Hi @Alvin Chung
Welcome to Microsoft Q&A! Thanks for posting the question.
The ApplicationInsights feature of Azure monitor will be a suitable choice to monitor database connections from any type of hosting (App Service, VM, Container Instance or AKS). Especially, the Dependency rates, response times, and failure rates scenario would be useful for monitoring the external dependency related scenario.
For more details, please review the article for Monitor layers of AKS with Container Insights. AppInsights comes under level 4. Apart from that, you can also monitor the performance of individual services using other insights available, for example storage, SQL, VM etc.
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