Re: [Neo4j] neo4j-python Database Connection Pooling
Hi James, Neo4j-python uses the Neo4j Embedding capabilities. This means that there is no such thing as a connection, and thus nothing to pool. You definitely don't want to startup and shut down the database for each request. What you want to do is tie the lifecycle of Neo4j to the lifecycle of your application. The fact that Neo4j-python embeds Neo4j has one drawback though. It limits you to only being able to use the Neo4j database from one process. This is a shortcoming we intend to solve in Q1 of 2011. Cheers, Tobias On Tue, Dec 21, 2010 at 7:43 PM, James Thornton ja...@jamesthornton.comwrote: Hello - How do you set up a connection pool in neo4j-python? -- I am new to neo4. I am working on setting up neo4j-python in Pyramid (the new Pylons), and I don't want to build up and tear down DB connections each time. Thank you. James ___ 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
Re: [Neo4j] LuceneSail queries returning empty result
Your exception is thrown because you've got a '*' as the first
character of your query. By default the lucene query parser doesn't
allow this, but you can override that by a call to
QueryParser#setAllowLeadingWildcard(boolean). How you would do that in
your setting I don't know, though.
Den tisdag 21 december 2010 skrev Schmidt, Dennisdennis.schm...@sap.com:
Hi all,
I am currently using the LuceneSail on top of a
DirectTypeHierarchyInferencer, ForwardChainingRDFSInferencer and a
MemoryStore.
When using the following query, the LuceSail is obviously already working
somehow, since the queries are roughly twice as fast as before. Still not the
real performance gain I was expecting from using Lucene (side note: the
Strings are in fact only short text snippets of usually no more than 30
characters).
SELECT entity, name, type
FROM {entity} rdfs:label {name} rdf:type {type}
WHERE name LIKE *search this* IGNORE CASE
The LuceneSail homepage
(http://dev.nepomuk.semanticdesktop.org/wiki/LuceneSail) introduces a
different query format for using LuceneSail, so I was using this instead to
see what happens. I changed the query to look like this then:
PREFIX search:http://www.openrdf.org/contrib/lucenesail#
SELECT ?entity ?name ?type WHERE {
?entity search:matches ?match ;
rdf:type ?type .
?match search:query *search this* . }
I only changed from SERQL to SPARQL because SPARQL was used in the example as
well. With this, the query is being executed correctly (meaning no Exceptions
or anything) but then, there are never any results returned and the query
execution is blazingly fast (which leads me to the conclusion it is in fact
not executed as expected).
So am I missing something there or what might be the reason? Another to me
unexpected behaviour is that, when using a wildcard character at the
beginning of a search string, I get the following error message. Why can I
not use a wildcard at the beginning here? Doesn't make any sense to me.
org.openrdf.sail.lucene.LuceneQueryIterator - There was a problem evaluating
query '*search this*' for property 'null!
org.apache.lucene.queryParser.ParseException: Cannot parse '*search this*':
'*' or '?' not allowed as first character in WildcardQuery
Thanks a lot in advance,
Dennis
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Re: [Neo4j] REST support for neo4j-spatial
Jan, there are a number of things to it. Right now, we are working on exposing some of the spatial functionality via JRuby and the Neo4j ruby bindings in order to make it easy and bloggable, especially regarding OpenStreetMap operation. After that, we are planning 2 things: 1. Look into integration into the Neo4j Index API 2. If integrated as an index, this will automatically be available in the REST API as just one more available index, if you drop the Neo4j-Spatial jars into /plugins. 