[Pacemaker] Configuring 3rd Node as Quorum Node in 2 Node Cluster
Andrew Martin
amartin at xes-inc.com
Wed Mar 7 09:38:32 EST 2012
Hi Andrew,
I've installed pacemaker and updated my ha.cf on the quorum node, removing ccm and replacing it with the pacemaker respawn line. You're correct - migration happens quickly and does not need to wait for these timeouts. I then reverted crmd-integration-timeout to its default 3m value.
Thanks,
Andrew
----- Original Message -----
From: "Andrew Beekhof" < andrew at beekhof.net >
To: "The Pacemaker cluster resource manager" < pacemaker at oss.clusterlabs.org >
Sent: Monday, February 27, 2012 5:25:46 AM
Subject: Re: [Pacemaker] Configuring 3rd Node as Quorum Node in 2 Node Cluster
It looks like we're waiting for the other node to respond, which it wont do.
Is running pacemaker on the other node but with standby=true an option for you?
On Sat, Feb 25, 2012 at 6:25 AM, Andrew Martin < amartin at xes-inc.com > wrote:
> Hi Andreas,
>
> Thanks, adding "respawn hacluster /usr/lib/heartbeat/ccm" to ha.cf worked.
> Since quorum-node is in standby, it shows up as "OFFLINE (standby)" in
> crm_mon. It seems that "cl_status nodestatus quorum-node" always returns
> "active", even if heartbeat is stopped on the quorum node. However,
> "cl_status hblinkstatus quorum-node br0" can correctly detect if heartbeat
> is down on quorum-node so I can use that to check its connectivity.
>
> I was able to successfully test resources automatically stopping once quorum
> was lost. I did this by shutting down node2 so that only node1 and
> quorum-node remained. I then stopped heartbeat on quorum-node, which
> resulted in node1 losing quorum and the resources stopping (as expected).
> After starting heartbeat on quorum-node again, node1 reestablished quorum
> within about 1 minute. However, it took significantly longer (around 18
> minutes) for the resources on node1 to start again. Looking through the
> logs, I discovered that this is because of the values of
> the cluster-recheck-interval (displayed as "PEngine Recheck Timer" in the
> logs) and crmd-integration-timeout (displayed as "Integration Timer" in the
> logs) properties. Here's the sequence of events as I understand it:
> 1. quorum is reestablished
> 2. the cluster-recheck-interval timer pops, sees that quorum has been
> reestablished, and schedules crmd-integration-timeout to run
> 3. after crmd-integration-timeout's timeout period, it pops and also sees
> that quorum has been restablished and thus starts the resources
>
> Based on this, the maximum wait time for resources to start once quorum has
> been reestablished is the value of cluster-recheck-interval plus the value
> of crmd-integration-timeout, or (15m + 3m). I have confirmed this value
> through several runs of this test. This seems like a very long time to me,
> so I adjusted both of these values down to 1m. Running the test again I was
> able to confirm that the resources started 2m after quorum was
> reestablished:
> ## quorum reestablished
> 12:35:31 node1 ccm: [27015]: debug: quorum plugin: majority
> 12:35:31 node1 ccm: [27015]: debug: cluster:linux-ha, member_count=2,
> member_quorum_votes=200
> 12:35:31 node1 ccm: [27015]: debug: total_node_count=3,
> total_quorum_votes=300
> 12:35:31 node1 crmd: [27020]: info: crmd_ccm_msg_callback: Quorum
> (re)attained after event=NEW MEMBERSHIP (id=14)
> 12:35:31 node1 crmd: [27020]: info: crm_update_quorum: Updating quorum
> status to true (call=366)
> ## cluster-recheck-interval pops, schedules crmd-integration-timeout to run
> after its timout
> 12:36:18 node1 crmd: [27020]: info: crm_timer_popped: PEngine Recheck Timer
> (I_PE_CALC) just popped (60000ms)
> 12:36:18 node1 crmd: [27020]: info: do_state_transition: State transition
> S_IDLE -> S_POLICY_ENGINE [ input=I_PE_CALC cause=C_TIMER_POPPED
> origin=crm_timer_popped ]
> 12:36:18 node1 crmd: [27020]: info: do_state_transition: Progressed to state
> S_POLICY_ENGINE after C_TIMER_POPPED
> ## crmd-integration-timeout runs, starts the resources
> 12:37:18 node1 crmd: [27020]: ERROR: crm_timer_popped: Integration Timer
