porunov
JJanusGraph
•Created by frank on 2/13/2025 in #questions
Janus support of openCypher or GQL
Here is also TinkerPop Wide about GQL to Gremlin: https://youtu.be/Kd0i-ieni6M
4 replies
JJanusGraph
•Created by frank on 2/13/2025 in #questions
Janus support of openCypher or GQL
Translation of query languages is better suited in the Gremlin group I believe, so you could check more up-to date information on supported TinkerPop query languages in their Discord group.
That said, there are solutions (I didn’t test them personally):
1. GQL to Gremlin compiler: https://github.com/WSaffery/GQL-Compiler
2. openCypher to Gremlin: https://github.com/opencypher/cypher-for-gremlin
As such, you can translate your openCypher or GQL or SPARQL into Gremlin language which will be evaluated by JanusGraph.
4 replies
JJanusGraph
•Created by NeO on 10/23/2024 in #questions
custom vertex id (String) feature to avoid duplicate vertex
The issue I explained above is related to anything where the generated column key is unique per element. Meaning: Any edge and any property with cardinality LIST or SET. Properties with cardinality SINGLE will be replaced as they have key equal to PropertyKey id.
8 replies
JJanusGraph
•Created by NeO on 10/23/2024 in #questions
custom vertex id (String) feature to avoid duplicate vertex
As for vertex itself, yes, by using the same custom vertex id you will always map to the same partition. Thus, it's impossible to create 2 duplicate vertices in such case. However, it doesn't mean it won't be possible to create duplicate vertex properties. In fact, there is a chance you will create some duplicate vertex properties in your partition. Meaning, if you have 2 processes which are writing a vertex by id "myId123" with a property LIST like "myProperty=foo,bar" then there is a chance you will have "myProperty=foo,bar,foo,bar" as you pushed 4 properties with different ids to your partition. In other words, it's not safe to rely on the internal vertex id to overcome potential concurrency issues. If you need to ensure uniquencess, I would suggest relying on locking mechanisms (either pessimistic or optimistic locking could work in your case). I would use pessimistic locking if it's critical not to have a duplicate at any moment in time. Otherwise, if it's OK to have eventual correct state then I would use optimistic locking.
8 replies
JJanusGraph
•Created by karthikraju on 9/24/2024 in #questions
Need advice on setting up janusgraph as a microservice
Graphs are isolated. Those two graphs have their own keyspace and don't share any user-space data between each other. You can also define different schema for different graphs.
4 replies
JJanusGraph
•Created by karthikraju on 9/24/2024 in #questions
Need advice on setting up janusgraph as a microservice
Hey! You might want to try dynamic graphs. Generally speaking, you can just bind multiple graphs to Gremlin Server and use them as needed. I.e.
graph1.traversal().V()...
graph2.traversal().V()...
https://docs.janusgraph.org/operations/dynamic-graphs/4 replies
JJanusGraph
•Created by oc007us on 9/17/2024 in #questions
What is the latest version of Cassandra is supported by 1.1.0-SNAPSHOT?
Hey! Cassandra 4 was used for testing. It seems JanusGraph doesn't support Cassandra 5 for now, but I think it should be possible to add Cassandra 5 support. Haven't look at breaking changes yet
2 replies
ATApache TinkerPop
•Created by Neptunion on 9/11/2024 in #questions
JanusGraph AdjacentVertex Optimization
TinkerPop applies all optimization strategies to all queries (including JanusGraph internal optimizations). However, JanusGraph skips some of the optimizations as it sees necessary. We don't currently store information if the optimization strategy modified any part of the query or was simply skipped (potential feature request). Thus, the way I would test if the optimization strategy actually makes any changes or not is to debug the query with the breaking point placed in the necessary optimization strategy.
I.e. in your case I would place a breaking point here: https://github.com/JanusGraph/janusgraph/blob/c9576890b5e9dc48676ccc16a58552b8a665e5f0/janusgraph-core/src/main/java/org/janusgraph/graphdb/tinkerpop/optimize/strategy/AdjacentVertexOptimizerStrategy.java#L58C13-L58C28
If this part is triggered during your query execution - optimization works in this case.
4 replies
JJanusGraph
•Created by karthikraju on 8/8/2024 in #questions
What would be the ideal way to set up deep learning on janusgraph data?
I haven’t personally use DGL, so can’t direct you too much there.
Does DGL support distributed training? If so, I would look into OLAP via Spark to train embeddings in parallel on each node and then reduce those embeddings on the final stage into a single combined model.
However, I didn’t look into DGL and don’t know if it can even merge weights afterwards (so, it’s something to check out).
If your Graph is small then you might not need to use parallel training and probably you could use normal OLTP via Gremlin.
For example, you can produce a list of maps with outV, edge label, and inV as you asked above by using something like this:
g.E().project(“from_vertex”, “relationship”, “to_vertex”).by(outV().id()).by(label()).by(inV().id()).toList()
5 replies
JJanusGraph
•Created by Aiman on 6/24/2024 in #questions
How do we generate transaction logs ?
