Metric Baselines: Determining Valid Metric Thresholds

Determining what metric threshold values accurately reflect the performance monitoring needs of your environment is not trivial. Rather than relying on trial and error to determine the correct values, Enterprise Manager provides metric baselines. Metric baselines are well-defined time intervals (baseline periods) over which Enterprise Manager has captured system performance metrics, creating statistical characterizations of system performance over specific time periods. This historical data greatly simplifies the task of determining valid metric threshold values by providing normalized views of system performance. Baseline normalized views of metric behavior help administrators explain and understand event occurrences.

The underlying assumption of metric baselines is that systems with relatively stable performance should exhibit similar metric observations (values) over times of comparable workload. Two types of baseline periods are supported:

• Moving Window Baseline Periods: Moving window baseline periods are defined as some number of days prior to the current date (Example: Last 7 days). This allows comparison of current metric values with recently observed history. Moving window baselines are useful for operational systems with predictable workload cycles (Example: OLTP days and batch nights).

• Static Baseline Periods: Static baselines are periods of time you define that are of particular interest to you (Example: End of the fiscal year). These baselines can be used to characterize workload periods for comparison against future occurrences of that workload (Example: Compare the end of the fiscal year from one calendar year to the next).