Check out the documentation for creating a unique composite index.

Here's an example Gremlin Console session which creates a unique composite index on name. When you attempt to set a non-unique name, it will throw a SchemaViolationException.

gremlin> graph = JanusGraphFactory.open('inmemory')
==>standardjanusgraph[inmemory:[127.0.0.1]]
gremlin> mgmt = graph.openManagement()
==>org.janusgraph.graphdb.database.management.ManagementSystem@2eadc9f6
gremlin> name = mgmt.makePropertyKey('name').dataType(String.class).cardinality(Cardinality.SINGLE).make()
==>name
gremlin> nameIndex = mgmt.buildIndex('nameIndex', Vertex.class).addKey(name).unique().buildCompositeIndex()
==>nameIndex
gremlin> mgmt.commit()
==>null
gremlin> graph.addVertex('name', 'huupon')
==>v[4184]
gremlin> graph.addVertex('name', 'huupon')
Adding this property for key [name] and value [huupon] violates a uniqueness constraint [nameIndex]

-- Jason

On Wednesday, June 21, 2017 at 4:34:22 AM UTC-4, huupon wrote:

Hi, all:

       How can i keep the vertex which i want to add is unique？  get and add?  whether have any other methods to add unique vertex ？

Hi Mike,

Seeing no expert answers uptil now, I can only provide a general reply. I see the following lines of thinking in explaining your situation:

• HBase fails in providing row based consistency: extremely unlikely given the many applications that rely on this
• JanusGraph fails in providing consistency between instances (e.g. using out of date caches). Do you use multiple JanusGraph instances? Or multiple threads that access the same JanusGraph instance?
• Your application fails in handling exceptions in the right way (e.g. ignoring them)
• Your application has logic faults: not so likely because you have been debugging for some while.
  

If you want to proceed on this, could you provide the code you use on github? So, others can confirm the behavior and/or inspect configs. Ideally, you would provide your code in the form of a:
 https://github.com/JanusGraph/janusgraph/blob/236dd930a7af35061e393ea8bb1ee6eb65f924b2/janusgraph-hbase-parent/janusgraph-hbase-core/src/test/java/org/janusgraph/graphdb/hbase/HBasePartitionGraphTest.java

Other ideas still welcome!

Marc

Op zondag 18 juni 2017 08:38:02 UTC+2 schreef mi...@...:

Hi! I'm running into an issue and wondering if anyone has tips. I'm using HBase (also tried this with cassandra with the same issue) and running into an issue where preprocessing our data yields inconsistent results. We run through a query and for each vertex with a given property, we run a traversal on it and calculate properties or insert edges that weren't inserted on upload to boost performance of our eventual traversal.

Our tests run perfectly with a tinkergraph, but when using HBase or Cassandra backend, sometimes the tests fail, sometimes the calculated properties are completely wrong, and sometimes edges aren't created when needed. A preprocess task may depend on the output of a previous preprocess task that may have taken place seconds earlier. I think this is caused by eventual consistency breaking the traversal, but I'm not sure how to get 100% accuracy (where the current preprocess task can be 100% confident it gets the correct value from a previous preprocessing task). 

I create a transaction for each preprocessing operation, then commit it once successful, but this doesn't seem to fix the issues. Any ideas?

Thanks,

Mike

Hello,

Does anyone know if there is a way to stream a graph to a viewer such as Gephi from Janus Java client.  When using the gremlin console you can use the  tinkerpop.gephi plugin and redirect a graph Gephi.  Is there a way to do that from a Java  that has created a graph?  I did not find any mention of this in the documentation. 

Thanks

JGZ

I saw in many places of documentation/tutorials, that the mixed indexes have this

mgmt.buildIndex("vertices", Vertex.class).addKey(key).buildMixedIndex(INDEX_NAME); // With INDEX_NAME ='search', mostly

Will this create one index in ElasticSearch/SOLR for one property or all properties are clubbed under a single index? 

Also does JanusGraph partition these text based indexes, in case they get too large?

--

Ravi

Hi, all 

        We want to use janusgraph in our production, but we use hbase 1.2.x and ES 5.3.0 in our system, so I want to know when janusgraph can support ES 5.x in the future ,next version  0.2.0 ?

Hi, all:

       How can i keep the vertex which i want to add is unique？  get and add?  whether have any other methods to add unique vertex ？

When initializing the JanusGraph, is there a way to disable indexing backend? The below code always assumes using elasticsearch.

       Configuration c = new BaseConfiguration();

        

        c.setProperty("gremlin.graph", "org.janusgraph.core.JanusGraphFactory");

        c.setProperty("storage.backend", "cassandrathrift");

        Graph graph = GraphFactory.open(c);

Thanks

Chris R

Hi Marc,

Thanks so much for your information, however, I was wondering is there any complete code example about how to use 

"bulk-loading" in Janusgraph without Hadoop?


Thanks again!

Elis

On Thursday, June 15, 2017 at 9:59:10 PM UTC+8, HadoopMarc wrote:

Hi Elizabeth,

For JanusGraph you should also take into account the TinkerPop documentation. A relevant pointer for you is:
https://groups.google.com/forum/#!searchin/gremlin-users/csv%7Csort:relevance/gremlin-users/AetuGcLiBxo/KW966WAyAQAJ

Cheers,    Marc

Op woensdag 14 juni 2017 18:44:16 UTC+2 schreef Elizabeth:

Hi all,

I am new to Janusgraph, I have dived into docs of Janusgraph for almost two weeks, nothing found.

I could only gather the scatted information and most of the time it will prompt some errors.

Could anyone supply a complete example of bulk loading or loading a CSV file into Janusgraph, please?

Any little help is appreated!

Best regards,

Elis.

You could keep your schema-less data in your existing NoSQL db and then add a graph database for storing relations.

Or try a multi-model graph database. There are several listed here http://tinkerpop.apache.org/#graph-systems

There's no one right way to do it.

Robert Dale

On Tue, Jun 20, 2017 at 2:32 PM, Jane <sh...@...> wrote:

Can I/Has anyone use Janus Graph as a replacement for NOSQL databases in web applications? I'm talking about high throughput on both reads and writes (non-bulk, randomly generated by user traffic). A lot of examples that are getting tossed around here are just a bunch of people exporting their data from somewhere else and bulk importing it into Janus Graph for analysis. 

It seems that a blocking issue for me with Janus Graph is that for it to remotely even perform decently it requires an index and schema to be pre-generated for the data set. With my use case it is simply not possible to determine everything that a user might want to possibly upload to the database and hence why we use a NOSQL database. However, the data is also highly relational and would benefit from being stored in a graph database. 

Has anyone gotten over this hurdle or have any advice? 

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Hi Elizabeth,

For JanusGraph you should also take into account the TinkerPop documentation. A relevant pointer for you is:
https://groups.google.com/forum/#!searchin/gremlin-users/csv%7Csort:relevance/gremlin-users/AetuGcLiBxo/KW966WAyAQAJ

Cheers,    Marc

Op woensdag 14 juni 2017 18:44:16 UTC+2 schreef Elizabeth:

Hi all,

I am new to Janusgraph, I have dived into docs of Janusgraph for almost two weeks, nothing found.

I could only gather the scatted information and most of the time it will prompt some errors.

Could anyone supply a complete example of bulk loading or loading a CSV file into Janusgraph, please?

Any little help is appreated!

Best regards,

Elis.