Install and Configure ksqlDB for Confluent Platform

Youp have a number of options for installing and configuring ksqlDB.

ksqlDB is available as part of Confluent Platform and Confluent Cloud. For Confluent Platform, the binaries are included in the Confluent Platform bundle available at https://www.confluent.io/download/. ksqlDB requires access to a running Apache Kafka® cluster.

You can also install ksqlDB individually using the Docker images available at Docker Hub.

Start the ksqlDB Server

The command to start the server is ksql-server-start ${CONFLUENT_HOME}/etc/ksqldb/ksql-server.properties.

You must specify configuration parameters, including required parameters like bootstrap.servers and listeners. You can set these in the ksqlDB properties file or the KSQL_OPTS environment variable, which takes precedence. The default settings are bootstrap.servers=localhost:9092 and listeners=http://0.0.0.0:8088.

Confluent Control Center can also be configured to interact with ksqlDB Server. This involves settings like confluent.controlcenter.ksql.<ksql-cluster-name>.url and confluent.controlcenter.ksql.<ksql-cluster-name>.advertised.url. Ensure these URLs are reachable from the Confluent Control Center machine and any browser using the ksqlDB web interface. There are also settings for HTTP Basic Authentication and Secure Sockets Layer (SSL) configuration.

Start the ksqlDB Command Line Interface (CLI)

Start the CLI by using the ksql command provided with the Confluent Platform distribution. The CLI provides options like --output to specify the output format (JSON or TABULAR), and --password or -p for authentication, if configured.