aodh/doc/source/measurements.rst

Measurements

Three type of meters are defined in ceilometer:

double: meter; cumulative double: meter; gauge double: meter; delta

Type	Definition
Cumulative	Increasing over time (instance hours)
Gauge	Discrete items (floating IPs, image uploads) and fluctuating values (disk I/O)
Delta	Changing over time (bandwidth)

Units

1. Whenever a volume is to be measured, SI approved units and their approved symbols or abbreviations should be used. Information units should be expressed in bits ('b') or bytes ('B').
2. For a given meter, the units should NEVER, EVER be changed.
3. When the measurement does not represent a volume, the unit description should always described WHAT is measured (ie: apples, disk, routers, floating IPs, etc.).
4. When creating a new meter, if another meter exists measuring something similar, the same units and precision should be used.
5. Samples (aka "meters" or "counters") should always document their units in Ceilometer (API and Documentation) and new sampling code should not be merged without the appropriate documentation.

Dimension	Unit	Abbreviations	Note
None Volume Time	N/A byte seconds	B s	Dimension-less variable

Here are the meter types by components that are currently implemented:

Compute (Nova)

Name	Type	Unit	Resource	Note
instance instance:<type>	Gauge Gauge		inst ID inst ID	Duration of instance Duration of instance <type> (openstack types)
memory	Gauge	B	inst ID	Volume of RAM in MB
cpu	Cumulative	ns	inst ID	CPU time used
vcpus	Gauge	vcpu	inst ID	Number of VCPUs
disk.root.size	Gauge	B	inst ID	Size of root disk in GB
disk.ephemeral.size	Gauge	B	inst ID	Size of ephemeral disk in GB
disk.io.requests	Cumulative	requests	inst ID	Number of disk io requests
disk.io.bytes	Cumulative	B	inst ID	Volume of disk io in bytes
network.incoming.bytes	Cumulative	B	iface ID	number of incoming bytes on the network
network.outgoing.bytes	Cumulative	B	iface ID	number of outgoing bytes on the network
network.incoming.packets	Cumulative	packets	iface ID	number of incoming packets
network.outgoing.packets	Cumulative	packets	iface ID	number of outgoing packets

Network (Quantum)

Name	Type	Unit	Resource	Note
network	Gauge	network	netw ID	Duration of network
network.create	Delta	network	netw ID	Creation requests for this network
network.update	Delta	network	netw ID	Update requests for this network
subnet	Gauge	subnet	subnt ID	Duration of subnet
subnet.create	Delta	subnet	subnt ID	Creation requests for this subnet
subnet.update	Delta	subnet	subnt ID	Update requests for this subnet
port	Gauge	port	port ID	Duration of port
port.create	Delta	port	port ID	Creation requests for this port
port.update	Delta	port	port ID	Update requests for this port
router	Gauge	router	rtr ID	Duration of router
router.create	Delta	router	rtr ID	Creation requests for this router
router.update	Delta	router	rtr ID	Update requests for this router
ip.floating	Gauge	ip	ip ID	Duration of floating ip
ip.floating.create	Delta	ip	ip ID	Creation requests for this floating ip
ip.floating.update	Delta	ip	ip ID	Update requests for this floating ip

Image (Glance)

Name	Type	Unit	Resource	Note
image	Gauge	image	image ID	Image polling -> it (still) exists
image.size	Gauge	B	image ID	Uploaded image size
image.update	Delta	image	image ID	Number of update on the image
image.upload	Delta	image	image ID	Number of upload of the image
image.delete	Delta	image	image ID	Number of delete on the image
image.download	Delta	B	image ID	Image is downloaded
image.serve	Delta	B	image ID	Image is served out

Volume (Cinder)

Name	Type	Unit	Resource	Note
volume	Gauge	volume	vol ID	Duration of volune
volume.size	Gauge	GiB	vol ID	Size of volume

Object Storage (Swift)

Name	Type	Volume	Resource	Note
storage.objects	Gauge	objects	store ID	Number of objects
storage.objects.size	Gauge	B	store ID	Total size of stored objects
storage.objects.containers	Gauge	containers	store ID	Number of containers
storage.objects.incoming.bytes	Delta	B	store ID	Number of incoming bytes
storage.objects.outgoing.bytes	Delta	B	store ID	Number of outgoing bytes

Energy (Kwapi)

Name	Type	Volume	Resource	Note
energy	Cumulative	kWh	probe ID	Amount of energy
power	Gauge	W	probe ID	Power consumption

Dynamically retrieving the Meters via ceilometer client

To retrieve the available meters that can be queried given the actual resource instances available, use the meter-list command:

$ ceilometer meter-list -s openstack
+------------+-------+--------------------------------------+---------+----------------------------------+
| Name       | Type  | Resource ID                          | User ID | Project ID                       |
+------------+-------+--------------------------------------+---------+----------------------------------+
| image      | gauge | 09e84d97-8712-4dd2-bcce-45970b2430f7 |         | 57cf6d93688e4d39bf2fe3d3c03eb326 |

Naming convention

If you plan on adding meters, please follow the convention bellow:

1. Always use '.' as separator and go from least to most discriminent word. For example, do not use ephemeral_disk_size but disk.ephemeral.size
2. When a part of the name is a variable, it should always be at the end and start with a ':'. For example do not use <type>.image but image:<type>, where type is your variable name.
3. If you have any hesitation, come and ask in #openstack-metering