About DPA resource metric baselines
When you are viewing resource metrics on the Resources tab in DPA, you can display baselines to compare values from a specific period to historical norms. Baselines provide context for the current values. Metric values that are far above or below the baseline could indicate areas in need of tuning or reconfiguration.
Monitoring must be active for at least one day before baselines can be calculated, and baselines become more representative as more monitoring days pass.
Baselines are not available for metrics collected for the VM Option.
Show or hide baselines
Baselines are available when the selected time period is one week or less.
Click the Show baseline or Hide baseline button near the top of the Resources tab to show or hide baselines. When you show baselines:
- A dark line represents the average value.
- If the time period is less than one week, a shaded area represents values between the 10th and 90th percentiles.
How are baselines calculated?
Baselines are calculated for each one-hour period. By default, baselines are calculated using data only from weekdays (Monday through Friday). Each baseline is calculated using data from the corresponding hour for all weekdays, so the value for a specific hour is the same across all days. (For example, the value for 1 - 2 PM is the same Monday through Friday.)
Baselines are calculated using historical data from before the earliest time shown on the chart. For example, if a chart covers one week and starts on May 10th, all baselines are calculated using data from May 9th and earlier. For this reason, one-week charts show repeating patterns for each day.
Change the days included in baseline calculations
To change the days included in baseline calculations, update the advanced configuration option
METRICS_BASELINE_TYPICAL_HOUR_CALCULATION. This option can be set globally or for a specific monitored database instance.
Choose one of the following values:
|Weekday Only (M-F)||Baselines are computed for each one-hour period using data from the corresponding hour on weekdays (Monday through Friday). This is the default.|
|All Days of the Week||Baselines are computed for each one-hour period using data from the corresponding hour on all days.|
|Same Day of Week||Baselines are computed for each one-hour period using data from the corresponding hour on the corresponding day. (For example, the value for 1 - 2 PM on Monday uses data from the corresponding hour on Mondays, and is therefore different than the value for 1 - 2 PM on Friday.) Be aware that this option increases the number of baselines per metric from 24 to 168.|