[ClusterLabs] How to check if a resource on a cluster node is really back on after a crash

Ludovic Vaugeois-Pepin ludovicvp at gmail.com
Fri May 12 05:27:59 EDT 2017


Yes I haven't been using the "nodes" element in the XML, only the
"resources" element. I couldn't find "node_state" elements or attributes in
the XML, so after some searching I found that it is in the CIB that can be
gotten with "pcs cluster cib foo.xml". I will start exploring this as an
alternative to  crm_mon/"pcs status".


However I still find what happens to be confusing, so below I try to better
explain what I see:


Before "pcs cluster start test3" at 10:45:36.362 (test3 has been HW
shutdown a minute ago):

crm_mon -1:

    Stack: corosync
    Current DC: test1 (version 1.1.15-11.el7_3.4-e174ec8) - partition with
quorum
    Last updated: Fri May 12 10:45:36 2017          Last change: Fri May 12
09:18:13 2017 by root via crm_attribute on test1

    3 nodes and 4 resources configured

    Online: [ test1 test2 ]
    OFFLINE: [ test3 ]

    Active resources:

     Master/Slave Set: pgsql-ha [pgsqld]
         Masters: [ test1 ]
         Slaves: [ test2 ]
     pgsql-master-ip        (ocf::heartbeat:IPaddr2):       Started test1


crm_mon -X:

    <resources>
    <clone id="pgsql-ha" multi_state="true" unique="false" managed="true"
failed="false" failure_ignored="false" >
        <resource id="pgsqld" resource_agent="ocf::heartbeat:pgha"
role="Master" active="true" orphaned="false" managed="true" f
    ailed="false" failure_ignored="false" nodes_running_on="1" >
            <node name="test1" id="1" cached="false"/>
        </resource>
        <resource id="pgsqld" resource_agent="ocf::heartbeat:pgha"
role="Slave" active="true" orphaned="false" managed="true" fa
    iled="false" failure_ignored="false" nodes_running_on="1" >
            <node name="test2" id="2" cached="false"/>
        </resource>
        <resource id="pgsqld" resource_agent="ocf::heartbeat:pgha"
role="Stopped" active="false" orphaned="false" managed="true"
    failed="false" failure_ignored="false" nodes_running_on="0" />
    </clone>
    <resource id="pgsql-master-ip" resource_agent="ocf::heartbeat:IPaddr2"
role="Started" active="true" orphaned="false" managed
    ="true" failed="false" failure_ignored="false" nodes_running_on="1" >
        <node name="test1" id="1" cached="false"/>
    </resource>
    </resources>



At 10:45:39.440, after "pcs cluster start test3", before first "monitor" on
test3 (this is where I can't seem to know that resources on test3 are down):

crm_mon -1:

    Stack: corosync
    Current DC: test1 (version 1.1.15-11.el7_3.4-e174ec8) - partition with
quorum
    Last updated: Fri May 12 10:45:39 2017          Last change: Fri May 12
10:45:39 2017 by root via crm_attribute on test1

    3 nodes and 4 resources configured

    Online: [ test1 test2 test3 ]

    Active resources:

     Master/Slave Set: pgsql-ha [pgsqld]
         Masters: [ test1 ]
         Slaves: [ test2 test3 ]
     pgsql-master-ip        (ocf::heartbeat:IPaddr2):       Started test1


crm_mon -X:

    <resources>
    <clone id="pgsql-ha" multi_state="true" unique="false" managed="true"
failed="false" failure_ignored="false" >
        <resource id="pgsqld" resource_agent="ocf::heartbeat:pgha"
role="Master" active="true" orphaned="false" managed="true" failed="false"
failure_ignored="false" nodes_running_on="1" >
            <node name="test1" id="1" cached="false"/>
        </resource>
        <resource id="pgsqld" resource_agent="ocf::heartbeat:pgha"
role="Slave" active="true" orphaned="false" managed="true" failed="false"
failure_ignored="false" nodes_running_on="1" >
            <node name="test2" id="2" cached="false"/>
        </resource>
        <resource id="pgsqld" resource_agent="ocf::heartbeat:pgha"
role="Slave" active="true" orphaned="false" managed="true" failed="false"
failure_ignored="false" nodes_running_on="1" >
            <node name="test3" id="3" cached="false"/>
        </resource>
    </clone>
    <resource id="pgsql-master-ip" resource_agent="ocf::heartbeat:IPaddr2"
role="Started" active="true" orphaned="false" managed="true" failed="false"
failure_ignored="false" nodes_running_on="1" >
        <node name="test1" id="1" cached="false"/>
    </resource>
    </resources>



At 10:45:41.606, after first "monitor" on test3 (I can now tell the
resources on test3 are not ready):

crm_mon -1:

    Stack: corosync
    Current DC: test1 (version 1.1.15-11.el7_3.4-e174ec8) - partition with
quorum
    Last updated: Fri May 12 10:45:41 2017          Last change: Fri May 12
10:45:39 2017 by root via crm_attribute on test1

    3 nodes and 4 resources configured

    Online: [ test1 test2 test3 ]

    Active resources:

     Master/Slave Set: pgsql-ha [pgsqld]
         Masters: [ test1 ]
         Slaves: [ test2 ]
     pgsql-master-ip        (ocf::heartbeat:IPaddr2):       Started test1


crm_mon -X:

