Required external components
Druid uses an SQL database to store metadata. Consult the Druid documentation for a list of supported databases and setup instructions.
Feature specific: S3 and cloud deep storage
Deep storage is where segments are stored. Druid offers multiple storage backends. For the local storage there are no prerequisites. HDFS deep storage can be set up with the Stackable Operator for Apache HDFS. For S3 deep storage or the Google Cloud and Azure storage backends, you need to set up the storage.
Read the deep storage usage guide to learn more about configuring Druid deep storage.