3. Write some spatial server plugins that can expose more targeted spatial queries, see http://components.neo4j.org/neo4j-examples/1.2-SNAPSHOT/server-plugins.html We hope to have the first index-integration going in January, but don't quote me on that ;) Cheers, /peter neubauer GTalk: neubauer.peter Skype peter.neubauer Phone +46 704 106975 LinkedIn http://www.linkedin.com/in/neubauer Twitter http://twitter.com/peterneubauer http://www.neo4j.org - Your high performance graph database. http://www.thoughtmade.com - Scandinavia's coolest Bring-a-Thing party. On Tue, Dec 21, 2010 at 9:09 PM, Jan Boonen jan.boo...@geodan.nl wrote: I don't know if people have already spoken about this topic on the chat, but if so, could anyone post the outcome of the discussion on REST support for neo4j-spatial? Many thanks, Jan Sounds fine to me. The main idea behind this suggestion is to support concurrent access and the new server component. I can think of many use cases where data is inserted in aa database from any type of client and the result is accessed via e.g. geoserver. Currently we'd use PostGIS for such an architecture, but Neo4j looks very promising for many projects. Anyway, if you need some support in this area, I'm willing to talk about cooperation. Drop me a line if needed. Cheers, Jan On 17-11-2010 18:13, Craig Taverner wrote: Very interesting option. I think I need to chat to the neo4j rest guys tomorrow to find out a little more about what would be required to make this happen. On Wed, Nov 17, 2010 at 5:41 PM, Javier de la Rosaver...@gmail.com wrote: On Wed, Nov 17, 2010 at 10:46, Jan Boonenjan.boo...@geodan.nl wrote: I was wondering if someone is planning to support REST for neo4j-spatial. It would be great for example if we can connect GeoTools to a Neo4j REST server. +1 -- Javier de la Rosa http://versae.es ___ 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
Re: [Neo4j] Problem connecting database
Boris, in the server component, dependency groupIdcom.sun.jersey/groupId artifactIdjersey-server/artifactId version1.4/version /dependency is used. HTH? Cheers, /peter neubauer GTalk: neubauer.peter Skype peter.neubauer Phone +46 704 106975 LinkedIn http://www.linkedin.com/in/neubauer Twitter http://twitter.com/peterneubauer http://www.neo4j.org - Your high performance graph database. http://www.thoughtmade.com - Scandinavia's coolest Bring-a-Thing party. On Wed, Dec 22, 2010 at 2:35 PM, Boris Zielinski boris.zielin...@informatik.hu-berlin.de wrote: Hi all, im new to neo4j and just set up a database on a linux box. This part was easy.DB works testing it with the curl examples. Now i was trying to connect to that database using Java - im using the Create Simple Graph example. I downloaded and imported external jars, jersey client and core. Trying to run the examle script i keep getting the error : java.lang.NoClassDefFoundError: javax/ws/rs/ext/Providers Some google brings out Class Providers is not part of all releases of jersey. so what release do i have to use to get it work - or did i miss something different? Cheers Boris ___ 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
Re: [Neo4j] REST support for neo4j-spatial
Sounds great. Thanks for answering my question and keep up the good work! Jan, there are a number of things to it. Right now, we are working on exposing some of the spatial functionality via JRuby and the Neo4j ruby bindings in order to make it easy and bloggable, especially regarding OpenStreetMap operation. After that, we are planning 2 things: 1. Look into integration into the Neo4j Index API 2. If integrated as an index, this will automatically be available in the REST API as just one more available index, if you drop the Neo4j-Spatial jars into /plugins. 3. Write some spatial server plugins that can expose more targeted spatial queries, see http://components.neo4j.org/neo4j-examples/1.2-SNAPSHOT/server-plugins.html We hope to have the first index-integration going in January, but don't quote me on that ;) Cheers, /peter neubauer GTalk: neubauer.peter Skype peter.neubauer Phone +46 704 106975 LinkedIn http://www.linkedin.com/in/neubauer Twitter http://twitter.com/peterneubauer http://www.neo4j.org - Your high performance graph database. http://www.thoughtmade.com - Scandinavia's coolest Bring-a-Thing party. On Tue, Dec 21, 2010 at 9:09 PM, Jan Boonenjan.boo...