Re: [Neo4j] How to query based on properties
Since your values are discrete, Davids solution would be a good one. Connecting each node to a node representing the value of the property. So if each node has 5 properties (in your example below), there would be five relationships to value nodes, each of which would in turn be related to their property node. student --IN_YEAR-- '2nd year' -- VALUE -- years This is like having a bunch of category indexes that you can use to find all students with a particular property/value pair. But for your combined property/value search, I think you would still end up traversing through quite a lot of the graph to get your answer. So there is an elaboration on this which takes it one step further. Create nodes that represent the combinations of values. If you have 10 properties, each with on average 5 possible values, you have a maximum of 5^10 theoretically possible values. The real maximum number of combinations will also never be more than the number of students. If it does reach the number of students, there are no students in common, so that is unlikely. If each student is connected instead to one of these nodes, then finding students in common is a trivial depth 2 traversal. However, the complexity is now moved to the step for creating the graph. As you load students into the graph, you need a fast way to see if that students combination of properties and values already exists, and if so, link it, and if not, create it and link it. There are two solutions to this: - make a hash of all the values and index that in lucene, so you can find it later - use the amanz-index https://github.com/craigtaverner/amanzi-index(still in progress). This is a pure tree index that builds basically the same structure I described above. The lucene approach is better known, since Neo4j has had lucene for years. My index is still a prototype. On Thu, Feb 24, 2011 at 8:54 AM, agam...@gmail.com wrote: Hi David I was thinking on these lines my self, but was unable to formulate it. I think Ill elaborate on the actual problem as you've suggested. There are a number of college students who I have gathered various information about, example: 1. What their major is (4 options) 2. What year they are in (4 options) 3. Favourite genre of music and movies (4 options each) 4. A few yes/no questions 5. I have a list of who's friends with who in this sample Now I want to see the people belonging to Person A's most populated common property set. Assuming that number is 5properties out of 10, I next want to see for 4 properties (which may be different, but obviously for the same5-1 as well). I hope this makes it clearer. Thanks! Sent on my BlackBerry® from Vodafone -Original Message- From: David Montag david.mon...@neotechnology.com Sender: user-boun...@lists.neo4j.org Date: Wed, 23 Feb 2011 23:30:11 To: Neo4j user discussionsuser@lists.neo4j.org Reply-To: Neo4j user discussions user@lists.neo4j.org Subject: Re: [Neo4j] How to query based on properties Agam, Depending on the set of possible values, you could represent the properties with relationships instead. A unique property value can then be represented by a node, which would be linked to all nodes that have that value. The relationship type could indicate the property. The value nodes would then be indexed so that you can find the right node when setting the property (i.e. creating a relationship to the value node). Also, it would be great if you could elaborate a bit more on the actual use case behind this algorithm. That way, a more suitable solution might emerge, solving your problem in a different way. Thanks, David On Wed, Feb 23, 2011 at 10:36 PM, Agam Dua agam...@gmail.com wrote: Hey I'm a graph database and Neo4j newbie and I'm in a bit of a fix: *Problem Description* Let's say I have 'n' nodes in the graph, representing the same type of object. They have certain undirected links between them. Now each of these 'n' nodes has the same 10 properties, the *values* of which may differ. *Problem Statement* Take starting node A. I need to find a way to traverse all the nodes of the graph and print out which nodes have the most properties in common with A. For example, if A, C, D, E, F, G have 'x' properties in common I want to print the nodes. Then, I want to print the nodes which have 'x-1' properties with the same value. Then 'x-2', and so on. *Question* Now my question is, is this possible? If so, what would be the best way to go about it? Thanks in advance! Agam. * * ___ Neo4j mailing list User@lists.neo4j.org https://lists.neo4j.org/mailman/listinfo/user -- David Montag Neo Technology, www.neotechnology.com Cell: 650.556.4411 david.mon...@neotechnology.com ___ Neo4j mailing list User@lists.neo4j.org https://lists.neo4j.org/mailman/listinfo/user
Re: [Neo4j] [Blog Post] Using graph databases for knowledge representation and reasoning.
