JG Schema - addConnection seem to create duplicate connections

[molipet]

• Version: 0.6
• Storage Backend: Cassandra v3.11.11
• Mixed Index Backend: none
• Link to discussed bug: https://lists.lfaidata.foundation/g/janusgraph-users/message/6334
• Expected Behavior: two connections should be created for "toEdge"
• Current Behavior: four connections are created for "toEdge"
• Steps to Reproduce:
  1. Creating dynamic graph and schema

     map = new HashMap();
     map.put("storage.backend","cql");
     map.put("storage.hostname","cassandra");
     map.put("query.force-index", "false");
     map.put("schema.default", "default");
     map.put("schema.constraints", "false");
     map.put("graph.graphname", "transactionGraph")
     ConfiguredGraphFactory.createConfiguration(new MapConfiguration(map));
     
     graph = ConfiguredGraphFactory.open("transactionGraph");
     mgmt = graph.openManagement();
     
     transaction = mgmt.makeVertexLabel('transaction').make();
     person = mgmt.makeVertexLabel('person').make();
     entity = mgmt.makeVertexLabel('entity').make();
     
     fromEdge = mgmt.makeEdgeLabel('FROM').multiplicity(ONE2ONE).make()
     mgmt.addConnection(fromEdge, person, transaction)
     mgmt.addConnection(fromEdge, entity, transaction)
     
     toEdge = mgmt.makeEdgeLabel('TO').multiplicity(ONE2ONE).make()
     mgmt.addConnection(toEdge, transaction, person)
     mgmt.addConnection(toEdge, transaction, entity)
     
     mgmt.commit()
     

  2. Checking connections of the schema

     mgmt = graph.openManagement()
     edges = mgmt.getRelationTypes(EdgeLabel.class)
     fromEdge = edges[0]
     toEdge = edges[1]
     
     fromEdge.mappedConnections().size() // as I would expect, it has two connections
     toEdge.mappedConnections().size() // why 4 connections are here? I would expect only two connections similarly to the FROM edge
     

  3. Note that Marc was able to reproduce the same issue also with inmemory backend (graph = JanusGraphFactory.open('conf/janusgraph-inmemory.properties')). See the reply from Marc here https://lists.lfaidata.foundation/g/janusgraph-users/message/6348

[farodin91]

It should be fixable by a basic check during the insert. For already inserted connections it will be more complicated.