A bank built its CloudWatch dashboard in a central monitoring account, but widgets for two application accounts stay empty. Those accounts have not shared their metrics with the monitoring account. What must happen before the central dashboard can graph them?
Select an answer to reveal the explanation.
Short Explanation
Owning the picture frame does not put the photographs in it. You built the dashboard in the monitoring account, but CloudWatch will not pull another account's metrics until that account shares them. A trail records API calls, and an alarm topic carries notifications, so neither one fills an empty metric widget.
Full Explanation
CloudWatch cross-account observability lets a monitoring account graph metrics that source accounts have chosen to share. Creating the dashboard in the central account only creates the widgets. Until each application account is configured as a source and shares the metrics, those widgets have nothing to query and stay empty. Moving the dashboard into one application account still leaves the other account's metrics unshared, and a screenshot is not a dashboard. An organization trail records management events. It does not copy metric datapoints into another account. An SNS subscription delivers alarm notifications to people or endpoints. It does not grant the monitoring account permission to read the metric streams. Caveat: sharing metrics is separate from sharing log groups, so a metrics widget can still be empty after logs are shared. Operational check: from the monitoring account, open the widget's metric and confirm the source account's namespace returns fresh datapoints before you call the dashboard done.