Tile rendering extremly slow

Question

I imported germany and tried to render a tile on 10/535/341. It took like 10 Minutes.

Specs:

16gb Ram
8 Cores

I used the openstreetmap carto style and my import command was:

osm2pgsql --create --slim --flat-nodes /home/renderer/update_tiles/flat-nodes.raw --hstore -C 13000 --number-processes 8 -d gis -h 192.168.2.2 -p 5432 -U renderer --tag_transform-script /home/renderer/src/style/openstreetmap-carto.lua -S /home/renderer/src/openstreetmap-carto.style /home/renderer/import_file.osm.pbf

I tried to tune my postgres server through configuration but nothing helped.

Important is that the postgres and tile server are running in docker containers.

I checked the disk writing speed with:

sudo hdparm -t /dev/mapper/

And got Timing buffered disk reads: 3232 MB in 3.00 seconds = 1077.17 MB/sec

My renderd.conf:

[renderd]
num_threads=8
tile_dir=/var/lib/mod_tile
stats_file=/var/run/renderd/renderd.stats

[mapnik]
plugins_dir=/usr/lib/mapnik/3.0/input
font_dir=/usr/share/fonts/truetype
font_dir_recurse=1

[ajt]
URI=/hot/
TILEDIR=/var/lib/mod_tile
XML=/home/renderer/src/style/mapnik.xml
HOST=localhost
TILESIZE=256
MAXZOOM=20

My render Command:

renderd -f -c /usr/local/etc/renderd.conf

If you need any more information just ask and thanks for reading and maybe helping.

Accepted Answer

2

It is not unusual for tiles below zoom 12 to be rather slow. Have you created the indexes as recommended in the openstreetmap-carto setup instructions? That may help a little but not much.

Note that if you've got a standard renderd setup, you have not rendered one tile but 64 tiles (the "meta tile" on which your tile resides). And Germany only has about 20 of them - so even if they take 10 minutes to render, you'll be done in 4 hours. Everyone pre-renders tiles on zoom 0-12 or so.

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answered 10 Mar '20, 14:40

Frederik Ramm ♦
82.5k●92●720●1273
accept rate: 23%

"Note that if you've got a standard renderd setup, you have not rendered one tile but 64 tiles (the "meta tile" on which your tile resides)"

What do you mean?

Why are there 64 tiles rendered for every actual tile? is it always like that? How to turn that off?

(11 Mar '20, 07:39) kartman1

This is explained in the context of "Tirex" here but just as valid for renderd setups: https://wiki.openstreetmap.org/wiki/Tirex/Overview#Metatiles -- You do not want to switch it off.

(11 Mar '20, 07:43) Frederik Ramm ♦

Indexing reduced the render time by 25%. After that i tuned my postgis with this turorial https://wiki.openstreetmap.org/wiki/User:Species/PostGIS_Tuning which saved me another 20%

(11 Mar '20, 10:54) Arthurle

Tile rendering extremly slow

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