@geodan.nl wrote: I don't know if people have already spoken about this topic on the chat, but if so, could anyone post the outcome of the discussion on REST support for neo4j-spatial? Many thanks, Jan Sounds fine to me. The main idea behind this suggestion is to support concurrent access and the new server component. I can think of many use cases where data is inserted in aa database from any type of client and the result is accessed via e.g. geoserver. Currently we'd use PostGIS for such an architecture, but Neo4j looks very promising for many projects. Anyway, if you need some support in this area, I'm willing to talk about cooperation. Drop me a line if needed. Cheers, Jan On 17-11-2010 18:13, Craig Taverner wrote: Very interesting option. I think I need to chat to the neo4j rest guys tomorrow to find out a little more about what would be required to make this happen. On Wed, Nov 17, 2010 at 5:41 PM, Javier de la Rosaver...@gmail.com wrote: On Wed, Nov 17, 2010 at 10:46, Jan Boonenjan.boo...@geodan.nl wrote: I was wondering if someone is planning to support REST for neo4j-spatial. It would be great for example if we can connect GeoTools to a Neo4j REST server. +1 -- Javier de la Rosa http://versae.es ___ 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
Re: [Neo4j] Problem connecting database
Peter, thanks for the quick help. For those who encounter the same problem: i solved it by using jersey client and core 1.5.ea08 jars (may work with 1.4 too). since the jars appear to miss some classes(!), i added the missing classes from source manually.now i works like charm. Cheers Boris Am 22.12.2010 14:59, schrieb Peter Neubauer: Boris, in the server component, dependency groupIdcom.sun.jersey/groupId artifactIdjersey-server/artifactId version1.4/version /dependency is used. HTH? Cheers, /peter neubauer GTalk: neubauer.peter Skype peter.neubauer Phone +46 704 106975 LinkedIn http://www.linkedin.com/in/neubauer Twitter http://twitter.com/peterneubauer http://www.neo4j.org - Your high performance graph database. http://www.thoughtmade.com - Scandinavia's coolest Bring-a-Thing party. On Wed, Dec 22, 2010 at 2:35 PM, Boris Zielinski boris.zielin...@informatik.hu-berlin.de wrote: Hi all, im new to neo4j and just set up a database on a linux box. This part was easy.DB works testing it with the curl examples. Now i was trying to connect to that database using Java - im using the Create Simple Graph example. I downloaded and imported external jars, jersey client and core. Trying to run the examle script i keep getting the error : java.lang.NoClassDefFoundError: javax/ws/rs/ext/Providers Some google brings out Class Providers is not part of all releases of jersey. so what release do i have to use to get it work - or did i miss something different? Cheers Boris ___ 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] Fatty Stack Trace to Lift your Spirits
Hi Neo4jians, So I bumped Blueprints 0 .4-SNAPSHOT to use 1.2M06 and during the test suite evaluation, I was getting fatty stack traces being thrown all up in my face left, right, and yes, center. My random thought on the matter---Luca and I have been having *potentially* similar problems with OrientDB and shutting down, opening, and deleting the DB really fast. Don't know if this is the same issue now showing up in Neo4j? The TestSuite will, in general, create a graph (directory), use it, close it, open it, delete the directory, create a new graph (directory), etc. Is the OS not having happy good time? Why happy good time with 1.2M05? Solve my problem or be destroyed, Marko. Testing testClear... - org.apache.maven.surefire.booter.SurefireBooter.main(SurefireBooter.java:997)java.lang.RuntimeException: org.apache.lucene.store.LockObtainFailedException: Lock obtain timed out: NativeFSLock@/private/tmp/blueprints_test/index/lucene/relationship/edges/write.lock at org.neo4j.index.impl.lucene.LuceneDataSource.getIndexWriter(LuceneDataSource.java:581) at