Set up the Gremlin console to connect to a Neptune DB instance

To install the Gremlin Console and connect to Neptune

1. The Gremlin Console binaries require Java 8 or Java 11. These instructions assume usage of Java 11. You can install Java 11 on your EC2 instance as follow:

   • If you're using Amazon Linux 2 (AL2):

     sudo amazon-linux-extras install java-openjdk11

   • If you're using Amazon Linux 2023 (AL2023):

     sudo yum install java-11-amazon-corretto-devel

   • For other distributions, use whichever of the following is appropriate:

     sudo yum install java-11-openjdk-devel

     or:

     sudo apt-get install openjdk-11-jdk

2. Enter the following to set Java 11 as the default runtime on your EC2 instance.

   sudo /usr/sbin/alternatives --config java

   When prompted, enter the number for Java 11.

3. Download the appropriate version of the Gremlin console from the Apache web site. You can check the java gremlin client page for the Neptune engine version you are currently running to determine which Gremlin version it supports. For example, for version 3.7.2, you can download the Gremlin console from the Apache Tinkerpop3 website onto your EC2 instance like this:

   wget https://archive.apache.org/dist/tinkerpop/3.7.2/apache-tinkerpop-gremlin-console-3.7.2-bin.zip

4. Unzip the Gremlin Console zip file.

   unzip apache-tinkerpop-gremlin-console-3.7.2-bin.zip

5. Change directories into the unzipped directory.

   cd apache-tinkerpop-gremlin-console-3.7.2

6. In the conf subdirectory of the extracted directory, create a file named neptune-remote.yaml with the following text. Replace your-neptune-endpoint with the hostname or IP address of your Neptune DB instance. The square brackets ([ ]) are required.

   Note

   For information about finding the hostname of your Neptune DB instance, see the Connecting to Amazon Neptune Endpoints section.

   hosts: [your-neptune-endpoint]
   port: 8182
   connectionPool: { enableSsl: true }
   serializer: { className: org.apache.tinkerpop.gremlin.util.ser.GraphBinaryMessageSerializerV1,
                 config: { serializeResultToString: true }}

   Note

   Serializers were moved from the gremlin-driver module to the new gremlin-util module in version 3.7.0. The package changed from org.apache.tinkerpop.gremlin.driver.ser to org.apache.tinkerpop.gremlin.util.ser.

7. In a terminal, navigate to the Gremlin Console directory (apache-tinkerpop-gremlin-console-3.7.2), and then enter the following command to run the Gremlin Console.

   bin/gremlin.sh

   You should see the following output:

            \,,,/
            (o o)
   -----oOOo-(3)-oOOo-----
   plugin activated: tinkerpop.server
   plugin activated: tinkerpop.utilities
   plugin activated: tinkerpop.tinkergraph
   gremlin> 

   You are now at the gremlin> prompt. You will enter the remaining steps at this prompt.

8. At the gremlin> prompt, enter the following to connect to the Neptune DB instance.

   :remote connect tinkerpop.server conf/neptune-remote.yaml

9. At the gremlin> prompt, enter the following to switch to remote mode. This sends all Gremlin queries to the remote connection.

   :remote console

10. Enter the following to send a query to the Gremlin Graph.

    g.V().limit(1)

11. When you are finished, enter the following to exit the Gremlin Console.

    :exit