Work is in progress to get Ironic to emit notifications from data provided by IPMI sensors (such as cpu temp and voltage). Ceilometer needs to be updated to consume, transform and record these notifications.
The Ironic project is doing work to emit notifications on the message bus containing IPMI sensor data. If Ceilometer processes these notifications other services will be able use queries and alarms to monitor and scale as required.
It is not possible to simply dump a message on the bus and for Ceilometer to handle it. Instead a notification plugin is required, in Ceilometer, to hear notifications at an exchange and topic and transform them into samples.
Add a new notification plugin for Ironic to transform sensor data into samples, using existing NotficationBase implementations as a model. To do this effectively a complete sample of the expected sensor data is required to determine the relevant types of samples.
Handling notifications is the standard and preferred method for gathering data into Ceilometer. The other option is polling which has known scalability issues, including over-frequent polling of IPMI. If Ironic is sending notifications it can continue to own the credentials for the IPMI access and also control the cadence with which sensors are polled. Using notifications also allows other services to consume the sensor data.
There will be additional valid values in query parameters but no changes to API endpoints.
Unknown. The data being provided by the Ironic notifier is still being decided. Only when it is available will it be possible to determine what, if any, transformations may be usefully done in the pipeline.
No new impacts. Pre-existing concerns with capacity at the notification and storage handling layers remain.
Who is leading the writing of the code? Or is this a blueprint where you’re throwing it out there to see who picks it up?
If more than one person is working on the implementation, please designate the primary author and contact.
In the future new types of notifications are expected from the Ironic controller. These will need to be handled either by additional notification plugins or (hopefully) generic notification handling. The Ceilometer team will be responsible for collaborating with the Ironic team to ensure these are handled smoothly.
The primary dependency is work described in an Ironic spec. Once that is implemented, notifications will be present on the bus.
In addition to unit tests, Tempest tests which confirm that Ceilometer consumes notifications produced by Ironic would be useful. Such tests depend on there being a tool to provide sensor data in the testing environment. Such a tool would be similar to bm_poseur which fakes baremetal instances in devstack. In the event that such a tool is not available as long as the sample data used in unit tests is sufficiently representative then the tests themselves ought to be as well.