycluster:my-gfs2.1: jid=3:Looking at journal...
Aug 24 18:58:29 web2 kernel: GFS2: fsid=mycluster:my-gfs2.1: jid=3: Done
Aug 24 18:58:30 web2 clurgmgrd[3300]: <notice> Taking over serviceservice:webserver from down member web1
Aug 24 18:58:32 web2 avahi-daemon[3174]: Registering new address record for192.168.12.233 on eth0.
Aug 24 18:58:33 web2 clurgmgrd[3300]: <notice> Service service:webserverstarted
通过观察日志可以发现，qdiskd进程会首先将节点web1从集群隔离，然后由fenced进程将web1成功fence掉，最后，web2才接管了web1的服务和IP资源。这里有个先后问题，也就是说，只有Fence成功，集群资源切换才会进行。
如果fenced进程没有成功将web1节点fence掉，那么RHCS会进入等待状态，此时集群系统GFS2共享存储也将变得不可读写，直到Fence进程返回成功信息，集群才开始进行资源切换，同时GFS2文件系统也将恢复读写。
此时，在web2节点通过cman_tool查看集群状态，信息如下：
[root@web2 ~]# cman_tool status
Version: 6.2.0
Config Version: 40
Cluster Name: mycluster
Cluster Id: 56756
Cluster Member: Yes
Cluster Generation: 3092
Membership state: Cluster-Member
Nodes: 3
Expected votes: 6
Quorum device votes: 2
Total votes: 5
Quorum: 3
Active subsystems: 9
Flags: Dirty
Ports Bound: 0 177
Node name: web2
Node ID: 1
Multicast addresses: 239.192.221.146
Node addresses: 192.168.12.240
从输出可知，集群节点数变为3，同时Quorum值也有原来的4变为3，Quorum值是通过N/2整除加一得到的，其中N为所有集群节点的投票数加上表决磁盘投票值。其实也就在这里的“Total votes”值。
接着陆续将Mysql2、Mysql1异常宕机，宕机完成，在web2节点通过cman_tool查看集群状态，信息如下：
[root@web2 ~]# cman_tool status
Version: 6.2.0
Config Version: 40
Cluster Name: mycluster
Cluster Id: 56756
Cluster Member: Yes
Cluster Generation: 3100
Membership state: Cluster-Member
Nodes: 1
Expected votes: 6
Quorum device votes: 2
Total votes: 3
Quorum: 2
Active subsystems: 9
Flags: Dirty
Ports Bound: 0 177
Node name: web2
Node ID: 1
Multicast addresses: 239.192.221.146
Node addresses: 192.168.12.240
从输出可知，整个集群系统节点数已经变为一个，但是集群系统仍然可用，GFS2仍然可以正常读写，这些都是Qdisk的功能，一个RHCS集群中，如果没有表决磁盘的话，
仅剩一个节点的集群是不能工作的。
二、存储集群测试
GFS2文件系统是RHCS集群中的共享存储，在集群各个节点挂载GFS2共享文件系统，然后在任意节点对共享分区进行数据的读写操作，例如：
在节点web2上创建一个文件ixdba：
[root@web2 gfs2]# echo "This is GFS2 Files test" >/gfs2/ixdba
然后在节点web1查看此文件
[root@web1 gfs2]# more /gfs2/ixdba
This is GFS2 Files test
可以看到，写操作正常。
接着测试同时读写文件，首先在节点web1上编辑文件ixdba，然后同时在节点web2也编辑ixdba，此时会提示该文件locked。
到这里为止，RHCS所有功能点都已经测试完成了，在测试集群功能时，观察日志信息是很有必要的，通过观察日志输出，可以知道RHCS更加详细的切换过程，如果切换失败，也会在日志中输出，然后根据错误信息，就可以很容易的定位问题。
目前，RHCS已经广泛应用在企业的各个领域，与其它HA软件相比，RHCS可能显得比较复杂，管理和维护会比较困难，但是RHCS的可靠性和稳定性是毋庸置疑的，随着人们对业务实时性和稳定性需求的不断提升，RHCS的应用毕将越来越广泛。
（待续）
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