[ClusterLabs] Coming in Pacemaker 2.0.4: crm_mon --node

[Ken Gaillot]

Hi all,

We're probably going to release the first release candidate for
Pacemaker 2.0.4 later this week. Klaus Wenninger will be handling the
release this time.

One last feature that made it in: crm_mon now has a --node option to
show output only for one particular node or set of nodes. For example
"crm_mon --node node1" will show only resources that are active on
node1, action failures that happened on node1, etc.

To specify multiple nodes, we are taking advantage of a longstanding
but little-used pacemaker feature called "tags". The CIB can contain a
section like:

   <tags>
      <tag id="dbnodes">
         <obj_ref id="1"/>
         <obj_ref id="2"/>
      </tag>
   </tags>

and then if you run "crm_mon --node dbnodes", it will show only
information relating to the nodes with the IDs 1 and 2 (tags are always
by ID rather than uname).

Higher-level tools can provide a more convenient interface for
configuring tags.

The main advantage of using tags is that if you are interested in the
same particular nodes repeatedly, you don't have to list them all every
time you run crm_mon. Another goal is simply to make tags more useful
and familiar, so they can be used for more things in the future.
-- 
Ken Gaillot <kgaillot at redhat.com>