AdvisorWhat's your appetite for increasing your CloudWatch costs and some DIY scripting? You would just need to configure the CloudWatch agent to submit system metrics and DIY something to submit anything it doesn't do out-of-box as a custom metric. With LM Cloud, an add-on module, the cloud collector can fetch any CloudWatch metric, custom or otherwise, as long as the Datapoint metric path can be constructed without much logic.
As for RDS MS SQL Server instances, with LM Cloud, you do have access to the CloudWatch metrics. You can install a collector on an existing app server (one that already talks to the database) to perform custom queries/assign custom datasources.
The last option is to deploy the collector like an agent (e.g. nano or small sized). I wouldn't recommend it though. This was a management nightmare for us but granted this for an on-premises customer and they were very strict as to what we were allowed to do. YMMV.
