[Pacemaker] [Question] About "quorum-policy=freeze" and "promote".

Andrew Beekhof andrew at beekhof.net
Fri May 9 05:04:43 UTC 2014


On 9 May 2014, at 2:05 pm, renayama19661014 at ybb.ne.jp wrote:

> Hi Andrew,
> 
> Thank you for comment.
> 
>>> Is it responsibility of the resource agent side to prevent a state of these plural Master?
>> 
>> No.
>> 
>> In this scenario, no nodes have quorum and therefor no additional instances should have been promoted.  Thats the definition of "freeze" :)
>> Even if one partition DID have quorum, no instances should have been promoted without fencing occurring first.
> 
> Okay.
> I wish this problem is revised by the next release.

crm_report?

> 
> Many Thanks!
> Hideo Yamauchi.
> 
> --- On Fri, 2014/5/9, Andrew Beekhof <andrew at beekhof.net> wrote:
> 
>> 
>> On 8 May 2014, at 1:37 pm, renayama19661014 at ybb.ne.jp wrote:
>> 
>>> Hi All,
>>> 
>>> I composed Master/Slave resource of three nodes that set quorum-policy="freeze".
>>> (I use Stateful in Master/Slave resource.)
>>> 
>>> ---------------------------------
>>> Current DC: srv01 (3232238280) - partition with quorum
>>> Version: 1.1.11-830af67
>>> 3 Nodes configured
>>> 9 Resources configured
>>> 
>>> 
>>> Online: [ srv01 srv02 srv03 ]
>>> 
>>> Resource Group: grpStonith1
>>>      prmStonith1-1      (stonith:external/ssh): Started srv02 
>>> Resource Group: grpStonith2
>>>      prmStonith2-1      (stonith:external/ssh): Started srv01 
>>> Resource Group: grpStonith3
>>>      prmStonith3-1      (stonith:external/ssh): Started srv01 
>>> Master/Slave Set: msPostgresql [pgsql]
>>>      Masters: [ srv01 ]
>>>      Slaves: [ srv02 srv03 ]
>>> Clone Set: clnPingd [prmPingd]
>>>      Started: [ srv01 srv02 srv03 ]
>>> ---------------------------------
>>> 
>>> 
>>> Master resource starts in all nodes when I interrupt the internal communication of all nodes.
>>> 
>>> ---------------------------------
>>> Node srv02 (3232238290): UNCLEAN (offline)
>>> Node srv03 (3232238300): UNCLEAN (offline)
>>> Online: [ srv01 ]
>>> 
>>> Resource Group: grpStonith1
>>>      prmStonith1-1      (stonith:external/ssh): Started srv02 
>>> Resource Group: grpStonith2
>>>      prmStonith2-1      (stonith:external/ssh): Started srv01 
>>> Resource Group: grpStonith3
>>>      prmStonith3-1      (stonith:external/ssh): Started srv01 
>>> Master/Slave Set: msPostgresql [pgsql]
>>>      Masters: [ srv01 ]
>>>      Slaves: [ srv02 srv03 ]
>>> Clone Set: clnPingd [prmPingd]
>>>      Started: [ srv01 srv02 srv03 ]
>>> (snip)
>>> Node srv01 (3232238280): UNCLEAN (offline)
>>> Node srv03 (3232238300): UNCLEAN (offline)
>>> Online: [ srv02 ]
>>> 
>>> Resource Group: grpStonith1
>>>      prmStonith1-1      (stonith:external/ssh): Started srv02 
>>> Resource Group: grpStonith2
>>>      prmStonith2-1      (stonith:external/ssh): Started srv01 
>>> Resource Group: grpStonith3
>>>      prmStonith3-1      (stonith:external/ssh): Started srv01 
>>> Master/Slave Set: msPostgresql [pgsql]
>>>      Masters: [ srv01 srv02 ]
>>>      Slaves: [ srv03 ]
>>> Clone Set: clnPingd [prmPingd]
>>>      Started: [ srv01 srv02 srv03 ]
>>> (snip)
>>> Node srv01 (3232238280): UNCLEAN (offline)
>>> Node srv02 (3232238290): UNCLEAN (offline)
>>> Online: [ srv03 ]
>>> 
>>> Resource Group: grpStonith1
>>>      prmStonith1-1      (stonith:external/ssh): Started srv02 
>>> Resource Group: grpStonith2
>>>      prmStonith2-1      (stonith:external/ssh): Started srv01 
>>> Resource Group: grpStonith3
>>>      prmStonith3-1      (stonith:external/ssh): Started srv01 
>>> Master/Slave Set: msPostgresql [pgsql]
>>>      Masters: [ srv01 srv03 ]
>>>      Slaves: [ srv02 ]
>>> Clone Set: clnPingd [prmPingd]
>>>      Started: [ srv01 srv02 srv03 ]
>>> ---------------------------------
>>> 
>>> I think even if the cluster loses Quorum, being "promote" the Master / Slave resource that's specification of Pacemaker.
>>> 
>>> Is it responsibility of the resource agent side to prevent a state of these plural Master?
>> 
>> No.
>> 
>> In this scenario, no nodes have quorum and therefor no additional instances should have been promoted.  Thats the definition of "freeze" :)
>> Even if one partition DID have quorum, no instances should have been promoted without fencing occurring first.
>> 
>>> * I think that drbd-RA has those functions.
>>> * But, there is no function in Stateful-RA.
>>> * As an example, I think that the mechanism such as drbd is necessary by all means when I make a resource of Master/Slave newly.
>>> 
>>> Will my understanding be wrong?
>>> 
>>> Best Regards,
>>> Hideo Yamauchi.
>>> 
>>> 
>>> _______________________________________________
>>> Pacemaker mailing list: Pacemaker at oss.clusterlabs.org
>>> http://oss.clusterlabs.org/mailman/listinfo/pacemaker
>>> 
>>> Project Home: http://www.clusterlabs.org
>>> Getting started: http://www.clusterlabs.org/doc/Cluster_from_Scratch.pdf
>>> Bugs: http://bugs.clusterlabs.org
>> 
>> 

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