org.neo4j.index.impl.lucene.CommitContext.ensureWriterInstantiated(CommitContext.java:60) at org.neo4j.index.impl.lucene.LuceneCommand$AddRelationshipCommand.perform(LuceneCommand.java:211) at org.neo4j.index.impl.lucene.LuceneTransaction.doCommit(LuceneTransaction.java:231) at org.neo4j.kernel.impl.transaction.xaframework.XaTransaction.commit(XaTransaction.java:319) at org.neo4j.kernel.impl.transaction.xaframework.XaResourceManager.commit(XaResourceManager.java:447) at org.neo4j.kernel.impl.transaction.xaframework.XaResourceHelpImpl.commit(XaResourceHelpImpl.java:65) at org.neo4j.kernel.impl.transaction.TransactionImpl.doCommit(TransactionImpl.java:517) at org.neo4j.kernel.impl.transaction.TxManager.commit(TxManager.java:623) at org.neo4j.kernel.impl.transaction.TxManager.commit(TxManager.java:586) at org.neo4j.kernel.impl.transaction.TransactionImpl.commit(TransactionImpl.java:105) at org.neo4j.kernel.TopLevelTransaction.finish(TopLevelTransaction.java:86) at com.tinkerpop.blueprints.pgm.impls.neo4j.Neo4jGraph.autoStopTransaction(Neo4jGraph.java:331) at com.tinkerpop.blueprints.pgm.impls.neo4j.Neo4jGraph.addEdge(Neo4jGraph.java:216) at com.tinkerpop.blueprints.pgm.GraphTestSuite.testClear(GraphTestSuite.java:48) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:597) at com.tinkerpop.blueprints.pgm.impls.neo4j.Neo4jGraphTest.doTestSuite(Neo4jGraphTest.java:94) at com.tinkerpop.blueprints.pgm.impls.neo4j.Neo4jGraphTest.testGraphTestSuite(Neo4jGraphTest.java:43) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:597) at junit.framework.TestCase.runTest(TestCase.java:168) at junit.framework.TestCase.runBare(TestCase.java:134) at junit.framework.TestResult$1.protect(TestResult.java:110) at junit.framework.TestResult.runProtected(TestResult.java:128) at junit.framework.TestResult.run(TestResult.java:113) at junit.framework.TestCase.run(TestCase.java:124) at junit.framework.TestSuite.runTest(TestSuite.java:232) at junit.framework.TestSuite.run(TestSuite.java:227) at org.junit.internal.runners.JUnit38ClassRunner.run(JUnit38ClassRunner.java:79) at org.apache.maven.surefire.junit4.JUnit4TestSet.execute(JUnit4TestSet.java:62) at org.apache.maven.surefire.suite.AbstractDirectoryTestSuite.executeTestSet(AbstractDirectoryTestSuite.java:140) at org.apache.maven.surefire.suite.AbstractDirectoryTestSuite.execute(AbstractDirectoryTestSuite.java:127) at org.apache.maven.surefire.Surefire.run(Surefire.java:177) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:597) at org.apache.maven.surefire.booter.SurefireBooter.runSuitesInProcess(SurefireBooter.java:338) at org.apache.maven.surefire.booter.SurefireBooter.main(SurefireBooter.java:997) Caused by: org.apache.lucene.store.LockObtainFailedException: Lock obtain timed out:
[Neo4j] I built my metamodel, now what?
I've been looking at the metamodel component and found a few good examples of how to create a metamodel. My question is, once it's created, what can I do with it? Say I create a 'Person' metamodel class with properties like first_name (string), last_name (string), birthday (date), etc. Can I then instantiate an object of the 'Person' class and have the property restictions automatically applied? In other words, can I create a node that is associated with a particular metamodel class and use some generic interface to set properties that enforces the metamodel restrictions? Or is the metamodel component mainly a way to store the metamodel information and it is left up to the programmer to inspect it and enforce the rules defined within it? Thanks, Adam ___ Neo4j mailing list User@lists.neo4j.org https://lists.neo4j.org/mailman/listinfo/user
Re: [Neo4j] New Index API replacing the old one in REST
