Classifying dates and times for data analysis
All days and hours are not equivalent in data analysis. The system utilization is generally lower at night, during weekends and holidays.
While performing an analysis, you may apply a filter so that only data from a given class is taken into account.
A day (hour) class is a label that classifies each day (hour) as member of a homogeneous group of days (hours).
For example, a day class may be Working Day, ranging from from Monday to Friday of each week. Another day class may be a Holiday, including December 25th. An example of hour classes could be: Day Hours, from 9am to 7pm and Night Hours, from 0am to 9am and from 7pm to 12pm.
All the definitions of hour and day classes are contained in the BMC TrueSight Capacity Optimization Calendar. As some definitions might overlap, a concept of priority is present: each day or hour class is given a fixed priority number; when two definitions overlap, the class with the lower priority value takes precedence and assigns its label.
All the definitions of hour and day classes are contained in the Calendar. To use the Calendar feature, navigate to Administration > Data Warehouse > Calendar.
The following figure shows three day classes definitions with the corresponding descriptions and colors into the calendar.
Adding a day class
Only BMC TrueSight Capacity Optimization administrators can modify the calendar. Beware that adding a day class impacts the data collection and classification activities. A new day class might also increase the BMC TrueSight Capacity Optimization database size and load. Moreover, it is impossible to delete a class. Thus, you should only add a new class if it is necessary.
Every day class is composed by three parts:
- The definition: You assign the class name, description and color used to mark its days when you create it
- The rules: You set the rules used to assign days to this class through the Add a definition form located at the bottom of the Calendar page
- The definitions: You define the time at which hour classes start and stop, i.e. the hours that constitute a day of this class, in the day class detail page
To create a day class, click the Add class button in the Day classes table and fill in the form specifying the class name, description and color. Click Save to confirm; you will be taken to the class detail page.
Day class definition
Every day class must have some rules defining how to match the days that belong to it. Rules are characterized by the following five filters:
- Weekday (1=Sunday, 2=Monday, ..., 7=Saturday)
- Month week (1-5 where week 1 starts on the first day of the month and ends on the seventh) when used in conjunction with weekday filter allow to specify rules like "third friday of the month"
You can either set a specific value for each of these properties, or set an asterisk (*) as a wildcard, meaning that every value of that property is valid for that class.
Leaving the field empty is the same as using an asterisk (*).
The following example, setting a definition as shown in the code block means that this class includes the second Tuesday of February of every year.
year = *, month = 2, day = *, week day = 3, month week = 2
By adding rules to the definition, you can tailor the day class to your specific needs.
The following figure displays an example of day class definition:
Day class definition: holidays (HOL) are 1/1, 6/2, 8/15, 12/8, 12/25 and Sundays; Saturdays are classified using a different class (SAT)
After a new day class has been created, you have to assign it a priority so that classification conflicts can be resolved. To do this, click the Change order button and move the classes in the order you prefer. Classes displayed at the top of the list take precedence over those at the bottom.
After specifying the days a day class is made of, you should configure its hour classes.
The Add a definition form in a day class detail page lets you select an existing hour class and match it to a time range. Hours must be specified in the HH:MM format.
If the available hour classes are not enough, you can add new ones. To do so, click on the Add class button in the Hour classes table and choose a name, description and color. When done, click Save.
The following figures show an example of hours definition for the day class WD. All day classes share the same hour class tags.
Hour classes tags
Hour classes definition
Hour class browser
The Calendar browser helps you recognize the various day classes in the selected month. To change the displayed month, use the drop-down selection and then click Apply. The Calendar is used to filter all collected data and, during an analysis, you can choose to exclude points belonging to specific classes.