Storage API

This module contains the API for working with data storages.

Adding a new data store

To add a new data storage you need:

• Add a new module;
• Implement interfaces:
  • org.apache.ignite.internal.storage.DataStorageModule;
  • org.apache.ignite.internal.storage.engine.StorageEngine;
  • org.apache.ignite.internal.storage.engine.TableStorage;
  • org.apache.ignite.internal.storage.PartitionStorage;
  • org.apache.ignite.internal.storage.index.SortedIndexStorage;
• Add configuration:
  • Add an inheritor of org.apache.ignite.configuration.schemas.store.DataStorageConfigurationSchema, with type equal to org.apache.ignite.internal.storage.engine.StorageEngine.name;
  • If necessary, add a specific configuration of the data storage engine;
  • Implement org.apache.ignite.internal.configuration.ConfigurationModule;
• Add services (which are loaded via java.util.ServiceLoader.load(java.lang.Class<S>)):
  • Implementation of org.apache.ignite.internal.storage.DataStorageModule;
  • Implementation of org.apache.ignite.internal.configuration.ConfigurationModule.

Take org.apache.ignite.internal.storage.chm.TestConcurrentHashMapStorageEngine as an example.

Usage

For each table, you need to specify the data storage, which is located in org.apache.ignite.configuration.schemas.table.TableConfigurationSchema.dataStorage.

Configuration example in HOCON:

tables.table {
    name = schema.table,
    columns.id {name = id, type.type = STRING, nullable = true},
    primaryKey {columns = [id], colocationColumns = [id]},
    indices.foo {type = HASH, name = foo, colNames = [id]},
    dataStorage {name = rocksdb, dataRegion = default}
}

Configuration example in java:

TableConfiguration tableConfig = ...;

// Change data storage.
tableConfig.dataStorage().change(c -> c.convert(RocksDbDataStorageChange.class).changeDataRegion("default")).get(1, TimeUnit.SECONDS);

// Get data storage.
RocksDbDataStorageView dataStorageView = (RocksDbDataStorageView) tableConfig().dataStorage().value();

String dataRegion = dataStorageView.dateRegion();

To get the data storage engine, you need to use org.apache.ignite.internal.storage.DataStorageManager.engine(org.apache.ignite.configuration.schemas.store.DataStorageConfiguration).