Bug 1368106

Summary: qnetd is not checked for usage when killed
Product: Red Hat Enterprise Linux 7 Reporter: Roman Bednář <rbednar>
Component: pcsAssignee: Tomas Jelinek <tojeline>
Status: CLOSED DUPLICATE QA Contact: cluster-qe <cluster-qe>
Severity: unspecified Docs Contact:
Priority: unspecified    
Version: 7.3CC: cfeist, cluster-maint, idevat, omular, rbednar, tojeline
Target Milestone: rc   
Target Release: ---   
Hardware: x86_64   
OS: Linux   
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Last Closed: 2016-09-13 07:42:13 UTC Type: Bug
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Description Roman Bednář 2016-08-18 12:40:12 UTC
There is no check that qdevice is actually used by a cluster.
It is possible to kill it any time without any warning or prompt.

# pcs qdevice status net
QNetd address:			*:5403
TLS:				Supported (client certificate required)
Connected clients:		4
Connected clusters:		1
Cluster "STSRHTS10485":
    Algorithm:		LMS
    Tie-breaker:	Node with lowest node ID
    Node ID 1:
        Client address:		::ffff:192.168.0.137:35018
        Configured node list:	1, 2, 3, 4
        Membership node list:	1, 2, 3, 4
        Vote:			ACK (ACK)
    Node ID 2:
        Client address:		::ffff:192.168.0.140:59852
        Configured node list:	1, 2, 3, 4
        Membership node list:	1, 2, 3, 4
        Vote:			ACK (ACK)
    Node ID 3:
        Client address:		::ffff:192.168.0.141:35462
        Configured node list:	1, 2, 3, 4
        Membership node list:	1, 2, 3, 4
        Vote:			ACK (ACK)
    Node ID 4:
        Client address:		::ffff:192.168.0.142:52374
        Configured node list:	1, 2, 3, 4
        Membership node list:	1, 2, 3, 4
        Vote:			ACK (ACK)


# pcs qdevice kill net
quorum device killed

# pcs qdevice status net
QNetd address:			*:5403
TLS:				Supported (client certificate required)
Connected clients:		0
Connected clusters:		0


corosync-qnetd-2.4.0-3.el7.x86_64
corosynclib-2.4.0-3.el7.x86_64
corosync-qdevice-2.4.0-3.el7.x86_64
corosync-2.4.0-3.el7.x86_64
pcs-0.9.152-6.el7.x86_64

Comment 2 Tomas Jelinek 2016-08-24 08:06:09 UTC
That is how it was designed.  Is it wrong?  What behavior do you expect?

We could check if qdevice is in use in "pcs qdevice kill" based on "pcs qdevice status" output.  But the kill command is expected to be used when things go terribly wrong and the user needs to forcefully stop the qdevice.  In that case we cannot rely on "pcs qdevice status" to be working.

Moreover qdevice can be killed by the "kill" and "killall" commands at any time without any prompt or warning.

So far this looks like NOTABUG for me.

Comment 3 Roman Bednář 2016-09-06 10:46:52 UTC
Alright, can't argue with that logic. So how about the stop command? Is it also intended for that one not to check the status/usage? 
You're right that kill command is a forcefull way and should be a last resort, but a stopping action seems reasonable to have a check/prompt there.
Keeping in mind that user can stop the service anytime using other tools anyway, same as killing it as you mentioned, but that's why we have pcs right? To make things easier, faster and help users avoid mistakes.

Also with latest build the kill command does not seem to work at all, do we need a separate BZ to track this?

# pcs qdevice kill net
quorum device killed

# systemctl is-active corosync-qnetd.service 
active

# pcs qdevice status net
QNetd address:			*:5403
TLS:				Supported (client certificate required)
Connected clients:		4
Connected clusters:		1
Cluster "STSRHTS16137":
    Algorithm:		LMS
    Tie-breaker:	Node with lowest node ID
    Node ID 1:
        Client address:		::ffff:192.168.0.35:40572
        Configured node list:	1, 2, 3, 4
        Membership node list:	1, 2, 3, 4
        Vote:			ACK (ACK)
    Node ID 4:
        Client address:		::ffff:192.168.0.43:40480
        Configured node list:	1, 2, 3, 4
        Membership node list:	1, 2, 3, 4
        Vote:			ACK (ACK)
    Node ID 2:
        Client address:		::ffff:192.168.0.36:42636
        Configured node list:	1, 2, 3, 4
        Membership node list:	1, 2, 3, 4
        Vote:			ACK (ACK)
    Node ID 3:
        Client address:		::ffff:192.168.0.42:46054
        Configured node list:	1, 2, 3, 4
        Membership node list:	1, 2, 3, 4
        Vote:			ACK (ACK)


=================================
corosynclib-2.4.0-4.el7.x86_64
corosync-2.4.0-4.el7.x86_64
corosync-qdevice-2.4.0-4.el7.x86_64
corosync-qnetd-2.4.0-4.el7.x86_64
pcs-0.9.152-8.el7.x86_64

Comment 4 Tomas Jelinek 2016-09-06 13:43:36 UTC
Fair enough, we can add the check when stopping a qdevice.

Are you sure the killing does not work?  I suspect that another instance of qnetd was started by systemd just after you killed it.  Can you check that?

Comment 5 Roman Bednář 2016-09-08 12:29:00 UTC
>Are you sure the killing does not work?  I suspect that another instance of >qnetd was started by systemd just after you killed it.  Can you check that?

Checked that, it's exactly the case.

Comment 6 Tomas Jelinek 2016-09-13 07:42:13 UTC
This has been reported and fixed in the original pcs qdevice bz.

*** This bug has been marked as a duplicate of bug 1158805 ***