Thresholds embedded in Sensors schema | Redfish Specification Forum

johannes
Minnow

Posts: 10

Thresholds embedded in Sensors schema Feb 23, 2023 13:07:33 GMT

Quote

Post by johannes on Feb 23, 2023 13:07:33 GMT

Hi,

I am currently working on an redfish API for a PDU product line. Therefore i have to display many sensor values.
To save on the SensorCollection under "RackPDUs/{id}/Sensors" or with ne new spec under "Chassis/PDU/Sensors" i decided just to include the thresholds in

Outlets, Branches or Metrics themself. So besides the value, there are also the the thresholds of the sensors schema.

Redfish-Service-Validator seems to be happy with it. I even provide the possibility to change threshold through these resources.

These ressources get kind of large, but in my opinion still manageable.

{
    "@odata.type": "#Outlet.v1_4_0.Outlet",
    "Id": "{outletID}",
    "Name": "PDU Outlet",
    "UserLabel": "Socket 01",
    "VoltageType": "AC",
    "PowerState": "On",
    "PowerEnabled": true,
    "CurrentAmps": {
        "Reading": 0,
        "Thresholds": {
            "UpperCautionUser": {
                "Reading": 0,
                "Activation": "Decreasing"
            },
            "LowerCautionUser": {
                "Reading": 0,
                "Activation": "Decreasing"
            },
            "UpperCriticalUser": {
                "Reading": 0,
                "Activation": "Decreasing"
            },
            "LowerCriticalUser": {
                "Reading": 0,
                "Activation": "Decreasing"
            }
        }
    },
    "PowerWatts": {
        "Reading": 0,
        "Thresholds": {
            "UpperCautionUser": {
                "Reading": 0,
                "Activation": "Decreasing"
            },
            "LowerCautionUser": {
                "Reading": 0,
                "Activation": "Decreasing"
            },
            "UpperCriticalUser": {
                "Reading": 0,
                "Activation": "Decreasing"
            },
            "LowerCriticalUser": {
                "Reading": 0,
                "Activation": "Decreasing"
            }
        },
        "ApparentVA": 0,
        "ReactiveVAR": 0,
        "PowerFactor": 0
    },
    "EnergykWh": {
        "Reading": 0
    },
    "Actions": {
        "#Outlet.PowerControl": {
            "target": "/redfish/v1/PowerEquipment/RackPDUs/{PDUid}/Outlets/{outletID}/Actions/Outlet.PowerControl"
        }
    },
    "Links": {
        "BranchCircuit": {
            "@odata.id": "/redfish/v1/PowerEquipment/RackPDUs/{PDUid}/Branches/{branchID}"
        }
    },
    "@odata.id": "/redfish/v1/PowerEquipment/RackPDUs/{PDUid}/Outlets/{outletID}"
}

A PATCH-request on all the thresholds (and the userLabel) could look like this:

{
    "UserLabel": "coffee pot",
    "CurrentAmps": {
        "Thresholds": {
            "UpperCautionUser": {
                "Reading": 0
            },
            "LowerCautionUser": {
                "Reading": 0
            },
            "UpperCriticalUser": {
                "Reading": 0
            },
            "LowerCriticalUser": {
                "Reading": 0
            }
        }
    },
    "PowerWatts": {
        "Thresholds": {
            "UpperCautionUser": {
                "Reading": 0
            },
            "LowerCautionUser": {
                "Reading": 0
            },
            "UpperCriticalUser": {
                "Reading": 0
            },
            "LowerCriticalUser": {
                "Reading": 0
            }
        }
    }
}

Is it allowed to embedd properties of the sensors schema in such a way?

The next thing is that most of our thresholds are disabled, if they are set to 0. I did not find a way in sensors schema to display this behavior. I would have expected another enum value in activation but there is no "disabled".

best regards
Johannes

jautor
Administrator

Posts: 502

Thresholds embedded in Sensors schema Feb 23, 2023 15:05:32 GMT

Quote

Post by jautor on Feb 23, 2023 15:05:32 GMT

Feb 23, 2023 13:07:33 GMT johannes said:

Hi,

I am currently working on an redfish API for a PDU product line. Therefore i have to display many sensor values.
To save on the SensorCollection under "RackPDUs/{id}/Sensors" or with ne new spec under "Chassis/PDU/Sensors" i decided just to include the thresholds in

Outlets, Branches or Metrics themself. So besides the value, there are also the the thresholds of the sensors schema.

Redfish-Service-Validator seems to be happy with it. I even provide the possibility to change threshold through these resources.

These ressources get kind of large, but in my opinion still manageable.

Is it allowed to embedd properties of the sensors schema in such a way?

I need to go back and look at the specification definitions for the schema "excerpt" to see what we said, but I believe you *can* show anything valid for the source schema/resource - and almost certainly the validator is allowing that.

And if these were read-only properties my opinion on what you're showing would probably be different - because you'd just be displaying "extra information you deem useful". But as these are read-write properties, you're creating a new and different path for the user to change those thresholds, and that won't be interoperable. Code written for your PDU wouldn't work on others, nor would code written for the Sensor collection work on yours. And that's not good.

So I'd recommend against this, and recommend the Sensor route. You can absolutely do a very minimal Sensor resource (probably share code for a lot of these instances). But yes, PDUs end up with a lot of Sensor instances - but that's the most important data for the product, so I think that's justified...

The next thing is that most of our thresholds are disabled, if they are set to 0. I did not find a way in sensors schema to display this behavior. I would have expected another enum value in activation but there is no "disabled".

best regards
Johannes

Oh, that may be an issue. We added those user-defined Thresholds, but the original definition was built on the assumption that if the service populated a threshold, it was using it. (you wouldn't have a disabled threshold for an internal, product-defined one - although I can think of some use cases where even that assumption doesn't hold.)

I'll take a look, but I think your suggestion is going to be the right answer - add a "Disabled" enumeration to `Activation` (and make that a read-write property if it isn't already).

Thanks for the feedback!
Jeff

mraineri
Administrator

Posts: 1,048

Thresholds embedded in Sensors schema Feb 23, 2023 15:21:21 GMT jautor likes this

Quote

Post by mraineri on Feb 23, 2023 15:21:21 GMT

Feb 23, 2023 15:05:32 GMT jautor said:

I need to go back and look at the specification definitions for the schema "excerpt" to see what we said, but I believe you *can* show anything valid for the source schema/resource - and almost certainly the validator is allowing that.

It's not valid. If you look at the JSON Schema, we call out an explicit "Excerpt" object definition, which just has a subset of properties from the full resource. We need to address this in the validator.

jautor
Administrator

Posts: 502

Thresholds embedded in Sensors schema Mar 21, 2023 22:04:31 GMT

Quote

Post by jautor on Mar 21, 2023 22:04:31 GMT

Johannes,

After discussion with the group, your suggestion to add "Disabled" as an enumeration value for `Activation` has been approved by the DMTF Redfish Forum, and is intended to be included in the next release of the Redfish Schema bundle (DSP8010).

Thanks for the feedback,

Jeff