[ClusterLabs] Antw: [EXT] Re: Determine a resource's current host in the CIB

[Ulrich Windl]

>>> Christopher Lumens <clumens at redhat.com> schrieb am 24.09.2020 um 17:48 in
Nachricht <801519843.20826233.1600962508662.JavaMail.zimbra at redhat.com>:
> This is the kind of stuff I've been working on a lot, so hopefully I've
> added enough tools to make this easy to do.  If not, I guess I've got
> more work to do.
> 
> What's your time frame, are you lucky enough to be able to use the latest
> pacemaker releases, and are you going to use command line tools or the
> library?
> 
>> > A quick look to the code shows that crm_resource ‑ where we would
>> > have ‑‑locate ‑does have the ‑‑xml‑file as well. But that seems
>> > not to do what I expected althoughI haven't looked into the details.
>> 
>> This is an interesting option... I can see that it shows me running
>> resources only (not what resources are configured but off). It does show
>> more directly "VM x is on node y";
> 
> Coming eventually, crm_resource will support ‑‑output‑as=xml, which means
> you'd potentially get the output of "crm_resource ‑W" in a structured
> format you could easily parse.
> 
> You could also use crm_mon and xmllint to do this right now on the
> command line.  First you could use crm_mon to dump a single resource as
> XML:
> 
> $ crm_mon ‑‑include=none,resources ‑‑resource dummy ‑‑output‑as xml
> <pacemaker‑result api‑version="2.3" request="crm_mon
‑‑include=none,resources 
> ‑‑resource dummy ‑‑output‑as xml">
>   <resources>
>     <resource id="dummy" resource_agent="ocf::pacemaker:Dummy"
role="Started" 
> active="true" orphaned="false" blocked="false" managed="true" failed="false"

> failure_ignored="false" nodes_running_on="1">
>       <node name="cluster02" id="2" cached="true"/>
>     </resource>
>   </resources>
>   <status code="0" message="OK"/>
> </pacemaker‑result>
> 
> And then you construct an xpath query to get just the attribute you
> want:
> 
> $ crm_mon ‑‑include=none,resources ‑‑resource dummy ‑‑output‑as xml |
xmllint ‑‑xpath 
> '//resource/node/@name' ‑
> name="cluster02"
> 
> You could do the same kinds of queries using libxml2 once you've parsed
> stdout of crm_mon.  We've got examples scattered throughout the
> pacemaker code, or I could probably try to remember how it's done.

Hi!

A few years ago I wrote a (Perl) tool that parses and linearizes the XML CIB.
For example using that tool to sort all resources by operation execution time,
the command was:

./pmkrstat.pl --cib-object=status --query '*:exec-time' \
--attribute id=1 --attribute operation=2 --attribute on_node=3 \
--attribute rc-code=4 --attribute queue-time=5 --attribute exec-time=6 \
--attribute last-run=7 \
--show full_path=0 --show name=0 --show attr_name=0 --no-handle-values | \
sed -e 's/(//' -e 's/)//' -e 's/"//g' -e 's/,/ /g' | grep "$1" | sort -k6n
-k1

So on output you have 7 fields: id, operation, on_node, rc-code, queue-time,
exec-time, and last-run

So an output line could be:
prm_db_last_0 start node-13 0 0 31858 1592836459

Ugly, isn't it?

Regards,
Ulrich

> 
> ‑ Chris
> 
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