My guess would be that the long pause times is because you start traversing parts of the graph that is not cached at all. The memory mapped buffers are assigned 1800M but the db is much larger than that. Solution would be to install more memory or switch to a SSD.
You could also try lower heap size and switch to cache_type=weak freeing up some memory for the memory mapped buffers. Regards, Johan On Tue, Nov 30, 2010 at 11:43 AM, Martin Grimmer <martin.grim...@unister.de> wrote: > Hi, > > here the extra output: > > Physical mem: 3961MB > Heap size: 1809MB > store_dir=/neo4j_database/ > rebuild_idgenerators_fast=true > neostore.propertystore.db.index.keys.mapped_memory=1M > logical_log=/neo4j_database//nioneo_logical.log > neostore.propertystore.db.strings.mapped_memory=69M > neostore.propertystore.db.arrays.mapped_memory=1M > neo_store=/neo4j_database//neostore > neostore.relationshipstore.db.mapped_memory=1372M > neostore.propertystore.db.index.mapped_memory=1M > create=true > neostore.propertystore.db.mapped_memory=275M > dump_configuration=true > neostore.nodestore.db.mapped_memory=91M > dir=/neo4j_database//lucene-fulltext > > > > Am 23.11.2010 11:07, schrieb Johan Svensson: >> Hi, >> >> Could you add the following configuration parameter: >> >> dump_configuration=true >> >> and send the output printed to standard out when starting up. Other >> useful information would be some thread dumps while executing a query >> that takes long time (send kill -3 signal to the process). >> >> Regards, >> Johan >> >> On Tue, Nov 23, 2010 at 10:53 AM, Martin Grimmer >> <martin.grim...@unister.de> wrote: >> >>> Hello, >>> >>> while running my benchmark i did the following: >>> added: -verbose:gc to see gc usage >>> run sar -u 1 100 >>> >>> and here are the results: >>> on a 4 core cpu >>> >>> CPU %user %nice %system %iowait %steal %idle >>> all 0,75 0,00 0,62 18,81 0,00 79,82 >>> >>> >>> -> Scaled to 1 core: actually the cpu does nothing to compute the >>> queries. Only 0.75% * 4 = 3% CPU usage for a single core, and 18,81% * 4 >>> = 75,24% io wait for a single core, the rest is divided into system and >>> idle. >>> >>> The gc output: >>> ... >>> [GC 806876K->326533K(1852416K), 0.2419270 secs] >>> ... many queries ... >>> [GC 873349K->423494K(1837760K), 0.3257520 secs] >>> ... many queries ... >>> [GC 956678K->502630K(1643648K), 0.3619280 secs] >>> ... many queries ... >>> [GC 839654K->551462K(1686720K), 0.3088770 secs] >>> ... >>> >>> So its not the GC. >>> >>> Thanks to all of you, _______________________________________________ Neo4j mailing list User@lists.neo4j.org https://lists.neo4j.org/mailman/listinfo/user
