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[mkgmap-dev] splitter questions

From Gerd Petermann gpetermann_muenchen at hotmail.com on Thu Oct 22 09:49:23 BST 2020

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.


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


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

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

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)?


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