Measure cloud resources¶

Telemetry measures cloud resources in OpenStack. It collects data related to billing. Currently, this metering service is available through only the ceilometer command-line client.

To model data, Telemetry uses the following abstractions:

Meter

Measures a specific aspect of resource usage, such as the existence of a running instance, or ongoing performance, such as the CPU utilization for an instance. Meters exist for each type of resource. For example, a separate cpu_util meter exists for each instance. The lifecycle of a meter is decoupled from the existence of its related resource. The meter persists after the resource goes away.

A meter has the following attributes:

• String name
• A unit of measurement
• A type, which indicates whether values increase monotonically (cumulative), are interpreted as a change from the previous value (delta), or are stand-alone and relate only to the current duration (gauge)

Sample

An individual data point that is associated with a specific meter. A sample has the same attributes as the associated meter, with the addition of time stamp and value attributes. The value attribute is also known as the sample volume.

Statistic

A set of data point aggregates over a time duration. (In contrast, a sample represents a single data point.) The Telemetry service employs the following aggregation functions:

• count. The number of samples in each period.
• max. The maximum number of sample volumes in each period.
• min. The minimum number of sample volumes in each period.
• avg. The average of sample volumes over each period.
• sum. The sum of sample volumes over each period.

Alarm

A set of rules that define a monitor and a current state, with edge-triggered actions associated with target states. Alarms provide user-oriented Monitoring-as-a-Service and a general purpose utility for OpenStack. Orchestration auto scaling is a typical use case. Alarms follow a tristate model of ok, alarm, and insufficient data. For conventional threshold-oriented alarms, a static threshold value and comparison operator govern state transitions. The comparison operator compares a selected meter statistic against an evaluation window of configurable length into the recent past.

This example uses the openstack client to create an auto-scaling stack and the ceilometer client to measure resources.

1. Create an auto-scaling stack by running the following command. The -f option specifies the name of the stack template file, and the -P option specifies the KeyName parameter as heat_key:

   $ openstack stack create --template cfn/F17/AutoScalingCeilometer.yaml \
     --parameter "KeyName=heat_key" mystack
   

2. List the heat resources that were created:

   $ openstack stack resource list mystack
   +---------------+--------------------------------------+------------------+-----------------+---------------------+
   | resource_name | physical_resource_id                 | resource_type    | resource_status | updated_time        |
   +---------------+--------------------------------------+------------------+-----------------+---------------------+
   | server        | 1b3a7c13-42be-4999-a2a1-8fbefd00062b | OS::Nova::Server | CREATE_COMPLETE | 2013-10-02T05:53:41Z |
   | ...           | ...                                  | ...              | ...             | ...                  |
   +---------------+--------------------------------------+------------------+-----------------+---------------------+
   

3. List the alarms that are set:

   $ ceilometer alarm-list
   +--------------------------------------+------------------------------+-------------------+---------+------------+----------------------------------+
   | Alarm ID                             | Name                         | State             | Enabled | Continuous | Alarm condition                  |
   +--------------------------------------+------------------------------+-------------------+---------+------------+----------------------------------+
   | 4f896b40-0859-460b-9c6a-b0d329814496 | as-CPUAlarmLow-i6qqgkf2fubs  | insufficient data | True    | False      | cpu_util < 15.0 during 1x 60s |
   | 75d8ecf7-afc5-4bdc-95ff-19ed9ba22920 | as-CPUAlarmHigh-sf4muyfruy5m | insufficient data | True    | False      | cpu_util > 50.0 during 1x 60s |
   +--------------------------------------+------------------------------+-------------------+---------+------------+----------------------------------+
   

4. List the meters that are set:

   $ ceilometer meter-list
   +-------------+------------+----------+--------------------------------------+----------------------------------+----------------------------------+
   | Name        | Type       | Unit     | Resource ID                          | User ID                          | Project ID                       |
   +-------------+------------+----------+--------------------------------------+----------------------------------+----------------------------------+
   | cpu         | cumulative | ns       | 3965b41b-81b0-4386-bea5-6ec37c8841c1 | d1a2996d3b1f4e0e8645ba9650308011 | bf03bf32e3884d489004ac995ff7a61c |
   | cpu         | cumulative | ns       | 62520a83-73c7-4084-be54-275fe770ef2c | d1a2996d3b1f4e0e8645ba9650308011 | bf03bf32e3884d489004ac995ff7a61c |
   | cpu_util    | gauge      | %        | 3965b41b-81b0-4386-bea5-6ec37c8841c1 | d1a2996d3b1f4e0e8645ba9650308011 | bf03bf32e3884d489004ac995ff7a61c |
   +-------------+------------+----------+--------------------------------------+----------------------------------+----------------------------------+
   

5. List samples:

   $ ceilometer sample-list -m cpu_util
   +--------------------------------------+----------+-------+---------------+------+---------------------+
   | Resource ID                          | Name     | Type  | Volume        | Unit | Timestamp           |
   +--------------------------------------+----------+-------+---------------+------+---------------------+
   | 3965b41b-81b0-4386-bea5-6ec37c8841c1 | cpu_util | gauge | 3.98333333333 | %    | 2013-10-02T10:50:12 |
   +--------------------------------------+----------+-------+---------------+------+---------------------+
   

6. View statistics:

   $ ceilometer statistics -m cpu_util
   +--------+---------------------+---------------------+-------+---------------+---------------+---------------+---------------+----------+---------------------+---------------------+
   | Period | Period Start        | Period End          | Count | Min           | Max           | Sum           | Avg           | Duration | Duration Start      | Duration End        |
   +--------+---------------------+---------------------+-------+---------------+---------------+---------------+---------------+----------+---------------------+---------------------+
   | 0      | 2013-10-02T10:50:12 | 2013-10-02T10:50:12 | 1     | 3.98333333333 | 3.98333333333 | 3.98333333333 | 3.98333333333 | 0.0      | 2013-10-02T10:50:12 | 2013-10-02T10:50:12 |
   +--------+---------------------+---------------------+-------+---------------+---------------+---------------+---------------+----------+---------------------+---------------------+