Hi, I've had some time to look into this issue and it seems that when using the "ReadOnly" versions of the classes, I get the memory mapping warnings and when using the "Writable" versions of the classes, the warning does not occur (I'm assuming memory mapping gets enabled).
I'm not against using the "writable" versions of the classes; my only concern is performance. Are the "readonly" versions faster that the "writable" versions? And if they are; then if memory mapping is not enabled, are they faster that the "writable" versions with memory mapping? I'll run some tests, but I guess I would like an expert opinion. Regards, Marc On Mon, Mar 22, 2010 at 10:24 AM, Tobias Ivarsson < [email protected]> wrote: > Hi, > > We have seen this message before emitted as a warning from Neo4j. Are you > seing this as a warning as well, or are you getting an exception thrown to > your application code? > > It's hard to deal with these errors since nio only throws IOException, and > not any more semantic information than that, I believe we deal with all > cases by issuing a warning and then falling back to another method of > performing the same operation, but if you are getting exceptions we need to > resolve it. If you are indeed getting exceptions, some code that triggers > it > would be very helpful. > > Cheers, > Tobias > > On Wed, Mar 17, 2010 at 1:47 PM, Marc Preddie <[email protected]> wrote: > > > Hi, > > > > I've look at the mailing list and found 1 similar situation, but no real > > solution. So I was hoping someone could shed some light on this. > > > > I seem to have an issue with neo4j being able to use memory mapped files. > > I've run my service on Win XP 64bit, Mac OSX Snow Leopard 10.6.2 and > Centos > > 5.x 64bit and always get the same error when launching. I'm using APOC > 1.0 > > and have a DB of approx 600M. In my neo config I allocate about 5M more > for > > each type of file than the actual file size (I've tried multiple > different > > settings). On each machine I also leave at least 1.5G for the OS and have > > at > > least 2.5G heap for the Java process. I'm also using the > > classes EmbeddedReadOnlyGraphDatabase and LuceneReadOnlyIndexService to > > access and browse DB. > > > > Neo config > > > > neostore.nodestore.db.mapped_memory=10M > > neostore.relationshipstore.db.mapped_memory=110M > > neostore.propertystore.db.mapped_memory=85M > > neostore.propertystore.db.index.mapped_memory=10M > > neostore.propertystore.db.index.keys.mapped_memory=10M > > neostore.propertystore.db.strings.mapped_memory=320M > > neostore.propertystore.db.arrays.mapped_memory=10M > > > > Here is the error > > > > org.neo4j.kernel.impl.nioneo.store.MappedMemException: Unable to map > > pos=3005872 recordSize=33 totalSize=1153416 > > at > > > > > org.neo4j.kernel.impl.nioneo.store.MappedPersistenceWindow.<init>(MappedPersistenceWindow.java:59) > > at > > > > > org.neo4j.kernel.impl.nioneo.store.PersistenceWindowPool.allocateNewWindow(PersistenceWindowPool.java:530) > > at > > > > > org.neo4j.kernel.impl.nioneo.store.PersistenceWindowPool.refreshBricks(PersistenceWindowPool.java:430) > > at > > > > > org.neo4j.kernel.impl.nioneo.store.PersistenceWindowPool.acquire(PersistenceWindowPool.java:122) > > at > > > > > org.neo4j.kernel.impl.nioneo.store.CommonAbstractStore.acquireWindow(CommonAbstractStore.java:459) > > at > > > > > org.neo4j.kernel.impl.nioneo.store.RelationshipStore.getChainRecord(RelationshipStore.java:248) > > at > > > > > org.neo4j.kernel.impl.nioneo.xa.NeoReadTransaction.getMoreRelationships(NeoReadTransaction.java:103) > > at > > > > > org.neo4j.kernel.impl.nioneo.xa.NioNeoDbPersistenceSource$ReadOnlyResourceConnection.getMoreRelationships(NioNeoDbPersistenceSource.java:275) > > at > > > > > org.neo4j.kernel.impl.persistence.PersistenceManager.getMoreRelationships(PersistenceManager.java:93) > > at > > > > > org.neo4j.kernel.impl.core.NodeManager.getMoreRelationships(NodeManager.java:585) > > at > > > org.neo4j.kernel.impl.core.NodeImpl.getMoreRelationships(NodeImpl.java:332) > > at > > > > > org.neo4j.kernel.impl.core.NodeImpl.ensureFullRelationships(NodeImpl.java:320) > > at > > > > > org.neo4j.kernel.impl.core.NodeImpl.getAllRelationshipsOfType(NodeImpl.java:129) > > at > > > > > org.neo4j.kernel.impl.core.NodeImpl.getSingleRelationship(NodeImpl.java:179) > > at > > > > > org.neo4j.kernel.impl.core.NodeProxy.getSingleRelationship(NodeProxy.java:98) > > .... > > Caused by: java.io.IOException: Access is denied > > at sun.nio.ch.FileChannelImpl.truncate0(Native Method) > > at sun.nio.ch.FileChannelImpl.map(FileChannelImpl.java:728) > > at > > > > > org.neo4j.kernel.impl.nioneo.store.MappedPersistenceWindow.<init>(MappedPersistenceWindow.java:53) > > ... 78 more > > > > > > Regards > > Marc > > _______________________________________________ > > Neo mailing list > > [email protected] > > https://lists.neo4j.org/mailman/listinfo/user > > > > > > -- > Tobias Ivarsson <[email protected]> > Hacker, Neo Technology > www.neotechnology.com > Cellphone: +46 706 534857 > _______________________________________________ > Neo mailing list > [email protected] > https://lists.neo4j.org/mailman/listinfo/user > _______________________________________________ Neo mailing list [email protected] https://lists.neo4j.org/mailman/listinfo/user