The transaction log is processed on the server side and not on the client side.
Thus, you would need to create a log processor on your server side (as showed in the documentation). The log processor will be triggered anytime a mutation for that particular log happens.
You may potentially have many same log processors listening to the same log on each of your JanusGraph servers or just a single log processor if that’s what you are looking for.
You can use JanusGraph in embedded mode to open change processor OR you may send your groovy script using the remote connection. As you are using a remote connection, you may wish to connect to your JanusGraph server and send a groovy script which does exactly what documentation says (i.e. opens a log processor with your custom logic).
In case your server is secured against groovy scripts and you cannot send non-gremlin compliant scripts you may want to add your groovy script to the startup of GremlinServer (please, refer to TinkerPop documentation on how to attach your custom scripts to your servers).
16 replies
JJanusGraph
•Created by Aiman on 6/24/2024 in #questions
How do we generate transaction logs ?
I am not sure if you checked the documentation I posted above but that’s exactly what examples the documentation provides. I.e. any mutation operations (create / update / remove) is tracked by the transaction log.
There is also WAL available which tracks everything before transaction is committed or after transaction is committed.
Please, check the documentation and let us know if there are any sections which are confusing.
16 replies
JJanusGraph
•Created by Aiman on 6/24/2024 in #questions
How do we generate transaction logs ?
The documentation provides sample code. I’m not sure what exactly you are looking for as the documentation provides you both samples:
- how to register change processors
- how to build a transaction which uses your log message bus
16 replies
JJanusGraph
•Created by paull8147 on 6/25/2024 in #questions
Text predicate not serializable (containsPhrase, notContainsX, etc)
I haven’t looked at it myself, but I believe this is the related issue:
https://github.com/JanusGraph/janusgraph/issues/1565
Would be great if you can contribute this improvement into JanusGraph
5 replies
JJanusGraph
•Created by Aiman on 6/24/2024 in #questions
How do we generate transaction logs ?
@Aiman Sharief check documentation regarding Transaction Log here: https://docs.janusgraph.org/advanced-topics/transaction-log/
16 replies
JJanusGraph
•Created by HailDevil on 5/29/2024 in #questions
Java 17 support
No, there is no any timeline for Java 17 support. I don’t know if anyone is actually working on adding that support into JanusGraph. I think it’s not hard adding it, as we defined steps previously:
- dropping Java 8 support
- adding Java 17 support
However, I don’t know if there are any volunteers who are interested in this. Last time I believe @farodin91 was working on it.
12 replies
JJanusGraph
•Created by HailDevil on 5/29/2024 in #questions
Java 17 support
Yes. We have such a setup where we use JanusGraph inside Java 17 application. Storage backend CQL, mixed index backend ElasticSearch. Everything works as expected.
12 replies
JJanusGraph
•Created by HailDevil on 5/29/2024 in #questions
Java 17 support
JanusGraph supports Java 17 in embedded mode, but can’t be separately built using Java 17 as for now. There are plans to drop support for Java 8 and start supporting builds using Java 17
12 replies
ATApache TinkerPop
•Created by porunov on 5/18/2024 in #questions
Should `barrier` step merge Edge properties with the same key and value?
Thank you for the detailed description!
I believe LazyBarrierStrategy is not used for any traversal which has at least one “drop” step, but I might be wrong (have to check).
Internally it looks like bulking just increments the counter of equal traversers while storing only the first property.
The problem is that we actually use barrier steps as an optimisation for batch queries and this time we want to optimise “drop” step itself.
I believe in this case our best bet would be to make additional implementation of “NoOpBarrier” step which skips edge properties and meta properties and use that step instead of the standard “NoOpBarrierStep” for our batch optimisation strategy.
The related PR: https://github.com/apache/tinkerpop/pull/2612
7 replies
JJanusGraph
•Created by gdotv on 5/22/2024 in #questions
Creating a customer serializer Io Registry in Java
We do use custom serializers on the server side (to be able to pass data from JanusGraph to TinkerGraph and back), but I never played with custom serializers on the client driver side. I believe it should be possible like you described because we do use custom serializers for some type (like Geoshape for example just fine).
If you find a proper way to do that, please share it here (or directly into the documentation) so that we can document it once and for all.
Otherwise I will check this later and document it.
12 replies
JJanusGraph
•Created by Eathren on 5/16/2024 in #questions
Kill a query?
If you use gremlin server you can set “scriptEvaluationTime” to desired max evaluation time after which the query should be interrupted.
If you use any GLV or direct API then your query is executed your own managed thread. In such case you should interrupt your thread (‘yourThread.interrupt()’).
Notice, however, that of you are interrupting a mutation query with disabled storage atomicity you may potentially end up with partially mutated data (didn’t really test this case, so just guessing).
3 replies