Package org.apache.druid.metadata.segment

Class SqlSegmentMetadataTransactionFactory

java.lang.Object

org.apache.druid.metadata.segment.SqlSegmentMetadataReadOnlyTransactionFactory

org.apache.druid.metadata.segment.SqlSegmentMetadataTransactionFactory

All Implemented Interfaces:

SegmentMetadataTransactionFactory

public class SqlSegmentMetadataTransactionFactory
extends SqlSegmentMetadataReadOnlyTransactionFactory

Factory for SegmentMetadataTransactions. If the SegmentMetadataCache is enabled and ready, the transaction may read/write from the cache as applicable.

This class serves as a wrapper over the SQLMetadataConnector to perform transactions specific to segment metadata.

Only the Overlord can perform write operations on the metadata store or the cache via this transaction factory. The Coordinator performs read operations directly on the metadata store and uses the cache only to build the timeline in SqlSegmentsMetadataManagerV2. There is currently only one method called by the Coordinator that could benefit from reading from the cache, MetadataResource.getUsedSegmentsInDataSourceForIntervals(), but for now, it continues to read directly from the metadata store for consistency with older Druid versions.

Constructor Summary

Constructors

Constructor	Description
SqlSegmentMetadataTransactionFactory(com.fasterxml.jackson.databind.ObjectMapper jsonMapper, MetadataStorageTablesConfig tablesConfig, SQLMetadataConnector connector, DruidLeaderSelector leaderSelector, SegmentMetadataCache segmentMetadataCache, ServiceEmitter emitter)

Method Summary

Modifier and Type	Method	Description
<T> T	inReadOnlyDatasourceTransaction(String dataSource, SegmentMetadataReadTransaction.Callback<T> callback)	Creates and executes a new read-only transaction for the given datasource.
<T> T	inReadWriteDatasourceTransaction(String dataSource, SegmentMetadataTransaction.Callback<T> callback)	Creates and executes a new read-write transaction for the given datasource.

Methods inherited from class org.apache.druid.metadata.segment.SqlSegmentMetadataReadOnlyTransactionFactory

createSqlTransaction, executeReadAndClose, getMaxRetries, getQuietRetries

Methods inherited from class java.lang.Object

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

Constructor Details

SqlSegmentMetadataTransactionFactory

@Inject
public SqlSegmentMetadataTransactionFactory(com.fasterxml.jackson.databind.ObjectMapper jsonMapper,
 MetadataStorageTablesConfig tablesConfig,
 SQLMetadataConnector connector,
 DruidLeaderSelector leaderSelector,
 SegmentMetadataCache segmentMetadataCache,
 ServiceEmitter emitter)

Method Details

inReadOnlyDatasourceTransaction

public <T> T inReadOnlyDatasourceTransaction(String dataSource,
 SegmentMetadataReadTransaction.Callback<T> callback)

Description copied from interface: SegmentMetadataTransactionFactory

Creates and executes a new read-only transaction for the given datasource. The implementation may retry the transaction until it succeeds.

Specified by:

inReadOnlyDatasourceTransaction in interface SegmentMetadataTransactionFactory

Overrides:

inReadOnlyDatasourceTransaction in class SqlSegmentMetadataReadOnlyTransactionFactory

inReadWriteDatasourceTransaction

public <T> T inReadWriteDatasourceTransaction(String dataSource,
 SegmentMetadataTransaction.Callback<T> callback)

Description copied from interface: SegmentMetadataTransactionFactory

Creates and executes a new read-write transaction for the given datasource. The implementation may retry the transaction until it succeeds.

Specified by:

inReadWriteDatasourceTransaction in interface SegmentMetadataTransactionFactory

Overrides:

inReadWriteDatasourceTransaction in class SqlSegmentMetadataReadOnlyTransactionFactory