[Pacemaker] Re: Understanding rules: location, colocation, order. Using with Master/Slave

Serge Dubrouski sergeyfd at gmail.com
Tue Oct 28 12:33:43 UTC 2008 

On Tue, Oct 28, 2008 at 6:29 AM, Adrian Chapela
<achapela.rexistros at gmail.com> wrote:
> Serge Dubrouski escribió:
>>
>> On Mon, Oct 27, 2008 at 12:43 PM, Adrian Chapela
>> <achapela.rexistros at gmail.com> wrote:
>>
>>>
>>> Serge Dubrouski escribió:
>>>
>>>>
>>>> Something like this:
>>>>
>>>>     <rsc_order id="drbd0_before_myGroup" first="ms-drbd0"
>>>> then="myGroup" then-action="start" first-action="promote"/>
>>>>     <rsc_colocation id="myGroup_on_drbd0" rsc="myGroup"
>>>> with-rsc="ms-drbd0" with-rsc-role="Master" score="INFINITY"/>
>>>>     <rsc_location id="primNode" rsc="myGroup">
>>>>       <rule id="prefered_primNode" score="1000">
>>>>         <expression attribute="#uname" id="expression.id2242728"
>>>> operation="eq" value="fc-node1"/>
>>>>       </rule>
>>>>     </rsc_location>
>>>>
>>>> See that cib.xml that I sent you a couple of days ago. First rule will
>>>> promote DRBD before starting a group, second will collocate master and
>>>> a group, third one will place group and master to the desired node.
>>>>
>>>>
>>>
>>> Yes, I bases my rules on yours, but I can't update my config with your
>>> rules
>>> directly.
>>> <rsc_order id="drbd0_before_myGroup" first="ms-drbd0" then="mail_Group"
>>> then-action="start" first-action="promote"/>
>>>
>>> This could be like:
>>> <rsc_order id="drbd0_before_myGroup" from="mail_Group" action="start"
>>> to="ms-drbd0" to_action="promote"/>
>>>
>>> What is the version of your heartbeat ? My 2.99.1 heartbeat didn't
>>>
>>
>> It's processed by pacemaker, not heartbeat. That rule worked all right
>> under 0.6, 0.7, 1.0:
>>
>> Refresh in 3s...
>>
>> ============
>> Last updated: Mon Oct 27 14:52:47 2008
>> Current DC: fc-node2 (ad6f19b7-228a-48b7-bae0-f95a838bde2a)
>> 2 Nodes configured.
>> 3 Resources configured.
>> ============
>>
>> Node: fc-node1 (b88f98c6-50f2-463a-a6eb-51abbec645a9): online
>> Node: fc-node2 (ad6f19b7-228a-48b7-bae0-f95a838bde2a): online
>>
>> Full list of resources:
>>
>> Clone Set: DoFencing
>>    child_DoFencing:0   (stonith:external/xen0):        Started fc-node1
>>    child_DoFencing:1   (stonith:external/xen0):        Started fc-node2
>> Master/Slave Set: ms-drbd0
>>    drbd0:0     (ocf::heartbeat:drbd):  Master fc-node1
>>    drbd0:1     (ocf::heartbeat:drbd):  Started fc-node2
>> Resource Group: myGroup
>>    myIP        (ocf::heartbeat:IPaddr):        Started fc-node1
>>    fs0 (ocf::heartbeat:Filesystem):    Started fc-node1
>>    myPgsql     (ocf::heartbeat:pgsql): Started fc-node1
>>
>> [root at fc-node1 crm]# rpm -qa | grep pacemaker
>> libpacemaker3-1.0.0-2.1
>> pacemaker-1.0.0-2.1
>> [root at fc-node1 crm]#
>>
>>
>> What error do you get?
>>
>
> I can update the configuration now. I have Heartbeat 2.99.1 + Pacemaker 1.0.
> Bur now, I can't put Master on the node. Have you check fc-node2 as a master
> node?
>
> How are you using pingd ? As a clone instance or  configured in ha.cf ?

