com.google.cloud.spanner

Interface Spanner

All Superinterfaces:

AutoCloseable, com.google.cloud.Service<SpannerOptions>

public interface Spanner
extends com.google.cloud.Service<SpannerOptions>, AutoCloseable

An interface for Cloud Spanner. Typically, there would only be one instance of this for the lifetime of the application which must be closed by invoking close() when it is no longer needed. Failure to do so may result in leaking session resources and exhausting session quota.

Method Summary

Modifier and Type	Method and Description
void	close() Closes all the clients associated with this instance and frees up all the resources.
BatchClient	getBatchClient(DatabaseId db) Returns a BatchClient to do batch operations on Cloud Spanner databases.
DatabaseAdminClient	getDatabaseAdminClient() Returns a DatabaseAdminClient to do admin operations on Cloud Spanner databases.
DatabaseClient	getDatabaseClient(DatabaseId db) Returns a DatabaseClient for the given database.
InstanceAdminClient	getInstanceAdminClient() Returns an InstanceAdminClient to do admin operations on Cloud Spanner instances.
boolean	isClosed()

Methods inherited from interface com.google.cloud.Service

getOptions

Method Detail

getDatabaseAdminClient

DatabaseAdminClient getDatabaseAdminClient()

Returns a DatabaseAdminClient to do admin operations on Cloud Spanner databases.

getInstanceAdminClient

InstanceAdminClient getInstanceAdminClient()

Returns an InstanceAdminClient to do admin operations on Cloud Spanner instances.

getDatabaseClient

DatabaseClient getDatabaseClient(DatabaseId db)

Returns a DatabaseClient for the given database. It uses a pool of sessions to talk to the database.

 SpannerOptions options = SpannerOptions.newBuilder().build();
 Spanner spanner = options.getService();
 final String project = "test-project";
 final String instance = "test-instance";
 final String database = "example-db";
 DatabaseId db =
     DatabaseId.of(project, instance, database);
 DatabaseClient dbClient = spanner.getDatabaseClient(db);
 

getBatchClient

BatchClient getBatchClient(DatabaseId db)

Returns a BatchClient to do batch operations on Cloud Spanner databases. Batch client is useful when one wants to read/query a large amount of data from Cloud Spanner across multiple processes, even across different machines. It allows to create partitions of Cloud Spanner database and then read/query over each partition independently yet at the same snapshot.

For all other use cases, DatabaseClient is more appropriate and performant.

 SpannerOptions options = SpannerOptions.newBuilder().build();
 Spanner spanner = options.getService();
 final String project = "test-project";
 final String instance = "test-instance";
 final String database = "example-db";
 DatabaseId db =
     DatabaseId.of(project, instance, database);
 BatchClient batchClient = spanner.getBatchClient(db);
 

close

void close()

Closes all the clients associated with this instance and frees up all the resources. This method will block until it can clean up all the resources. Specifically, it deletes all the underlying sessions (which involves rpcs) and closes all the gRPC channels. Once this method called, this object is no longer usable. It is strongly advised to call this method when you are done with the Spanner object, typically when your application shuts down. There is a hard limit on number of sessions in Cloud Spanner and not calling this method can lead to unused sessions piling up on the backend.

Specified by:

close in interface AutoCloseable

isClosed

boolean isClosed()

Returns:

true if this Spanner object is closed.