Re: [cman] cant joint cluster after reboot

Yuriy Demchenko <demchenko.ya@xxxxxxxxx> · Fri, 08 Nov 2013 12:16:43 +0400

Thanks, the problem indeed in multicast. Switching to udpu brought 
cluster to normal operation.

Any tips how to fix multicast operation? igmp snooping on switch is 
disabled, firewall disabled too.
In fact, what confuses me is that node cant join cluster after reboot no 
matter how long i'll wait after reboot, no matter how many times i'll do 
"service cman restart" on that node - it just dont work until cman 
restarted on some other node.
Another strange thing - i've used tcpdump to capture udp traffic and 
there were no udp traffic at all from node-1 after reboot, no traffic 
after service restarts. But as soon as service restarted on other node - 
udp traffic to multicast address appeared from node-1.

I've also tried to switch igmp snooping on, but that caused cluster not 
working at all - each node saw only itself. On switch I saw that 
multicast group was created, each corresponded port became member of 
that group, but packet statistics shown only few "report v3" packets, no 
query/leave/error packets.

Yuriy Demchenko

On 11/07/2013 05:47 PM, Christine Caulfield wrote:
On 07/11/13 12:04, Yuriy Demchenko wrote:
Hi,

I'm trying to set up 3-node cluster (2 nodes + 1 standby node for
quorum) with cman+pacemaker stack, everything according this quickstart
article: http://clusterlabs.org/quickstart-redhat.html

Cluster starts, all nodes see each other, quorum gained, stonith
working, but I've run into problem with cman: node cant join cluster
after reboot - cman starts and cman_tool nodes reports only that node as
cluster-member, while on other 2 nodes it reports 2 nodes as
cluster-member and 3rd as offline. cman stop/start/restart on the
problem node does no effect - it still can see only itself, but if i'll
do cman restart on one of working nodes - everything goes back to
normal, all 3 nodes joins the cluster and subsequent cman service
restarts on any nodes works fine - node lefts cluster and rejoins
sucessfully. But again - only till node OS reboot.

For example:
[1] Working cluster:
[root@node-1 ~]# cman_tool nodes
Node  Sts   Inc   Joined               Name
   1   M    592   2013-11-07 15:20:54  node-1.spb.stone.local
   2   M    760   2013-11-07 15:20:54  node-2.spb.stone.local
   3   M    760   2013-11-07 15:20:54  vnode-3.spb.stone.local
[root@node-1 ~]# cman_tool status
Version: 6.2.0
Config Version: 10
Cluster Name: ocluster
Cluster Id: 2059
Cluster Member: Yes
Cluster Generation: 760
Membership state: Cluster-Member
Nodes: 3
Expected votes: 3
Total votes: 3
Node votes: 1
Quorum: 2
Active subsystems: 7
Flags:
Ports Bound: 0
Node name: node-1.spb.stone.local
Node ID: 1
Multicast addresses: 239.192.8.19
Node addresses: 192.168.220.21
Picture is same on all 3 nodes (except for node name and id) - same
cluster name, cluster id, multicast addres.

[2] I've put node-1 into reboot. After reboot complete, "cman_tool
nodes" on node-2 and vnode-3 shows this:
Node  Sts   Inc   Joined Name
   1   X    760                        node-1.spb.stone.local
   2   M    588   2013-11-07 15:11:23  node-2.spb.stone.local
   3   M    760   2013-11-07 15:20:54  vnode-3.spb.stone.local
[root@node-2 ~]# cman_tool status
Version: 6.2.0
Config Version: 10
Cluster Name: ocluster
Cluster Id: 2059
Cluster Member: Yes
Cluster Generation: 764
Membership state: Cluster-Member
Nodes: 2
Expected votes: 3
Total votes: 2
Node votes: 1
Quorum: 2
Active subsystems: 7
Flags:
Ports Bound: 0
Node name: node-2.spb.stone.local
Node ID: 2
Multicast addresses: 239.192.8.19
Node addresses: 192.168.220.22
But, on rebooted node-1 it shows this:
Node  Sts   Inc   Joined Name
   1   M    764   2013-11-07 15:49:01  node-1.spb.stone.local
   2   X      0                        node-2.spb.stone.local
   3   X      0                        vnode-3.spb.stone.local
[root@node-1 ~]# cman_tool status
Version: 6.2.0
Config Version: 10
Cluster Name: ocluster
Cluster Id: 2059
Cluster Member: Yes
Cluster Generation: 776
Membership state: Cluster-Member
Nodes: 1
Expected votes: 3
Total votes: 1
Node votes: 1
Quorum: 2 Activity blocked
Active subsystems: 7
Flags:
Ports Bound: 0
Node name: node-1.spb.stone.local
Node ID: 1
Multicast addresses: 239.192.8.19
Node addresses: 192.168.220.21
so, same cluster name, cluster id, multicast address - but it cant see
other nodes. And there are nothing in /var/log/messages and
/var/log/cluster/corosync.log on other two nodes - they seem not notice
node-1 coming back online at all, last records about node-1 leaving
cluster.

