Measurements

Three type of meters are defined in ceilometer:

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. Meters and samples 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 N/A   Dimension-less variable
Volume byte B  
Time seconds s  

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

Compute (Nova)

All meters are related to the guest machine, not the host.

Name Type* Unit Resource Origin** Support*** Note
instance g instance inst ID both 1, 2, 3 Existence of instance
instance:<type> g instance inst ID both 1, 2, 3 Existence of instance <type> (openstack types)
memory g MB inst ID n 1, 2 Volume of RAM allocated in MB
memory.usage g MB inst ID p 3 Volume of RAM used in MB
cpu c ns inst ID p 1, 2 CPU time used
cpu_util g % inst ID p 1, 2, 3 Average CPU utilisation
vcpus g vcpu inst ID n 1, 2 Number of VCPUs
disk.read.requests c request inst ID p 1, 2 Number of read requests
disk.read.requests.rate g request/s inst ID p 1, 2, 3 Average rate of read requests per second
disk.write.requests c request inst ID p 1, 2 Number of write requests
disk.write.requests.rate g request/s inst ID p 1, 2, 3 Average rate of write requests per second
disk.read.bytes c B inst ID p 1, 2 Volume of reads in B
disk.read.bytes.rate g B/s inst ID p 1, 2, 3 Average rate of reads in B per second
disk.write.bytes c B inst ID p 1, 2 Volume of writes in B
disk.write.bytes.rate g B/s inst ID p 1, 2, 3 Average volume of writes in B per second
disk.root.size g GB inst ID n 1, 2 Size of root disk in GB
disk.ephemeral.size g GB inst ID n 1, 2 Size of ephemeral disk in GB
network.incoming.bytes c B iface ID p 1, 2 Number of incoming bytes on a VM network interface
network.incoming.bytes.rate g B/s iface ID p 1, 2, 3 Average rate per sec of incoming bytes on a VM network interface
network.outgoing.bytes c B iface ID p 1, 2 Number of outgoing bytes on a VM network interface
network.outgoing.bytes.rate g B/s iface ID p 1, 2, 3 Average rate per sec of outgoing bytes on a VM network interface
network.incoming.packets c packet iface ID p 1, 2 Number of incoming packets on a VM network interface
network.incoming.packets.rate g packet/s iface ID p 1, 2, 3 Average rate per sec of incoming packets on a VM network interface
network.outgoing.packets c packet iface ID p 1, 2 Number of outgoing packets on a VM network interface
network.outgoing.packets.rate g packet/s iface ID p 1, 2, 3 Average rate per sec of outgoing packets on a VM network interface
Legend:
*
[g]: gauge
[c]: cumulative
**
[p]: pollster
[n]: notification
***
[1]: Libvirt support
[2]: HyperV support
[3]: Vsphere support

Contributors are welcome to extend other virtualization backends’ meters or complete the existing ones.

The meters below are related to the host machine.

By default, Nova will not collect the following meters related to the host compute node machine. Nova option ‘compute_monitors = ComputeDriverCPUMonitor’ should be set in nova.conf to enable meters.

Name Type Unit Resource Origin Note
compute.node.cpu.frequency Gauge MHz host ID notification CPU frequency
compute.node.cpu.kernel.time Cumulative ns host ID notification CPU kernel time
compute.node.cpu.idle.time Cumulative ns host ID notification CPU idle time
compute.node.cpu.user.time Cumulative ns host ID notification CPU user mode time
compute.node.cpu.iowait.time Cumulative ns host ID notification CPU I/O wait time
compute.node.cpu.kernel.percent Gauge % host ID notification CPU kernel percentage
compute.node.cpu.idle.percent Gauge % host ID notification CPU idle percentage
compute.node.cpu.user.percent Gauge % host ID notification CPU user mode percentage
compute.node.cpu.iowait.percent Gauge % host ID notification CPU I/O wait percentage
compute.node.cpu.percent Gauge % host ID notification CPU utilization

Network (Neutron)

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

Image (Glance)

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

Volume (Cinder)

Name Type Unit Resource Origin Note
volume Gauge volume vol ID notification Existence of volume
volume.size Gauge GB vol ID notification Size of volume

Make sure Cinder is properly configured first: see Installing Manually.

