Application Insights & Log Analytics workspace daily capping

Question

Application Insights & Log Analytics workspace daily capping

VIKARAN KARWASRA 0

Hi All, I am using log analytics workspace based Application Insights. I had configured single Log analytics workspace with multiple Application Insights. I had also configured Daily capping on application insight & didn't configured on log analytics workspace. As per, Microsoft document it suggests that it will take minimum of two. But I noticed that it is not considered the capping of application insight & exceeding the data ingestion,even though it minimum with respect to log analytics workspace capping. Is there any workaround, as I want daily capping based on each application insight irrespective of log analytics workspace.

VIKARAN KARWASRA 0 Reputation points

2023-11-24T04:22:19.1933333+00:00

Thanks @Ben Gimblett as per the shared link I understand that for make capping effective at application insight side need to move to application insight connection string. Is it correct if we move to application insight connection string than capping work as expected?
Ben Gimblett 4,560 Reputation points Microsoft Employee

2023-11-24T10:13:40.4966667+00:00

As per my colleagues input below - it is recommended and it will help if you have resources in different regions.

I should also mention for completeness --- we dont really recommend customers use capping. It's a "hard stop" and this is most often not what you want for an APM (App Performance monitoring) solution. As once the cap is exceeded data is dropped meaning you cant use it to troubleshoot

A better approach is to use Sampling - this means you can reduce cost / ingestion volume but you'll always get data to help you troubleshoot

https://learn.microsoft.com/en-us/azure/azure-monitor/app/sampling-classic-api

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VIKARAN KARWASRA 0 Reputation points

2023-11-24T04:22:19.1933333+00:00

Thanks @Ben Gimblett as per the shared link I understand that for make capping effective at application insight side need to move to application insight connection string. Is it correct if we move to application insight connection string than capping work as expected?
Ben Gimblett 4,560 Reputation points Microsoft Employee

2023-11-24T10:13:40.4966667+00:00

As per my colleagues input below - it is recommended and it will help if you have resources in different regions.

I should also mention for completeness --- we dont really recommend customers use capping. It's a "hard stop" and this is most often not what you want for an APM (App Performance monitoring) solution. As once the cap is exceeded data is dropped meaning you cant use it to troubleshoot

A better approach is to use Sampling - this means you can reduce cost / ingestion volume but you'll always get data to help you troubleshoot

https://learn.microsoft.com/en-us/azure/azure-monitor/app/sampling-classic-api

Answer 1

Hi - thanks for the question

If I understand - you have some LA workspace backed app insights resources (all point at the same workspace) and you've set caps on each AI resource but not on the workspace itself, that is correct? But still you see more data ingested than you expected.

In the first instance please can you check here https://learn.microsoft.com/en-us/troubleshoot/azure/azure-monitor/app-insights/daily-cap-unexpected-behaviors

As there's some things to be aware of. Can you let us know if this helps or not?

Answer 2

VIKARAN KARWASRA, thank you for this question on Microsoft Q&A.

In additional to the answer provided by Ben above, please note the following information:

As I understand you are using a single Log Analytics workspace with multiple ApplicationInsights instances. I would suggest rechecking the workspace for all these AppInsights instance to ensure that this understanding about the configuration is correct to avoid any confusion. You can check this by examining the Workspace field in Properties of each Application Insights.
As mentioned in the doc, the capping takes minimum of what is specified. As you have multiple instances of AppInsights sending data to a single LA workspace, the capping will have to be set on All AppInsight instance. There could be scenario that you configure if on one AppInsights instance and it works, but the LA size is more because there are other AppInsights too sending data to it.
As mentioned in the following doc, the capping has to be specified on both - AppInsights level and at LA level. Only then the smaller of the 2 values are taken into consideration - When to use a daily cap
As mentioned in this doc, while the connection string is not mandatory for capping to take effect, it might resolve issues related to regionality. Also, it is strongly suggested to migrate to Connection String based setting as the InstrumentationKey is set to end by March 31, 2025. Therefore, I would suggest migrating to ConnectionString based setting to avoid this issue.

Hope this helps.

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Application Insights & Log Analytics workspace daily capping

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