[3] If now i do "service cman restart" on node-2 or vnode-3 - everything
goes back to normal operation as in [1]
in logs it shows as node-2 leaving cluster (service stop) and
simultaneously joining of both node-2 and node-1 (service start)
Nov  7 11:47:06 vnode-3 corosync[26692]: [QUORUM] Members[2]: 2 3
Nov  7 11:47:06 vnode-3 corosync[26692]:   [TOTEM ] A processor joined
or left the membership and a new membership was formed.
Nov  7 11:47:06 vnode-3 kernel: dlm: closing connection to node 1
Nov  7 11:47:06 vnode-3 corosync[26692]:   [CPG   ] chosen downlist:
sender r(0) ip(192.168.220.22) ; members(old:3 left:1)
Nov  7 11:47:06 vnode-3 corosync[26692]:   [MAIN  ] Completed service
synchronization, ready to provide service.
Nov  7 11:53:28 vnode-3 corosync[26692]:   [QUORUM] Members[1]: 3
Nov  7 11:53:28 vnode-3 corosync[26692]:   [TOTEM ] A processor joined
or left the membership and a new membership was formed.
Nov  7 11:53:28 vnode-3 corosync[26692]:   [CPG   ] chosen downlist:
sender r(0) ip(192.168.220.14) ; members(old:2 left:1)
Nov  7 11:53:28 vnode-3 corosync[26692]:   [MAIN  ] Completed service
synchronization, ready to provide service.
Nov  7 11:53:28 vnode-3 kernel: dlm: closing connection to node 2
Nov  7 11:53:30 vnode-3 corosync[26692]:   [TOTEM ] A processor joined
or left the membership and a new membership was formed.
Nov  7 11:53:30 vnode-3 corosync[26692]:   [QUORUM] Members[2]: 1 3
Nov  7 11:53:30 vnode-3 corosync[26692]:   [QUORUM] Members[2]: 1 3
Nov  7 11:53:30 vnode-3 corosync[26692]:   [QUORUM] Members[3]: 1 2 3
Nov  7 11:53:30 vnode-3 corosync[26692]:   [QUORUM] Members[3]: 1 2 3
Nov  7 11:53:30 vnode-3 corosync[26692]:   [QUORUM] Members[3]: 1 2 3
Nov  7 11:53:30 vnode-3 corosync[26692]:   [CPG   ] chosen downlist:
sender r(0) ip(192.168.220.21) ; members(old:1 left:0)
Nov  7 11:53:30 vnode-3 corosync[26692]:   [MAIN  ] Completed service
synchronization, ready to provide service.

I've set up such cluster before in quite same configuration and never
had any problems, but now I'm completely stuck.
So, what is wrong with my cluster and how to fix it?

OS Centos 6.4 with lastest updates, firewall disabled, selinux
permissive, all 3 nodes inside same network. Multicast working - checked
with omping.
cman.x86_64                   3.0.12.1-49.el6_4.2 @centos6-updates
corosync.x86_64               1.4.1-15.el6_4.1 @centos6-updates
pacemaker.x86_64              1.1.10-1.el6_4.4 @centos6-updates

omping working doesn't guaratee that multicast is working. If it fails 
then it doesn't work but the converse is not necessarily true.

I suspect that multicast is causing the trouble here, so try broadcast 
or udpu as transport and see if that helps. Often the switch will take 
some time to recognise the multicast addresses when a node starts up 
and that will break the join protocol.

Chrissie

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