IllegalStateException : Gremlin Server must be configured to use the JanusGraphManager

Question

Set graphNames = JanusGraphFactory.getGraphNames();
for(String name:graphNames) {
    System.out.println(name);
}

The above snippet produ

Answer 1

This answer to this is similar to this other question.

The call to JanusGraphFactory.getGraphNames() needs to be sent to the remote server. If you're working in the Gremlin Console, first establish a remote sessioned connection then set remote console mode.

gremlin> :remote connect tinkerpop.server conf/remote.yaml session
==>Configured localhost/127.0.0.1:8182

gremlin> :remote console
==>All scripts will now be sent to Gremlin Server - [localhost:8182]-[5206cdde-b231-41fa-9e6c-69feac0fe2b2] - type ':remote console' to return to local mode

Then as described in the JanusGraph docs for "Listing the Graphs":

ConfiguredGraphFactory.getGraphNames() will return a set of graph names for which you have created configurations using the ConfigurationManagementGraph APIs.

JanusGraphFactory.getGraphNames() on the other hand returns a set of graph names for which you have instantiated and the references are stored inside the JanusGraphManager.

If you are not using the Gremlin Console, then you should be using a remote client, such as the TinkerPop gremlin-driver (Java), to send your requests to the Gremlin Server.