Hi there, do things work better with the 1.2.M06 milstone? Cheers, /peter neubauer GTalk: neubauer.peter Skype peter.neubauer Phone +46 704 106975 LinkedIn http://www.linkedin.com/in/neubauer Twitter http://twitter.com/peterneubauer http://www.neo4j.org - Your high performance graph database. http://www.thoughtmade.com - Scandinavia's coolest Bring-a-Thing party. On Tue, Dec 21, 2010 at 3:03 AM, J T jt4websi...@googlemail.com wrote: Unfortunately I get an undefined class error when trying to add a node using curl. I'll investigate a bit further tomorrow and replu properly then. On Mon, Dec 20, 2010 at 10:30 PM, Peter Neubauer peter.neuba...@neotechnology.com wrote: Well, just tried the download. That one doesn't even start since there are dependencies missing. Need to check why that is happening tomorrow. But http://buildbox.neo4j.org/hudson/job/neo4j-standalone/ws/trunk/target/neo4j-1.2-SNAPSHOT-unix.tar.gz should work, just tried it. From the beginning, there are not indexes, so oyu can create one (on nodes) with curl -HContent-Type:application/json -X POST -d 'http://localhost:7474/db/data/node/123;' http://localhost:7474/db/data/index/node/my_nodes/foo/bar then, surfing to http://localhost:7474/db/data/index/node should show you the HTML rendering (in Firefox) or the JSON representation of that index. Same for relatoinships. Does that work? Cheers, /peter neubauer GTalk: neubauer.peter Skype peter.neubauer Phone +46 704 106975 LinkedIn http://www.linkedin.com/in/neubauer Twitter http://twitter.com/peterneubauer http://www.neo4j.org - Your high performance graph database. http://www.thoughtmade.com - Scandinavia's coolest Bring-a-Thing party. On Mon, Dec 20, 2010 at 9:57 PM, J T jt4websi...@googlemail.com wrote: Peter, You say the version of the server (with relationship indexes) be available in M06. Is it already available in the snapshot download ? e.g. thsi one: http://neo4j.org/get?file=neo4j-1.2-SNAPSHOT-unix.tar.gz?? I tried earlier but that didnt seem to have any rest index support. JT On Mon, Dec 20, 2010 at 4:48 PM, Peter Neubauer peter.neuba...@neotechnology.com wrote: Javier, look at http://components.neo4j.org/neo4j-server/0.1-SNAPSHOT/rest.html#Listing_node_indexes for the version that will come out now. Pretty similar to the old way except that it supports even relationship indexes. Let us know if you have any questions! Cheers, /peter neubauer GTalk: neubauer.peter Skype peter.neubauer Phone +46 704 106975 LinkedIn http://www.linkedin.com/in/neubauer Twitter http://twitter.com/peterneubauer http://www.neo4j.org - Your high performance graph database. http://www.thoughtmade.com - Scandinavia's coolest Bring-a-Thing party. On Mon, Dec 20, 2010 at 1:03 PM, Peter Neubauer peter.neuba...@neotechnology.com wrote: Javier, we are trying to be compatible with the existing API, but will move it to a location that is future prove (that is, for the more powerful indexing features there will be new URLs added). Will decide on the location after lunch :) Cheers, /peter neubauer GTalk: neubauer.peter Skype peter.neubauer Phone +46 704 106975 LinkedIn http://www.linkedin.com/in/neubauer Twitter http://twitter.com/peterneubauer http://www.neo4j.org - Your high performance graph database. http://www.thoughtmade.com - Scandinavia's coolest Bring-a-Thing party. On Mon, Dec 20, 2010 at 12:21 PM, Javier de la Rosa ver...@gmail.com wrote: On Mon, Dec 20, 2010 at 12:18, Peter Neubauer peter.neuba...@neotechnology.com wrote: Graphytes, the exposure of the new Index on relationships and nodes in the Neo4j REST API will be part of M06, so anyone using the Index in their bindings will need to switch to that API. I am thinking of the PHP, .NET, Ruby and Perl bindings (Max, @onewheelgood, Javier and all others). Great news! Where is the documentation to apply the new changes on the index behaviour? -- Javier de la Rosa http://versae.es ___ 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
[Neo4j] Visualisation tools for Neo4J 1.2?
I'm currently using Neo4J 1.0 because I find Neoclipse useful for exploring my database structure and Neoclipse does not work with version 1.2. But I'd like to take advantage of all the new features. What out-of-the-box options exist for visualising v1.2 databases? --Nat www.natpryce.com ___ Neo4j mailing list User@lists.neo4j.org https://lists.neo4j.org/mailman/listinfo/user
Re: [Neo4j] Visualisation tools for Neo4J 1.2?
