[mkgmap-dev] Memory limits for mkgmap and splitter

Fri Aug 7 08:32:57 BST 2009

Tested this latest version on my American extract with -Xmx4000m:

With 1.2 million nodes the Java VM crashed due to lack of memory. Using 
  1 million nodes the split succeeded with 367 areas in 3:20 hours. Some 
swapping was noticed (bad for speed).

Although I'd rather use the 1.2 million setting, as that is a nice 
balance between the number of failed map builds and map size worldwide, 
using 1 million now enables me to do all the work myself instead of 
relying on others. Great, thanks a million!

Next up: splitting the whole world on my laptop and process the output 
with mkgmap. See which areas need fixing manually...

  Chris Miller wrote:
> I've built a new version that *might* be able to handle the planet OK. I 
> don't know how many areas North America breaks in to, but if you're able 
> to handle 255 areas (at 1,600,000 nodes each) with an older version of the 
> splitter, then I think this version should work for the whole planet:
> 
> http://redyeti.net/splitter.jar
> 
> If you still can't get it to work but are able to at least generate areas.list, 
> then you could try reducing the number of nodes per area since that will 
> directly reduce the amount of memory required when the split files are being 
> written out.
> 
> Assuming no one finds any serious problems with this build, I'll get it checked 
> in and released properly so everyone can benefit.
> 