Active baselining in passive data environments

In order to decide if systems are running according to their usual trend, it is necessary to compare against a performance baseline that defines an operating envelope. We describe how baselines can be derived from passive stores of performance data, which are typically flat text files or databases. Baselines can be built as needed by varying the baseline norm, granularity, update frequency, etc. Baselining outputs are sets of alert thresholds stratified by system, metric, and hour. The role and usage of baselines in automated alerting is discussed, with examples of reports that can be produced.