In Data Discovery, you have a notification system that allows you to get an e-mail if one of your data sources for some reason fails to refresh data according to the schedule you have set up.
A prerequisite is, that you have setup an SMTP server within your Data Discovery environment.
You need to go to settings - which is activated by clicking the gear wheels symbol found in the Data Sources tab (pre 2022 Winter look in the upper right corner - from 2022 winter look in the lower left corner)
In the Settings, pick the Notifications tab and tick Enable email notifications:
Now go to the SMTP (subtab) and register your SMTP server:
If you want to be notified on evens on all data sources in the environment (not recommended) - go back to the Notification settings (subtab) and fill in information on the e-mail(s) supposed to be notified on all events for every data source:
Once you have setup the SMTP server for the notifications, you can utilize the notification system on "local level" - where you define within a certain data source that you wish to be notified if that data source fails to refresh data.
Example below shows a SQL Server Data Source that is supposed to update Every day at midnight:
Notice the Notifications button in the screenshot above - if you click it, you get a dialogue that allows you to setup notifications on this particular data source:
Now you have surveillance on this data source.