{{ :blocks:logo-apl.png? nolink |}} ======Zabbix Report===== ======Conceptual documentation for measurements==== ====General definition==== A measurement is a digital quantity (to be opposed to an "information" or a "state") captured at a given moment, once or regularly and recorded in a measurement recording system for further operations and visualization. Measurements can represent several things depending on how they are obtained: * A quantity directly observable at the time of the measurement (e.g., the temperature of a liquid read on a thermometer at a time **t**) * Counting a number of events from the beginning (absolute value) * Counting a number of events in a given period (The measurement only makes sense in relation to the "examination range") * The sum (or calculation) of a certain number of quantities at an instant **t** (calculated measurement) * The sum (or calculation) of a certain number of quantities in a given period (aggregated measurement) ====Examination range==== When observing a source for a certain amount of time, a measurement can be produced. * Sample: The examination range is zero, the measurement is instantaneous (in the source, even if it can internally represent an aggregation over time) * Common durations: examination ranges of 1 hour, 1 day, 1 week, 1 month are commonly defined. The measurement is a calculation of a quantity that requires the observation of the source during this time (e.g. number of connections to a data service **in the day**). ====Sampling frequency==== A measurement may be taken only once, but in general it is taken at regular intervals. The sampling frequency defines the frequency of the sampling. ====Aggregated measures==== An aggregate measurement combines several other measurements using an **aggregation function**. Most common functions are **counting**, **sum**, **medium**. The measurements are aggregated on a **aggregation space**, i.e. a number of contexts that define which basic measures are included in the calculation. It might be a time period or an "administrative" division. Example: Average over the month for the "Europe" region ---- ==== Credits ==== * 2022 Valéry Frémaux (valery@activeprolearn.com) [[:report:zabbix|Back to Zabbix report index]] - [[:plugins|Back to plugin index]] - [[:start|Back to catalog]]