Metric thresholds can now trigger detection

Detection rules now support metrics. An incident can be raised when a collected metric crosses a threshold.

• Choose the metric to watch and how to narrow it down (dimensions), then set how the evaluation window is aggregated (average, maximum, minimum, median, p90 / p95 / p99), the comparison, and the threshold
• When the target covers several series, you can decide by their average or by how many series crossed the threshold
• You can choose how missing data is treated (as normal or as breaching) — useful when you want to detect that collection itself has stopped
• Identifier labels let you evaluate targets separately, and the page shows how many targets that produces
• Before saving, press “Preview” to re-evaluate the most recent period with your current settings and see the result