Adding historical baselines to a chart

Use the values from the current plot chart to identify daily trends in threshold conditions. You can then better anticipate problems by comparing current values with expected future values or with past values, and overlaying the chart with situation comparison criteria, one plotted line for each day specified.

Before you begin

The Add Historical Baseline tool does not appear in the plot chart tool bar if any of these conditions exists:

• Historical data collection has not been configured for the queried attribute group and started on the managed system (or managed systems) assigned to the Navigator item.
• A time span was specified. Click Specify Time Span for Query and select the Real time to remove the time span.
• Any of the chart values are the result of a calculation.
• Attribute(s) across multiple rows is selected. To see if it is, click Edit Properties in the view's toolbar, Style tab, then the plot area of the thumbnail graphic.

For historical data beyond the past 24 hours, you must have a Tivoli Data Warehouse configured and the warehouse proxy agent that transfers data to it.

1. Click Add Historical Baseline in a plot chart. The tool does not display if historical data collection has not be configured for the attribute group (indicated by the presence of the Time Span view tool).
2. To plot data samples taken yesterday, the same day last week, or a particular day or past days, select the check box for that time range.

   Show yesterday's data

   Draws a plot line of data samples from the previous 24 hours. For example, if it is May 30 at 8:45 AM, the samplings will be from May 29, starting at 8:45 AM. The legend indicates the line color for each plotted attribute value from Yesterday. As new samples are added, the oldest are removed from the chart.

   Show last week's data

   Draws a plot line of data samples from the same day last week. The legend shows the line color for each plotted attribute value from Last Week. For example, if this is Wednesday, the samples will be from last Wednesday.

   Show this day's data

   Draws a plot line of data samples that have been taken on the day shown. If you would like to see a different day, click the date button to open a calendar. Select a month and day prior to today. For example, you had selected the check box to show yesterday's data, you could select the day before yesterday in the calendar to show the past two days.

   Show data for last __

   Draws a plot line for each of the last number of weekdays or calendar days you specified. For example, if today is Saturday and you select the last 7 calendar days, today and all days through last Sunday are plotted. The last 7 weekdays would be Monday through Friday of this past week plus the Thursday and Friday of the week before.

   Time Column

   The time stamp type displayed will be shown along the X-axis. If the attribute group has other time stamp attributes, you can select one from the list. Not all time stamps will be displayed along the axis because of space limitations.

3. Click Apply to render the chart with a baseline for each chosen time range. The time ranges chosen are listed in the legend along with the color of the plot line, one line for each day.
4. Click OK to close the dialog box, and perform any of these actions:
   • Move the mouse pointer over a baseline to highlight it; move the mouse pointer over a plot point to see the value, name, and time stamp.
   • Click and drag a smaller time range to zoom in, then press Esc to zoom out, once for each time you zoomed.
   • Right-click a data value that falls outside normal statistical baseline and click Model Situation to open the Model Situation chart and populate the attributes table with the values from the data point. After performing additional analysis with the modeling tool, you can create a new situation with the calculated values and edit them as needed.

Example

The chart plots Disk Writes Per Second over a 12-hour period. We want to compare today's data, Monday, May 22, with the same period from the last two weekdays, Thursday, May 18, and Friday, May 19. In the Add Historical Baseline dialog box, select Show this day's data and Show data for last 2 weekdays. After you click OK, the two additional days are plotted. You can move the mouse pointer over a plot point to see the value and the date and time the sample was taken.