Is it possible in the new Dashboard app to show a chart with a trendline that represents the sum of multiple interfaces In (or Out) Bit Rate parameter, for example? How do you advise this to be done?
Might be difficult. To my knowledge:
The current trend graph in Dashboards allows you to display multiple metrics like bit rates from multiple interfaces in overlay, but does not support a stacked presentation yet.
You can build an aggregation rule on the view level and define a new metric there. This has the advantage that the sum would be calculated server-side continuously, and you can alarm and perform trending on that. But I believe you then will not be able to easily access that new metric in the Dashboards to display it there in a graph.
The GQI definitely also allows you already to aggregate on multiple interfaces and do things like sum, average, min, max, percentiles, etc. But that will show you the current aggregated value on your dashboard, and not a trend graph showing that value over time.
Other people might have some further perspectives on this. Because it is a common use case and we should ensure that we can support this easily.