now looking back at HA, I see here: " Porting your application to run on Neo4j-HA
As mentioned earlier the only thing that needs to change is the creation of the graph database service. In single machine operations the EmbeddedGraphDatabase class should be used while in multi machine HA environment the HighlyAvailableGraphDatabase class should be used. Depending on application type this either means modifying the code or the configuration of the container running the application. " so it looks like, HA is better than using neo4j server then , but I thought they were both using the same way to access data, via URI and weird messy stuff :) I'll then begin reading, many thanks Jim! On Thu, Jul 21, 2011 at 6:45 AM, cyuczi eekc <cyuczie...@gmail.com> wrote: > Yeah sorry about that :) > Bottom line is, EmbeddedReadOnlyGraphDb works. > It only displays the `lucene index not found error` when the database(path) > is already in use by another program. Otherwise it just works. > I should've said this, it's simpler to understand. > > To answer your question, I was trying to see if it worked to use the same > database(path) when using EmbeddedReadOnlyGraphDb, while I understood it > doesn't work when using EmbeddedGraphDatabase. Result: it doesn't work. > > But the noticed difference is, when using EmbeddedGraphDatabase the > exception is this: > > Exception in thread "main" org.neo4j.graphdb.TransactionFailureException: > Could not create data source [nioneodb], see nested exception for cause of > error > at > org.neo4j.kernel.impl.transaction.TxModule.registerDataSource(TxModule.java:153) > at org.neo4j.kernel.GraphDbInstance.start(GraphDbInstance.java:111) > at > org.neo4j.kernel.EmbeddedGraphDbImpl.<init>(EmbeddedGraphDbImpl.java:189) > at > org.neo4j.kernel.EmbeddedGraphDatabase.<init>(EmbeddedGraphDatabase.java:86) > at > org.neo4j.kernel.EmbeddedGraphDatabase.<init>(EmbeddedGraphDatabase.java:63) > at > org.neo4j.examples.CalculateShortestPath.main(CalculateShortestPath.java:53) > Caused by: java.lang.IllegalStateException: Unable to lock store > [neo4j-shortest-path\neostore], this is usually a result of some other Neo4j > kernel running usi > ng the same store. > at > org.neo4j.kernel.impl.nioneo.store.CommonAbstractStore.checkStorage(CommonAbstractStore.java:266) > at > org.neo4j.kernel.impl.nioneo.store.CommonAbstractStore.<init>(CommonAbstractStore.java:169) > at > org.neo4j.kernel.impl.nioneo.store.AbstractStore.<init>(AbstractStore.java:120) > at org.neo4j.kernel.impl.nioneo.store.NeoStore.<init>(NeoStore.java:65) > at > org.neo4j.kernel.impl.nioneo.xa.NeoStoreXaDataSource.<init>(NeoStoreXaDataSource.java:134) > at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native > Method) > at > sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:57) > at > sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) > at java.lang.reflect.Constructor.newInstance(Constructor.java:525) > at > org.neo4j.kernel.impl.transaction.XaDataSourceManager.create(XaDataSourceManager.java:76) > at > org.neo4j.kernel.impl.transaction.TxModule.registerDataSource(TxModule.java:147) > ... 5 more > > but when using EmbeddedReadOnlyGraphDatabase, the exception is this > instead: > Exception in thread "main" java.lang.IllegalArgumentException: No index > provider 'lucene' found > at > org.neo4j.kernel.IndexManagerImpl.getIndexProvider(IndexManagerImpl.java:76) > at > org.neo4j.kernel.IndexManagerImpl.getOrCreateNodeIndex(IndexManagerImpl.java:269) > at > org.neo4j.kernel.IndexManagerImpl.forNodes(IndexManagerImpl.java:255) > at > org.neo4j.kernel.IndexManagerImpl.forNodes(IndexManagerImpl.java:249) > at > org.neo4j.examples.CalculateShortestPath.main(CalculateShortestPath.java:54) > > that is what I was attempting to say in the previous xD > > Regards ;) > > > On Thu, Jul 21, 2011 at 6:16 AM, Michael Hunger < > michael.hun...