Merge "Add specs for Libvirt disk capacity,usage and allocation metrics"

specs/kilo/disk-info-meters.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
+
+==========================================================================
+Adds Disk Capacity, Allocation and Usage metrics implementation in Libvirt
+==========================================================================
+
+https://blueprints.launchpad.net/ceilometer/+spec/disk-info-meters
+
+Problem description
+===================
+
+Currently, Libvirt Inspector does not collect disk capacity, usage and
+allocation metrics. This feature can be added for Libvirt to monitor disk
+metrics : capacity, usage and allocation. It will help to manage disk
+resources for addition of Virtual Machinesusing same physical disk.
+
+Proposed change
+===============
+
+Implement the method 'inspect_disk_info' in Inspector for Libvirt. This method
+will return the disk capacity,usage and allocation per device. The values
+correspond to values monitored by domblkinfo command of Libvirt.
+
+Add CapacityPollster which create sample :
+
+* name='disk.capacity'
+* type=sample.TYPE_GAUGE
+* unit='B'
+
+Add PerDeviceCapacityPollster which create sample :
+
+* name='disk.device.capacity'
+* type=sample.TYPE_GAUGE
+* unit='B'
+
+Add AllocationPollster which create sample :
+
+* name='disk.allocation'
+* type=sample.TYPE_GAUGE
+* unit='B'
+
+Add PerDeviceAllocationPollster which create sample :
+
+* name='disk.device.allocation'
+* type=sample.TYPE_GAUGE
+* unit='B'
+
+Add PhysicalPollster which create sample :
+
+* name='disk.usage'
+* type=sample.TYPE_GAUGE
+* unit='B'
+
+Add PerDevicePhysicalPollster which create sample :
+
+* name='disk.device.usage'
+* type=sample.TYPE_GAUGE
+* unit='B'
+
+
+Alternatives
+------------
+
+None
+
+Data model impact
+-----------------
+
+None
+
+REST API impact
+---------------
+
+None
+
+Security impact
+---------------
+
+None
+
+Pipeline impact
+---------------
+
+None
+
+Other end user impact
+---------------------
+
+None
+
+Performance/Scalability Impacts
+-------------------------------
+
+None
+
+
+Other deployer impact
+---------------------
+
+In pipeline.yaml, if user is not having * in meters_sink
+then new meters disk.capacity, disk.allocation, disk.usage,
+disk.device.capacity, disk.device.usage and disk.device.allocation
+needs to be added
+
+Developer impact
+----------------
+
+None
+
+
+Implementation
+==============
+
+Assignee(s)
+-----------
+
+Primary assignee:
+  ahmed-nooras-saba
+
+
+Work Items
+----------
+
+* Add _DiskInfoPollsterBase base class for reading values and aggregating
+  for all devices
+* Add CapacityPollster , AllocationPollster , PhysicalPollster for disk
+  metrics at instance level
+* Add PerDeviceCapacityPollster , PerDeviceAllocationPollster and
+  PerDevicePhysicalPollster for disk metrics at device level of an instance
+* Add inspect_disk_info to Libvirt inspectors
+* Add new metrics definition in measurements.rst
+
+
+Future lifecycle
+================
+
+This feature will need testing for next two releases.
+
+
+Dependencies
+============
+
+libvirt 0.8.1 and above.
+
+
+Testing
+=======
+
+Unit tests are required to test all the new pollsters at Libvirt.
+The new meters should be discoverable when listing ceilometer meters.
+Example : ceilometer meter-list
+
+
+Documentation Impact
+====================
+
+Added the following metrics in ceilometer/doc/source/measurements.rst and
+"measurement section" of
+http://docs.openstack.org/developer/ceilometer/measurements.html needs to
+be updated.
+
+====================== = = ======= = = ===================================
+====================== = = ======= = = ===================================
+disk.capacity          g B inst ID n 1  Capacity of disk in B
+disk.allocation        g B inst ID n 1  Allocation of disk in B
+disk.usage             g B inst ID n 1  Usage of disk in B
+disk.device.capacity   g B disk ID n 1  Capacity per device of disk in B
+disk.device.allocation g B disk ID n 1  Allocation per device of disk in B
+disk.device.usage      g B disk ID n 1 Usage per device of disk in B
+====================== = = ======= = = ===================================
+
+
+References
+==========
+
+http://osdir.com/ml/libvir-list/2010-04/msg01300.html