Check if resource is used

Question

We have inherited an old project with tons of Azure resources (roughly 1600 in 30+ subscriptions). We were tasked to determined, whether they are still used or can be removed. We were able to identify a vast majority of these services via ARM templates, PowerShell scripts, etc. However, there remains ~250 resources which we are not sure about.

Is there any simple way (Kusto query, API endpoint, ...) to check whether a resource was actively used in the past 2-3 years? Some of our resources are used very irregularly (e.g.: only at the start of new year, during scale unit migration or as a backup during recovery), so the usual insights which go back only 30-90 days are not enough for us. I am especially interested in these types of resources:

• Cosmos DB
• Key Vaults
• SQL Servers/Databases
• Storage accounts

However, I would really appreciate some comments also for:

• Log Analytics Workspace
• Service Bus Namespace
• Microsfot Insights Action Groups

Answer 1

Hi @Lubomir Sokolovsky , welcome to Microsoft Q&A forum and apologies for delay in response.

Currently Activity log events are retained in Azure for 90 days and then deleted as you mentioned. For additional functionality such as longer retention, you should create a diagnostic setting and route the entires to another location based on your needs. See the criteria in the earlier section of below article.

Azure Activity log

There are specific ways we can check for different azure resources about last accessed date. As an example, please check below article for Azure SQL Database access:

Find the time when table was last accessed in SQL Server database

For Cosmos DB, we can check the '_ts' property of element by using similar below query:

SELECT top 1 c._ts FROM c order by c._ts desc  

Once we have the list of resources that are older than our requirements, we can remove them according to requirements.

Please let us know if you need any more details on this and we can discuss further.

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