Paul, are you on windows or Linux? ----- Reply message ----- From: "Paul Bandler" <[email protected]> Date: Tue, Jun 28, 2011 1:34 pm Subject: [Neo4j] Advantages of EmbeddedReadOnlyGraphDatabase ? [was NonWritableChannelException] To: "Neo4j user discussions" <[email protected]>
Are there advantages in accessing the database via the EmbeddedReadOnlyGraphDatabaseclass in a read-only application? A week or so back I posted the message below regarding a problem experienced while using EmbeddedReadOnlyGraphDatabase that regrettably didn't solicit any responses and since then I've been using the standard read-write EmbeddedGraphDatabase without repeat of the same issue even though my application is read-only. Are there any avoidable performance penalties using EmbeddedGraphDatabase in place of EmbeddedReadOnlyGraphDatabase? Along a similar lines, as my application is read-only, I'm not doing any explicit transaction management - is there any reason why I should? Begin forwarded message: > From: Paul Bandler <[email protected]> > Date: 21 June 2011 12:22:56 GMT+01:00 > To: Neo4j user discussions <[email protected]> > Subject: [Neo4j] NonWritableChannelException > Reply-To: Neo4j user discussions <[email protected]> > > The above exception is thrown from the call stack indicated below while > traversing a neo4j graph using the EmbededReadOnly database. Using 1.4M04. > > The application is running with 1gb of heap with defaulting all other > parameters except cache_type=weak on windows. > > I found some reports of this exception being thrown at shutdown back > in January but this is not happening at shutdown and I could find no posted > resolution of that thread anyway. > > Can anyone suggest what the cause if this exception is? > > Thanks > > Paul > >> > >> Exception in thread "main" java.nio.channels.NonWritableChannelException >> at sun.nio.ch.FileChannelImpl.write(Unknown Source) >> at >> org.neo4j.kernel.impl.nioneo.store.AbstractPersistenceWindow.writeOut(AbstractPersistenceWindow.java:104) >> at >> org.neo4j.kernel.impl.nioneo.store.PersistenceWindowPool.refreshBricks(PersistenceWindowPool.java:536) >> at >> org.neo4j.kernel.impl.nioneo.store.PersistenceWindowPool.acquire(PersistenceWindowPool.java:128) >> at >> org.neo4j.kernel.impl.nioneo.store.CommonAbstractStore.acquireWindow(CommonAbstractStore.java:526) >> at >> org.neo4j.kernel.impl.nioneo.store.RelationshipStore.getChainRecord(RelationshipStore.java:327) >> at >> org.neo4j.kernel.impl.nioneo.xa.ReadTransaction.getMoreRelationships(ReadTransaction.java:114) >> at >> org.neo4j.kernel.impl.nioneo.xa.ReadTransaction.getMoreRelationships(ReadTransaction.java:97) >> at >> org.neo4j.kernel.impl.persistence.PersistenceManager.getMoreRelationships(PersistenceManager.java:108) >> at >> org.neo4j.kernel.impl.core.NodeManager.getMoreRelationships(NodeManager.java:603) >> at >> org.neo4j.kernel.impl.core.NodeImpl.getMoreRelationships(NodeImpl.java:399) >> at >> org.neo4j.kernel.impl.core.IntArrayIterator.hasNext(IntArrayIterator.java:93) >> at >> org.neo4j.kernel.impl.core.NodeImpl.getSingleRelationship(NodeImpl.java:218) >> > _______________________________________________ > Neo4j mailing list > [email protected] > https://lists.neo4j.org/mailman/listinfo/user _______________________________________________ Neo4j mailing list [email protected] https://lists.neo4j.org/mailman/listinfo/user _______________________________________________ Neo4j mailing list [email protected] https://lists.neo4j.org/mailman/listinfo/user
