Azure Monitor Alert: Metrics vs Log based alerts
Metric Logs are stateful are alert – which mean it will change the status to Fired/Resolved based on the metric condition. Metrics Alert is much cheaper than Log based alerts. As of now, it’s 0.1$ per month, it doesn’t matter your check interval.
Logs based alerts are not stateful, it only “Fired” , it does not resolved. This alert can flood your mailbox. the way it works is , it runs a query, if that query meet your condition, it will triggered the alert. It doesn’t check the last run status to see if that has been triggered or not. Log based alerts are also very expensive, it depends on your check interval.