    <resources>
    <clone id="pgsql-ha" multi_state="true" unique="false" managed="true"
failed="false" failure_ignored="false" >
        <resource id="pgsqld" resource_agent="ocf::heartbeat:pgha"
role="Master" active="true" orphaned="false" managed="true" failed="false"
failure_ignored="false" nodes_running_on="1" >
            <node name="test1" id="1" cached="false"/>
        </resource>
        <resource id="pgsqld" resource_agent="ocf::heartbeat:pgha"
role="Slave" active="true" orphaned="false" managed="true" failed="false"
failure_ignored="false" nodes_running_on="1" >
            <node name="test2" id="2" cached="false"/>
        </resource>
        <resource id="pgsqld" resource_agent="ocf::heartbeat:pgha"
role="Stopped" active="false" orphaned="false" managed="true"
failed="false" failure_ignored="false" nodes_running_on="0" />
    </clone>
    <resource id="pgsql-master-ip" resource_agent="ocf::heartbeat:IPaddr2"
role="Started" active="true" orphaned="false" managed="true" failed="false"
failure_ignored="false" nodes_running_on="1" >
        <node name="test1" id="1" cached="false"/>
    </resource>
    </resources>

On Fri, May 12, 2017 at 12:45 AM, Ken Gaillot <kgaillot at redhat.com> wrote:

> On 05/11/2017 03:00 PM, Ludovic Vaugeois-Pepin wrote:
> > Hi
> > I translated the a Postgresql multi state RA
> > (https://github.com/dalibo/PAF) in Python
> > (https://github.com/ulodciv/deploy_cluster), and I have been editing it
> > heavily.
> >
> > In parallel I am writing unit tests and functional tests.
> >
> > I am having an issue with a functional test that abruptly powers off a
> > slave named says "host3" (hot standby PG instance). Later on I start the
> > slave back. Once it is started, I run "pcs cluster start host3". And
> > this is where I start having a problem.
> >
> > I check every second the output of "pcs status xml" until host3 is said
> > to be ready as a slave again. In the following I assume that test3 is
> > ready as a slave:
> >
> >     <nodes>
> >         <node name="test1" id="1" online="true" standby="false"
> > standby_onfail="false" maintenance="false" pending="false"
> > unclean="false" shutdown="false" expected_up="true" is_dc="false"
> > resources_running="2" type="member" />
> >         <node name="test2" id="2" online="true" standby="false"
> > standby_onfail="false" maintenance="false" pending="false"
> > unclean="false" shutdown="false" expected_up="true" is_dc="true"
> > resources_running="1" type="member" />
> >         <node name="test3" id="3" online="true" standby="false"
> > standby_onfail="false" maintenance="false" pending="false"
> > unclean="false" shutdown="false" expected_up="true" is_dc="false"
> > resources_running="1" type="member" />
> >     </nodes>
>
> The <nodes> section says nothing about the current state of the nodes.
> Look at the <node_state> entries for that. in_ccm means the cluster
> stack level, and crmd means the pacemaker level -- both need to be up.
>
> >     <resources>
> >         <clone id="pgsql-ha" multi_state="true" unique="false"
> > managed="true" failed="false" failure_ignored="false" >
> >             <resource id="pgsqld" resource_agent="ocf::heartbeat:pgha"
> > role="Slave" active="true" orphaned="false" managed="true"
> > failed="false" failure_ignored="false" nodes_running_on="1" >
> >                 <node name="test3" id="3" cached="false"/>
> >             </resource>
> >             <resource id="pgsqld" resource_agent="ocf::heartbeat:pgha"
> > role="Master" active="true" orphaned="false" managed="true"
> > failed="false" failure_ignored="false" nodes_running_on="1" >
> >                 <node name="test1" id="1" cached="false"/>
> >             </resource>
> >             <resource id="pgsqld" resource_agent="ocf::heartbeat:pgha"
> > role="Slave" active="true" orphaned="false" managed="true"
> > failed="false" failure_ignored="false" nodes_running_on="1" >
> >                 <node name="test2" id="2" cached="false"/>
> >             </resource>
> >         </clone>
> > By ready to go I mean that upon running "pcs cluster start test3", the
> > following occurs before test3 appears ready in the XML:
> >
> > pcs cluster start test3
> > monitor-> RA returns unknown error (1)
> > notify/pre-stop    -> RA returns ok (0)
> > stop   -> RA returns ok (0)
> > start-> RA returns ok (0)
> >
> > The problem I have is that between "pcs cluster start test3" and
> > "monitor", it seems that the XML returned by "pcs status xml" says test3
> > is ready (the XML extract above is what I get at that moment). Once
> > "monitor" occurs, the returned XML shows test3 to be offline, and not
> > until the start is finished do I once again have test3 shown as ready.
> >
> > I am getting anything wrong? Is there a simpler or better way to check
> > if test3 is fully functional again, ie OCF start was successful?
> >
> > Thanks
> >
> > Ludovic
>
> _______________________________________________
> Users mailing list: Users at clusterlabs.org
> http://lists.clusterlabs.org/mailman/listinfo/users
>
> Project Home: http://www.clusterlabs.org
> Getting started: http://www.clusterlabs.org/doc/Cluster_from_Scratch.pdf
> Bugs: http://bugs.clusterlabs.org
>



-- 
Ludovic Vaugeois-Pepin
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.clusterlabs.org/pipermail/users/attachments/20170512/1f283c38/attachment-0003.html>


More information about the Users mailing list