I've been wondering about what goes on behind the scenes on Tableau Server versus Desktop when it comes to displaying dashboards, and how it impacts performance. To give this some context, I have been developing a Sankey graph according to the steps outlined by Olivier Catherin (which is an excellent tutorial btw) and the plan is to use it in a dashboard that will be shared with other organization users via Tableau Server. For those who are not familiar with Sankey graphs, it's a way to visualize "flows" between start and end points.
Anyway, my Sankey graph has a highlight-on-hover feature that highlights all of the flows going out of a particular segment, and one of the frustrating things has been that even though this works great on Tableau Desktop (super responsive, instantaneous highlight, works just as you'd want), it's pretty slow on Tableau Server. It usually takes about a second or two before the highlight occurs when I hover over a flow or starting/ending segment on the graph. Even the tooltip isn't responsive, and disappears once I move the mouse pointer (and it's set to be responsive). This occurs even though the workbook and its data is running off of an extract and otherwise doesn't have to hit a live database. I understand that part of the problem could be that the Sankey graph involves duplicating rows in the underlying data set in order to plot the flow lines, but even so, the dashboard loads pretty quickly on Tableau Server. It's just the highlighting action/tooltip that is slow.
So I'm left wondering if there is something different going on behind the scenes in Tableau Server versus Desktop that could be causing this slowness with the graph? Is it because the dashboard is being served up via a network and not on a local machine? Or because it's being rendered in a web browser as opposed to in Tableau Desktop? Is there any way I can improve performance? As it stand now, the sankey dashboard is still functional and usable when viewed through Tableau Server, but for the user experience it would ideally be nice if it worked like it does in Desktop, with the same responsiveness.
For reference, I'm using Tableau 9.2.1