Metric Historical Basis

This page is accessed via Configuration and Administration > Metric Alert Management > Metric Historical Bases.

Note: You must be a DBA to access this page.

An historical basis is a definition of a historical value used by both cumulative and current thresholds. For example, an historical basis could define the average value over the last 5 days, the maximum value over the last 3 weeks, the total count over the last two hours, or the average over the last four days of the week (i.e. the last four Wednesdays if today is a Wednesday).

All historical bases used by cumulative and current thresholds are updated hourly when Persist Metrics is automatically run.

For cumulative thresholds, one basis is required to use as a recent value for comparison; another is optional to use as the base for historical comparison. For example, if you are interested in raising an alert when logging exceeds 10000 lines per hour, the recent value basis would be Count per 1 Hour. The historical comparison basis would be empty as it compares to a fixed value of 10,000; the comparison value would be 10000. Another example: if you are interested in alerting when the maximum bulk plan time for the day is 300% over the two week historical average, the recent value basis would be Max per 1 Day. The historical comparison basis would be Average per 2 Weeks and the comparison value would be 3.0.

• For cumulative thresholds, one data point for a value basis is sufficient for calculating the recent value.
• For cumulative and current thresholds with a historical basis for comparison, the comparison data must have at least the number of data points defined by the glog.metric.minHistoryCount property to trigger the threshold. This defaults to 1, assuming that any measured data is relevant. Another approach to handling missing data for cumulative comparison is to only fire a threshold if the comparison basis exceeds some minimum value. You can specify a Minimum Comparison Value on each cumulative and current threshold. Only threshold values that exceed this minimum will fire the threshold, regardless of the relative difference between the recent value and the comparison value. To see how missing data is handled, see the Missing Historical Data sections in Metric Cumulative Criterion and Metric Current Criterion.

Adding a Metric Historical Basis

1. Enter an Historical Basis ID.
2. Select a Domain Name.
3. Select a Type. Determines whether to calculate the average, maximum, or count.
4. Enter a Count. See above for examples of how to use the Count field.
5. Select an Interval. If you select Day of Week, you will be comparing Thursday to Thursday data, for example.
6. Click Finished.