Function app in Flex consumption plan not showing worker count in Azure portal diagnostic chart

[anandsowm]

For the Function apps that are in Flex Consumption plan , in the Diagnose and solve problems blade, for the 'HTTP functions Scaling' chart is not showing the worker instances count. However, in the corresponding AppInsights resource, for the direct kusto query as below, the instance count is correctly reported.

traces
| summarize dcount(cloud_RoleInstance) by bin(timestamp,30sec)
| render timechart

Region: West US 2

Expected behavior:

The instance count should be shown in the chart under the 'Diagnose and solve problem'

Actual behavior

As seen below, the instance count is not displayed.

[bhagyshricompany]

Hi @anandsowm Thanks for reporting please share the all steps for repro.

[anandsowm]

Here are the steps for repro :

1. Create a function app in Flex Consumption plan, with always ready instance as 1
2. Deploy code for the function app with Http trigger, from Azure pipeline [in my case it is C#, .net8 isolated]
3. Run the JMeter script that calls the Http trigger from multiple threads, duration of test can be 30min - 1hr
4. Open the "HTTP functions scaling" chart from Diagnose and Resolve problems blade in Azure portal
5. Notice that the "Number of workers allotted" trend is not reflecting the real number of worker instances launched during the above test run
6. Open the App Insights resource associated with the function app, execute the kusto query mentioned in the issue, notice that the worker instances launched during the test run is correctly captured in 'traces' table.

[fabiocav]

@nzthiago can you please help triage?

[nzthiago]

@anandsowm - thank you for reporting this. @FinVamp1 FYI to comment, who has been working to update those Diagnose and Resolve detectors to have values for Flex Consumption apps.

We're also working to have the Azure Monitor metric called "Automatic Scaling Instance Count" to be populated in the next few months.

[FinVamp1]

@anandsowm we're working on this and I will update the thread when the work is done.