That is to be expected. It is due to cache staleness issues in the ReadOnly instance.
Using cache_type=none should give the lowest probability of these things happening, but there are no guarantees. -t 2011/4/6 Alfredas Chmieliauskas <al.fre...@gmail.com> > Hey, > > Thanks for the ideas. > Both > readOnlyGraphDb.getConfig().getGraphDbModule().getNodeManager().clearCache() > and cache_type=none worked. > > But I've run into some issues down the road. > > To test i've taken the same db folder with some nodes, properties and > relations and created a read-only embedded db with it; later the same > folder for "standard" embedded db. > > When opening the db as read-only: > 1) node.getRelationships() is empty for all nodes whereas it is not > the case in the "standard" mode > 2) node.getPropertyKeys() sometimes throws > org.neo4j.kernel.impl.nioneo.store.InvalidRecordException: > Position[63] requested for operation is high id[24], store is ok[true] > > > org.neo4j.kernel.impl.nioneo.store.CommonAbstractStore.acquireWindow(CommonAbstractStore.java:521) > > > org.neo4j.kernel.impl.nioneo.store.AbstractDynamicStore.getLightRecords(AbstractDynamicStore.java:425) > > > org.neo4j.kernel.impl.nioneo.store.PropertyIndexStore.getRecord(PropertyIndexStore.java:196) > > > org.neo4j.kernel.impl.nioneo.xa.ReadTransaction.getPropertyIndex(ReadTransaction.java:201) > > > org.neo4j.kernel.impl.nioneo.xa.NioNeoDbPersistenceSource$ReadOnlyResourceConnection.loadIndex(NioNeoDbPersistenceSource.java:206) > > > org.neo4j.kernel.impl.persistence.PersistenceManager.loadIndex(PersistenceManager.java:84) > > > org.neo4j.kernel.impl.core.PropertyIndexManager.getIndexFor(PropertyIndexManager.java:141) > > org.neo4j.kernel.impl.core.NodeManager.getIndexFor(NodeManager.java:765) > > org.neo4j.kernel.impl.core.Primitive.getPropertyKeys(Primitive.java:117) > > org.neo4j.kernel.impl.core.NodeProxy.getPropertyKeys(NodeProxy.java:129) > > which works fine in the "standard" mode. > > I wonder am I doing something wrong or are these issues known? > > Alfredas > > On Wed, Apr 6, 2011 at 9:18 AM, Mattias Persson > <matt...@neotechnology.com> wrote: > > A "refresh", i.e. clearing of caches can be performed by (API may > change): > > > > > > > readOnlyGraphDb.getConfig().getGraphDbModule().getNodeManager().clearCache(); > > > > and you could maybe keep the default cache_type setting. That should do > what > > you're asking for. > > > > 2011/4/5 David Montag <david.mon...@neotechnology.com> > > > >> Alfredas, > >> > >> A solution based on EmbeddedReadOnlyGraphDatabase would not be able to > >> benefit from caching, as each "refresh" of the view would have to clear > the > >> caches. You could possibly achieve the solution you want by setting the > >> config parameter cache_type=none for the read-only instance. Then it > should > >> not cache anything and always read from disk or OS cache. This would > >> however > >> yield degraded performance if you repeatedly read the same data. > >> > >> If your processing could benefit from caching, then you're better off > >> creating a new instance, or manually clearing the caches. Or going with > the > >> HA-based solution that Jim and Mattias outlined. > >> > >> David > >> > >> On Tue, Apr 5, 2011 at 9:36 AM, Alfredas Chmieliauskas > >> <al.fre...@gmail.com>wrote: > >> > >> > Yes. The read only client would query the db at time intervals. > >> > > >> > Alfredas > >> > > >> > On Tue, Apr 5, 2011 at 5:40 PM, David Montag > >> > <david.mon...@neotechnology.com> wrote: > >> > > Alfredas, > >> > > When you say watch, do you mean "poll" the graph at some interval? > What > >> > > would the read-only client do? > >> > > Thanks, > >> > > David > >> > > > >> > > On Tue, Apr 5, 2011 at 5:26 AM, Alfredas Chmieliauskas < > >> > al.fre...@gmail.com> > >> > > wrote: > >> > >> > >> > >> Dear all, > >> > >> > >> > >> we have the following situation: > >> > >> - 1 client is writing to the embedded db (writer) > >> > >> - 1 client would like to watch that (read-only) > >> > >> > >> > >> is that possible with the EmbeddedReadOnlyGraphDatabase? > >> > >> Currently it seems that the read-only db does not see the updates > from > >> > >> the writer since its creation. It there a way to force refresh > besides > >> > >> creating a new instance? > >> > >> > >> > >> Also are there any other/better ways to do that (1 writer, 1 > reader) > >> > >> without going into the server mode? > >> > >> > >> > >> Thanks a lot, > >> > >> > >> > >> Alfredas > >> > >> _______________________________________________ > >> > >> Neo4j mailing list > >> > >> User@lists.neo4j.org > >> > >> https://lists.neo4j.org/mailman/listinfo/user > >> > > > >> > > > >> > > > >> > > -- > >> > > David Montag <david.mon...@neotechnology.com> > >> > > Neo Technology, www.neotechnology.com > >> > > Cell: 650.556.4411 > >> > > Skype: ddmontag > >> > > > >> > > >> > >> > >> > >> -- > >> David Montag <david.mon...@neotechnology.com> > >> Neo Technology, www.neotechnology.com > >> Cell: 650.556.4411 > >> Skype: ddmontag > >> _______________________________________________ > >> Neo4j mailing list > >> User@lists.neo4j.org > >> https://lists.neo4j.org/mailman/listinfo/user > >> > > > > > > > > -- > > Mattias Persson, [matt...@neotechnology.com] > > Hacker, Neo Technology > > www.neotechnology.com > > _______________________________________________ > > Neo4j mailing list > > User@lists.neo4j.org > > https://lists.neo4j.org/mailman/listinfo/user > > > _______________________________________________ > Neo4j mailing list > User@lists.neo4j.org > https://lists.neo4j.org/mailman/listinfo/user > -- Tobias Ivarsson <tobias.ivars...@neotechnology.com> Hacker, Neo Technology www.neotechnology.com Cellphone: +46 706 534857 _______________________________________________ Neo4j mailing list User@lists.neo4j.org https://lists.neo4j.org/mailman/listinfo/user
