Last Updated on 2020-12-30
KB00007: InfluxDB data frames / charts begin with zero or null values
EVA ICS versions: 3.2.4 and above
When InfluxDB is used as the notifier for historical metrics, obtained data frames and charts start from zero or null values, despite there is historical data collected.
This mostly happens for items, which state is changed rarely.
InfluxDB fill(previous) command does not fill data frames with the data, collected before the requested data frame start (https://github.com/influxdata/influxdb/issues/6878).
The solution is to use “interval” property for EVA ICS notifier to periodically fill InfluxDB with metrics for rarely updated items. The “interval” value should be less or equal than the minimal chart / data frame time step expected.chart, data, databases, influx