Great post. Despite that the examples you give can be replicated with rdf and spraql (forget owl). One might argue that OWL is a good example of over-engineering, as in practice only the owl:sameAs is used :-) But I think the real power of gremlin is within the grateful dead and spreading activation example. This is a radically different way that can be also used for reasoning and inference. I mean that example really has to get more publicity as its something completely different and useful :-) Afredas On Thu, Feb 24, 2011 at 8:05 AM, Peter Neubauer peter.neuba...@neotechnology.com wrote: Very nice post Marko, clean and to the point! 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://startupbootcamp.org/ - Öresund - Innovation happens HERE. http://www.thoughtmade.com - Scandinavia's coolest Bring-a-Thing party. On Thu, Feb 24, 2011 at 12:27 AM, Marko Rodriguez okramma...@gmail.com wrote: Hi, I wrote a blog post regarding knowledge representation and reasoning using graph databases: http://markorodriguez.com/2011/02/23/knowledge-representation-and-reasoning-with-graph-databases/ Automated reasoning is currently dominated by RDF and its stack of technologies. However, the standard meta modeling language OWL is restricted to description logics. While this is all fine and good, it must be said that there are numerous types of logics. I think that because graph databases don't have a such strict layered cake, the graph database scene is ripe to be a foundation for the exploration and exploitation of other reasoning structures and algorithms. Thats that, Marko. http://markorodriguez.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 ___ Neo4j mailing list User@lists.neo4j.org https://lists.neo4j.org/mailman/listinfo/user
Re: [Neo4j] Maven clean install error The source must not be a directory
Brendan, no this is not the cause but recovery tests that on purpose crash the recovery process. Could you try to exclude the tests with mvn clean install -Dmaven.test.skip=true And tell me if how/that works? Also, notice the git.cmd setting for windows in https://github.com/neo4j/graphdb/blob/master/kernel/pom.xml#L127 to make sure the Neo4j version is properly resolved. I am going to spend more cycles at getting windows builds to behave right next week. Many of these are due to messages.log not being closed properly on shutdown on Windows. 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://startupbootcamp.org/ - Öresund - Innovation happens HERE. http://www.thoughtmade.com - Scandinavia's coolest Bring-a-Thing party. On Thu, Feb 24, 2011 at 8:25 AM, Brendan Cheng ccp...@gmail.com wrote: With MVN clean install, there are more errors. I attached the log file. I notice some tests fail because of hard coded directory reference as 24-Feb-2011 15:20:55 org.neo4j.kernel.impl.transaction.xaframework.XaLogicalLog doInternalRecovery INFO: Non clean shutdown detected on log [target/var/xatest\nioneo_logical.log.1]. Recovery started ... is this the problem? On 24 February 2011 15:00, Peter Neubauer peter.neuba...@neotechnology.com wrote: Brendan, I saw something similar on Windows,I don't remember what was the cause, but could you run mvn clean install in order to make sure things are cleaned up properly? 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://startupbootcamp.org/ - Öresund - Innovation happens HERE. http://www.thoughtmade.com - Scandinavia's coolest Bring-a-Thing party. On Thu, Feb 24, 2011 at 6:03 AM, Brendan Cheng ccp...@gmail.com wrote: Hi, I tried to build from the source code with Maven but failed with The source must not be a directory. I did some search on internet found this is a unresolved bug. I wonder how do you overcome it? Cheers, Brendan --- maven-dependency-plugin:2.1:unpack-dependencies (get-sources) @ neo4j --- Unpacking C:\neo4j\com\target\classes to C:\neo4j\neo4j\target\sources with includes null and excludes:null org.codehaus.plexus.archiver.ArchiverException: The source must not be a directory. at org.codehaus.plexus.archiver.AbstractUnArchiver.validate(AbstractUnArchiver.java:174) at org.codehaus.plexus.archiver.AbstractUnArchiver.extract(AbstractUnArchiver.java:107) at org.apache.maven.plugin.dependency.AbstractDependencyMojo.unpack(AbstractDependencyMojo.java:260) at org.apache.maven.plugin.dependency.UnpackDependenciesMojo.execute(UnpackDependenciesMojo.java:90) at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo(DefaultBuildPluginManager.java:107) at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:209) at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:153) at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:145) at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:84) at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:59) at org.apache.maven.lifecycle.internal.LifecycleStarter.singleThreadedBuild(LifecycleStarter.java:183) at org.apache.maven.lifecycle.internal.LifecycleStarter.execute(LifecycleStarter.java:161) at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:319) at org.apache.maven.DefaultMaven.execute(DefaultMaven.java:156) at org.apache.maven.cli.MavenCli.execute(MavenCli.java:534) at org.apache.maven.cli.MavenCli.doMain(MavenCli.java:196) at org.apache.maven.cli.MavenCli.main(MavenCli.java:141) 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.codehaus.plexus.classworlds.launcher.Launcher.launchEnhanced(Launcher.java:290) at org.codehaus.plexus.classworlds.launcher.Launcher.launch(Launcher.java:230) at org.codehaus.plexus.classworlds.launcher.Launcher.mainWithExitCode(Launcher.java:409) at org.codehaus.plexus.classworlds.launcher.Launcher.main(Launcher.java:352)
