[OSM-dev] 404 from Apache2/mod_tile

[pavithran]

On 9 November 2012 01:32, Stefan Elspaß <stefan.elspass at gmail.com> wrote:

> I have set up (for the first time) an Ubuntu Server with Apache2 and renderd/mod_tile - using the instructions from switch2osm.org. I did the import to PostGIS/Postgres with osm2pgsql (hstore) and used the german style. With render_list I prerendered Germany up to zoom level 16 for performance reasons. Nearly everything is working fine, my Leaflet-page works. Except: when first accessing the (not prerendered) tiles in zoomlevel 17 and 18 I often receive quite quickly (29-49ms) a HTTP 404 response. When accessing the same tiles again some seconds later they are sent without any problems (HTTP 200).

I understand you have set out the timeout configs but why is 17 or 18
level tile not getting rendered on the fly ? Is it because of a very
slow hardware or dense location ( which is obvious due to map quality
in germany) . But I think its the postgres which is slowing you down .
Try keeping the postgres on a different machine if possible .

Also regarding your choice of mod_tile , mod_tile is a meta tile
caching  mechanism where the meta tile (8x8) is rendered . mod_tile is
good for prerendering and also serving large postion of tiles helpful
in panning , but the first request for a new tile in new location is
going to take time . :(

Do an $iotop to see whats going on with respect to IO , remember
virtual machines have bad IO , so also a better file system would
increase performance .

Regards,
pavithran



-- 
pavithran sakamuri
http://look-pavi.blogspot.com