[Talk-it] Fwd: Differences between osm.org tiles and WMF tiles

Lorenzo Perone lorenzo.perone a gmail.com
Mar 7 Feb 2017 07:29:42 UTC

Ciao Nemo,
dalle prove che ho fatto usare vector tiles piuttosto che tiles
convenzionali avrebbe inoltre altri vantaggi, quali la possibilità di avere
stili diversi oltre che performance migliori a fronte di un carico sul
server decisamente più basso.
La generazione dei vector tiles rimane comunque onerosa in termini di
My two cents.

Lorenzo Perone
Sostieni Ricostruzione Trasparente
twitter: @lorenzo_perone <https://twitter.com/lorenzo_perone>
photoblog: http://immagini.me

2017-02-07 7:56 GMT+01:00 Federico Leva (Nemo) <nemowiki a gmail.com>:

> Un sunto piuttosto utile su alcuni ulteriori motivi per cui serve
> https://maps.wikimedia.org/ .
> Nemo
> -------- Messaggio inoltrato --------
> Oggetto:        Re: [discovery] Differences between osm.org tiles and WMF
> tiles
> Data:   Mon, 06 Feb 2017 19:19:18 -0800
> Mittente:       Paul Norman
> Rispondi-a:     A public mailing list about Wikimedia Search and Discovery
> projects <discovery a lists.wikimedia.org>
> A:      discovery a lists.wikimedia.org
> On 2/6/2017 1:16 PM, Erika Bjune wrote:
>> Hi Svetlana,
>> While we do get data from OSM, we run our own tile server called
>> Kartotherian <https://github.com/kartotherian/kartotherian>, mainly
>> for the following reasons:
>>   * OSM's infrastructure is fragile and has cache challenges
>>   * Their datacenter is in London, which means latency becomes an issue
>>   * OSM's rendering stack can't scale horizontally well enough to be
>>     sure they could handle our load
>>   * Their map style is not mobile friendly
>>   * We require multilingual and vector tiles, which their stack can't
>>     do (currently)
>>   * We wanted to provide nicer map styling in general
> As a developer of both the WMF styles, OpenStreetMap Carto, and many map
> rendering components, I can provide some more detail. I'm not a server
> admin for either WMF or the OSMF, but I work closely with them.
> The default "standard" map on OpenStreetMap.org is a style called
> OpenStreetMap Carto (osm-carto). The particular tiles being served on
> osm.org (tile.osm.org) are rendered on OpenStreetMap Foundation (OSMF)
> resources. Their usage is controlled by the tile usage policy <
> https://operations.osmfoundation.org/policies/tiles/>, which would
> prohibit their use as a default map on Wikipedia.
> Aside from the policy reasons, tile.osm.org is not designed for
> Wikimedia's use, mainly because tile.osm.org is designed for providing
> mapper feedback, not efficient rendering.
> - tile.osm.org is designed to show changes in OSM data minutes after they
> were made. The cost of this is that caching is much less efficient, and
> more resources have to be used for each map view. Wikimedia doesn't need
> minutely updates, and I think right now updates daily. Most commercial OSM
> hosts also update hourly, daily, or weekly. This decision shows up
> throughout how tile.osm.org is setup, sometimes in subtle ways
> - tile.osm.org is not designed for multiple similar styles, e.g. high
> resolution "retina" tiles.
> - tile.osm.org isn't designed to export static map images, which is an
> important WMF use case
> - The tile.osm.org rendering stack doesn't provide some WMF-specific
> functionality needed, like integrations with Wikidata, etc.
> - Parts of the tile.osm.org rendering stack are in maintenance mode and
> have no active developers. This is fine if they do what you need, but would
> have been a problem for WMF needs
> For the record, I do think a deployment for WMF using the same software as
> tile.osm.org would have been possible and met the load requirements, but
> not have worked with static maps, multilingual maps, and some other WMF
> requirements
> I feel OpenStreetMap Carto, the style on tile.osm.org, is a good style
> when you look at its goals <https://github.com/gravitysto
> rm/openstreetmap-carto/blob/master/CARTOGRAPHY.md#main-goals>. Two of the
> goals are showing the richness of OSM data and providing mapper feedback.
> It doesn't have the goal of being a map where you can layer additional data
> on top, which is a key WMF use-case. Two osm-carto policy decisions that
> would have been a problem for WMF use are the use of only OSM data whenever
> possible, and rendering everything in the language of the region. The first
> is a problem because it requires design decisions which sacrifice
> cartographic quality, performance, and complexity, particularly at low
> zooms.
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