Re: [Neo4j] Cache sharding blog post
It would be nice to put this discussion in the blog comments too, so that outside people can benefit from that? Cheers Michael Am 24.02.2011 um 11:23 schrieb Jim Webber: Hi Mark, A nice clear post. The choice of Router is obviously key. For the given routing examples based on user or geo it should be possible to map a request to a server. For many other situations it may prove much harder to determine which server has a warm cache because there is no user and there is no overarching idea of locality that you have with the geo example to organise the graph into logical shards? Are you not left with the partitioning problem in these cases? Yeah you're right of course, if there's no natural key to establish a good route then you're sunk. You might as well go with sticky sessions. I think this approach is a valid interim pattern for domains where there is a natural key for routing. For those domains which exhibit random access to data, then it's not going to be very beneficial. But then I don't believe graph sharding will be helpful either - that's just about where to host graph nodes. Random behaviour means you'll normally pick the wrong place to host the node, and then some kind of consistency/replication protocol kicks in to redress that wrong choice. But in answering this, I wonder if there are actually two use cases here: 1. Speed - addressed by hitting caches, whether through routing or careful placement of nodes on db instances. 2. Size - for datasets way past machine limits (petabytes, exabytes), we just can't replicate the whole dataset on each machine because it's impractical. For (1) I think routing is fine and equivalent to, though simpler than, sharding. For (2) routing is a smaller part of the picture (Bloom filters to get requests routed to a hot replica is about is interesting), but sharding (the unsolved research problem) is super important. 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
Re: [Neo4j] Cache sharding blog post
Hi! I just added a reference to this thread as a comment on the blog post. /anders ___ Neo4j mailing list User@lists.neo4j.org https://lists.neo4j.org/mailman/listinfo/user
[Neo4j] Help with IndexWriter ramBufferSize exception
Hi all, I just got this exception: ramBufferSize 3584.0 is too large; should be comfortably less than 2048 SEVERE: org.apache.lucene.index.IndexWriter.setRAMBufferSizeMB(IndexWriter.java:1368) SEVERE: org.neo4j.index.impl.lucene.LuceneBatchInserterIndex.instantiateWriter(LuceneBatchInserterIndex.java:209) SEVERE: org.neo4j.index.impl.lucene.LuceneBatchInserterIndex.init(LuceneBatchInserterIndex.java:66) SEVERE: org.neo4j.index.impl.lucene.LuceneBatchInserterIndexProvider.index(LuceneBatchInserterIndexProvider.java:135) SEVERE: org.neo4j.index.impl.lucene.LuceneBatchInserterIndexProvider.nodeIndex(LuceneBatchInserterIndexProvider.java:102) SEVERE: com.era7.bioinfo.bio4j.programs.ImportGeneOntology.main(ImportGeneOntology.java:107) SEVERE: com.era7.bioinfo.bio4j.programs.ImportGeneOntology.execute(ImportGeneOntology.java:75) SEVERE: com.era7.lib.bioinfo.bioinfoutil.ExecuteFromFile.main(ExecuteFromFile.java:66) SEVERE: com.era7.bioinfo.bio4j.programs.CreateWholeBio4j.main(CreateWholeBio4j.java:28) when launching my Batch insertion program once I had updated the indexation to the new API any ideas about what should I do? I'm launching the program in a 68GB RAM machine with the following batchInserter.properties: neostore.nodestore.db.mapped_memory=10G neostore.relationshipstore.db.mapped_memory=12G neostore.propertystore.db.mapped_memory=12G neostore.propertystore.db.strings.mapped_memory=10G neostore.propertystore.db.arrays.mapped_memory=512M I don't know how or where to change that ramBufferSize' value, which by the way didn't specified at any point. Thanks in advance, Pablo -- Pablo Pareja Tobes LinkedInhttp://www.linkedin.com/in/pabloparejatobes Twitter http://www.twitter.com/pablopareja http://about.me/pablopareja http://www.ohnosequences.com ___ Neo4j mailing list User@lists.neo4j.org https://lists.neo4j.org/mailman/listinfo/user
[Neo4j] New Batch Inserter Index
Hi, I have found a surprising behavior in the BatchInserterIndex in the new 1.3 series. If I want to index a non-string: // Index node MapString, Object props = new HashMapString, Object(); props.put( key, 123L ); index.add( id, props ); index.flush(); // Search for node IndexHitsNode result = index.get(key, 123L); //result.size() = 0 The above code always returns an empty result set. But if instead we add the value as a string, but still search for an integer, we get a result. // Index node MapString, Object props = new HashMapString, Object(); props.put( key, Long.toString(123L) ); index.add( id, props ); index.flush(); // Search for node IndexHitsNode result = index.get(key, 123L); //result.size() = 1 This seems rather surprising to me. I would not have been surprised if the opposite was true, but this way round was unexpected. Is this correct behavior? And if so, why? Regards, Craig ___ Neo4j mailing list User@lists.neo4j.org https://lists.neo4j.org/mailman/listinfo/user
[Neo4j] Exception in indexer framework when commiting transaction
