Your organization may have some planned or ad-hoc periods of time during which your system undergoes maintenance activities that might cause service disruption. During such periods, you don't want to receive notifications that your services are down. Additionally, such periods shouldn't be taken into account when monitoring the availability of your system. To avoid such unpleasant situations, you can exclude these periods using maintenance windows.
Maintenance windows enable Dynatrace to identify periods of possibly abnormal operation, such as downtimes, reduced performance periods, and high-traffic events during load tests. Defining maintenance windows during abnormal operation times helps you reduce alert spam and keep your baseline clean for accurate monitoring and alerting.
In general, it's good practice to keep your performance monitoring system informed of scheduled maintenance to ensure accurate monitoring data. Dynatrace enables you to define maintenance windows using either the Configuration API or the web user interface.
Maintenance window types
Dynatrace distinguishes between two types of maintenance windows: planned and unplanned.
|Defined in advance||Defined retrospectively or for an ongoing outage.|
|Excluded from synthetic SLA report calculation.||Included to synthetic SLA report calculation.|
|Excluded from regular baseline calculation.||Excluded from regular baseline calculation.|
Maintenance window effects on baseline calculation
Once a maintenance window is defined, Dynatrace automatically excludes the configured time period from baseline calculations. With this approach, any response time anomalies that occur during the maintenance window won't negatively influence your overall service and application baselines.
It's a good idea to define your maintenance windows before performing any load testing. Using maintenance windows during load testing ensures that any load spikes, longer-than-usual response times, or increased error rates won't negatively influence your overall baselining.
How maintenance windows work
Once you've defined your maintenance windows, Dynatrace flags all problems that occur during maintenance windows with a special "wrench and bolt" maintenance icon (see examples below). The Problems page filters include an Under maintenance filter that enables you to view a list of problems that occurred during maintenance windows.
If you choose to completely disable problem detection during maintenance windows, no detected problems will be displayed on the Problems page. Note that in this case the detected problems will never be displayed, even if they still exist after the maintenance period is over.
Even if you're viewing an entity overview page and you select a global timeframe in which the selected host was under maintenance, Dynatrace shows you the details on the Maintenance tile. If the host is included in multiple maintenance periods, Dynatrace shows you the most recent window and a count of how many maintenance windows the host experienced during the selected timeframe.