Скачать или смотреть Cloud Optimized Archive Format for Planet-scale Vector Tilesets

Markus Tremmel

The last few month i worked with COMTiles (https://github.com/mactrem/com-tiles) on a case study of a streamable and read optimized cloud native archive format with the focus on the visualization of planet-scale tilesets in the browser. One main design goal of COMTiles is to minimize the number of HTTP GET range requests for the download of parts of the index for performance and cost reasons. In a COMTiles archive most of the time only one additional pre-fetch per zoom level is needed before accessing the map tiles for the current viewport of the map. This is bearly or not at all noticeable for the user regarding the user experience and workflow (see    • Serving COMTiles from a AWS S3 standard st...  ). With ordering the index on space-filling curves (Hilbert, Z-Order, Row-Major), packing tile pyramids into directories and aggregating the index in fragments three different approaches has been evaluated and should be presented in this talk. COMTiles are already successfully used in some projects with significantly reducing the hosting costs because no tile server or backend (database, server) is needed.

Proposed structure of the talk

Basic concepts of COMTiles e.g. how to structure the index (pyramid of directories vs space-filling curves vs fragments) and how to define a tileset as part of the metadata based on the ""OGC Two Dimensional Tile Matrix Set"" draft

Concept of tile request batching to reduce the number of requests by up to 90%

Comparison of existing cloud native (vector) formats regarding the visualization of large geospatial datasets in the browser (PMTiles, FlatGeobuf, Tapalcatl, Cotar, COMTiles)

Advantages regarding browser based visualization of streamable archive formats (like COMTiles or PMTiles) over directly hosting the map tiles in the cloud and over extending existing chunked formats like Zarr or TileDB for geospatial support