Eu recebo o erro deste no console do gremlin

cegprakash@cegprakash:~/workspace/janusgraph-0.2.1-hadoop2$ ./bin/gremlin.sh 

         \,,,/
         (o o)
-----oOOo-(3)-oOOo-----
plugin activated: janusgraph.imports
plugin activated: tinkerpop.server
plugin activated: tinkerpop.utilities
SLF4J: Class path contains multiple SLF4J bindings.
SLF4J: Found binding in [jar:file:/home/cegprakash/workspace/janusgraph-0.2.1-hadoop2/lib/slf4j-log4j12-1.7.12.jar!/org/slf4j/impl/StaticLoggerBinder.class]
SLF4J: Found binding in [jar:file:/home/cegprakash/workspace/janusgraph-0.2.1-hadoop2/lib/logback-classic-1.1.2.jar!/org/slf4j/impl/StaticLoggerBinder.class]
SLF4J: See http://www.slf4j.org/codes.html#multiple_bindings for an explanation.
SLF4J: Actual binding is of type [org.slf4j.impl.Log4jLoggerFactory]
19:10:12 WARN  org.apache.hadoop.util.NativeCodeLoader  - Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
plugin activated: tinkerpop.hadoop
plugin activated: tinkerpop.spark
plugin activated: tinkerpop.tinkergraph
gremlin> def graph=ConfiguredGraphFactory.create("mygraph")
org.janusgraph.graphdb.management.utils.ConfigurationManagementGraphNotEnabledException: Please add a key named "ConfigurationManagementGraph" to the "graphs" property in your YAML file and restart the server to be able to use the functionality of the ConfigurationManagementGraph class.
Type ':help' or ':h' for help.
Display stack trace? [yN]

Editar: Também segui os passos de Jason Plurad na resposta.

conf / gremlin-server / gremlin-server.yaml

host: 0.0.0.0
port: 8182
scriptEvaluationTimeout: 30000
channelizer: org.apache.tinkerpop.gremlin.server.channel.WebSocketChannelizer
graphs: {
  ConfigurationManagementGraph: conf/janusgraph-cassandra-configurationgraph.properties
}
plugins:
  - janusgraph.imports
scriptEngines: {
  gremlin-groovy: {
    imports: [java.lang.Math],
    staticImports: [java.lang.Math.PI],
    scripts: [scripts/empty-sample.groovy]}}
serializers:
  - { className: org.apache.tinkerpop.gremlin.driver.ser.GryoMessageSerializerV1d0, config: { ioRegistries: [org.janusgraph.graphdb.tinkerpop.JanusGraphIoRegistry] }}
  - { className: org.apache.tinkerpop.gremlin.driver.ser.GryoLiteMessageSerializerV1d0, config: {ioRegistries: [org.janusgraph.graphdb.tinkerpop.JanusGraphIoRegistry] }}
  - { className: org.apache.tinkerpop.gremlin.driver.ser.GryoMessageSerializerV1d0, config: { serializeResultToString: true }}
  - { className: org.apache.tinkerpop.gremlin.driver.ser.GraphSONMessageSerializerGremlinV1d0, config: { ioRegistries: [org.janusgraph.graphdb.tinkerpop.JanusGraphIoRegistryV1d0] }}
  - { className: org.apache.tinkerpop.gremlin.driver.ser.GraphSONMessageSerializerGremlinV2d0, config: { ioRegistries: [org.janusgraph.graphdb.tinkerpop.JanusGraphIoRegistry] }}
  - { className: org.apache.tinkerpop.gremlin.driver.ser.GraphSONMessageSerializerV1d0, config: { ioRegistries: [org.janusgraph.graphdb.tinkerpop.JanusGraphIoRegistryV1d0] }}
processors:
  - { className: org.apache.tinkerpop.gremlin.server.op.session.SessionOpProcessor, config: { sessionTimeout: 28800000 }}
  - { className: org.apache.tinkerpop.gremlin.server.op.traversal.TraversalOpProcessor, config: { cacheExpirationTime: 600000, cacheMaxSize: 1000 }}
metrics: {
  consoleReporter: {enabled: true, interval: 180000},
  csvReporter: {enabled: true, interval: 180000, fileName: /tmp/gremlin-server-metrics.csv},
  jmxReporter: {enabled: true},
  slf4jReporter: {enabled: true, interval: 180000},
  gangliaReporter: {enabled: false, interval: 180000, addressingMode: MULTICAST},
  graphiteReporter: {enabled: false, interval: 180000}}
maxInitialLineLength: 4096
maxHeaderSize: 8192
maxChunkSize: 8192
maxContentLength: 65536
maxAccumulationBufferComponents: 1024
resultIterationBatchSize: 64
writeBufferLowWaterMark: 32768
writeBufferHighWaterMark: 65536

