Dynamic maps are maps with underlying data that changes over time. Election results are a good example of such maps. You can see such a map here: http://maps.nrc.nl/ps2015/ps2015-100pct.php and during this article i'll describe our solution to the problem of the changing data, thus recreating map tiles and the need for a reliable cache. The cache is of essence in our example, because the vast majority of users will use the map while it is in flux. And that means extreme high server load. As long as a tile is in cache, the impact of a client hitting the server is minimal, we can serve the still valid tile to the user and spare our limited resources.
By xiffy - March 20th, 2015