pingd is broken in 1.0 :-( Andrew fixed it in the latest dev release.
>
>>
>>
>>>
>>> understand the rule.
>>>
>>>>
>>>> On Mon, Oct 27, 2008 at 12:24 PM, Adrian Chapela
>>>> <achapela.rexistros at gmail.com> wrote:
>>>>
>>>>
>>>>>
>>>>> Serge Dubrouski escribió:
>>>>>
>>>>>
>>>>>>
>>>>>> On Mon, Oct 27, 2008 at 12:07 PM, Adrian Chapela
>>>>>> <achapela.rexistros at gmail.com> wrote:
>>>>>>
>>>>>>
>>>>>>
>>>>>>>>
>>>>>>>> Hello!
>>>>>>>>
>>>>>>>> I am working on a cluster with a two Master/Slave instances.
>>>>>>>>
>>>>>>>> I have: 2 drbd Master/Slave instance, 1 pingd clone instance, 1
>>>>>>>> group
>>>>>>>> with
>>>>>>>> Filesystem resource.
>>>>>>>>
>>>>>>>> ms-drbd0 is the first Master/Slave
>>>>>>>> ms-drbd1 is the second Master/Slave
>>>>>>>> mail_Group is the first group, it depends on ms-drbd0
>>>>>>>> samba_Group is the second group, it depends on ms-drbd1
>>>>>>>>
>>>>>>>> I have the next rules:
>>>>>>>>
>>>>>>>> <rsc_order id="mail-drbd0_before_fs0" from="Montaxe_mail"
>>>>>>>> action="start"
>>>>>>>> to="ms-drbd0" to_action="promote"/>
>>>>>>>> <rsc_order id="samba-drbd1_before_fs0" from="Montaxe_samba"
>>>>>>>> action="start"
>>>>>>>> to="ms-drbd1" to_action="promote"/>
>>>>>>>> (starts Montaxe_mail when ms-drbd0 has been promoted, start
>>>>>>>> Montaxe_samba
>>>>>>>> when ms-drbd1 has been promoted. These rules are ok, I think)
>>>>>>>>
>>>>>>>> <rsc_colocation id="mail_Group_on_ms-drbd0" to="ms-drbd0"
>>>>>>>> to_role="master"
>>>>>>>> from="mail_Group" score="INFINITY"/>
>>>>>>>> <rsc_colocation id="samba_Group_on_ms-drbd1" to="ms-drbd1"
>>>>>>>> to_role="master" from="samba_Group" score="INFINITY"/>
>>>>>>>> (Run mail_Group only on the master node, run samba_Group on the
>>>>>>>> master
>>>>>>>> node)
>>>>>>>>
>>>>>>>> <rsc_location id="mail:drbd" rsc="ms-drbd0">
>>>>>>>> <rule id="rule:ms-drbd0" role="master" score="100">
>>>>>>>>  <expression  attribute="#uname" operation="eq"
>>>>>>>> value="debianquagga2"/>
>>>>>>>> </rule>
>>>>>>>> <rule id="mail_Group:pingd:rule" score="-INFINITY" boolean_op="or">
>>>>>>>>  <expression id="mail_Group:pingd:expr:undefined" attribute="pingd"
>>>>>>>> operation="not_defined"/>
>>>>>>>>  <expression id="mail_Group:pingd:expr:zero" attribute="pingd"
>>>>>>>> operation="lte" value="0"/>
>>>>>>>> </rule>
>>>>>>>> </rsc_location>
>>>>>>>> <rsc_location id="samba:drbd" rsc="ms-drbd1">
>>>>>>>> <rule id="rule:ms-drbd1" role="master" score="100">
>>>>>>>>  <expression  attribute="#uname" operation="eq"
>>>>>>>> value="debianquagga2"/>
>>>>>>>> </rule>
>>>>>>>> <rule id="samba_Group:pingd:rule" score="-INFINITY" boolean_op="or">
>>>>>>>>  <expression id="samba_Group:pingd:expr:undefined" attribute="pingd"
>>>>>>>> operation="not_defined"/>
>>>>>>>>  <expression id="samba_Group:pingd:expr:zero" attribute="pingd"
>>>>>>>> operation="lte" value="0"/>
>>>>>>>> </rule>
>>>>>>>> </rsc_location>
>>>>>>>> (Select debianquagga2 as Master and if the node lost its connection
>>>>>>>> take
>>>>>>>> the score -INFINITY to do failover, it applies to ms-drbd0 and
>>>>>>>> ms-drbd1)
>>>>>>>>
>>>>>>>> With this rules all is working very well but the node selected as
>>>>>>>> master
>>>>>>>> isn't "debianquagga2",   Why could be the reason ?
>>>>>>>>
>>>>>>>> I using Heartbeat 2.1.4
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>
>>>>>>> I have attached the cib xml file. If I delete two groups, Master is
>>>>>>> debianQuagga2, If not, Master is debianQuagga1.
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>
>>>>>> That probably has something to do with how scores are counted for
>>>>>> groups. In your rsc_location rule for masters you have a really low
>>>>>> score for assigning master role to debianquagga2. It's possible that
>>>>>> groups outscore them with default values. I'm not sure in that, that's
>>>>>> just mu guess. You probably can check this with show score scripts.
>>>>>>
>>>>>>
>>>>>>
>>>>>
>>>>> I will check that, thank you!
>>>>>
>>>>>
>>>>>>
>>>>>> I'd try to assign rsc_location rules to groups, not to master role.
>>>>>> Your collocation rule will control that groups are on the same nodes
>>>>>> with the masters. Or you can try to increase your scores from 100 to
>>>>>> something higher.
>>>>>>
>>>>>>
>>>>>>
>>>>>
>>>>> Ok, but I need that node be a master before than start group because it
>>>>> depends on the master / slave resource, is that possible changing
>>>>> collocation ? Could you open my eyes with a simple example ?
>>>>>
>>>>>
>>>>>
>>>>>>>
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>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>
>>>>>>
>>>>>
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>>>>>
>>>>>
>>>>>
>>>>
>>>>
>>>>
>>>
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>>>
>>
>>
>>
>>
>
>
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-- 
Serge Dubrouski.

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