Hi, after transition to the new indexer framework, I tried to rebuild the index on a small test database with 11,000 nodes. It failed with the following exception: java.lang.IllegalArgumentException: name and value cannot both be empty at org.apache.lucene.document.Field.init(Field.java:398) at org.apache.lucene.document.Field.init(Field.java:371) at org.apache.lucene.document.Field.init(Field.java:350) at org.neo4j.index.impl.lucene.IndexType.instantiateField(IndexType.java:331) at org.neo4j.index.impl.lucene.IndexType$CustomType.addToDocument(IndexType.java:159) at org.neo4j.index.impl.lucene.LuceneCommand$AddCommand.perform(LuceneCommand.java:187) 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) Thu Feb 24 14:21:56 CET 2011: --- CONFIGURATION START --- Thu Feb 24 14:21:56 CET 2011: Physical mem: 7999MB, Heap size: 5333MB Thu Feb 24 14:21:56 CET 2011: Kernel version: Neo4j - Graph Database Kernel 1.2-SNAPSHOT (revision: 8112) Thu Feb 24 14:21:56 CET 2011: Operating System: Linux; version: 2.6.35-25-generic; arch: amd64; cpus: 8 Thu Feb 24 14:21:56 CET 2011: VM Name: OpenJDK 64-Bit Server VM Thu Feb 24 14:21:56 CET 2011: VM Vendor: Sun Microsystems Inc. Thu Feb 24 14:21:56 CET 2011: VM Version: 19.0-b09 I made sure that I only add non-null values to the index. Does anyone have an idea what's going wrong? Greetings Axel ___ Neo4j mailing list User@lists.neo4j.org https://lists.neo4j.org/mailman/listinfo/user
Re: [Neo4j] New Batch Inserter Index
It's not expected behaviour, it's a bug in the batch inserting code which I introduced when meddling with ValueContext.numeric behaviour. I'm planning to get rid of that ValueContext thing and instead, when indexing a number, index that in lucene as a string (just as usual) _and_ numerically (for optimized/cool number range queries). Hopefully next milestone. But for now I'll fix this bug. 2011/2/24 Craig Taverner cr...@amanzi.com: Hi, I have found a surprising behavior in the BatchInserterIndex in the new 1.3 series. If I want to index a non-string: // Index node MapString, Object props = new HashMapString, Object(); props.put( key, 123L ); index.add( id, props ); index.flush(); // Search for node IndexHitsNode result = index.get(key, 123L); //result.size() = 0 The above code always returns an empty result set. But if instead we add the value as a string, but still search for an integer, we get a result. // Index node MapString, Object props = new HashMapString, Object(); props.put( key, Long.toString(123L) ); index.add( id, props ); index.flush(); // Search for node IndexHitsNode result = index.get(key, 123L); //result.size() = 1 This seems rather surprising to me. I would not have been surprised if the opposite was true, but this way round was unexpected. Is this correct behavior? And if so, why? Regards, Craig ___ 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
Re: [Neo4j] Cache sharding blog post
But in answering this, I wonder if there are actually two use cases here Yes, I see the use cases as the design decision points you are forced to make at varying points in the scale of increasing data volumes: 1) 0-10s of gigabytes: Slam in the RAM on a single server and all is plain sailing 2) Hundreds of Gigabytes Too big to hold all in RAM on a single server but not too big to worry about the cost of replicating the data on disk. Use the suggested intelligent cache router to favour replica servers with a likelihood of a pre-warmed cache for the given keys. The cost of a cache miss is not too catastrophic ( a local disk read vs RAM access) 3) Terabytes and above Too big for RAM, too big to store or replicate in its entirety on each server. The cost of not finding what you are after in RAM is then potentially very large - not just a local disk read but due to sharding potentially a network hop and related issues of the traversal state must now be exchanged between server processes. Cheers Mark ___ Neo4j mailing list User@lists.neo4j.org https://lists.neo4j.org/mailman/listinfo/user
Re: [Neo4j] New Batch Inserter Index
Thanks, I'll leave my Long.toString(123) workaround in place for now. Let me know when the bug is fixed, and I can slightly simplify my code again :-) On Thu, Feb 24, 2011 at 3:02 PM, Mattias Persson matt...@neotechnology.comwrote: It's not expected behaviour, it's a bug in the batch inserting code which I introduced when meddling with ValueContext.numeric behaviour. I'm planning to get rid of that ValueContext thing and instead, when indexing a number, index that in lucene as a string (just as usual) _and_ numerically (for optimized/cool number range queries). Hopefully next milestone. But for now I'll fix this bug. 2011/2/24 Craig Taverner cr...@amanzi.com: Hi, I have found a surprising behavior in the BatchInserterIndex in the new 1.3 series. If I want to index a non-string: // Index node MapString, Object props = new HashMapString, Object(); props.put( key, 123L ); index.add( id, props ); index.flush(); // Search for node IndexHitsNode result = index.get(key, 123L); //result.size() = 0 The above code always returns an empty result set. But if instead we add the value as a string, but still search for an integer, we get a result. // Index node MapString, Object props = new HashMapString, Object(); props.put( key, Long.toString(123L) ); index.add( id, props ); index.flush(); // Search for node IndexHitsNode result = index.get(key, 123L); //result.size() = 1 This seems rather surprising to me. I would not have been surprised if the opposite was true, but this way round was unexpected. Is this correct behavior? And if so, why? Regards, Craig ___ 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
Re: [Neo4j] Help with IndexWriter ramBufferSize exception
