openstack/aodh
Code Issues Proposed changes

Added documentation for selectable aggregates

Browse Source 
Documented available aggregate functions
and added example syntax showing how to use
improved Statistics API, which allows the user to
selectively access aggregate functions. Also
documented the Capabilities API, which allows
the user to find out what functionality is supported
by their storage driver.

Closes-Bug: #1290924
Change-Id: I9739d2102baf6040de017843ae20391c4c9b6fff
This commit is contained in:
Ana Malagon 2014-03-13 10:15:57 -04:00
parent 9a489b5d41
commit 654dab111e
2 changed files with 125 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
ceilometer/api/controllers/v2.py
View File

@ -2419,6 +2419,9 @@ class CapabilitiesController(rest.RestController):
@wsme_pecan.wsexpose(Capabilities)
def get(self):
"""Returns a flattened dictionary of API capabilities supported
by the currently configured storage driver.
"""
# variation in API capabilities is effectively determined by
# the lack of strict feature parity across storage drivers
driver_capabilities = pecan.request.storage_conn.get_capabilities()

124
doc/source/webapi/v2.rst
View File

@ -37,6 +37,41 @@ Samples and Statistics
.. autotype:: ceilometer.api.controllers.v2.Statistics
:members:
When a simple statistics request is invoked (using GET /v2/meters/<meter_name>/statistics), it will return the standard set of *Statistics*: *avg*, *sum*,
*min*, *max*, and *count*.
Selectable Aggregates
+++++++++++++++++++++
The Statistics API has been extended to include the aggregate functions *stddev* and *cardinality*. You can explicitly select these functions or any from the
standard set by specifying an aggregate function in the statistics query::
GET /v2/meters/<meter_name>/statistics?aggregate.func=<name>&aggregate.param=<value>
(where aggregate.param is optional). See the :ref:`functional-examples`
section for more detail.
.. note:: Currently only *cardinality* needs aggregate.param to be specified.
.. autotype:: ceilometer.api.controllers.v2.Aggregate
:members:
Capabilities
============
The Capabilities API allows you to directly discover which functions from the
V2 API functionality, including the selectable aggregate functions, are
supported by the currently configured storage driver. A capabilities query
returns a flattened dictionary of properties with associated boolean values -
a 'False' or absent value means that the corresponding feature is not
available in the backend.
.. rest-controller:: ceilometer.api.controllers.v2:CapabilitiesController
:webprefix: /v2/capabilities
.. autotype:: ceilometer.api.controllers.v2.Capabilities
:members:
.. _alarms-api:
Alarms
@ -193,6 +228,15 @@ You can specify multiple filters by using an array of queries (order matters)::
"?q.field=metadata.event_type&q.value=compute.instance.exists"\
"&q.field=timestamp&q.op=gt&q.value=2013-07-03T13:34:17"
A query to find the maximum value and standard deviation (*max*, *stddev*) of
the CPU utilization for a given instance (identified by *resource_id*)::
curl -H 'X-Auth-Token: <inserttokenhere>' \
"http://localhost:8777/v2/meters/cpu_util/statistics?aggregate.func=max&aggregate.func=stddev"\
"&q.field=resource_id&q.op=eq&q.value=64da755c-9120-4236-bee1-54acafe24980"
.. note:: If any of the requested aggregates are not supported by the storage driver, a HTTP 400 error code will be returned along with an appropriate error message.
JSON based example::
@ -207,6 +251,7 @@ JSON based example with multiple filters::
"'{"field": "project_id","op": "eq","value":"8d6057bc-5b90-4296-afe0-84acaa2ef909"}]}' \
http://localhost:8777/v2/meters/instance
.. _functional-examples:
Functional examples
+++++++++++++++++++
@ -227,7 +272,8 @@ Get the list of samples about instances running for June 2013::
