Bug 1840382

Summary:	Mandatory stop ordering constraints are treated as optional
Product:	Red Hat Enterprise Linux 8	Reporter:	Reid Wahl <nwahl>
Component:	pacemaker	Assignee:	Ken Gaillot <kgaillot>
Status:	NEW ---	QA Contact:	cluster-qe <cluster-qe>
Severity:	medium	Docs Contact:
Priority:	medium
Version:	8.2	CC:	cluster-maint, fdanapfe, shwu
Target Milestone:	rc	Keywords:	Triaged
Target Release:	8.3
Hardware:	All
OS:	Linux
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Description Reid Wahl 2020-05-26 20:25:59 UTC

Description of problem:

Ordering constraints of the form "stop A then stop B" with kind=Mandatory (the default) are treated as kind=Optional.

It does seem to act like an Optional constraint rather than being ignored completely. I used a modified ocf:heartbeat:Dummy resource agent with a 5-second sleep in the stop operation for the dummy_stop_delay resource below.

[root@fastvm-rhel-8-0-23 ~]# pcs constraint order
Ordering Constraints:
stop dummy_stop_delay then stop dummy2 (kind:Mandatory)

When I banned dummy2, dummy_stop_delay remained online. However, when I placed the node in standby (so that both resources would be scheduled to stop), dummy2 did not initiate its stop operation until after dummy_stop_delay finished stopping.

May 26 13:15:22 fastvm-rhel-8-0-23 pacemaker-controld[1811]: notice: Initiating stop operation dummy_stop_delay_stop_0 locally on fastvm-rhel-8-0-23
May 26 13:15:27 fastvm-rhel-8-0-23 pacemaker-controld[1811]: notice: Initiating stop operation dummy2_stop_0 locally on fastvm-rhel-8-0-23

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Version-Release number of selected component (if applicable):

pacemaker-2.0.2-3.el8_1.2.x86_64

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How reproducible:

Always

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Steps to Reproduce:
1. Create a mandatory stop ordering constraint of the form "stop rsc_A then stop rsc_B".
2. Force rsc_B to stop (e.g., by banning it).

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Actual results:

rsc_A remains running.

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Expected results:

rsc_A stops before rsc_B.

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Additional info:

https://bugs.clusterlabs.org/show_bug.cgi?id=5416