Hi Azurebegginer,
As you have mentioned “application (database)” in the question and also as you have mentioned “The application is database” in the comment of this recent question which looks fairly related to current question so to avoid confusion and to help us provide you better recommendation(s) please provide more context w.r.t your architecture i.e., what is your web/app tier and how does it connect to your data tier?
On the other hand, as you have mentioned “Any changes needed on the database server” in the current question and as you have mentioned “The application will be moved as it is lift and shift” in this recent question so is your application and/or database running in an on-premise server / machine and are you doing lift and shift of it to an Azure VM? If Yes, “when the database is down” i.e.,
- considering a service in the Azure VM is down, you can automatically monitor it by installing an Azure Log Analytics agent in the Azure VM. Upon it, you may create an Azure alert rule to directly get notified by an email (via action group) on a particular log is observed in Azure Log Analytics repository. For more details w.r.t email filtering, please refer this Email section of the document.
- or considering it’s not a service in the Azure VM but a log file that gets updated with a particular content when the database is down, then leverage Azure Monitor Custom Logs and again upon it, you may create an Azure alert rule to directly get notified by an email (via action group) on a particular log is observed in Azure Log Analytics repository. For more details w.r.t email filtering, please refer this Email section of the document. Also, please refer this document to learn more about other supported data sources similar to custom logs.
I believe this is not your case but just FYI, in case the web/app tier and/or data tier is somehow just a simple single Azure Web App then leverage this, this and this documents to configure monitoring the app.
Related references:
Monitoring Azure virtual machines with Azure Monitor
Azure Databases
Monitor Azure SQL Database using Azure SQL Analytics
Azure App Service
Azure App Service Overview