There are two cases where a resource is decommissioned:
A Metrics Advisor resource is created, but no data feed has been onboarded within 90 days. The resource will be decommissioned after 90 days due to inactivity.
If one or multiple data feeds have been created but there isn't any new data being ingested into Metrics Advisor, the service will enter idle mode with no data to be processed. The system will still try to grab data regularly from the source according to the metrics granularity. However, if it continues to have no data available or no single time series to be processed for a period of 90 consecutive days, the resource will be decommissioned. All historical data associated with the resource will be lost when it's decommissioned.
It's recommended to create a new resource and delete the old one, if you would like to restart the usage.