There's this hardcoded setting for batch inserter indexes that increases the ram buffer size to increase overall performance during batch insertion. The formula is: double atLeast = writer.getRAMBufferSizeMB(); double heapHint = (double)(Runtime.getRuntime().maxMemory()/(1024*1024*16)); double ramBufferSize = Math.max( atLeast, heapHint ); writer.getRAMBufferSizeMB( ramBufferSize ); It's just something which I ballparked and obviously has problems for heaps of your size. It's a tough one to fix in your case since you cannot parameterize that calculation. The only way would be to modify source code and build a new jar, or wait for it to be fixed (maybe by limiting the max amount to 2Gb as Lucene seem to suggest). Hopefully it can be addressed soon. 2011/2/24 Pablo Pareja ppar...@era7.com: Hi all, I just got this exception: ramBufferSize 3584.0 is too large; should be comfortably less than 2048 SEVERE: org.apache.lucene.index.IndexWriter.setRAMBufferSizeMB(IndexWriter.java:1368) SEVERE: org.neo4j.index.impl.lucene.LuceneBatchInserterIndex.instantiateWriter(LuceneBatchInserterIndex.java:209) SEVERE: org.neo4j.index.impl.lucene.LuceneBatchInserterIndex.init(LuceneBatchInserterIndex.java:66) SEVERE: org.neo4j.index.impl.lucene.LuceneBatchInserterIndexProvider.index(LuceneBatchInserterIndexProvider.java:135) SEVERE: org.neo4j.index.impl.lucene.LuceneBatchInserterIndexProvider.nodeIndex(LuceneBatchInserterIndexProvider.java:102) SEVERE: com.era7.bioinfo.bio4j.programs.ImportGeneOntology.main(ImportGeneOntology.java:107) SEVERE: com.era7.bioinfo.bio4j.programs.ImportGeneOntology.execute(ImportGeneOntology.java:75) SEVERE: com.era7.lib.bioinfo.bioinfoutil.ExecuteFromFile.main(ExecuteFromFile.java:66) SEVERE: com.era7.bioinfo.bio4j.programs.CreateWholeBio4j.main(CreateWholeBio4j.java:28) when launching my Batch insertion program once I had updated the indexation to the new API any ideas about what should I do? I'm launching the program in a 68GB RAM machine with the following batchInserter.properties: neostore.nodestore.db.mapped_memory=10G neostore.relationshipstore.db.mapped_memory=12G neostore.propertystore.db.mapped_memory=12G neostore.propertystore.db.strings.mapped_memory=10G neostore.propertystore.db.arrays.mapped_memory=512M I don't know how or where to change that ramBufferSize' value, which by the way didn't specified at any point. Thanks in advance, Pablo -- Pablo Pareja Tobes LinkedIn http://www.linkedin.com/in/pabloparejatobes Twitter http://www.twitter.com/pablopareja http://about.me/pablopareja http://www.ohnosequences.com ___ 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
Re: [Neo4j] Cache sharding blog post
Hey Mark, That's a really fantastic and useful design metric. Can paraphrase it a bit and write it up on the Neo4j blog/my blog? I'll credit my source, naturally :-) Jim On 24 Feb 2011, at 14:08, Mark Harwood wrote: But in answering this, I wonder if there are actually two use cases here Yes, I see the use cases as the design decision points you are forced to make at varying points in the scale of increasing data volumes: 1) 0-10s of gigabytes: Slam in the RAM on a single server and all is plain sailing 2) Hundreds of Gigabytes Too big to hold all in RAM on a single server but not too big to worry about the cost of replicating the data on disk. Use the suggested intelligent cache router to favour replica servers with a likelihood of a pre-warmed cache for the given keys. The cost of a cache miss is not too catastrophic ( a local disk read vs RAM access) 3) Terabytes and above Too big for RAM, too big to store or replicate in its entirety on each server. The cost of not finding what you are after in RAM is then potentially very large - not just a local disk read but due to sharding potentially a network hop and related issues of the traversal state must now be exchanged between server processes. Cheers Mark ___ 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] Exception in indexer framework when commiting transaction
Use the source, Luke. Consulting the lucene source I see that you're trying to add something where both key and value are empty. Not null, but empty strings that is. You should have checks for that as well in your code. 2011/2/24 Axel Morgner a...@morgner.de: Hi, after transition to the new indexer framework, I tried to rebuild the index on a small test database with 11,000 nodes. It failed with the following exception: java.lang.IllegalArgumentException: name and value cannot both be empty at org.apache.lucene.document.Field.init(Field.java:398) at org.apache.lucene.document.Field.init(Field.java:371) at org.apache.lucene.document.Field.init(Field.java:350) at org.neo4j.index.impl.lucene.IndexType.instantiateField(IndexType.java:331) at org.neo4j.index.impl.lucene.IndexType$CustomType.addToDocument(IndexType.java:159) at org.neo4j.index.impl.lucene.LuceneCommand$AddCommand.perform(LuceneCommand.java:187) 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) Thu Feb 24 14:21:56 CET 2011: --- CONFIGURATION START --- Thu Feb 24 14:21:56 CET 2011: Physical mem: 7999MB, Heap size: 5333MB Thu Feb 24 14:21:56 CET 2011: Kernel version: Neo4j - Graph Database Kernel 1.2-SNAPSHOT (revision: 8112) Thu Feb 24 14:21:56 CET 2011: Operating System: Linux; version: 2.6.35-25-generic; arch: amd64; cpus: 8 Thu Feb 24 14:21:56 CET 2011: VM Name: OpenJDK 64-Bit Server VM Thu Feb 24 14:21:56 CET 2011: VM Vendor: Sun Microsystems Inc. Thu Feb 24 14:21:56 CET 2011: VM Version: 19.0-b09 I made sure that I only add non-null values to the index. Does anyone have an idea what's going wrong? Greetings Axel ___ 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
Re: [Neo4j] Help with IndexWriter ramBufferSize exception
