logo separator

[mkgmap-dev] splitter questions

From Gerd Petermann gpetermann_muenchen at hotmail.com on Thu Oct 22 10:17:00 BST 2020

Hi Karl,

the main purpose of --keep-complete is to have complete multipolygons in each tile to avoid empty parts of large lakes or flooded areas near large lakes.
There is also an effect on routing regarding turn restrictions and route relations.

Anyhow, if you really want to produce a very large map on such a limited system you probably run into other problems when calculating the global index in mkgmap.

Gerd


________________________________________
Von: mkgmap-dev <mkgmap-dev-bounces at lists.mkgmap.org.uk> im Auftrag von 7770 <7770 at foskan.eu>
Gesendet: Donnerstag, 22. Oktober 2020 10:59
An: Development list for mkgmap
Betreff: Re: [mkgmap-dev] splitter questions

Hi Gerd.
Yes, it is 64-bit, but i don't have a lot of memory.
--keep-complete=false, can it impact routing possibilities (routing may not
work well) or is it mainly affecting how the map will look?


Regards
Karl

On torsdag 22 oktober 2020 kl. 10:49:23 CEST Gerd Petermann wrote:
> Hi Karl,
>
> if you are running a 64 Bit OS make sure to install a 64 Bit java runtime.
> This allows to increase the -Xmx option. You probably need > 5G for this.
> With a 32 Bit OS you can only try to disable the keep-complete option.
>
> Gerd
>
> ________________________________________
> Von: mkgmap-dev <mkgmap-dev-bounces at lists.mkgmap.org.uk> im Auftrag von 7770
> <7770 at foskan.eu> Gesendet: Donnerstag, 22. Oktober 2020 10:45
> An: mkgmap-dev at lists.mkgmap.org.uk
> Betreff: [mkgmap-dev] splitter questions
>
> Hi.
>
> I am trying to split data for some 15 countries. First step is to combine
> the country data (with osmconvert) to one large o5m file and then try to
> split the combined file.
> The o5m file is about 14 GB in size.
>
> When running splitter i give java -Xmx1600m
> options to splitter are: --max-nodes=1500000 --no-trim
>
> Splitter calculates around 640 areas/tiles to be created.
> If i understand correctly, ways are parsed completely and then starts
> relations.
>
> After 100 000 relations i get:
> ***** Full GC *****
> and soon thereafter:
> Exception in thread "main" Exception in thread "worker-0"
>  java.lang.OutOfMemoryError: GC overhead limit exceeded... and many more
> lines.
>
> After this, one thread (out of two) dies but the other seems to hang doing
> nothing... and i have to manually kill it later.
>
>
>
> Now, i can give java a little bit more memory to java, say up to 1800m.
>
> setting  --max-nodes= larger should use less memory says documentation.
> With a larger max-nodes, will those tiles be faster or slower to display on
> a GPS unit?
> What is a reasonable value, 10 000 000 nodes or 2 000 000?
>
>
> Would --max-areas help my situation?
> If i use --max-areas=350 (approx half of total expected tiles), based on
> your experience would it be enough, or shall i better try with a value of
> 220 (~1/3 of the total tiles)?
>
> Regards
> Karl
>
>
> _______________________________________________
> mkgmap-dev mailing list
> mkgmap-dev at lists.mkgmap.org.uk
> http://www.mkgmap.org.uk/mailman/listinfo/mkgmap-dev
> _______________________________________________
> mkgmap-dev mailing list
> mkgmap-dev at lists.mkgmap.org.uk
> http://www.mkgmap.org.uk/mailman/listinfo/mkgmap-dev




_______________________________________________
mkgmap-dev mailing list
mkgmap-dev at lists.mkgmap.org.uk
http://www.mkgmap.org.uk/mailman/listinfo/mkgmap-dev


More information about the mkgmap-dev mailing list