How Relevant are "ReportSequence" & "@odata.id" attributes ?

ginugeorge
Minnow

Posts: 29

How Relevant are "ReportSequence" & "@odata.id" attributes ? Mar 11, 2021 9:16:40 GMT

Quote

Post by ginugeorge on Mar 11, 2021 9:16:40 GMT

With reference to MetricReport.v1_2_0.json schema,

"MetricReport": {
         .....
         "properties": {
                .....
         },
         "required": [
                "ReportSequence",
                "@odata.id",
                "@odata.type",
                "Id",
                "Name"
         ],
         "type": "object"
}

"ReportSequence" and "@odata.id" are required attributes, in addition to the others("@odata.type",
"Id" and "Name").

With reference to MetricReport.v1_3_0.json schema and above,

"MetricReport": {
         .....
         "properties": {
                .....
         },
         "required": [
                "@odata.id",
                "@odata.type",
                "Id",
                "Name"
         ],
         "type": "object"
}

"ReportSequence" is deprecated. But "@odata.id" is a required attribute, in addition to the others("@odata.type",
"Id" and "Name").

In the case of Metric Reports internally generated for each of the MetricReportDefinitions Resource(https://{{ip}}/redfish/v1/TelemetryService/MetricReportDefinitions) created by the user, "ReportSequence" and "@odata.id" are relevant attributes.

But in the case of SubmitTestMetricReport(POST https://{{ip}}/redfish/v1/TelemetryService/Actions/TelemetryService.SubmitTestMetricReport) , a dummy Metric Report will be generated based on the values passed in the Request Body to the above POST Request. Sample Request Body mentioned as below:

{
    "MetricReportName": "Average_Temperature_Reading",
    "GeneratedMetricReportValues": [
        {
            "MetricId": "Average_Temp_Reading",
            "MetricProperty": "/redfish/v1/Chassis/Self/Thermal#/Temperatures/7_0/ReadingCelsius",
            "MetricValue": "23",
            "Timestamp": "2019-07-01T06:05:52+05:00"
        }
    ]
}

In the above SubmitTestMetricReport scenario, are the "ReportSequence" and "@odata.id" attributes relevant ? If so, what should be the values for the two attributes "ReportSequence" and "@odata.id" ? Or it should be ignored, since it is a dummy report ?

Regards,
Ginu George

Last Edit: Mar 11, 2021 9:17:20 GMT by ginugeorge

mraineri
Administrator

Posts: 1,132

How Relevant are "ReportSequence" & "@odata.id" attributes ? Mar 11, 2021 20:25:17 GMT

Quote

Post by mraineri on Mar 11, 2021 20:25:17 GMT

Both of those properties are service-side generated values, meaning that it's really up to the service to assign the proper "ReportSequence" and "@odata.id" values. Given the client the ability to set those values can be problematic, since they can interfere with the service's bookkeeping of the resources in the data model.

Since this action is going to produce a metric report that is transmitted to event listeners, "@odata.id" is even less relevant since the metric report itself is not even in the data model; it would be awkward to assign a URI for this type of metric report. The same sort of behavior holds true for metric reports configured to only be transmitted as events and not stored in the metric report collection. This is similar to how asynchronous events are formed and sent to listeners; there shouldn't be an "@odata.id" property since a client is not able to perform a GET on the URI.

So, when the client invokes a SubmitTestMetricReport action, I would expect the service would generate a new metric report with the data provided by the client, generate its own value for "ReportSequence" based on previous values of "ReportSequence", and transmit the report to any listeners.

Last Edit: Mar 11, 2021 20:26:33 GMT by mraineri

ginugeorge
Minnow

Posts: 29

How Relevant are "ReportSequence" & "@odata.id" attributes ? May 25, 2021 8:19:28 GMT

Quote

Post by ginugeorge on May 25, 2021 8:19:28 GMT

Mar 11, 2021 20:25:17 GMT mraineri said:

Both of those properties are service-side generated values, meaning that it's really up to the service to assign the proper "ReportSequence" and "@odata.id" values. Given the client the ability to set those values can be problematic, since they can interfere with the service's bookkeeping of the resources in the data model.

Since this action is going to produce a metric report that is transmitted to event listeners, "@odata.id" is even less relevant since the metric report itself is not even in the data model; it would be awkward to assign a URI for this type of metric report. The same sort of behavior holds true for metric reports configured to only be transmitted as events and not stored in the metric report collection. This is similar to how asynchronous events are formed and sent to listeners; there shouldn't be an "@odata.id" property since a client is not able to perform a GET on the URI.

So, when the client invokes a SubmitTestMetricReport action, I would expect the service would generate a new metric report with the data provided by the client, generate its own value for "ReportSequence" based on previous values of "ReportSequence", and transmit the report to any listeners.

Hi mraineri

I am clear about @odata.id attribute but I am having the below mentioned clarification about the "ReportSequence" attribute.

When "ReportUpdates" Attribute is either of these values - Overwrite, AppendStopsWhenFull or AppendWrapsWhenFull , the "ReportSequence" attribute will have its value incremented by 1 for every MetricReport generated/updated with the passage of time.

Whereas, When "ReportUpdates" Attribute is having a value "NewReport" , the "ReportSequence" attribute will have its value as 1 always for every MetricReport generated.

So, in the case of SubmitTestMetricReport action, assuming that, we are generating a new report every time, can we have the value of ReportSequence as 1 always ? or we need to keep on incrementing the value of ReportSequence by 1 for every SubmitTestMetricReport action triggered ?

Please suggest.

mraineri
Administrator

Posts: 1,132

How Relevant are "ReportSequence" & "@odata.id" attributes ? May 25, 2021 12:48:48 GMT

Quote

Post by mraineri on May 25, 2021 12:48:48 GMT

ReportSequence will keep incrementing in that case. Think of it as a unique value that covers the history of your telemetry service. In cases where a client is monitoring metric reports via SSE, the ReportSequence value tells the client where in the stream each metric report fits. So, if they're disconnected for some reason, they can reconnect and request any missed metric reports based on the ReportSequence. At least this was the intent prior to deprecating the property; SSE has its own constructs for assigning this unique identifier in the stream, so forcing it into a dedicated property was problematic in practice.