Nat, the current trunk NeoClipse version is running against Neo4j 1.2 builds. We are just sorting out the licensing in order to be able to put it as a public download. Hope to solve this first thing after the Holidays. Otherwise, Gephi is coming along with lazy-traveral support (initially just depth-limit, but really great to see it emerging), so that should be an upcoming good option too as it matures. If you need a NeoClipse prebuilt version now, contact me off-list and I will get it to you! Cheers, /peter neubauer GTalk: neubauer.peter Skype peter.neubauer Phone +46 704 106975 LinkedIn http://www.linkedin.com/in/neubauer Twitter http://twitter.com/peterneubauer http://www.neo4j.org - Your high performance graph database. http://www.thoughtmade.com - Scandinavia's coolest Bring-a-Thing party. On Wed, Dec 22, 2010 at 8:27 PM, Nat Pryce nat.pr...@gmail.com wrote: I'm currently using Neo4J 1.0 because I find Neoclipse useful for exploring my database structure and Neoclipse does not work with version 1.2. But I'd like to take advantage of all the new features. What out-of-the-box options exist for visualising v1.2 databases? --Nat www.natpryce.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
Re: [Neo4j] Fatty Stack Trace to Lift your Spirits
On Wed, Dec 22, 2010 at 6:11 PM, Marko Rodriguez okramma...@gmail.com wrote: So I bumped Blueprints 0 .4-SNAPSHOT to use 1.2M06 and during the test suite evaluation, I was getting fatty stack traces being thrown all up in my face left, right, and yes, center. As long as they are not coming from below, there is no reason for alarm. However... My random thought on the matter---Luca and I have been having *potentially* similar problems with OrientDB and shutting down, opening, and deleting the DB really fast. Don't know if this is the same issue now showing up in Neo4j? The TestSuite will, in general, create a graph (directory), use it, close it, open it, delete the directory, create a new graph (directory), etc. Is the OS not having happy good time? Why happy good time with 1.2M05? I slapped up a loop doing pretty much that - create a db, store+index a few things, close, [open, read, close] (in a loop), delete, do over, for around 50 iterations. Using straight up (no tinkerpop stack) vanilla 1.2M06 on Ubuntu 10.10. No problems so far. I will leave it to run for a while, to teach my HDD some manners and I will check it again later. That lock file left behind, however, smells like crash/improper shutdown (or overlapping instances?). That really fast open/shutdown cycle you speak of, how do you do it, shell script or from main()? Does the problem appear in every cycle or intermittently? cheers, CG ___ Neo4j mailing list User@lists.neo4j.org https://lists.neo4j.org/mailman/listinfo/user
Re: [Neo4j] Fatty Stack Trace to Lift your Spirits
Mattias, could this be related to the Index locking optimizations you have been doing? Cheers, /peter neubauer GTalk: neubauer.peter Skype peter.neubauer Phone +46 704 106975 LinkedIn http://www.linkedin.com/in/neubauer Twitter http://twitter.com/peterneubauer http://www.neo4j.org - Your high performance graph database. http://www.thoughtmade.com - Scandinavia's coolest Bring-a-Thing party. On Wed, Dec 22, 2010 at 5:11 PM, Marko Rodriguez okramma...@gmail.com wrote: Hi Neo4jians, So I bumped Blueprints 0 .4-SNAPSHOT to use 1.2M06 and during the test suite evaluation, I was getting fatty stack traces being thrown all up in my face left, right, and yes, center. My random thought on the matter---Luca and I have been having *potentially* similar problems with OrientDB and shutting down, opening, and deleting the DB really fast. Don't know if this is the same issue now showing up in Neo4j? The TestSuite will, in general, create a graph (directory), use it, close it, open it, delete the directory, create a new graph (directory), etc. Is the OS not having happy good time? Why happy good time with 1.2M05? Solve my problem or be destroyed, Marko. Testing testClear... - org.apache.maven.surefire.booter.SurefireBooter.main(SurefireBooter.java:997)java.lang.RuntimeException: org.apache.lucene.store.LockObtainFailedException: Lock obtain timed out: NativeFSLock@/private/tmp/blueprints_test/index/lucene/relationship/edges/write.lock at org.neo4j.index.impl.lucene.LuceneDataSource.getIndexWriter(LuceneDataSource.java:581) at org.neo4j.index.impl.lucene.CommitContext.ensureWriterInstantiated(CommitContext.java:60) at org.neo4j.index.impl.lucene.LuceneCommand$AddRelationshipCommand.perform(LuceneCommand.java:211) at