How to get free storage size percent by NRQL for a RDS cluster?

In order to monitor a RDS cluster’s free storage size on AWS, this query only get the real size of storage

FROM Metric SELECT average(`aws.rds.FreeLocalStorage`) FACET `aws.rds.DBClusterIdentifier` WHERE `aws.rds.DBClusterIdentifier` = 'cluster_name'

Such as 6.00G

But we want to get the 80% threshold. How to do it with NRQL?

Hi, @miantianlai: Looking at the documentation for the Amazon RDS monitoring integration, I don’t see the metrics you are using in your query, such as aws.rds.DBClusterIdentifier and aws.rds.FreeLocalStorage. How did you find these metrics?

Thank you.
I checked metrics here

But it should be FreeStorageSpace and there isn’t DBClusterIdentifier.
Is it need to use DBInstanceIdentifier instead of DBClusterIdentifier for these metrics?

  • CPUUtilization
  • FreeStorageSpace – DBInstanceIdentifier Only
  • DatabaseConnections – Both DBInstanceIdentifier and DBClusterIdentifier available

In order to know the percentage of free space, you will need to know the total space, so you can calculate free space / total space. I do not see a metric that reports total space; without it, you will not be able to calculate free space percent.

Thank you. I didn’t find a total space metric in the list, too. So it seems it’s impossible to calculate percentage for free storage space data.