@neotechnology.com> wrote: > >> If you run into errors, please make sure to include the exceptions in the >> e-mail. >> >> Verbal descriptions are sometimes hard to follow without having the code >> and the environment. >> >> You mean you take the same program and exchange the code line to use >> EmbeddedReadOnlyGraphDb ? >> >> Why do you do that? Why don't you create a second program that uses >> EmbeddedReadOnlyGraphDb, you can't >> do modifying operations anyway. >> >> Cheers >> >> Michael >> >> Am 21.07.2011 um 06:12 schrieb cyuczi eekc: >> >> > It is not necessary however your reply made me retest, and it works as >> it >> > were, but it only shows that error, if, I run the program with >> > EmbeddedGraphDatabase and put it in an 100 second sleep(so that it keeps >> the >> > database open), and then I change it to EmbeddedReadOnlyGraphDatabase >> and >> > run it again as second program (while first is already running as >> > EmbeddedGraphDatabase). In this case, this second program shows that >> error. >> > If I run both programs with EmbeddedReadOnlyGraphDatabase, the exact >> thing >> > happens :) >> > I guess it's the way the second program complains that the index >> (and/or >> > the database, since it's in the same path) is already in use by the >> first >> > program. >> > >> > On Thu, Jul 21, 2011 at 6:03 AM, Michael Hunger < >> > michael.hun...@neotechnology.com> wrote: >> > >> >> Probably you have to add that for the other project too ? >> >> >> >> Am 21.07.2011 um 05:57 schrieb cyuczi eekc: >> >> >> >>> Thanks Michael, that is good to know... >> >>> I would've tried that right now, for tests, but unfortunately I get >> that >> >>> silly error "No index provider 'lucene' found", but only when using >> >>> EmbeddedReadOnlyGraphDatabase, not EmbeddedGraphDatabase. Perhaps it >> >> would >> >>> be worth mentioning that in order to not get the error for >> >>> EmbeddedGraphDatabase, I had to add the folder >> >>> ".\lucene-index\src\main\resources\" to classpath, since I am not >> using >> >> any >> >>> .jars, instead I'm using the source files directly from github (in >> >> eclipse) >> >>> >> >>> regarding my topic, I am reading this currently: >> >>> http://wiki.neo4j.org/content/Using_the_Neo4j_Server_with_Java >> >>> but it seems a bit messy, so I will probably limit myself to using >> >> embedded >> >>> database for now :) >> >>> >> >>> >> >>> >> >>> On Thu, Jul 21, 2011 at 5:44 AM, Michael Hunger < >> >>> michael.hun...@neotechnology.com> wrote: >> >>> >> >>>> If you want to have a "read-only-snapshot" view of the database you >> can >> >>>> also use >> >>>> >> >>>> new EmbeddedReadOnlyGraphDatabase(path); >> >>>> >> >>>> Cheers >> >>>> >> >>>> Michael >> >>>> >> >>>> Am 21.07.2011 um 05:31 schrieb Jim Webber: >> >>>> >> >>>>> Hi Cyuczi, >> >>>>> >> >>>>> You can't open the same database twice in two programs. If you want >> >> data >> >>>> to be replicated between Neo4j instances, look into HA: >> >>>>> >> >>>>> http://docs.neo4j.org/chunked/stable/ha-how.html >> >>>>> http://wiki.neo4j.org/content/High_Availability_Cluster >> >>>>> >> >>>>> Jim >> >>>>> _______________________________________________ >> >>>>> 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 >> >>>> >> >>> _______________________________________________ >> >>> 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 >> >> >> > _______________________________________________ >> > 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 >> > > _______________________________________________ Neo4j mailing list User@lists.neo4j.org https://lists.neo4j.org/mailman/listinfo/user
