Configuration

Learn how to configure the extensions for Apache Iceberg.

Here, you will find the configuration properties for the Apache Iceberg extension.

Configuration

The Apache Iceberg extension connects to an Iceberg catalog. You configure it through the Jikkou client configuration property jikkou.provider.iceberg.

Example (JDBC catalog with PostgreSQL):

jikkou {
  provider.iceberg {
    enabled = true
    type = io.streamthoughts.jikkou.iceberg.IcebergExtensionProvider
    config = {
      # Required — type of Iceberg catalog.
      # Accepted values: rest, hive, jdbc, glue, nessie, hadoop
      catalogType = "jdbc"

      # The catalog name used to identify this catalog instance.
      catalogName = "default"

      # The URI of the catalog endpoint (REST URL, Hive Metastore URI, JDBC URL, etc.)
      catalogUri = "jdbc:postgresql://localhost:5432/iceberg"

      # The warehouse root location (e.g., local path, S3 bucket path, HDFS path)
      warehouse = "/tmp/iceberg-warehouse"

      # Extra catalog-specific properties passed directly to CatalogUtil.buildIcebergCatalog()
      catalogProperties {
        jdbc.user     = "iceberg"
        jdbc.password = "iceberg"
      }

      # Enable verbose debug logging for catalog operations (default: false)
      debugLoggingEnabled = false
    }
  }
}

Configuration Properties

Property	Type	Required	Default	Description
`catalogType`	String	yes	—	Iceberg catalog type: `rest`, `hive`, `jdbc`, `glue`, `nessie`, `hadoop`
`catalogName`	String	no	`default`	The catalog instance name
`catalogUri`	String	no	—	Catalog endpoint URI (REST API URL, Hive Metastore thrift URI, JDBC URL, Nessie server URL)
`warehouse`	String	no	—	Warehouse root location (e.g., `s3://bucket/warehouse`, `/tmp/iceberg`)
`catalogProperties`	Map	no	—	Additional catalog properties forwarded verbatim to the Iceberg `CatalogUtil`
`debugLoggingEnabled`	Boolean	no	`false`	Enable debug-level logging for catalog operations

Catalog Types

JDBC Catalog (PostgreSQL)

Stores catalog metadata (namespaces, table specs) in a relational database. The PostgreSQL JDBC driver is bundled in the Jikkou CLI distribution.

config = {
  catalogType = "jdbc"
  catalogUri  = "jdbc:postgresql://localhost:5432/iceberg"
  warehouse   = "/tmp/iceberg-warehouse"
  catalogProperties {
    jdbc.user     = "iceberg"
    jdbc.password = "iceberg"
  }
}

REST Catalog

Connects to any Iceberg REST Catalog API (e.g., Polaris, Gravitino, Unity Catalog):

config = {
  catalogType = "rest"
  catalogUri  = "https://polaris.example.com/api/catalog"
  warehouse   = "s3://my-bucket/warehouse"
  catalogProperties {
    rest.signing-name   = "execute-api"
    rest.signing-region = "us-east-1"
  }
}

Hive Metastore

Connects to an Apache Hive Metastore (requires iceberg-hive-metastore on the classpath):

config = {
  catalogType = "hive"
  catalogUri  = "thrift://hive-metastore:9083"
  warehouse   = "hdfs://namenode:8020/user/hive/warehouse"
}

AWS Glue

Connects to AWS Glue Data Catalog (requires iceberg-aws on the classpath):

config = {
  catalogType = "glue"
  warehouse   = "s3://my-bucket/warehouse"
  catalogProperties {
    glue.region = "us-east-1"
  }
}

Nessie

Nessie exposes a standard Iceberg REST catalog endpoint at /iceberg. Using catalogType = "rest" is recommended because it relies only on iceberg-core (always bundled in the Jikkou CLI). The catalogType = "nessie" variant requires the optional iceberg-nessie JAR on the classpath.

# Recommended: use Nessie's built-in Iceberg REST endpoint
config = {
  catalogType = "rest"
  catalogUri  = "http://nessie:19120/iceberg"
  warehouse   = "s3://my-bucket/warehouse"
  catalogProperties {
    prefix = "main"   # Nessie branch
  }
}

Controller Settings

The table and view controllers expose additional options to control reconciliation behaviour. These are set inside the provider config block.

Table Controller

Property	Type	Default	Description
`delete-orphans`	Boolean	`false`	Drop tables that exist in the catalog but are not defined in any resource
`delete-orphan-columns`	Boolean	`false`	Drop columns present in the live table but absent from the spec
`delete-purge`	Boolean	`false`	Purge underlying data files when dropping a table (irreversible)
`tables.deletion.exclude`	List<Pattern>	`[]`	Regex patterns — matching table names are never deleted

View Controller

Property	Type	Default	Description
`delete-orphans`	Boolean	`false`	Drop views that exist in the catalog but are not defined in any resource
`views.deletion.exclude`	List<Pattern>	`[]`	Regex patterns — matching view names are never deleted

Note

The delete-orphans property applies independently to tables and views. The IcebergNamespaceController always uses delete-orphans = false to prevent accidental deletion of namespaces that may still contain tables. To delete a namespace, use the DELETE reconciliation mode explicitly.

Example:

jikkou {
  provider.iceberg {
    enabled = true
    type = io.streamthoughts.jikkou.iceberg.IcebergExtensionProvider
    config = {
      catalogType = "rest"
      catalogUri  = "http://localhost:8181"
      warehouse   = "s3://my-bucket/warehouse"

      # Table reconciliation safety settings
      delete-orphans        = false
      delete-orphan-columns = false
      delete-purge          = false

      # Never delete tables whose name starts with "audit_"
      tables.deletion.exclude = ["^audit_.*"]

      # Never delete views whose name starts with "v_core_"
      views.deletion.exclude = ["^v_core_.*"]
    }
  }
}