org.neo4j.index.impl.lucene.LuceneTransaction.doCommit(LuceneTransaction.java:231) at org.neo4j.kernel.impl.transaction.xaframework.XaTransaction.commit(XaTransaction.java:319) at org.neo4j.kernel.impl.transaction.xaframework.XaResourceManager.commit(XaResourceManager.java:447) at org.neo4j.kernel.impl.transaction.xaframework.XaResourceHelpImpl.commit(XaResourceHelpImpl.java:65) at org.neo4j.kernel.impl.transaction.TransactionImpl.doCommit(TransactionImpl.java:517) at org.neo4j.kernel.impl.transaction.TxManager.commit(TxManager.java:623) at org.neo4j.kernel.impl.transaction.TxManager.commit(TxManager.java:586) at org.neo4j.kernel.impl.transaction.TransactionImpl.commit(TransactionImpl.java:105) at org.neo4j.kernel.TopLevelTransaction.finish(TopLevelTransaction.java:86) at com.tinkerpop.blueprints.pgm.impls.neo4j.Neo4jGraph.autoStopTransaction(Neo4jGraph.java:331) at com.tinkerpop.blueprints.pgm.impls.neo4j.Neo4jGraph.addEdge(Neo4jGraph.java:216) at com.tinkerpop.blueprints.pgm.GraphTestSuite.testClear(GraphTestSuite.java:48) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:597) at com.tinkerpop.blueprints.pgm.impls.neo4j.Neo4jGraphTest.doTestSuite(Neo4jGraphTest.java:94) at com.tinkerpop.blueprints.pgm.impls.neo4j.Neo4jGraphTest.testGraphTestSuite(Neo4jGraphTest.java:43) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:597) at junit.framework.TestCase.runTest(TestCase.java:168) at junit.framework.TestCase.runBare(TestCase.java:134) at junit.framework.TestResult$1.protect(TestResult.java:110) at junit.framework.TestResult.runProtected(TestResult.java:128) at junit.framework.TestResult.run(TestResult.java:113) at junit.framework.TestCase.run(TestCase.java:124) at junit.framework.TestSuite.runTest(TestSuite.java:232) at junit.framework.TestSuite.run(TestSuite.java:227) at org.junit.internal.runners.JUnit38ClassRunner.run(JUnit38ClassRunner.java:79) at org.apache.maven.surefire.junit4.JUnit4TestSet.execute(JUnit4TestSet.java:62) at org.apache.maven.surefire.suite.AbstractDirectoryTestSuite.executeTestSet(AbstractDirectoryTestSuite.java:140) at org.apache.maven.surefire.suite.AbstractDirectoryTestSuite.execute(AbstractDirectoryTestSuite.java:127) at org.apache.maven.surefire.Surefire.run(Surefire.java:177) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
Re: [Neo4j] I built my metamodel, now what?
The metamodel component only allows you to store meta information about the entities in the database and offers no further functionality, except for importing rdfs data. To use the metamodel component in an application to do constraint verification, you will have to write the logic yourself, although this quite a straight forward exercise. For my own projects I use a wrapper around Node and Relationship to make them metamodel aware, and don't use the standard API for node and relationship in any other parts of the software than in this wrapper. The current metamodel component as a modelling tool has a few shortcomings I ended up addressing in my own projects: * It's not possible to model metaobjects (including namespaces)* It's not possible to model the referencenode* The metaobjects don't allow the modelling of graph layout (ie. dense versus bipartite layout). When using a bipartite layout, extra options become available: Relationships and Properties can have Relationships and Properties. It is not possible to directly model that in the current metamodel component. Niels Date: Wed, 22 Dec 2010 11:45:37 -0700 From: amend...@gmail.com To: user@lists.neo4j.org Subject: [Neo4j] I built my metamodel, now what? I've been looking at the metamodel component and found a few good examples of how to create a metamodel. My question is, once it's created, what can I do with it? Say I create a 'Person' metamodel class with properties like first_name (string), last_name (string), birthday (date), etc. Can I then instantiate an object of the 'Person' class and have the property restictions automatically applied? In other words, can I create a node that is associated with a particular metamodel class and use some generic interface to set properties that enforces the metamodel restrictions? Or is the metamodel component mainly a way to store the metamodel information and it is left up to the programmer to inspect it and enforce the rules defined within it? Thanks, Adam ___ 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
Re: [Neo4j] Transaction and REST API
