Package org.apache.druid.segment.metadata

Class CentralizedDatasourceSchemaConfig

java.lang.Object

org.apache.druid.segment.metadata.CentralizedDatasourceSchemaConfig

public class CentralizedDatasourceSchemaConfig
extends Object

Config for caching and managing datasource schema on the Coordinator. This config is used by the following services:

• Coordinator: to enable backfill of segment schema in the metadata store and caching of schema in memory.
• Overlord: to enable publish of schema when segments are committed.
• Peons: to enable inclusion of schema in segment publish requests.
• Brokers: to enable polling of cached schema from the Coordinator.

The corresponding segment schemas table is created in the metadata store only when this config is enabled for the first time on a cluster. Subsequent disabling of this config does not drop the table but the services do not read or update it anymore.

Field Summary

Fields

Modifier and Type	Field	Description
static final String	PROPERTY_PREFIX
static final int	SCHEMA_VERSION	Currently supported version of segment schema format.

Constructor Summary

Constructors

Constructor	Description
CentralizedDatasourceSchemaConfig(Boolean enabled, Boolean backFillEnabled, Long backFillPeriod, Boolean taskSchemaPublishDisabled)

Method Summary

Modifier and Type	Method	Description
static CentralizedDatasourceSchemaConfig	create()
static CentralizedDatasourceSchemaConfig	enabled(boolean enabled)
long	getBackFillPeriodInMillis()	Period in milliseconds dictating the frequency of the schema backfill job.
boolean	isBackFillEnabled()
boolean	isEnabled()
boolean	isTaskSchemaPublishDisabled()	Config used to disable publishing of schema when a task commits segments.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

PROPERTY_PREFIX

public static final String PROPERTY_PREFIX

See Also:

• Constant Field Values

SCHEMA_VERSION

public static final int SCHEMA_VERSION

Currently supported version of segment schema format. The schema cache can contain schemas for only this version.

See Also:

• Constant Field Values

Constructor Details

CentralizedDatasourceSchemaConfig

public CentralizedDatasourceSchemaConfig(@Nullable
 Boolean enabled,
 @Nullable
 Boolean backFillEnabled,
 @Nullable
 Long backFillPeriod,
 @Nullable
 Boolean taskSchemaPublishDisabled)

Method Details

isEnabled

public boolean isEnabled()

isBackFillEnabled

public boolean isBackFillEnabled()

getBackFillPeriodInMillis

public long getBackFillPeriodInMillis()

Period in milliseconds dictating the frequency of the schema backfill job.

isTaskSchemaPublishDisabled

public boolean isTaskSchemaPublishDisabled()

Config used to disable publishing of schema when a task commits segments. This config is used only in integration tests to verify that schema is populated correctly even when tasks fail to publish the schema.

create

public static CentralizedDatasourceSchemaConfig create()

Returns:

Default config with schema management and caching disabled.

enabled

public static CentralizedDatasourceSchemaConfig enabled(boolean enabled)