Hi Mattias, I guess that my only option would then be limiting the max amount to 2GB as you say, however this will make the insertion phase way longer than what I expected and counted on. Just to confirm, am I then supposed to launch my java process with at most -Xmx2G ?? I really think this is an important flaw to work on. I look forward to seeing it fixed in the near future. Cheers, Pablo On Thu, Feb 24, 2011 at 3:19 PM, Mattias Persson matt...@neotechnology.comwrote: There's this hardcoded setting for batch inserter indexes that increases the ram buffer size to increase overall performance during batch insertion. The formula is: double atLeast = writer.getRAMBufferSizeMB(); double heapHint = (double)(Runtime.getRuntime().maxMemory()/(1024*1024*16)); double ramBufferSize = Math.max( atLeast, heapHint ); writer.getRAMBufferSizeMB( ramBufferSize ); It's just something which I ballparked and obviously has problems for heaps of your size. It's a tough one to fix in your case since you cannot parameterize that calculation. The only way would be to modify source code and build a new jar, or wait for it to be fixed (maybe by limiting the max amount to 2Gb as Lucene seem to suggest). Hopefully it can be addressed soon. 2011/2/24 Pablo Pareja ppar...@era7.com: Hi all, I just got this exception: ramBufferSize 3584.0 is too large; should be comfortably less than 2048 SEVERE: org.apache.lucene.index.IndexWriter.setRAMBufferSizeMB(IndexWriter.java:1368) SEVERE: org.neo4j.index.impl.lucene.LuceneBatchInserterIndex.instantiateWriter(LuceneBatchInserterIndex.java:209) SEVERE: org.neo4j.index.impl.lucene.LuceneBatchInserterIndex.init(LuceneBatchInserterIndex.java:66) SEVERE: org.neo4j.index.impl.lucene.LuceneBatchInserterIndexProvider.index(LuceneBatchInserterIndexProvider.java:135) SEVERE: org.neo4j.index.impl.lucene.LuceneBatchInserterIndexProvider.nodeIndex(LuceneBatchInserterIndexProvider.java:102) SEVERE: com.era7.bioinfo.bio4j.programs.ImportGeneOntology.main(ImportGeneOntology.java:107) SEVERE: com.era7.bioinfo.bio4j.programs.ImportGeneOntology.execute(ImportGeneOntology.java:75) SEVERE: com.era7.lib.bioinfo.bioinfoutil.ExecuteFromFile.main(ExecuteFromFile.java:66) SEVERE: com.era7.bioinfo.bio4j.programs.CreateWholeBio4j.main(CreateWholeBio4j.java:28) when launching my Batch insertion program once I had updated the indexation to the new API any ideas about what should I do? I'm launching the program in a 68GB RAM machine with the following batchInserter.properties: neostore.nodestore.db.mapped_memory=10G neostore.relationshipstore.db.mapped_memory=12G neostore.propertystore.db.mapped_memory=12G neostore.propertystore.db.strings.mapped_memory=10G neostore.propertystore.db.arrays.mapped_memory=512M I don't know how or where to change that ramBufferSize' value, which by the way didn't specified at any point. Thanks in advance, Pablo -- Pablo Pareja Tobes LinkedInhttp://www.linkedin.com/in/pabloparejatobes Twitter http://www.twitter.com/pablopareja http://about.me/pablopareja http://www.ohnosequences.com ___ 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 -- Pablo Pareja Tobes LinkedInhttp://www.linkedin.com/in/pabloparejatobes Twitter http://www.twitter.com/pablopareja http://about.me/pablopareja http://www.ohnosequences.com ___ Neo4j mailing list User@lists.neo4j.org https://lists.neo4j.org/mailman/listinfo/user
Re: [Neo4j] Help with IndexWriter ramBufferSize exception
Using the formula I supplied in my previous reply I'd say you can go with a 32G heap or just slightly lower. 2011/2/24 Pablo Pareja ppar...@era7.com: Hi Mattias, I guess that my only option would then be limiting the max amount to 2GB as you say, however this will make the insertion phase way longer than what I expected and counted on. Just to confirm, am I then supposed to launch my java process with at most -Xmx2G ?? I really think this is an important flaw to work on. I look forward to seeing it fixed in the near future. Cheers, Pablo On Thu, Feb 24, 2011 at 3:19 PM, Mattias Persson matt...@neotechnology.comwrote: There's this hardcoded setting for batch inserter indexes that increases the ram buffer size to increase overall performance during batch insertion. The formula is: double atLeast = writer.getRAMBufferSizeMB(); double heapHint = (double)(Runtime.getRuntime().maxMemory()/(1024*1024*16)); double ramBufferSize = Math.max( atLeast, heapHint ); writer.getRAMBufferSizeMB( ramBufferSize ); It's just something which I ballparked and obviously has problems for heaps of your size. It's a tough one to fix in your case since you cannot parameterize that calculation. The only way would be to modify source code and build a new jar, or wait for it to be fixed (maybe by limiting the max amount to 2Gb as Lucene seem to suggest). Hopefully it can be addressed soon. 2011/2/24 Pablo Pareja ppar...@era7.com: Hi all, I just got this exception: ramBufferSize 3584.0 is too large; should be comfortably less than 2048 SEVERE: org.apache.lucene.index.IndexWriter.setRAMBufferSizeMB(IndexWriter.java:1368) SEVERE: org.neo4j.index.impl.lucene.LuceneBatchInserterIndex.instantiateWriter(LuceneBatchInserterIndex.java:209) SEVERE: org.neo4j.index.impl.lucene.LuceneBatchInserterIndex.init(LuceneBatchInserterIndex.java:66) SEVERE: org.neo4j.index.impl.lucene.LuceneBatchInserterIndexProvider.index(LuceneBatchInserterIndexProvider.java:135) SEVERE: org.neo4j.index.impl.lucene.LuceneBatchInserterIndexProvider.nodeIndex(LuceneBatchInserterIndexProvider.java:102) SEVERE: com.era7.bioinfo.bio4j.programs.ImportGeneOntology.main(ImportGeneOntology.java:107) SEVERE: com.era7.bioinfo.bio4j.programs.ImportGeneOntology.execute(ImportGeneOntology.java:75) SEVERE: com.era7.lib.bioinfo.bioinfoutil.ExecuteFromFile.main(ExecuteFromFile.java:66) SEVERE: