[Tilesathome] Deploying Map - Architecture planning

[Florian Lohoff]

On Fri, Sep 12, 2008 at 03:20:12PM +0300, Zsombor Szabó wrote:
> From: Zsombor Szabó <zsombor at gmail.com>
> Subject: [Tilesathome] Deploying Map - Architecture planning
> 
> Hi t at h people,
> 
> I'm a newbie to OSM and I am thrilled to see that there exists such a  
> project.
> All things short, basically I want to deploy a map for mobile devices  
> from OSM data with the following features:
> 
> - map tiles should be up to date (preferably they should change after  
> K*hour if edited)
> - map tiles should be smaller size than the default 256x256
> - don't want to load OSM servers with heavy traffic
> - want to have a high availability and scalable architecture
> 
> Looking through the documentation at http://wiki.openstreetmap.org/index.php/Deploying_your_own_Slippy_Map
> it lead me to plan the following architecture:
> 
> - mobile devices will request maptiles from local sqlite database
> - mobile devices will fallback to request maptiles from Amazon S3  
> buckets if a maptile doesn't exist in the local sqlite database
> - initialy all maptiles will be uploaded into the S3 buckets (to save  
> space use oceantiles and emptyland(?))
> - maptiles will be generated with a modified tilesGen.pl script on  
> Amazon EC2 instances which will upload the maptiles into the S3 buckets
> - the EC2 instances will check periodically (K*hour) for updated tiles  
> through the OSM API call GET /api/0.5/changes?hours=[K*1]&zoom=[12-17]  
> and they will render them and upload them to S3 buckets

I would track the osc files on planet.openstreetmap.org which is much
easier and also does not put that much load on the main db. Also the
history is for multiple days if needed ...

> - mobile devices request the timestamp of the tiles from the EC2  
> instances while panning/zooming and compare them to their local  
> maptiles' timestamps so they know when to request changed maptiles  
> from S3
> 
> drawbacks:
> - if for some reason the EC2 system/program will be out more than 24  
> hours, the system will have to rerender all maptiles since the current  
> OSM 0.5 API doesn't let request a time span larger than 24 hours at  
> GET /api/0.5/changes

See above . when using the change files there is no such problem.

> - the map's look and feel is not so slick than the one rendered with  
> Mapnik

> Question: How many gigabytes is currently the world with t at h tiles?

Its not clear right now - anywhere between 1 and 1.5TB the estimate
says.

Flo
-- 
Florian Lohoff                  flo at rfc822.org             +49-171-2280134
	Those who would give up a little freedom to get a little 
          security shall soon have neither - Benjamin Franklin
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 189 bytes
Desc: Digital signature
URL: <http://lists.openstreetmap.org/pipermail/tilesathome/attachments/20080912/793bee02/attachment.pgp>