[Tile-serving] Performance problem serving tiles from planet file

[Paul Norman]

On 1/2/2017 8:14 AM, Theodor Foerster wrote:
> Hi all,
> I am currently setting up an OSM instance serving tiles based on the 
> planet file. The spec is:
> - Ubuntu 14.04
> - 32 GB RAM, 8 cores, 1 TB of virtual volume (500 MB/sec throughput)

The sequential performance of the drive doesn't matter much for tile 
rendering. What is its read IOPS performance like?

> I followed the script by http://opentileserver.org/
>
> I witness utterly bad performance. Parts of the query take around 300+ 
> seconds. Serving a tile takes approx. 20 minutes (1 tile!).

On slower hardware, these times aren't uncommon for zoom 5 metatiles 
with a badly optimized style or setup. OSM Bright is also more prone to 
these problems.

> autovaccuum and fsync are turned off. The obvious performance measures 
> have been applied.

You should have autovacuum and fsync turned *on*, but neither will 
impact rendering performance. work_mem has some impact on rendering 
speed, but really, no PostgreSQL GUCs can significantly increase 
low-zoom render speed. The solutions there involve queries, partial 
indexes, and pre-rendering low zooms.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.openstreetmap.org/pipermail/tile-serving/attachments/20170102/5ce06171/attachment.html>