74 lines
1.7 KiB
ReStructuredText
74 lines
1.7 KiB
ReStructuredText
..
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This work is licensed under a Creative Commons Attribution 3.0 Unported
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License.
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http://creativecommons.org/licenses/by/3.0/legalcode
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======================
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Convergence Observer
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======================
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https://blueprints.launchpad.net/heat/+spec/convergence-observer
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As a step toward implementing the ``convergence`` specification, Heat
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will split operations which fall into the "observing reality" category
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into a separate "observer" process.
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Problem description
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===================
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External systems hosting the physical resources of a stack will change
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independent of operations in Heat. There is a need to have a way to record
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and respond to these changes.
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Proposed change
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===============
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* Observer is responsible for managing the model of reality
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* polls nova/neutron/etc using resource `check` methods.
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* conceptually polls heat stack descriptions to update internal resources
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* Data model will need to store "observed state"
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* REST API will need to display "observed state"
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Note that no change will be necessary to the resource plugin API. Also
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note that subscribing to notifications will be done in a separate
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blueprint named `convergence-continuous-observer`.
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Alternatives
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------------
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-
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Implementation
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==============
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Assignee(s)
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-----------
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Work should be spread between all developers as much as possible to help
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spread awareness of how things work.
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Milestones
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----------
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Target Milestone for completion:
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Juno-2
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Work Items
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----------
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* Modify data model to record resource state
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* Modify public API to display observed state
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* Create new observer RPC API calls
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* Create new observer entry point
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* Move "check_active" and "check" calls to use observer API
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Dependencies
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============
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-
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