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Flink Integration#

Connecting to the Feature Store from an external Flink cluster, such as AWS EMR and GCP DataProc requires configuring it with the Hopsworks certificates. This guide explains step by step how to connect to the Feature Store from an external Flink cluster.

Download the Hopsworks Certificates#

In the Project Settings, select the integration tab and scroll to the Configure Spark Integration section. Click on Download certificates.

Spark integration tab
The Spark Integration gives access to Jars and configuration for an external Spark cluster

Hopsworks uses X.509 certificates for authentication and authorization. If you are interested in the Hopsworks security model, you can read more about it in this blog post. The certificates are composed of three different components: the keyStore.jks containing the private key and the certificate for your project user, the trustStore.jks containing the certificates for the Hopsworks certificates authority, and a password to unlock the private key in the keyStore.jks. The password is displayed in a pop-up when downloading the certificate and should be saved in a file named material_passwd.


When you copy-paste the password to the material_passwd file, pay attention to not introduce additional empty spaces or new lines.

The three files (keyStore.jks, trustStore.jks and material_passwd) should be accessible by your Flink application.

Add the following configuration to the flink-conf.yaml: replace_this_with_actual_path/keyStore.jks replace_this_with_actual_path/trustStore.jks replace_this_with_actual_path/material_passwd

Generating an API Key#

For instructions on how to generate an API key follow this user guide. For the Flink integration to work correctly make sure you add the following scopes to your API key:

  1. featurestore
  2. project
  3. job
  4. kafka

Connecting to the Feature Store#

You are now ready to connect to the Hopsworks Feature Store from Flink:

//Establish connection with Hopsworks.
HopsworksConnection hopsworksConnection = HopsworksConnection.builder()
  .host("my_instance")                      // DNS of your Feature Store instance
  .port(443)                                // Port to reach your Hopsworks instance, defaults to 443
  .project("my_project")                    // Name of your Hopsworks Feature Store project 
  .apiKeyValue("api_key")                   // The API key to authenticate with the feature store
  .hostnameVerification(false)              // Disable for self-signed certificates

//get feature store handle
FeatureStore fs = hopsworksConnection.getFeatureStore();

Next Steps#

For more information and how to integrate Flink streaming feature pipeline to the Hopsworks Feature store follow the tutorial.