Object Storage (Swift)

Name Type Unit Resource Origin Note
storage.objects Gauge object store ID pollster Number of objects
storage.objects.size Gauge B store ID pollster Total size of stored objects
storage.objects.containers Gauge container store ID pollster Number of containers
storage.objects.incoming.bytes Delta B store ID notification Number of incoming bytes
storage.objects.outgoing.bytes Delta B store ID notification Number of outgoing bytes
storage.api.request Delta request store ID notification Number of API requests against swift
storage.containers.objects Gauge object str ID/cont pollster Number of objects in container
storage.containers.objects.size Gauge B str ID/cont pollster Total size of stored objects in container

In order to use storage.objects.incoming.bytes and storage.outgoing.bytes, one must configure Swift as described in Installing Manually. Note that they may not be updated right after an upload/download, since Swift takes some time to update the container properties.

Orchestration (Heat)

Name Type Unit Resource Origin Note
stack.create Delta stack stack ID notification Creation requests for a stack successful
stack.update Delta stack stack ID notification Updating requests for a stack successful
stack.delete Delta stack stack ID notification Deletion requests for a stack successful
stack.resume Delta stack stack ID notification Resuming requests for a stack successful
stack.suspend Delta stack stack ID notification Suspending requests for a stack successful

To enable Heat notifications configure Heat as described in Installing Manually.

Energy (Kwapi)

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

Network (From SDN Controller)

These meters based on OpenFlow Switch metrics. In order to enable these meters, each driver needs to be configured.

Meter Type Unit Resource Origin Note
switch Gauge switch switch ID pollster Existence of switch
switch.port Gauge port switch ID pollster Existence of port
switch.port.receive.packets Cumulative packet switch ID pollster Received Packets
switch.port.transmit.packets Cumulative packet switch ID pollster Transmitted Packets
switch.port.receive.bytes Cumulative B switch ID pollster Received Bytes
switch.port.transmit.bytes Cumulative B switch ID pollster Transmitted Bytes
switch.port.receive.drops Cumulative packet switch ID pollster Receive Drops
switch.port.transmit.drops Cumulative packet switch ID pollster Transmit Drops
switch.port.receive.errors Cumulative packet switch ID pollster Receive Errors
switch.port.transmit.errors Cumulative packet switch ID pollster Transmit Errors
switch.port.receive.frame_error Cumulative packet switch ID pollster Receive Frame Alignment Errors
switch.port.receive.overrun_error Cumulative packet switch ID pollster Receive Overrun Errors
switch.port.receive.crc_error Cumulative packet switch ID pollster Receive CRC Errors
switch.port.collision.count Cumulative count switch ID pollster Collisions
switch.table Gauge table switch ID pollster Duration of Table
switch.table.active.entries Gauge entry switch ID pollster Active Entries
switch.table.lookup.packets Gauge packet switch ID pollster Packet Lookups
switch.table.matched.packets Gauge packet switch ID pollster Packet Matches
switch.flow Gauge flow switch ID pollster Duration of Flow
switch.flow.duration.seconds Gauge s switch ID pollster Duration(seconds)
switch.flow.duration.nanoseconds Gauge ns switch ID pollster Duration(nanoseconds)
switch.flow.packets Cumulative packet switch ID pollster Received Packets
switch.flow.bytes Cumulative B switch ID pollster Received Bytes

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 below:

  1. Always use ‘.’ as separator and go from least to most discriminant 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-ceilometer

User-defined sample metadata for Nova

Users are allowed to add additional metadata to samples of nova meter. These additional metadata are stored in ‘resource_metadata.user_metadata.*’ of the sample To do so, users should add nova user metadata prefixed with ‘metering.’:

::
$ nova boot –meta metering.custom_metadata=a_value my_vm

Note: The name of the metadata shouldn’t exceed 256 characters otherwise it will be cut off. Also, if it has ‘.’, this will be replaced by a ‘_’ in ceilometer.

User-defined sample metadata for Swift

It’s possible to add additional metadata to sample of Swift meter as well. You might specify headers whose values will be stored in resource_metadata as ‘resource_metadata.http_header_$name’, where $name is a name of the header with ‘-‘ replaced by ‘_’.

This is done using ‘metadata_headers’ option in middleware configuration, refer to Installing Manually for details.

For example, this could be used to distinguish external and internal users. You’d have to implement a custom Swift middleware that sets a proper header and just add it to metadata_headers.