com.era7.bioinfo.bio4j.programs.CreateWholeBio4j.main(CreateWholeBio4j.java:28) when launching my Batch insertion program once I had updated the indexation to the new API any ideas about what should I do? I'm launching the program in a 68GB RAM machine with the following batchInserter.properties: neostore.nodestore.db.mapped_memory=10G neostore.relationshipstore.db.mapped_memory=12G neostore.propertystore.db.mapped_memory=12G neostore.propertystore.db.strings.mapped_memory=10G neostore.propertystore.db.arrays.mapped_memory=512M I don't know how or where to change that ramBufferSize' value, which by the way didn't specified at any point. Thanks in advance, Pablo -- Pablo Pareja Tobes LinkedIn http://www.linkedin.com/in/pabloparejatobes Twitter http://www.twitter.com/pablopareja http://about.me/pablopareja http://www.ohnosequences.com ___ 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 -- Pablo Pareja Tobes LinkedIn http://www.linkedin.com/in/pabloparejatobes Twitter http://www.twitter.com/pablopareja http://about.me/pablopareja http://www.ohnosequences.com ___ 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
Re: [Neo4j] Help with IndexWriter ramBufferSize exception
Cool, I thought I'd have to decrease the heap size much more. Anyways, thanks a lot for the quick response and support. Cheers, Pablo On Thu, Feb 24, 2011 at 3:44 PM, Mattias Persson matt...@neotechnology.comwrote: Using the formula I supplied in my previous reply I'd say you can go with a 32G heap or just slightly lower. 2011/2/24 Pablo Pareja ppar...@era7.com: Hi Mattias, I guess that my only option would then be limiting the max amount to 2GB as you say, however this will make the insertion phase way longer than what I expected and counted on. Just to confirm, am I then supposed to launch my java process with at most -Xmx2G ?? I really think this is an important flaw to work on. I look forward to seeing it fixed in the near future. Cheers, Pablo On Thu, Feb 24, 2011 at 3:19 PM, Mattias Persson matt...@neotechnology.comwrote: There's this hardcoded setting for batch inserter indexes that increases the ram buffer size to increase overall performance during batch insertion. The formula is: double atLeast = writer.getRAMBufferSizeMB(); double heapHint = (double)(Runtime.getRuntime().maxMemory()/(1024*1024*16)); double ramBufferSize = Math.max( atLeast, heapHint ); writer.getRAMBufferSizeMB( ramBufferSize ); It's just something which I ballparked and obviously has problems for heaps of your size. It's a tough one to fix in your case since you cannot parameterize that calculation. The only way would be to modify source code and build a new jar, or wait for it to be fixed (maybe by limiting the max amount to 2Gb as Lucene seem to suggest). Hopefully it can be addressed soon. 2011/2/24 Pablo Pareja ppar...@era7.com: Hi all, I just got this exception: ramBufferSize 3584.0 is too large; should be comfortably less than 2048 SEVERE: org.apache.lucene.index.IndexWriter.setRAMBufferSizeMB(IndexWriter.java:1368) SEVERE: org.neo4j.index.impl.lucene.LuceneBatchInserterIndex.instantiateWriter(LuceneBatchInserterIndex.java:209) SEVERE: org.neo4j.index.impl.lucene.LuceneBatchInserterIndex.init(LuceneBatchInserterIndex.java:66) SEVERE: org.neo4j.index.impl.lucene.LuceneBatchInserterIndexProvider.index(LuceneBatchInserterIndexProvider.java:135) SEVERE: org.neo4j.index.impl.lucene.LuceneBatchInserterIndexProvider.nodeIndex(LuceneBatchInserterIndexProvider.java:102) SEVERE: com.era7.bioinfo.bio4j.programs.ImportGeneOntology.main(ImportGeneOntology.java:107) SEVERE: com.era7.bioinfo.bio4j.programs.ImportGeneOntology.execute(ImportGeneOntology.java:75) SEVERE: com.era7.lib.bioinfo.bioinfoutil.ExecuteFromFile.main(ExecuteFromFile.java:66) SEVERE: com.era7.bioinfo.bio4j.programs.CreateWholeBio4j.main(CreateWholeBio4j.java:28) when launching my Batch insertion program once I had updated the indexation to the new API any ideas about what should I do? I'm launching the program in a 68GB RAM machine with the following batchInserter.properties: neostore.nodestore.db.mapped_memory=10G neostore.relationshipstore.db.mapped_memory=12G neostore.propertystore.db.mapped_memory=12G neostore.propertystore.db.strings.mapped_memory=10G neostore.propertystore.db.arrays.mapped_memory=512M I don't know how or where to change that ramBufferSize' value, which by the way didn't specified at any point. Thanks in advance, Pablo -- Pablo Pareja Tobes LinkedInhttp://www.linkedin.com/in/pabloparejatobes Twitter http://www.twitter.com/pablopareja http://about.me/pablopareja http://www.ohnosequences.com ___ 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 -- Pablo Pareja Tobes LinkedInhttp://www.linkedin.com/in/pabloparejatobes Twitter http://www.twitter.com/pablopareja http://about.me/pablopareja http://www.ohnosequences.com ___ 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 -- Pablo Pareja Tobes LinkedInhttp://www.linkedin.com/in/pabloparejatobes Twitter http://www.twitter.com/pablopareja http://about.me/pablopareja http://www.ohnosequences.com ___ Neo4j mailing list User@lists.neo4j.org
Re: [Neo4j] Exception in indexer framework when commiting transaction