"value": "2013-07-01T00:00:00"}]
Get the list of samples about instances running for June 2013 for a particular project::
Get the list of samples about instances running for June 2013 for a particular
project::
GET /v2/meters/instance
q: [{"field": "timestamp",
@ -240,7 +286,8 @@ Get the list of samples about instances running for June 2013 for a particular p
"op": "eq",
"value": "8d6057bc-5b90-4296-afe0-84acaa2ef909"}]
Get the list of samples about instances with *m1.tiny* flavor running for June 2013 for a particular project::
Get the list of samples about instances with *m1.tiny* flavor running for June
2013 for a particular project::
GET /v2/meters/instance:m1.tiny
q: [{"field": "timestamp",
@ -361,6 +408,79 @@ With the return values::
"resource_id": "eaed9cf4-fc99-4115-93ae-4a5c37a1a7d7"},
"unit": "image"}]
You can request specific aggregate functions as well. For example, if you only
want the average CPU utilization, the GET request would look like this::
GET /v2/meters/cpu_util/statistics?aggregate.func=avg
Use the same syntax to access the aggregate functions not in the standard set,
e.g. *stddev* and *cardinality*. A request for the standard deviation of CPU utilization would take the form::
GET /v2/meters/cpu_util/statistics?aggregate.func=stddev
And would give a response such as the example::
[{"aggregate": {"stddev":0.6858829535841072},
"duration_start": "2014-01-30T11:13:23",
"duration_end": "2014-01-31T16:07:13",
"duration": 104030.0,
"period": 0,
"period_start": "2014-01-30T11:13:23",
"period_end": "2014-01-31T16:07:13",
"groupby": null,
"unit" : "%"}]
The request syntax is similar for *cardinality* but with the aggregate.param
option provided. So, for example, if you want to know the number of distinct
tenants with images, you would do::
GET /v2/meters/image/statistics?aggregate.func=cardinality
&aggregate.param=project_id
For a more involved example, consider a requirement for determining, for some
tenant, the number of distinct instances (*cardinality*) as well as the total
number of instance samples (*count*). You might also want to see this
information with 15 minute long intervals. Then, using the *period* and
*groupby* options, a query would look like the following::
GET /v2/meters/instance/statistics?aggregate.func=cardinality
&aggregate.param=resource_id
&aggregate.func=count
&groupby=project_id&period=900
This would give an example response of the form::
[{"count": 19,
"aggregate": {"count": 19.0, "cardinality/resource_id": 3.0},
"duration": 328.478029,
"duration_start": "2014-01-31T10:00:41.823919",
"duration_end": "2014-01-31T10:06:10.301948",
"period": 900,
"period_start": "2014-01-31T10:00:00",
"period_end": "2014-01-31T10:15:00",
"groupby": {"project_id": "061a5c91811e4044b7dc86c6136c4f99"},
"unit": "instance"},
{"count": 22,
"aggregate": {"count": 22.0, "cardinality/resource_id": 4.0},
"duration": 808.00384,
"duration_start": "2014-01-31T10:15:15",
"duration_end": "2014-01-31T10:28:43.003840",
"period": 900,
"period_start": "2014-01-31T10:15:00",
"period_end": "2014-01-31T10:30:00",
"groupby": {"project_id": "061a5c91811e4044b7dc86c6136c4f99"},
"unit": "instance"},
{"count": 2,
"aggregate": {"count": 2.0, "cardinality/resource_id": 2.0},
"duration": 0.0,
"duration_start": "2014-01-31T10:35:15",
"duration_end": "2014-01-31T10:35:15",
"period": 900,
"period_start": "2014-01-31T10:30:00",
"period_end": "2014-01-31T10:45:00",
"groupby": {"project_id": "061a5c91811e4044b7dc86c6136c4f99"},
"unit": "instance"}]
If you want to retrieve all the instances (not the list of samples, but the
resource itself) that have been run during this month for a given project,
you should ask the resource endpoint for the list of resources (all types: