preferred approach for Sensor PeakReading property in dbus-sensors and bmcweb

[Harshit Aghera]

I'd like to get your input on the preferred approach for adding support for the Redfish Sensor properties PeakReading and PeakReadingTime. Per the Redfish schema, the Sensor resource should also support the ResetMetrics action for the PeakReading property.
https://redfish.dmtf.org/schemas/v1/Sensor.v1_2_0.yaml

Context: We have a GPU device that provides PeakReading and PeakReadingTime for its Power sensor via an MCTP VDM command. We plan to implement support in the dbus-sensors app nvidiagpusensor.

I've outlined a few options below. If there's a better alternative, please suggest.


  1.  Use xyz.openbmc_project.Common.Statistics PDI
     *   Use the Statistics interface to represent different sensor value statistics, with PeakReading as one such statistic.
     *   PDI patch: https://gerrit.openbmc.org/c/openbmc/phosphor-dbus-interfaces/+/78348
     *   ResetMetrics would be supported by implementing a DBus interface at the same object path.
     *   Open question: which phosphor DBus interface to use for ResetMetrics?
  2.  Use xyz.openbmc_project.Telemetry.Report
     *   Configure OperationType as Maximum.
     *   This interface already supports the ResetMetrics action.
  3.  Treat PeakReading as a standard sensor (Sensor.Value PDI)
     *   Expose a DBus object under sensors/power/<sensor_name> with a well-known name (e.g., peak_...).
     *   The association to the "actual" sensor would be handled in bmcweb.
     *   ResetMetrics would be supported by implementing a DBus interface at the same object path.
  4.  Same as option 3, but use a dedicated namespace
     *   Define a new path: sensor/power/peak/<sensor_name>.
     *   The association to the "actual" sensor would be handled in bmcweb.
     *   ResetMetrics would be supported by implementing a DBus interface at the same object path.
  5.  Use an OEM PDI
     *   Implement PeakReading/PeakReadingTime via an OEM interface.
     *   ResetMetrics would be supported by implementing a DBus interface at the same object path.


Looking forward to your feedback on the preferred approach.


Harshit.

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