[ClusterLabs] Questions regarding crm_mon tool

[Ken Gaillot]

On Fri, 2018-09-28 at 19:41 +0000, Brian Vagnini wrote:
> Greetings,
> We are implementing an HA cluster solution and as a part of it, are
> using crm_mon. Part of my job is to document training materials for
> certain things. I am running into a problem in defining some of the
> information that gets outputted when running the crm_mon command.
>  
> One of my principle engineers responded with this comment.
>  
> crm_mon
>  online -> explain the different states online, offline, pending and
> standby (there might be more)
>  last updated/change (lookup what these mean but i think one of them
> shows when the cluster last had a config change or maybe changed
> states
> My dilemma is that I can’t seem to find that within the help system
> or anywhere else. I’m hoping that you can assist me with this.
>  
> Thanks in advance,
>  
> Brian K. Vagnini
> Training & Documentation Coordinator
> Tallahassee office
> 850-270-0387
> Slack (@bkvagnini)

Hi,

Those are good questions. We are planning some significant enhancements
to crm_mon over the next couple of releases to improve configurability
and general usefulness. (Already lined up for the next release is
display of failed and pending fence actions.)

We definitely could use better documentation of the output format,
unfortunately there are many higher priorities in the queue. It should
definitely include this information.

Possible node states:

online - node is a functioning member of both the cluster layer
(corosync) and its daemon peer group

pending - node is a cluster member, but not a peer group member (this
typically means it is in the process of starting or shutting down)

standby - node is online but in standby mode. This may optionally be
followed by (on-fail) meaning that it is in standby because a resource
with on-fail=standby resources failed, or (with active resources) which
is new and indicates that even though the node is in standby, it is
still in the process of moving resources off.

maintenance - node is online but in maintenance mode

UNCLEAN - node must be fenced. This will be followed by (online),
(pending) or (offline).

OFFLINE - node cleanly left the cluster. This may optionally be
followed by (standby) or (maintenance).


Last updated is the time the crm_mon display was last refreshed.

Last change is the time the CIB (cluster configuration and status) last
changed.
-- 
Ken Gaillot <kgaillot at redhat.com>