Well, as you said there are number of ways to do it. This post describe a way to do ithttp://jcalcote.wordpress.com/2009/08/06/restful-transactions/, but it's not the post that is the main issue but the comments below it. There is still no consensus about what is the RESTful way of doing tx in RESTful web service. For sure POST a tx start url and POST for commit (while holding a real database tx) is not a good solution for me. It's not scalable and will block users from even READ depend on my isolation level in the database. I guess it all comes down to how specific my RESTful interface. In my example the current need for tx is to create or delete both node and link, then I might as well create a resource that handle it and work with it. The problem off course is that later on (sooner then I think) I will need to create two links in one tx, and then I will need a new resource for two links and so on. BULK resource are not so likable on RESTful people, but I guess it can work really well for my case. I'll create a BULK change resource, fill it with the changes I want to do and finally change it state to commit which will then and only then start a DB tx, do the changes (maybe check ETag to make sure nothing change in between) and finally commit the tx. That's what I'm thinking about it. Ido On Mon, Dec 20, 2010 at 9:42 PM, Christopher Schmidt fakod...@googlemail.com wrote: I written a couple of REST services and clients over the past years and it is always a subject of discussions: How to map transactions with a stateless RESTful service? We always did it like Neo4j, every REST call is a implicit transaction. If this is not sufficient we implemented BULK or combined calls for bulk deletions or creations etc. But the question is: Is it really impossible to implement transactions? We can use - the session context with invalidating a session or timeout is a rollback (this will be expensive...) - or POSTing a new transaction returning a Trx ID, subsequent write or update operations are containing a transaction ID - using custom HTTP header - (whatever) All this violates the stateless paradigm. But the reality of the Web is: we do have HTTP sessions, cookies, baskets etc. And scalability is a question of server implementation, isn't it? What do you think? On Mon, Dec 20, 2010 at 12:28 PM, Jim Webber j...@neotechnology.com wrote: Hi Ido, Those make good sense. And I think I have some reasonable RESTful approaches in mind for tackling them which don't need transactions (using Ian Robinson's typed links to forms approach here). 1. Bulk create of nodes and relations: - PUT a set of nodes and relations to the server, relative to some node, or to the graph itself. - Work needed: define a graph format (e.g. using JSON) to describe nodes and relations. 2. Remove relations: - GET a removal form (optional, will be cacheable for a long time anyway) - Populate the removal form with the nodes to be deleted, POST it to the server - Server responds with the URI of a (transient) resource that represents all the nodes and relations you previously specified. - DELETE the transient resource - Work needed: design a removal form (effectively a deletion manifest), a little processing logic on the server side 3. Clone subgraphs - Use a form to select a start node, terminating condition (e.g. depth), POST its URI to the cloning URI with a traversal description (or just something as simple as a termination condition for a df/bf search) which itself is created by filling in a form. - Work needed: a clone algorithm for the server; form that allows us to describe the graph for the clone; URI to POST back the form to the graph. OK, so there's some substantial work to be done here. But there's a positive point to take away from this. In the latest milestone release we have a Plugin mechanism where end users are able to extend the behaviour of graphs/nodes in order to implement all these kinds of domain specific things. Right now as we're testing the new Plugin stuff, I'm going to implement a simple clone subgraph plugin. I'll post the code and the wire-level HTTP here when I'm done so you can see how you might implement similar stuff for your domain (the code will also be in SVN under examples/server-extension). Jim PS - It occurs to me though, that if 3rd party plugins become very popular, we could over time bring them into core and take some responsibility for them. Perhaps. ___ Neo4j mailing list User@lists.neo4j.org https://lists.neo4j.org/mailman/listinfo/user -- Christopher twitter: @fakod blog: http://blog.fakod.eu ___ Neo4j mailing list User@lists.neo4j.org https://lists.neo4j.org/mailman/listinfo/user ___ Neo4j mailing list
