8:43 p.m.
This is the infamous "sync" problem. We have been desperately trying to avoid
this - it was very complex and hard to get right in RHQ. You did not mention sync'ing
resources themselves, but once we go down this road, I suspect that will be next.
But of course anything is possible. I will say if we are to do this, it will involve a
*major* change to the agent code because we purposefully did not design it to work like
RHQ did. The RT metadata gets stored and updated, not at startup in one big synchronous
block of processing, but rather at the time resource discovery occurs. It happens piece by
piece, asynchronously, as individual resources are discovered. And it happens well after
the agent has started.
----- Original Message -----
Hey,
the current way we implement the Hawkular-part of the MiQ ui is static,
where we write .haml files that show what properties and relations to
show.
Basically for each resource type one such page exists.
Adding a new kind of server like e.g. Apache Tomcat would need to add
a ton new .haml files.
In RHQ we had a pretty generic UI that was driven off of the metadata
inside the plugin descriptor. If a resource type had <operation>
elements,
then the UI showed the operations tab. Similar for the list of metrics
or the Events tab etc. Also for the resource configuration, the tab and
the
list of configuration properties was driven off of the plugin
descriptor.
See also [1].
The idea is now to apply the same mechanics to the ManageIQ UI so that
the resource type definitions coming from the agent can drive the UI.
We most probably need to extend the current config [2] to show
- what is shown by default
- how relations are to be shown
- which properties should be grouped together
The agent would store those in the resource type, which MiQ
can pull and build the UI from those definitions.
There is currently a rough spot: how to deal with one / more "competing"
WildFly RTs?
In RHQ we had the one canonical definition of a
resource type. Now each agent could send a different one. While
technically we can
work with that, it may be confusing if 2 WF-standalone look different.
It will not happen
often though - especially in container-land, where the config is "backed
into the image".
I wonder if we should change this way of inventory a bit to be similar
to RHQ (but more
simple):
- RT definition is done on the server
- agent asks for the RT definition on 1st start
- MiQ also gets the RT definition from the server.
With Inventory.v3 this may mean that some startup code needs to populate
RTs
and probably periodically refresh them.
Thoughts?
[1]
https://github.com/pilhuhn/misc_writing/blob/master/HowToWriteAnRhqPlugin...
[2]
https://github.com/hawkular/hawkular-agent/blob/master/hawkular-javaagent...