Thanks Michael. About Lucene internally caches its indexes: does that part of the memory come from neo4j's dbms.pagecache.memory portion? Your answers seem to suggest that it doesn't.
On Tuesday, June 9, 2015 at 11:47:41 PM UTC-7, Michael Hunger wrote: > > > Am 08.06.2015 um 22:24 schrieb Zongheng Yang <[email protected] > <javascript:>>: > > I'm using Neo4j 2.2.2 community edition, embedded in a Java app, and no > concurrency in queries at all. > > (1) *Caching of the indexes.* What components in Neo4j are responsible > for caching the indexes (on node properties)? The manual doesn't seem to > have mentioned this, and it seems that the page cache is purely for the > data (nodes, relationships, properties, etc.). > > > Lucene internally caches the index data. Going forward we will build our > own exact-indexes which utilize the same page-cache structures we use for > our store-files today. > > > (2) *The object cache (reference caches).* What are some files / > packages in the source code that implement these? > > > Don't bother, it's gone in 2.3 anyway > > > (3) *Memory config for a small-memory machine.* Say the physical memory > is M = ~4GB, the indexes are about 4GB, and the store files are much larger > (say ~20GB). > > > Why would you do a perf test on such a machine for a large graph like this? > In general I would try 2.3-M02 for that and use 1G heap, 2.5G page-cache > (leave .5G for OS and it's work) and cross my fingers. But I wouldn't trust > in these performance numbers :) > > > Suppose I'd want to benchmark performance of a particular query, say > getting all nodes that have property1 to be val1. If I'd want the index > (of size ~M) to mostly fit in memory, how should I set the JVM heap size & > dbms.pagecache.memory? Also, is it right that in this case pagecache size > is not as important? > > Another query: say this time it doesn't involve indexes, and I'm just > traversing random portions of a graph. I imagine for this I'd need to set > a large pagecache size and small JVM heap? Could someone give a concrete > suggestion? > > Thanks in advance. > > Zongheng > > -- > You received this message because you are subscribed to the Google Groups > "Neo4j" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected] <javascript:>. > For more options, visit https://groups.google.com/d/optout. > > > -- You received this message because you are subscribed to the Google Groups "Neo4j" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
