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A Night at the Office

30.11.2010 | Frederik Ramm

We are sometimes asked how we produce the files on our download server. Read this if you are one of those asking.

It is 22:30 in Central Europe, and the lights come on in the Geofabrik office. (The HDD LEDs, that is.) One of the servers, named bonne, begins downloading the collected works of mappers around the world from the last 24 hours

osmosis --rri --simc --write-xml-change 2010-11-16-22:30.osc (duration 00:01:30)

and then applies them to a locally held, full copy of the OSM database (the “planet file”).

osmosis --read-xml-change 2010-11-16-22:30.osc --read-bin current-planet.osm.pbf --apply-change --write-bin new-planet.osm.pbf compress=none (00:28:09)

The newly created planet file is transferred to another server, named hammer, where a script converts it to a simple CSV-like format (the “tbf” format) and then analyzes and converts it in several steps, creating statistics and a number of shape files. The shape files are later copied to our off-site tools server where they are used by the OSM Inspector.

But bonne, of course, doesn’t sit idle. More …

Today we finally received our author’s copies of our brand-new English OSM book. Old news, you might say; after all, this was featured on opengeodata.org a month ago. But it took a while for the books to reach us here at Geofabrik — we’ve been told that the first batch of books had to be dispatched to the US immediately because of the high demand there!

As you probably know, Jochen and I published the first OSM book ever in spring 2008, in German; a second edition came out in 2009, and a third in 2010. The book is of course a niche product as books go — with roughly 4,000 copies sold altogether. But we’ve been getting great feedback from the community and were encouraged to do an English version basically from day one. And so we did! At first we toyed with the idea of doing the book on our own with a print-on-demand place like lulu.com but we tried a few and were unhappy with the results. It took us a while to find a proper publisher with whom we could work, but we finally found a great, if small, publisher in UIT (Cambridge, UK). Just as with the German book, we not only wrote the content, but also did the typesetting, layout, and book cover ourselves, and we are very pleased with the finished product. It looks, feels, even smells like a proper book.

OSM Book

We had great help from one of the old OSM hands in England, Steve Chilton, who made sure that the English version properly reflects the international aspects of OSM, and fixed up our translation. Like the German book, the English one has 384 pages, 32 of them in full colour. (The English language is a bit more concise than German, so we managed to squeeze in a few extra illustrations and examples!) It covers everything there is to know about OSM, from the origins and the community to web services, editors (with detailed descriptions of Potlatch and JOSM), how to render your own maps (including how to write Mapnik and Osmarender style sheets), and how to access OSM data through API, planet files, or diff updates.

If you’re serious about OSM, you should really get this book. (If only to prove to others that the project you’re spending half your waking life on is something serious, you know, something people write books about!)

The sad thing is, like so often with publishing, the distribution, or more specifically, amazon.com; you can order the book at bookdepository.co.uk (free shipping) and it is also in stock at amazon.co.uk, but amazon.com says it “ships in 1 to 3 weeks”. (Also, both amazon sites have the wrong cover image, reflecting an early draft.) I hope that these initial distribution problems will soon be flushed out. This is the one drawback of doing a traditionally printed book – the stuff has to be shipped from printers to wholesalers to retailers and all that takes time.

More information on the book is also at www.openstreetmap.info.

New file format for OSM downloads

22.09.2010 | Frederik Ramm

Geofabrik has been providing the OSM community with cut-down data extracts for various continents, countries, and smaller administrative divisions for over two years now. Our downloads at download.geofabrik.de form the basis of many community projects, and we’re happy to make working with OSM data easier for so many people.

Today we’re launching experimental downloads in a new binary format. The new “protobuf binary format” (.osm.pbf) is 30% smaller than the bzip2-compressed OSM XML, and it can be processed or extracted much faster than bzip2 files. Also, while we will continue supporting the bzip2 files for a while, we hope that we can ultimately free up some resources by dropping bz2 support, and use these resources to produce an even wider set of daily updated OSM extracts.

The protobuf binary format was developed by Scott Crosby and presented to the OSM community in April this year (wiki article with details). As the name implies, it relies on Google’s “Protocol Buffers” for its internal data representation. The format is supported by Osmosis starting with version 0.37; .osm.pbf files can be read directly by Osmosis, or converted to plain XML OSM first using a command like

osmosis --read-pbf myfile.osm.pbf --write-xml myfile.osm

The above command will run significantly faster than a bz2 decompression, and the .osm.pbf files made available by Geofabrik are 100% lossless. The format offers further compression options by stripping of metadata or minimally reducing precision, but Geofabrik extracts will remain lossless.

Not only are .osm.pbf smaller and faster to process than their bz2 counterparts; they are also likely to appear faster on the Geofabrik download site than the regular .osm.bz2 files. Everyone is encouraged to give them a try.

(Edit on 2010-11-16: Initially the command line options to use were called “read-bin” and “write-bin”, but later releases of Osmosis now use “read-pbf” and “write-pbf”.)

OpenStreetMap WMS servers are hard to come by – because they are hard to operate. Running a WMS server always means a trade-off. You can have it render from vector data which makes it slow, or render from pre-computed raster tiles which makes intermediate zoom levels and reprojection ugly. You can use clever preprocessing but then you’re unlikely to be able to trace OSM updates quickly, or you opt for high-frequency updates but that again causes more load on your server. You can use Mapnik but the available WMS servers for that are not so good, or you can use the established UMN Map Server or Geoserver which have excellent WMS support but don’t achieve what has become the “standard” look and feel for OSM maps.