Thanks Matthias, yes, I had one empty key/value property. After adding checks, it now works fine. Greetings Axel Am 24.02.2011 15:28, schrieb Mattias Persson: Use the source, Luke. Consulting the lucene source I see that you're trying to add something where both key and value are empty. Not null, but empty strings that is. You should have checks for that as well in your code. 2011/2/24 Axel Morgnera...@morgner.de: Hi, after transition to the new indexer framework, I tried to rebuild the index on a small test database with 11,000 nodes. It failed with the following exception: java.lang.IllegalArgumentException: name and value cannot both be empty at org.apache.lucene.document.Field.init(Field.java:398) at org.apache.lucene.document.Field.init(Field.java:371) at org.apache.lucene.document.Field.init(Field.java:350) at org.neo4j.index.impl.lucene.IndexType.instantiateField(IndexType.java:331) at org.neo4j.index.impl.lucene.IndexType$CustomType.addToDocument(IndexType.java:159) at org.neo4j.index.impl.lucene.LuceneCommand$AddCommand.perform(LuceneCommand.java:187) 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) Thu Feb 24 14:21:56 CET 2011: --- CONFIGURATION START --- Thu Feb 24 14:21:56 CET 2011: Physical mem: 7999MB, Heap size: 5333MB Thu Feb 24 14:21:56 CET 2011: Kernel version: Neo4j - Graph Database Kernel 1.2-SNAPSHOT (revision: 8112) Thu Feb 24 14:21:56 CET 2011: Operating System: Linux; version: 2.6.35-25-generic; arch: amd64; cpus: 8 Thu Feb 24 14:21:56 CET 2011: VM Name: OpenJDK 64-Bit Server VM Thu Feb 24 14:21:56 CET 2011: VM Vendor: Sun Microsystems Inc. Thu Feb 24 14:21:56 CET 2011: VM Version: 19.0-b09 I made sure that I only add non-null values to the index. Does anyone have an idea what's going wrong? Greetings Axel ___ Neo4j mailing list User@lists.neo4j.org https://lists.neo4j.org/mailman/listinfo/user -- Axel Morgner Creative Solutions - Software Engineering GUI UX Design - Project Management c/o inxire GmbH Hanauer Landstr. 293a 60314 Frankfurt Germany Phone +49 151 40522060 e-maila...@morgner.de Webhttp://www.morgner.de ___ Neo4j mailing list User@lists.neo4j.org https://lists.neo4j.org/mailman/listinfo/user
Re: [Neo4j] Cache sharding blog post
Cache sharding = super nice iterative/interim improvement. It makes use of aggregate resources (RAM CPU) across multiple servers (as would be the case with a truly sharded Neo4j) without bothering about partitioning (even basic consistent hashing) algorithms. You get a viable partitioning solution by moving the logic to the client-side. Neo4j doesn't need to worry about some of the engineering headaches that true partitioning would bring - like performing transactions between multiple different partitions, or load balancing partition replicas across available servers - but clients still get some of the benefits of true partitioning. Like! Some other thoughts... As mentioned, you don't get around the difficult partitioning problem: achieving locality in a big graph of unknown topology/access. Also, you don't make the best use of aggregate resources. For example, if you wanted to run one very large (read: forbidden/not-graphy) traversal like page-rank on the entire graph you (1) would hit disk (2) would not make use of aggregate resources (CPU,RAM). I think that's an orthogonal problem though... regardless of how you cut your graph, the way you then traverse it has to be resource-aware: it has to know about, and be capable of using, the compute resources on other machines. E.g. Neo4j graph walking vs Pregel vertex gossiping... but maybe that can be left to future discussions. On Thu, Feb 24, 2011 at 3:26 PM, Mark Harwood markharw...@gmail.com wrote: That's a really fantastic and useful design metric. Can paraphrase it a bit and write it up on the Neo4j blog/my blog? I'd be honoured. ___ 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] [Blog Post] Using graph databases for knowledge representation and reasoning.
This is very cool. Thanks Marko! I am a huge supporter of knowledge representation using graph stores/databases. Here are a couple of blogs from a couple of years ago illustrating a very simple reasoner on top of Zentity (called Famulus back then). http://savas.me/blog/898 http://savas.me/blog/900 I agree that traditional the first-order and description logic approaches do not scale. I am a huge believer of probabilistic reasoning and latent semantics. Great stuff. Cheers, .savas. On 2/23/11 3:27 PM, Marko Rodriguez okramma...@gmail.com wrote: Hi, I wrote a blog post regarding knowledge representation and reasoning using graph databases: http://markorodriguez.com/2011/02/23/knowledge-representation-and-reasonin g-with-graph-databases/ Automated reasoning is currently dominated by RDF and its stack of technologies. However, the standard meta modeling language OWL is restricted to description logics. While this is all fine and good, it must be said that there are numerous types of logics. I think that because graph databases don't have a such strict layered cake, the graph database scene is ripe to be a foundation for the exploration and exploitation of other reasoning structures and algorithms. Thats that, Marko. http://markorodriguez.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
[Neo4j] flocking algorithms perhaps interesting for visualization (esp. over time) in graphs
http://harry.me/2011/02/17/neat-algorithms---flocking/ Cheers Michael ___ Neo4j mailing list User@lists.neo4j.org https://lists.neo4j.org/mailman/listinfo/user
Re: [Neo4j] flocking algorithms perhaps interesting for visualization (esp. over time) in graphs
Nice. Added to http://wiki.neo4j.org/content/Visualization_options_for_graphs#JavaScript 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://startupbootcamp.org/ - Öresund - Innovation happens HERE. http://www.thoughtmade.com - Scandinavia's coolest Bring-a-Thing party. On Fri, Feb 25, 2011 at 1:22 AM, Michael Hunger michael.hun...@neotechnology.com wrote: http://harry.me/2011/02/17/neat-algorithms---flocking/ Cheers Michael ___ 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
