Merge "event to sample publisher"

specs/mitaka/event-to-sample-publisher.rst

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+..
+ This work is licensed under a Creative Commons Attribution 3.0 Unported
+ License.
+ http://creativecommons.org/licenses/by/3.0/legalcode
+
+===============================
+Event To Sample Publisher
+===============================
+https://blueprints.launchpad.net/ceilometer/+spec/event-to-sample-publisher
+
+Problem description
+===================
+Bracket events like compute.instance.create.latency created from BP:
+Transformers for events pipeline
+https://blueprints.launchpad.net/ceilometer/+spec/events-pipeline-transformers
+need to be published and stored as sample.
+
+The bracket events created from transformers in events pipeline are new
+events/metrics with any kind of latency time spans like time.instance.creation
+or time.instance.life that is a delta time between
+compute.instance.create.start/end, compute.instance.create.end/delete.end, etc.
+
+Proposed change
+===============
+Add a new notifier publisher and use this publisher in event transformer,
+when there is a new transformed event from events pipeline
+transformers, convert it to notification, send it back to ceilometer notificaton listener,
+the notification payload is generated from event traits,
+then the sample pipeline will convert and publish it into sample.
+
+For example, for compute.instance.create.latency event,
+Firstly, add this publisher(for example: tosamplenotifier://)
+to sink in event transformer for this event ::
+
+    - name: instance_create_bracketer_sink
+      transformers:
+          - name: "bracket"
+            parameters:
+              ........
+      publishers:
+          - tosamplenotifier://
+
+then, add meter schema in meters.yaml ::
+
+  - name: 'compute.instance.create.latency'
+    event_type:
+      - 'compute.instance.create.latency'
+    type: 'gauge'
+    unit: 's'
+    volume: $.payload.latency
+    user_id: $.payload.user_id
+    project_id: $.payload.tenant_id
+    resource_id: $.payload.instance_id
+
+The notification payload send back to message bus is generated from event traits, will be like this ::
+ {'latency': 0.355098, 'user_id': u'0f1b1e94ec2045af9f49f9b7e1d6b409', 'service': u'network.yuntong-ThinkStation',
+ 'resource_id': u'67d1c4b3-84aa-42d1-a857-2d1481fe21dd', 'tenant_id': u'c8ce7938e38b4612a8b3daab441b804c',
+ 'request_id': u'req-597a85ec-ebab-492f-8288-b6b72fc476b5', 'project_id': u'c8ce7938e38b4612a8b3daab441b804c',
+ 'publisher_id': 'compute.yuntong-ThinkStation'}
+
+and finally, the compute.instance.create.latency sample will be like this ::
+ +--------------------------------------+---------------------------------+-------+----------+------+----------------------------+
+ | Resource ID                          | Name                            | Type  | Volume   | Unit | Timestamp                  |
+ +--------------------------------------+---------------------------------+-------+----------+------+----------------------------+
+ | e8e8adf5-8ba1-4247-b1af-1e8c928563e7 | compute.instance.create.latency | gauge | 7.133763 | s    | 2015-09-16T07:04:58.540929 |
+ +--------------------------------------+---------------------------------+-------+----------+------+----------------------------+
+
+
+Alternatives
+------------
+
+None.
+
+Data model impact
+-----------------
+
+None.
+
+REST API impact
+---------------
+
+None.
+
+Security impact
+---------------
+
+None.
+
+Pipeline impact
+---------------
+
+This spec proposes additional publisher for event transformers
+in event_pipeline.yaml
+
+Other end user impact
+---------------------
+
+None.
+
+Performance/Scalability Impacts
+-------------------------------
+
+None
+
+Other deployer impact
+---------------------
+
+Configuration options in event_pipeline.yaml.
+Configuration options in meter.yaml.
+
+Developer impact
+----------------
+
+None.
+
+Implementation
+==============
+
+Assignee(s)
+-----------
+
+Primary assignee:
+  yuntongjin
+
+Ongoing maintainer:
+  yuntongjin
+
+
+Work Items
+----------
+
+- Add a new publisher that will send the convert notification to sample listener.
+
+
+Future lifecycle
+================
+
+None
+
+Dependencies
+============
+
+Transformers for events pipeline https://review.openstack.org/#/c/162167/
+
+Testing
+=======
+
+- Extend messaging publisher testing.
+
+Documentation Impact
+====================
+
+- Capture new meters which from event brackelet transformers.
+
+References
+==========
+
+https://blueprints.launchpad.net/ceilometer/+spec/events-pipeline-transformers