Geofabrik WMS displayed in Quantum GIS.

We think we have struck a nice balance between all these goals with our WMS server, which is available to customers immediately starting from EUR 35 per month. (We regret that we cannot make this available for free due to the cost involved for us, but will consider granting free access for OSM community projects.) The server runs from a continuously updated OSM database covering the whole world, and offers a clean Mapnik vector-based rendering in all projections and sizes. More on our product page.

At the same time, we’re making the software that runs our WMS – a special module for the Apache web server that talks directly to Mapnik – available as Open Source under the GPL license, which should allow anyone to install and run their own WMS server. There’s more on the OSM wiki.

Bericht von der SOTM2010

13.07.2010 | Frederik Ramm

Wir sind zurück von der State of the Map 2010, der internationalen OpenStreetMap-Konferenz, die dieses Jahr in Girona in Spanien stattfand.

Insgesamt lässt sich beobachten, dass das Interesse von Unternehmen an der Konferenz wächst; es wurden dieses Mal grob doppelt so viel Sponsorengelder eingesammelt wie letztes Mal (verbunden allerdings auch mit grob doppelt so hohen Kosten für die Konferenz), und viele “beruflich” OSM-Interessierte waren auch das ganze Wochenende da.

Dennoch schien ein großer Teil der Anwesenden eher technisch interessiert – kaum jemand im Publikum, der sich nicht schon einmal wenigstens in irgendeinen Aspekt von OSM tiefer eingearbeitet oder sogar Software geschrieben hatte. So war dann auch das Vortragsprogramm fast weniger spannend als die zahlreichen Gespräche mit Bastlern aus der ganzen Welt, die in den (spanientypisch sehr ausgedehnten) Kaffee- und Mittagspausen oder auch im Foyer vor den Vortagssälen geführt wurden.

Auf besonderes Interesse stiessen am “Business Day”, dem Freitag, die Ankündigungen von Microsoft (bing maps soll bald einen wählbaren OSM-Layer bekommen) und Aol (Mapquest will vollständig auf OSM umstellen, für Karten und Routing, und im kommenden Jahr eine Million US-Dollar bereitstellen, um das Projekt vorallem in den USA voranzubringen).

Von der Geofabrik gab es einen Vortrag über Geschwindigkeitsoptimierung bei osm2pgsql/Mapnik-basiertem Tile-Rendering (Folien hier) sowie Kurzvorstellungen der Tirex-Software und der zum Wochenende von Dennis Luxen am KIT (Karlsruher Institut für Technologie, ehemals Universität Karlsruhe) veröffentlichten schnellen Routing-Engine für OSM-Daten (Demo-Seite bei der Geofabrik, Ankündigung auf der Mailingliste.)

Als Mitglied der “Data Working Group” bei OpenStreetMap stellte Frederik ausserdem kurz die Arbeit in diesem Gremium vor, das sich mit der Bekämpfung von Vandalismus und Urheberrechtsverletzungen bei OpenStreetMap beschäftigt.

from StevenFeldman's Flickr photo stream

Am Freitag abend gewann die Geofabrik überraschend einen kleinen Preis für den “Best Elevator Pitch” – fünf kleinere OSM-Firmen waren aufgefordert, in einer Minute ihr Geschäftsmodell zu umreißen und zu erklären, was man macht, wer die Kunden sind, was man diesen Kunden bietet und warum sie zu einem kommen sollen. Frederik sagte für die Geofabrik in etwa folgendes:

“Unser Geschäftsmodell ist einfach, altmodisch, und langweilig: Sie zahlen uns Geld, und dafür arbeiten wir für Sie. Wir verkaufen unseren Kunden keine Software oder Leistungen, die sie nicht auch selber mit freier Software und anhand von Wiki-Anleitungen hinbekommen – wir verkaufen einfach Zeitersparnis. Die Kunden beauftragen uns, wenn sie ein Problem lieber von erfahrenen Experten lösen lassen möchten, anstatt selbst ein mehrfaches der Zeit zu investieren. Wir verwenden die Hälfte unserer Zeit darauf, mit der und für die OSM-Community zu arbeiten – dadurch weiss die Community auch, was wir können, und schickt potentielle Kunden in unsere Richtung.”

Das Publikum fand diese Beschreibung erfrischend einfach, und die Geofabrik gewann mit Abstand (“by a country mile”, wie Steven Feldman, Moderator des Wettbewerbs, sagte).

Den Abschluss der Veranstaltung bildete am Sonntag wieder, wie letztes Jahr in Amsterdam, eine langwierige Versteigerung sämtlicher übriggebliebenen Veranstaltungsgegenstände – Poster, Banner, Taschen, sogar einige Hardware und Weinflaschen wurden an den Mann oder an die Frau gebracht.

Wir hatten vier Vorab-Exemplare unseres demnächst auf englisch erscheinenden OSM-Buches dabei, die uns förmlich aus der Hand gerissen wurden (“wann kann man das kaufen? wo?…”) – nun wird es höchste Zeit, das endlich in den Handel zu bringen!