An alert processing rule changes action-group handling for already-fired alerts. Suppression removes their action groups but leaves the alerts visible. Those groups do not run later when the maintenance window ends. Where both suppression and an action-group addition match, suppression takes precedence. Microsoft Learn.
\nA processing rule’s targets must be in its subscription. Creation or modification can require up to thirty minutes to propagate; alerts during that interval might escape the change. Service Health alerts are outside this feature’s scope. Microsoft Learn.
\nThis procedure addresses Azure Monitor fired alerts covered by alert processing rules, excluding Service Health alerts. Use it for an approved maintenance notification window, not as a substitute for deciding which failures require investigation.
\nDSE recommends recording the affected resources, schedule, time zone and intended filters before enabling suppression. Allow for propagation in the change plan. Name someone to review the window’s alerts after maintenance instead of assuming they will generate delayed notifications. Keep unrelated resources outside the suppression scope and check other processing rules for conflicting intentions.
\nIn an approved rehearsal, compare a matching alert with a deliberately out-of-scope alert. Confirm which action groups were invoked and which alerts remain available for review. After the window, inspect suppressed incidents individually and record the disposition. Preserve the schedule and observed results with the maintenance record.
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