> (I_INTEGRATED) just popped in state S_INTEGRATION! (60000ms)
> 12:37:18 node1 crmd: [27020]: info: crm_timer_popped: Welcomed: 1,
> Integrated: 1
> 12:37:18 node1 crmd: [27020]: info: do_state_transition: State transition
> S_INTEGRATION -> S_FINALIZE_JOIN [ input=I_INTEGRATED cause=C_TIMER_POPPED
> origin=crm_timer_popped ]
> 12:37:18 node1 crmd: [27020]: WARN: do_state_transition: Progressed to state
> S_FINALIZE_JOIN after C_TIMER_POPPED
> 12:37:20 node1 crmd: [27020]: info: do_dc_join_final: Ensuring DC, quorum
> and node attributes are up-to-date
> 12:37:20 node1 crmd: [27020]: info: crm_update_quorum: Updating quorum
> status to true (call=379)
> 12:37:20 node1 pengine: [29916]: notice: LogActions: Leave
> p_drbd_r0:1#011(Stopped)
> 12:37:20 node1 pengine: [29916]: notice: LogActions: Leave
> p_drbd_r1:1#011(Stopped)
> 12:37:20 node1 pengine: [29916]: notice: LogActions: Leave
> p_drbd_r2:1#011(Stopped)
> 12:37:20 node1 pengine: [29916]: notice: LogActions: Leave
> p_libvirt-bin:1#011(Stopped)
> 12:37:20 node1 pengine: [29916]: notice: LogActions: Leave
> p_libvirt-bin:2#011(Stopped)
> 12:37:21 node1 crmd: [27020]: notice: run_graph: Transition 77 (Complete=24,
> Pending=0, Fired=0, Skipped=3, Incomplete=0,
> Source=/var/lib/pengine/pe-input-526.bz2): Stopped
> 12:37:21 node1 pengine: [29916]: notice: LogActions: Leave
> p_drbd_r0:1#011(Stopped)
> 12:37:21 node1 pengine: [29916]: notice: LogActions: Leave
> p_drbd_r1:1#011(Stopped)
> 12:37:21 node1 pengine: [29916]: notice: LogActions: Leave
> p_drbd_r2:1#011(Stopped)
> 12:37:21 node1 pengine: [29916]: notice: LogActions: Leave
> p_libvirt-bin:1#011(Stopped)
> 12:37:21 node1 pengine: [29916]: notice: LogActions: Leave
> p_libvirt-bin:2#011(Stopped)
> 12:37:23 node1 lrmd: [27017]: info: RA output: (p_vm:start:stdout) Domain
> MyVM started
> 12:38:23 node1 crmd: [27020]: info: crm_timer_popped: PEngine Recheck Timer
> (I_PE_CALC) just popped (60000ms)
> 12:38:23 node1 crmd: [27020]: info: do_state_transition: State transition
> S_IDLE -> S_POLICY_ENGINE [ input=I_PE_CALC cause=C_TIMER_POPPED
> origin=crm_timer_popped ]
> 12:38:23 node1 crmd: [27020]: info: do_state_transition: Progressed to state
> S_POLICY_ENGINE after C_TIMER_POPPED
> 12:38:23 node1 pengine: [29916]: notice: LogActions: Leave
> p_drbd_r0:1#011(Stopped)
> 12:38:23 node1 pengine: [29916]: notice: LogActions: Leave
> p_drbd_r1:1#011(Stopped)
>
> I've attached the full logs from this time period in addition to the excerpt
> above.
>
> Is there a better way to trigger the starting of resources once quorum has
> been reestablished? Or is modifying these two properties a good way of doing
> it?
>
> Thanks,
>
> Andrew
>
> ________________________________
> From: "Andreas Kurz" < andreas at hastexo.com >
> To: pacemaker at oss.clusterlabs.org
> Sent: Friday, February 24, 2012 7:26:59 AM
> Subject: Re: [Pacemaker] Configuring 3rd Node as Quorum Node
> in 2 Node Cluster
>
>
> Hello,
>
> On 02/23/2012 03:59 PM, Andrew Martin wrote:
>> I set up the 3rd node ("quorum") yesterday by only installing heartbeat,
>> not pacemaker. Is pacemaker necessary as well? I commented out the
>> following lines in its ha.cf since it is always going to be running in
>> standby:
>> autojoin none
>> mcast eth0 239.0.0.43 694 1 0
>> bcast eth0
>> warntime 5
>> deadtime 15
>> initdead 60
>> keepalive 2
>> node node1
>> node node2
>> node quorum
>> #crm respawn
>> #respawn hacluster /usr/lib/heartbeat/dopd
>> #apiauth dopd gid=haclient uid=hacluster
>>
>
> Hmm ... IIRC I had to enable ccm in ha.cf on the third node during my
> last heartbeat tests to enable a quorum node:
>
> respawn hacluster ccm
>
>> Since this quorum node only has a single ethernet interface, can it be
>> used for both the mcast and bcast parameters? How are both the multicast
>> and broadcast pathways used for node communication? After saving these
>> parameters and reloading heartbeat on all nodes, the "quorum" node is
>> listed as offline in the cluster. Is there something missing in my
>> configuration that is preventing it from communicating with the rest of
>> the cluster?