Aqui está o meu arquivo janusgraph-cassandra-configurationgraph.properties

gremlin.graph=org.janusgraph.core.ConfiguredGraphFactory
graph.graphname=ConfigurationManagementGraph
storage.backend=cassandrathrift
storage.hostname=127.0.0.1
cache.db-cache = true
cache.db-cache-clean-wait = 20
cache.db-cache-time = 180000
cache.db-cache-size = 0.5

Então eu fiz

./bin/janusgraph.sh clean
Are you sure you want to delete all stored data and logs? [y/N] y
Deleted data in /home/cegprakash/workspace/janusgraph-0.2.1-hadoop2/db
Deleted logs in /home/cegprakash/workspace/janusgraph-0.2.1-hadoop2/log

Seguido por

cegprakash@cegprakash:~/workspace/janusgraph-0.2.1-hadoop2$ ./bin/janusgraph.sh start
Forking Cassandra...
Running `nodetool statusthrift`.... OK (returned exit status 0 and printed string "running").
Forking Elasticsearch...
Connecting to Elasticsearch (127.0.0.1:9200)....... OK (connected to 127.0.0.1:9200).
Forking Gremlin-Server...
Connecting to Gremlin-Server (127.0.0.1:8182)..... OK (connected to 127.0.0.1:8182).
Run gremlin.sh to connect.

Seguido por

cegprakash@cegprakash:~/workspace/janusgraph-0.2.1-hadoop2$ ./bin/gremlin.sh 

         \,,,/
         (o o)
-----oOOo-(3)-oOOo-----
plugin activated: janusgraph.imports
plugin activated: tinkerpop.server
plugin activated: tinkerpop.utilities
SLF4J: Class path contains multiple SLF4J bindings.
SLF4J: Found binding in [jar:file:/home/cegprakash/workspace/janusgraph-0.2.1-hadoop2/lib/slf4j-log4j12-1.7.12.jar!/org/slf4j/impl/StaticLoggerBinder.class]
SLF4J: Found binding in [jar:file:/home/cegprakash/workspace/janusgraph-0.2.1-hadoop2/lib/logback-classic-1.1.2.jar!/org/slf4j/impl/StaticLoggerBinder.class]
SLF4J: See http://www.slf4j.org/codes.html#multiple_bindings for an explanation.
SLF4J: Actual binding is of type [org.slf4j.impl.Log4jLoggerFactory]
19:35:47 WARN  org.apache.hadoop.util.NativeCodeLoader  - Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
plugin activated: tinkerpop.hadoop
plugin activated: tinkerpop.spark
plugin activated: tinkerpop.tinkergraph
gremlin> :remote connect tinkerpop.server conf/remote.yaml session
==>Configured localhost/127.0.0.1:8182-[14455470-addc-49ed-ae54-a30de1fd8ae8]
gremlin> :remote console
==>All scripts will now be sent to Gremlin Server - [localhost/127.0.0.1:8182]-[14455470-addc-49ed-ae54-a30de1fd8ae8] - type ':remote console' to return to local mode
gremlin> def graph=ConfiguredGraphFactory.create("mygraph")
Please add a key named "ConfigurationManagementGraph" to the "graphs" property in your YAML file and restart the server to be able to use the functionality of the ConfigurationManagementGraph class.
Type ':help' or ':h' for help.
Display stack trace? [yN]