TITAN

问题 I am trying to import "https://github.com/thinkaurelius/titan/blob/1.0.0/titan-core/src/main/java/com/thinkaurelius/titan/graphdb/tinkerpop/io/graphson/TitanGraphSONModule.java" in gremlin by using command as import https://github.com/thinkaurelius/titan/blob/1.0.0/titan-core/src/main/java/com/thinkaurelius/titan/graphdb/tinkerpop/io/graphson/TitanGraphSONModule.java; But getting error like this: Invalid import definition: 'https://github.com/thinkaurelius/titan/blob/1.0.0/titan-core/src/main

问题 I want to retrieve all vertexes and for each one I want to count the number of 'Like' edges pointing at it. How do I write this kind of query in Gremlin? In SQL it could be something like.... SELECT *, (SELECT Count(*) FROM tbl_like l WHERE l.id = b.id) AS LikeCount FROM tbl_blah b 回答1: E.g. use sideEffect to put the counts in a map ( m ) m=[:];g.V.sideEffect{m[it]=it.inE.has('label','like').count()} An alternative which omits vertices with 0 likes: m=[:];g.V.inE('like').groupCount(m){it.inV

问题 i really cant figure out where my problem is. Im using Titan 0.5.0 (It's the same problem with the newer Titan versions...) I want to load a bunch of vertices and edges from a csv file with 100k entries (each line results in at least 3 nodes and some edges) into my graph. It's taking about 5 minutes to finally complete the import. So i tried the same with the configuration storage.batch-loading = true. Well it's significant faster with only 2 minutes to complete the import. But the problem is

问题 I have a titan graph setup using following versions of software. Cassandra version : 2.0.6 Titan version : 0.4.2 5 cassandra server with replication factor 3. Recently, all of sudden, we have started getting following error intermittently. com.esotericsoftware.kryo.KryoException: Buffer too small: capacity: 2, required: 8 I searched net and found that there is a bug filed relating to same error. Bug is pertaining to kryo API. https://code.google.com/p/kryo/issues/detail?id=124 Fix of above

问题 I'm migrating the entire Titan graph database from 0.44 to 0.5. There are about 120 million nodes and 90 million edges that's gigabytes of data. I tried the GraphML format, but it didn't work. Can you suggest methods to do the migration? 回答1: At the size you are describing you would probably execute the most efficient migration by using Titan-Hadoop/Faunus. The general process would be to: Use Faunus 0.4.x to extract the data from your graph as GraphSON and store that in HDFS Use Titan-Hadoop

问题 Every example I've been able to find in the Titan documentation creates indices using the Rexster console. You log in to a single Titan node, create your indices and commit. After a while the whole cluster is aware of the index and it can be used. I am wondering if there are other ways to do this. There are some benefits when creating indices from code e.g. in a Rexster extension: I use ENUMs for property keys and edge labels that offer toString methods I can use on index creation. This way

问题 I have a small Titan 0.5.0 cluster with 8 nodes. Every node runs Titan in Rexster 2.5.0 and Cassandra. They all are configured the same. Unfortunately nearly all the time one of them does not manage to start. In most cases this is one of the seed nodes. Using cassandra as storage backend I get the following in the Rexster/Titan log. WARN com.tinkerpop.rexster.config.GraphConfigurationContainer - Could not open global configuration com.thinkaurelius.titan.core.TitanException: Could not open

问题 I am using TitanGraphDB + Cassandra.I am starting Titan as follows cd titan-cassandra-0.3.1 bin/titan.sh config/titan-server-rexster.xml config/titan-server-cassandra.properties I have a Rexster shell that I can use to communicate to Titan+Cassandra above. cd rexster-console-2.3.0 bin/rexster-console.sh I am attempting to model a network topology using Titan Graph DB.I want to program the Titan Graph DB from my python program.I am using bulbs package for that. I create three types of vertices

问题 I am using TitanGraphDB + Cassandra.I am starting Titan as follows cd titan-cassandra-0.3.1 bin/titan.sh config/titan-server-rexster.xml config/titan-server-cassandra.properties I have a Rexster shell that I can use to communicate to Titan+Cassandra above. cd rexster-console-2.3.0 bin/rexster-console.sh I am attempting to model a network topology using Titan Graph DB.I want to program the Titan Graph DB from my python program.I am using bulbs package for that. I create three types of vertices

问题 I'm making a presentation about how some elements looks in Neo4j's Cypher and Titan's Gremlin i.e. add new vertex, look for relation etc. I have a problem with looking for cyclec. Is there any function in these 2 languages which can return a cycles i.e. for given vertex? 回答1: Here's how you do it in Gremlin: gremlin> g = TinkerGraphFactory.createTinkerGraph() ==>tinkergraph[vertices:6 edges:6] gremlin> g.v(2).addEdge("knows", g.v(6)) ==>e[0][2-knows->6] gremlin> g.v(6).addEdge("knows", g.v(1)