>
> cl_status and hbclient should give you some membership information, and
> there should be some log entries on the nodes running Pacemaker. I don't
> think the node will show up as ONLINE in crm_mon if no Pacemaker is
> running there.
>
> You only need the communication settings you also used for node1/2 on
> the shared network ... so only the mcast directive is needed/possible on
> node3.
>
>>
>> Also, another more general question about the failover - node1 and node2
>> are each connected to the shared network over br0 and connected directly
>> to each other with a crossover cable over br1:
>> -------------------- ----------
>> | Shared Network |------| quorum |
>> -------------------- ----------
>> |
>> br0 / \ br0
>> / \
>> --------- ---------
>> | node1 | --------- | node2 |
>> --------- br1 ---------
>>
>> The corresponding configuration in ha.cf is
>> autojoin none
>> mcast br0 239.0.0.43 694 1 0
>> bcast br1
>> warntime 5
>> ....
>>
>> If br0 to one of the nodes were to be cut when the "quorum" node was
>> down, would they still be able to communicate over br1 (e.g. to maintain
>> quorum between themselves and fail over to the other node that still has
>> an active br0)?
>
> as long as node1/2 can communicate the cluster has quorum, to fail over
> resources to the node with best connectivity: configure ping resource
> agent and constraints, there is a chapter in "Pacemake Explained" on
> clusterlabs.org ... http://goo.gl/x7dwK
>
> Regards,
> Andreas
>
> --
> Need help with Pacemaker?
> http://www.hastexo.com/now
>
>>
>> Thanks,
>>
>> Andrew
>>
>> ------------------------------------------------------------------------
>> *From: *"Andreas Kurz" < andreas at hastexo.com >
>> *To: *pacemaker at oss.clusterlabs.org
>> *Sent: *Monday, January 23, 2012 1:53:27 PM
>> *Subject: *Re: [Pacemaker] Configuring 3rd Node as Quorum Node in
>> 2 Node Cluster
>>
>> On 01/23/2012 03:36 PM, Andrew Martin wrote:
>>> I think I will configure the 3rd (quorum) node in standby mode. In the
>>> near future I am looking into setting up 2 additional clusters (each of
>>> these are also 2-node clusters) and would like to use this same server
>>> as the quorum node for those clusters as well. Is this possible? If so,
>>> how do I have to configure heartbeat (or multiple instances of
>>> heartbeat) to join multiple clusters at once and act as the quorum node
>>> in each?
>>
>> No, multiple heartbeat instances per node are not supported ... but why
>> not creating minimal VM instances ... though not to minimal, as you have
>> a good chance that theses standby instances become DC role.
>>
>> Regards,
>> Andreas
>>
>> --
>> Need help with Pacemaker?
>> http://www.hastexo.com/now
>>
>>>
>>> Thanks,
>>>
>>> Andrew
>>>
>>> ------------------------------------------------------------------------
>>> *From: *"Andreas Kurz" < andreas at hastexo.com >
>>> *To: *pacemaker at oss.clusterlabs.org
>>> *Sent: *Friday, January 13, 2012 6:35:48 AM
>>> *Subject: *Re: [Pacemaker] Configuring 3rd Node as Quorum Node in 2
>>> Node Cluster
>>>
>>> On 01/13/2012 12:32 PM, Ivan Savčić | Epix wrote:
>>>> On 1/11/2012 8:28 AM, Florian Haas wrote:
>>>>> Another option would be to permanently run the 3rd node in standby
>>>>> mode.
>>>>
>>>> Just wondering, wouldn't the standby mode prevent that node from
>>>> performing the fencing actions? Also, can it act as DC then?
>>>
>>> It would run no resources (including stonith resources) but can be the
>>> DC.
>>>
>>> Another option for running a "pure" quorum node would be to only start
>>> CCM but not pacemaker ... though that setup looks quite strange e.g. in
>>> crm_mon output ....
>>>
>>> Regards,
>>> Andreas
>>>
>>> --
>>> Need help with Pacemaker?
>>> http://www.hastexo.com/now
>>>
>>>>
>>>> Thanks,
>>>> Ivan
>>>>
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>>>
>>>
>>>
>>>
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>>>
>>>
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>>
>>
>>
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>>
>>
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>> Bugs: http://bugs.clusterlabs.org
>
>
>
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>
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>
>
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> Bugs: http://bugs.clusterlabs.org
>
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