Adjusting and comparing metrics over time

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Some of the dashboard charts show metrics that are based on a time range and other charts show only the most recent metrics. When a time selector is displayed in the Status Overview tab of a managed system instance, you can adjust the time range for the charts whose values are derived from historical data samples. For attributes that have data collected for multiple days and presented in a line chart, you can compare today's values with a previous day.

Before you begin

If you are comparing with a time range from a previous day, how far back you can go depends on the number of days that the Cloud APM server has saved and the type of data displayed on the page. For most resource monitoring data sets, data samples are stored for 8 days. The exact number is published in the agent or data collector attribute help and reference PDF (see PDF documentation). Transaction tracking data from the Response Time Monitoring Agent or middleware agents can only be displayed from the last 24 hours (or for the last 4 hours in some cases) and its retention period cannot be changed.

You can configure your Cloud APM server to store up to 32 days of resource monitoring data for some data sets. For more information, see Managing historical retention values.

Procedure

Take these steps to adjust the time range that is displayed in the line chart for a managed resource instance or to compare the values with the same time range from a previous day.

  1. If the Application Performance Dashboard is not displayed, select it from the Performance menu.
  2. Navigate to the dashboard page for an instance that shows historical line charts and click the Last 4 Hours time selector.
  3. Select one or more of the following options:
    • To change the time range displayed, select Last 4 hours, Last 12 hours, or Last 1 day.
    • To compare the time range displayed in a line chart with the metrics from a different day, select Compare to and select an earlier day up to the number of days shown in the pop-up calendar as available (a line is drawn through unavailable dates).
    • To have the time range applied to the dashboards of all defined applications in your monitored environment, select All Applications. Otherwise, leave the setting at Only This Application to apply the time range to only the current application (such as My Components). The Compare to selection is effective only for the current page.

Results

  • If you are viewing historical data without comparison, all dashboards in the current application (or all applications) are affected by the change.
  • If you are viewing a comparison, only line charts in the current page are affected. A line is drawn for each KPI to show the metrics from the chosen day. Some line charts are unavailable for comparison, as indicated by a watermark on the chart: No Comparison Available. This can happen with newer managed resources that have not yet collected data for the date specified. Try selecting a more recent date for the comparison.
  • Any widgets for which no historical data is collected continue to display the most recent values.
  • Data points are distributed along the full length of the chart for the selected time range. Time stamps are displayed on the axis label, starting with the earliest time stamp and ending with the most recent time stamp. Check the oldest data sample to confirm whether a partial range or the full range of historical data is displayed.
  • Data sent to the charts and tables is normalized to GMT (Greenwich Mean Time). The Timestamp axis prints time stamps based on the time zone of your browser. If your time zone uses Standard Time and Daylight Saving Time, the time stamp displayed during the transition hour is displaced by one hour. Consider, for example, that you are viewing a line chart in Spain and the time changes from 2:00 AM Standard Time to 3:00 AM Daylight Saving Time. The discrepancy between the GMT of the data and the local time of the time stamp results in the time stamps having a gap of one hour from 2:00 AM to 3:00 AM. If you are viewing the same chart in New Zealand during the switch from 3:00 AM Daylight Saving Time to 2:00 AM Standard Time, the time stamps from 2:00 AM to 3:00 AM are repeated.