ksqlDB is a database purpose-built for stream processing applications on top of Apache Kafka®.

Kpow can connect to your ksqlDB server like any other Kafka resource.

Use the following configuration to set up Kpow with ksqlDB. For documentation on ksqlDB usage within Kpow, see: %{ link id="ksqldb-usage" product="kpow-ee" /%}.



The following connects to a standard ksqlDB server using the standard REST API.

Kpow connects to a ksqlDB server with environment variables.

KSQLDB_NAMEfalseUI and logs friendly name for this ksqlDB server.
KSQLDB_HOSTtrueThe hostname for this ksqlDB server connection.
KSQLDB_PORTtrueThe port for this ksqlDB server connection.
KSQLDB_QUERY_MAX_ROWSfalseThe maximum number of rows to be returned from a pull query (default: 100).
KSQLDB_INSERT_MAX_ROWSfalseThe maximum number of rows to be buffered when inserting data (default: 200).
KSQLDB_USE_ALPNfalseSets whether ALPN should be used. Defaults to false.
KSQLDB_USE_TLSfalseSets whether TLS should be used. Defaults to false.
KSQLDB_VERIFY_HOSTfalseSets whether hostname verification (for TLS) is enabled. Defaults to true.
KSQLDB_TRUSTSTOREfalseSets the trust store path.
KSQLDB_TRUSTSTORE_PASSWORDfalseSets the trust store password.
KSQLDB_KEYSTOREfalseSets the key store path.
KSQLDB_KEYSTORE_PASSWORDfalseSets the key store password.
KSQLDB_KEY_PASSWORDfalseSets the key password.
KSQLDB_KEY_ALIASfalseSets the key alias.
KSQLDB_BASIC_AUTH_USERfalseSets the username to be used for HTTP basic authentication when connecting to the ksqlDB server.
KSQLDB_BASIC_AUTH_PASSWORDfalseSets the password to be used for HTTP basic authentication when connecting to the ksqlDB server.
KSQLDB_RESOURCE_IDSfalseComma separated list of unique ids. Only specify when configuring multiple ksqlDB servers.
KSQLDB_SCHEMA_REGISTRYfalseThe schema registry ID associated to this ksqlDB instance.

Confluent Cloud

Kpow's ksqlDB integration works with Confluent Cloud's hosted ksqlDB server.

Generate API keys

Generate an API key for Kpow to use. You can do this by installing the Confluent command-line tools and running:

confluent login
confluent environment use $ENVIRONMENT_NAME
confluent kafka cluster use $CLUSTER_ID
confluent api-key create --resource $KSQLDB_ID

You can find references to the various IDs of your resources inside Confluent Cloud's web UI.

Configure Kpow

The following example configuration connects Kpow to Confluent Cloud's managed ksqlDB:

KSQLDB_NAME="Confluent ksqlDB"

You can find the hostname for your ksqlDB server within Confluent Cloud's web UI.

The variables API_KEY and API_SECRET come from the secret key you generated in the previous step.

Secure connections (HTTPS/TLS)

If your ksqlDB server has been secured with TLS, you will need to set the KSQLDB_USE_TLS environment variable:

KSQLDB_NAME="Secure ksqlDB"

Additionally, you may need to configure a keystore or truststore as well.

If you use Application-Layer Protocol Negotiation you need to set the KSQLDB_USE_ALPN environment variable as well.

Refer to the configuration table above for a description of each environment variable.

Configuring multiple ksqlDB servers

Kpow supports multiple ksqlDB servers associated to a single Kafka cluster.

To configure multiple ksqlDB servers, use the environment variable KSQLDB_RESOURCE_IDS to define a comma separated list of ksqlDB servers. Kpow uses the resource ID as a prefix in the environment variable.

Example configuration when configuring two ksqlDB servers:


In this example we have defined connections to two ksqlDB resources: DEV1 and QA2

Note: The values for KSQLDB_RESOURCE_IDS must be upper-case like DEV1 and not dev1.

Schema Registry integration

Kpow can link together a ksqlDB server with any configured Schema Registry.

This integration provides inline schema information within the ksqlDB UI, as well quick links to edit schemas and inspect raw topic data using Avro, Protobuf or JSON Schema.

This feature is enabled automatically if you only have a single schema registry resource configured for your cluster.

If you have more than one schema registry configured (using SCHEMA_REGISTRY_RESOURCE_IDS), you can use the KSQLDB_SCHEMA_REGISTRY environment variable to link a ksqlDB server to a schema registry.

Example configuration linking a schema registry named LOCAL to a ksqlDB sever:


Access control

User permissions to Kafka cluster resources are defined by ksqlDB actions. See: User authorization.

See ksqlDB for more details about configuring RBAC policies for ksqlDB.