Hi Gerd, Thanks! From the java --version output (in the first mail) I assumed already beeing on a 64-bit JRE and, following your advice, set -Xmx4G. Bingo, succes in the first pass on the weak machine. /JVM Memory Info: Current 3990MB (1967MB used, 2023MB free) Max 4096MB/ I still wonder how to read the figures though, as for the former successfull passes only about 1300 MB where reported used. and every pass reportedly still had free memory, although "current" was = "max." on the fails. So, how to figure out an appropriate allocation? By map and/or machine? Altough reading up on splitters documentation I seem to have been derailled by the description for --max-areas parameter /Higher numbers ... require more memory/ /Note that the first stage of the processing has a fixed memory overhead regardless of what this is set to so if you are running out of memory before the areas.list file is generated, you need to either increase your -Xmx value.../ Therefore I fiddled with max-areas, but didn't try to use -Xmx myself. But, I now see, why --max-areas didn't change a thing in my case, as -for the map in question- I get: /Processing 293 areas in a single pass / // Felix On 20.03.24 15:16, Gerd Petermann wrote:
Hi Felix,
I guess your laptop is running a 32-bit JRE, so your first step should be to install a 64 bit version if you have a 64 bit OS. With this done you can increase the max heap to e.g. 4GB with something like java -Xmx4G -jar splitter.jar .... If you cannot increase the memory you can switch of the --keep-complete option (with the corresponding disadvantages)
Gerd
________________________________________ Von: mkgmap-dev<mkgmap-dev-bounces@lists.mkgmap.org.uk> im Auftrag von Felix Herwegh<mlmmduk@herwegh.de> Gesendet: Mittwoch, 20. März 2024 15:03 An:mkgmap-dev@lists.mkgmap.org.uk Betreff: [mkgmap-dev] Splitter Java Heap
Hi,
switching to my Ultrabook (6 GB) while travelling I recently faced some kind of borderline condition with splitter. On the first run it throws "OutOfMemoryError: Java heap space", on closely subsequent runs without any modifications it does not. Repeating the task after some delay fails again. I guess, there might be some self-optimization involved for this.
fail: ... 40.000.000 ways parsed... id=888262666 Number of stored tile combinations in multiTileDictionary: 4.525 41.000.000 ways parsed... id=929920953 Exception in thread "main" java.lang.OutOfMemoryError: Java heap space at uk.me.parabola.splitter.tools.SparseLong2IntMap$ChunkMem.<init>(SparseLong2IntMap.java:189) at uk.me.parabola.splitter.tools.SparseLong2IntMap.saveCurrentChunk(SparseLong2IntMap.java:627) at uk.me.parabola.splitter.tools.SparseLong2IntMap.replaceCurrentChunk(SparseLong2IntMap.java:886) at uk.me.parabola.splitter.tools.SparseLong2IntMap.put(SparseLong2IntMap.java:691) at uk.me.parabola.splitter.SplitProcessor.processWay(SplitProcessor.java:149) at uk.me.parabola.splitter.AbstractMapProcessor.consume(AbstractMapProcessor.java:84) at uk.me.parabola.splitter.OSMFileHandler.execute(OSMFileHandler.java:157) at uk.me.parabola.splitter.Main.writeTiles(Main.java:542) at uk.me.parabola.splitter.Main.start(Main.java:132) at uk.me.parabola.splitter.Main.main(Main.java:81) Elapsed time: 8m 0s Memory: Current 1466MB (1339MB used, 127MB free) Max 1466MB
success: ... 48.000.000 ways parsed... id=1262369277 Writing relations Tue Mar 19 10:50:36 CET 2024 100.000 relations parsed... id=1783690 200.000 relations parsed... id=4148045 300.000 relations parsed... id=7895430 400.000 relations parsed... id=11681672 500.000 relations parsed... id=15581604 coord Map: 312.851.126 stored long/int pairs require ca. 3 bytes per pair. 14.225.657 chunks are used, the avg. number of values in one 64-chunk is 21. coord Map details: ~852 MB, including 88 array(s) with 8 MB
way Map: 48.015.926 stored long/int pairs require ca. 3 bytes per pair. 3.974.651 chunks are used, the avg. number of values in one 64-chunk is 12. way Map details: ~123 MB, including 10 array(s) with 8 MB
JVM Memory Info: Current 1466MB (1357MB used, 109MB free) Max 1466MB Full Node tests: 62.230.523 Quick Node tests: 282.354.912 Thread worker-2 has finished ...
My main machine has 24 GB of main memory, and runs troublefree using the following memory allocation on the same task:
JVM Memory Info: Current 3342MB (2378MB used, 964MB free) Max 6000MB
Splitter 653 so far is involved without explicit memory allocation (java -jar .../splitter-latest/splitter.jar ...), using
java --version openjdk 11.0.22 2024-01-16 OpenJDK Runtime Environment (build 11.0.22+7-post-Debian-1deb10u1) OpenJDK 64-Bit Server VM (build 11.0.22+7-post-Debian-1deb10u1, mixed mode, sharing)
Following up on splitter tuning hints (areas.list gets generated in each case) I reduced --max-areas= from 4096 to 2048 to 1024, but to no avail (not even significantly on the runtimes), once I figured out the effect above. It fails on all first runs and succeeds on all shortly following next ones.
Unfortunately its not possible to increase main hardware memory on the small machine, but system tools report only about 2...3 GB being used anyway. Is it possible to tweak Java to overcome the problem without hurting the maps, preferably by machine, to be able to run identical scripts? Some pointers would be appreciated, also on how to monitor the Java memory situation.
Thanks, Felix
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