The aggregation functions, available in the graph widget of the dashboard, allow displaying an aggregated value for the chosen interval (5 minutes, an hour, a day), instead of all values.
The aggregation options are as follows:
The most exciting use of data aggregation is the possibility to create nice side-by-side comparisons of data for some period:
When hovering over a point in time in the graph, date and time is displayed, in addition to items and their aggregated values. Items are displayed in parentheses, prefixed by the aggregation function used. Note that this is the date and time of the point in the graph, not of the actual values.
The options for aggregation are available in data set settings when configuring a graph widget.
You may pick the aggregation function and the time interval. As the data set may comprise several items, there is also another option allowing to show aggregated data for each item separately or for all data set items as one aggregated value.
View the average request count per second per day to the Nginx server:
avgand specify interval
View the lowest disk space among clusters over a week.
cluster*, key "Free disk space on /data"
minand specify interval