3.2 Restart a Notebook Server

Introduction

Now that we have a working Kafka Instance we can connect to, we can try out sending and receiving messages from a Jupyter notebook. We’ll start a notebook and connect to your new Kafka instance. Then, we’ll show a different kind of application using the exact same prediction code to consume and produce streaming data.

For now, return to Red Hat OpenShift Data Science and navigate to JupyterHub.

Stopping a Notebook

If you’re notebook is currently running, you might want to restart with a new base image or different settings. In this case, we need to restart our notebook with our Kafka connection information from the Hub Control Panel (Start a notebook server page).

  • Navigate through the menu to File → Hub Control Panel

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  • Click the Stop My Server Button

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  • Wait for the Stop My Server button to disappear and then click the Start My Server Button

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Starting a Notebook to Connect to Kafka

This should bring you back to the now familar "Start a notebook server" page. We’re going to start a notebook with the environment variables necessary to connect to Kafka. Then we can make sure everything is working before we deploy our AI Application.

On the "Start a notebook server" page, enter in the fields.

  • Set Notebook image to TensorFlow.

  • Set Container size to Small

  • Add Environment variables
    To add environment variables click Add more variables for each variable and enter the variable info. Afterwards, to hide the value and save it in a Kubernetes secret, click the secret checkbox.
    Now, add the following three variables with the information you recorded during your Kafka instance creation:

    • Custom Variable

      • Variable name: KAFKA_BOOTSTRAP_SERVER

      • Variable value: Location of the Kafka Bootstrap Server. (e.g. "abc.xyz.kafka.rhcloud.com:443"

    • Custom Variable)

      • Variable name: KAFKA_USERNAME

      • Variable value: Client ID of the Service Account you created (e.g. "srvc-acct-1234-5678-abcd-efgj-12345678abcd")

    • Custom Variable

      • Variable name: KAFKA_PASSWORD

      • Variable value: Client secret of the Service Account you created. (e.g. "abcd1234-5678-abcd-efgj-12345678abcd")

KAFKA_BOOTSTRAP_SERVER
KAFKA_USERNAME
KAFKA_PASSWORD

 

  • Click Start server

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This will start your notebook server. Now you’re ready to head to the next section.