The message at the end of this email is some three months old. I have the same problem. The question is: How to use the new rate metrics in Gnocchi. I am using a Stein Devstack for my tests.

For example, I need the CPU rate, formerly named cpu_util. I created a new archive policy that uses rate:mean aggregation and has a 1 minute granularity:

$ gnocchi archive-policy show ceilometer-medium-rate
+---------------------+------------------------------------------------------------------+
| Field               | Value                                                            |
+---------------------+------------------------------------------------------------------+
| aggregation_methods | rate:mean, mean                                                  |
| back_window         | 0                                                                |
| definition          | - points: 10080, granularity: 0:01:00, timespan: 7 days, 0:00:00 |
| name                | ceilometer-medium-rate                                           |
+---------------------+------------------------------------------------------------------+

I added the new policy to the publishers in pipeline.yaml:

$ tail -n5 /etc/ceilometer/pipeline.yaml
sinks:
    - name: meter_sink
      publishers:
          - gnocchi://?archive_policy=medium&filter_project=gnocchi_swift
          - gnocchi://?archive_policy=ceilometer-medium-rate&filter_project=gnocchi_swift

After restarting all of Ceilometer, my hope was that the CPU rate would magically appear in the metric list. But no: All metrics are linked to archive policy medium, and looking at the details of an instance, I don't detect anything rate-related:

$ gnocchi resource show ae3659d6-8998-44ae-a494-5248adbebe11
+-----------------------+---------------------------------------------------------------------+
| Field                 | Value                                                               |
+-----------------------+---------------------------------------------------------------------+
...
| metrics               | compute.instance.booting.time: 76fac1f5-962e-4ff2-8790-1f497c99c17d |
|                       | cpu: af930d9a-a218-4230-b729-fee7e3796944                           |
|                       | disk.ephemeral.size: 0e838da3-f78f-46bf-aefb-aeddf5ff3a80           |
|                       | disk.root.size: 5b971bbf-e0de-4e23-ba50-a4a9bf7dfe6e                |
|                       | memory.resident: 09efd98d-c848-4379-ad89-f46ec526c183               |
|                       | memory.swap.in: 1bb4bb3c-e40a-4810-997a-295b2fe2d5eb                |
|                       | memory.swap.out: 4d012697-1d89-4794-af29-61c01c925bb4               |
|                       | memory.usage: 93eab625-0def-4780-9310-eceff46aab7b                  |
|                       | memory: ea8f2152-09bd-4aac-bea5-fa8d4e72bbb1                        |
|                       | vcpus: e1c5acaf-1b10-4d34-98b5-3ad16de57a98                         |
| original_resource_id  | ae3659d6-8998-44ae-a494-5248adbebe11                                |
...

| type                  | instance                                                            |
| user_id               | a9c935f52e5540fc9befae7f91b4b3ae                                    |
+-----------------------+---------------------------------------------------------------------+

Obviously, I am missing something. Where is the missing link? What do I have to do to get CPU usage rates? Do I have to create metrics? Do I have to ask Ceilometer to create metrics? How?

Right now, no instructions seem to exist at all. If that is correct, I would be happy to write documentation once I understand how it works.

Thanks a lot.

Bernd

Hello,

I am working on Watcher and we are currently changing how metrics are
retrieved from different datasources such as Monasca or Gnocchi. Because
of this major overhaul I would like to validate that everything is
working correctly.

Almost all of the optimization strategies in Watcher require the cpu
utilization of an instance as metric but with newer versions of
Ceilometer this has become unavailable.

On IRC I received the information that Gnocchi could be used to
configure an aggregate and this aggregate would then report cpu
utilization, however, I have been unable to find documentation on how to
achieve this.

I was also notified that cpu_util is something that could be computed
from other metrics. When reading
https://docs.openstack.org/ceilometer/rocky/admin/telemetry-measurements.html#openstack-compute
the documentation seems to agree on this as it states that cpu_util is
measured by using a 'rate of change' transformer. But I have not been
able to find how this can be computed.

I was hoping someone could spare the time to provide documentation or
information on how this currently is best achieved.

Kind Regards,
Corne Lukken (Dantali0n)