> ## Documentation Index
> Fetch the complete documentation index at: https://docs.streamnative.io/llms.txt
> Use this file to discover all available pages before exploring further.

# Configure KoP

Kafka on Pulsar (KoP) brings the native Apache Kafka protocol support to Apache Pulsar by introducing a Kafka protocol handler on Pulsar brokers. By adding the KoP protocol handler to your existing Pulsar cluster, you can now migrate your existing Kafka applications and services to Pulsar without modifying the code.

## Enable KoP

To enable KoP access within a Kubernetes cluster, you can configure the `<components>.kop` property of the StreamNative Platform in the `values.yaml` YAML file as follows, and use the `helm upgrade` command to update the resource.

1. Enable KoP.

   ```yaml theme={null}
   broker:
     kop:
       enabled: true
   ```

2. Apply the new configuration.

   ```bash theme={null}
   helm upgrade -f /path/to/your/values.yaml <release_name> streamnative/sn-platform -n <k8s_namespace>
   ```

<Note title="Note">
  To access KoP outside a Kubernetes cluster, you need to install [Istio](https://istio.io/latest/about/service-mesh/) and Istio Ingress Gateway, and enable TLS for Istio Ingress Gateway. For details, see [configure Istio](/private-cloud/v1/operating-streamnative-platform/network/istio).
</Note>

## Connect to your Pulsar cluster using the Kafka Java client

This example shows how to use the Kafka Java client to connect to a Pulsar cluster and then produce and consume messages to and from the Pulsar cluster.

Currently, StreamNative Platform supports Kafka Client v1.0.0 - v2.6.0.

### Prerequisites

* Install Java 1.8.0 or higher version.
* Install Istio. For details, see [install Istio for KoP access](/private-cloud/v1/operating-streamnative-platform/deploy/sn-plan#install-istio-for-kop-access).

### Steps

1. Grant produce and consume permission to the Admin role on the namespace.

   ```bash theme={null}
   pulsarctl namespaces grant-permission --role ROLE_NAME --actions produce,consume NAMESPACE_NAME
   ```

2. Configure [KoP SSL connection](id:tls-proxy#tls-encryption-kop) and enable KoP.

   KoP starts up together with the Pulsar broker. By default, KoP is enabled. You can set the following options based on your KoP SSL connection.

   ```yaml theme={null}
   broker:
     # set your own domain for accessing kop outside from the cluster
     advertisedDomain: ''
     kop:
       enabled: true
       tls:
         enabled: true
         # create a secret with keystore.jks and truststore.jks for kop tls security
         certSecretName: 'kop-secret'
         # create a secret for keystore and truststore cert
         passwordSecretRef:
           key: password
           name: kop-keystore-password
   ```

3. Get the external IP address of the Istio gateway service.

   ```bash theme={null}
   kubectl get svc/istio-ingressgateway -n <k8s_namespace>
   ```

4. Install Kafka client.

   a. Download the [Kafka client 2.2.0](https://kafka.apache.org/downloads). In this example, Kafka 2.2.0 is used because the default configuration of the producer's `retries` parameter is changed from `0` to `2147483647` since Kafka 2.1.0.

   ```bash theme={null}
   curl -O https://archive.apache.org/dist/kafka/2.2.0/kafka_2.11-2.2.0.tgz
   ```

   b. Extract the downloaded package.

   ```bash theme={null}
   tar -xf kafka_2.11-2.2.0.tgz
   ```

5. Prepare a file named `client-ssl.properties`. The file contains the following information.

   ```conf theme={null}
   security.protocol=SASL_SSL
   ssl.truststore.location=client.truststore.jks
   ssl.truststore.password=client
   ssl.endpoint.identification.algorithm=
   sasl.mechanism=PLAIN
   sasl.jaas.config=org.apache.kafka.common.security.scram.ScramLoginModule required username="USER_NAME" password="token:[YOUR_TOKEN]";
   ```

6. Run a Kafka client.

   a. Enter the Kafka client directory.

   ```bash theme={null}
   cd kafka_2.11-2.2.0
   ```

   b. Start a Kafka producer and send a message from the Kafka producer..

   ```bash theme={null}
   kafka-console-producer.sh --broker-list kop_service_url:9093 --topic TOPIC_NAME --producer.config client-ssl.properties
   > message-for-kafka-client
   ```

   c. Start a Kafka consumer.

   ```bash theme={null}
   kafka-console-consumer.sh --bootstrap-server kop_service_url:9093 --topic TOPIC_NAME --consumer.config client-ssl.properties
   ```

   At the same time, you can receive the message `message-for-kafka-client`.