[ClusterLabs] Overhaul of the OCF resource agent api spec

Lars Ellenberg lars.ellenberg at linbit.com
Tue Feb 10 21:09:53 UTC 2015


On Tue, Feb 10, 2015 at 09:44:40PM +0100, Lars Ellenberg wrote:
> Then we take it from there,
> and do the necessary overhaul of this OCF RA API spec.
> 
> I will followup with a list of items that need to be addressed
> (as I remember them from the discussions we had in Brno).

* versioning

  "This resource meta data intends to be consumed by
  someone able to understand at least spec version XYZ"

  or maybe use "features"?

  - optional features
    "if you understand feature F, you may take advantage of it"

  - required features
    "if you do NOT understand feature F,
    this RA will not work".

* document the "free form text message feedback"

  all the changes related to OCF_EXIT_REASON_PREFIX

  Maybe document or establish some conventions,
  how free exactly that free form is.

  Possibly this, or something like it, can be used to return
  "performance" data with the monitor option as well,
  for resource agents where that seems useful?

* reserve new exit codes for a probe/monitor action

  "running (Started/Slave), but degraded"
  "running (Master), but degraded"

  Optionally enriched with "free form text messages"
  via the above mentioned feedback mechanism.

  These both make failures, and "predicted failures",
  much more transparent for "consumers".

* enrich parameter definitions

  - more specific data types
    - integers, possibly valid value ranges
    - enums (choices of predefined strings)
  - optional "value-validation-pcre" regular expression?

* UI hints

  - "relevance level"
    that's a UI hint to present this parameter in the default "view", or
    possibly hide it even in an "extended view", unless you work under
    the "I am a control freak and need to manually set every possible
    parameter"-switch.



Anything I misunderstood: please clarify.
Anything I forgot: please add.

Thanks,

	Lars





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