org.apache.kudu.client

Class KuduClient

java.lang.Object

org.apache.kudu.client.KuduClient

All Implemented Interfaces:

AutoCloseable

@InterfaceAudience.Public
 @InterfaceStability.Evolving
public class KuduClient
extends Object
implements AutoCloseable

A synchronous and thread-safe client for Kudu.

This class acts as a wrapper around AsyncKuduClient which contains all the relevant documentation.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	KuduClient.KuduClientBuilder Builder class to use in order to connect to Kudu.

Field Summary

Fields

Modifier and Type	Field and Description
static org.slf4j.Logger	LOG

Method Summary

Modifier and Type	Method and Description
AlterTableResponse	alterTable(String name, AlterTableOptions ato) Alter a table on the cluster as specified by the builder.
void	close() Analogous to shutdown().
KuduTable	createTable(String name, Schema schema, CreateTableOptions builder) Create a table on the cluster with the specified name, schema, and table configurations.
DeleteTableResponse	deleteTable(String name) Delete a table on the cluster with the specified name.
byte[]	exportAuthenticationCredentials() Export serialized authentication data that may be passed to a different client instance and imported to provide that client the ability to connect to the cluster.
long	getDefaultAdminOperationTimeoutMs() Get the timeout used for admin operations.
long	getDefaultOperationTimeoutMs() Get the timeout used for operations on sessions and scanners.
String	getMasterAddressesAsString()
Statistics	getStatistics() Get the statistics object of this client.
ListTablesResponse	getTablesList() Get the list of all the tables.
ListTablesResponse	getTablesList(String nameFilter) Get a list of table names.
void	importAuthenticationCredentials(byte[] authnData) Import data allowing this client to authenticate to the cluster.
boolean	isAlterTableDone(String name) Helper method that checks and waits until the completion of an alter command.
boolean	isStatisticsEnabled() Check if statistics collection is enabled for this client.
ListTabletServersResponse	listTabletServers() Get the list of running tablet servers.
KuduScanner.KuduScannerBuilder	newScannerBuilder(KuduTable table) Creates a new KuduScanner.KuduScannerBuilder for a particular table.
KuduScanToken.KuduScanTokenBuilder	newScanTokenBuilder(KuduTable table) Creates a new KuduScanToken.KuduScanTokenBuilder for a particular table.
KuduSession	newSession() Create a new session for interacting with the cluster.
KuduTable	openTable(String name) Open the table with the given name.
void	shutdown() Performs a graceful shutdown of this instance.
boolean	tableExists(String name) Test if a table exists.

Methods inherited from class java.lang.Object

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

Field Detail

LOG

public static final org.slf4j.Logger LOG

Method Detail

createTable

public KuduTable createTable(String name,
                             Schema schema,
                             CreateTableOptions builder)
                      throws KuduException

Create a table on the cluster with the specified name, schema, and table configurations.

Parameters:

name - the table's name

schema - the table's schema

builder - a builder containing the table's configurations

Returns:

an object to communicate with the created table

Throws:

KuduException - if anything went wrong

deleteTable

public DeleteTableResponse deleteTable(String name)
                                throws KuduException

Delete a table on the cluster with the specified name.

Parameters:

name - the table's name

Returns:

an rpc response object

Throws:

KuduException - if anything went wrong

alterTable

public AlterTableResponse alterTable(String name,
                                     AlterTableOptions ato)
                              throws KuduException

Alter a table on the cluster as specified by the builder. When the method returns it only indicates that the master accepted the alter command, use isAlterTableDone(String) to know when the alter finishes.

Parameters:

name - the table's name, if this is a table rename then the old table name must be passed

ato - the alter table builder

Returns:

an rpc response object

Throws:

KuduException - if anything went wrong

isAlterTableDone

public boolean isAlterTableDone(String name)
                         throws KuduException

Helper method that checks and waits until the completion of an alter command. It will block until the alter command is done or the timeout is reached.

Parameters:

name - Table's name, if the table was renamed then that name must be checked against

Returns:

a boolean indicating if the table is done being altered

Throws:

KuduException - for any error returned by sending RPCs to the master

listTabletServers

public ListTabletServersResponse listTabletServers()
                                            throws KuduException

Get the list of running tablet servers.

Returns:

a list of tablet servers

Throws:

KuduException - if anything went wrong

getTablesList

public ListTablesResponse getTablesList()
                                 throws KuduException

Get the list of all the tables.

Returns:

a list of all the tables

Throws:

KuduException - if anything went wrong

getTablesList

public ListTablesResponse getTablesList(String nameFilter)
                                 throws KuduException

Get a list of table names. Passing a null filter returns all the tables. When a filter is specified, it only returns tables that satisfy a substring match.

Parameters:

nameFilter - an optional table name filter

Returns:

a deferred that contains the list of table names

Throws:

KuduException - if anything went wrong

tableExists

public boolean tableExists(String name)
                    throws KuduException

Test if a table exists.

Parameters:

name - a non-null table name

Returns:

true if the table exists, else false

Throws:

KuduException - if anything went wrong

openTable

public KuduTable openTable(String name)
                    throws KuduException

Open the table with the given name. If the table was just created, this method will block until all its tablets have also been created.

Parameters:

name - table to open

Returns:

a KuduTable if the table exists

Throws:

KuduException - if anything went wrong

newSession

public KuduSession newSession()

Create a new session for interacting with the cluster. User is responsible for destroying the session object. This is a fully local operation (no RPCs or blocking).

Returns:

a synchronous wrapper around KuduSession.

isStatisticsEnabled

public boolean isStatisticsEnabled()

Check if statistics collection is enabled for this client.

Returns:

true if it is enabled, else false

getStatistics

public Statistics getStatistics()

Get the statistics object of this client.

Returns:

this client's Statistics object

Throws:

IllegalStateException - thrown if statistics collection has been disabled

newScannerBuilder

public KuduScanner.KuduScannerBuilder newScannerBuilder(KuduTable table)

Creates a new KuduScanner.KuduScannerBuilder for a particular table.

Parameters:

table - the table you intend to scan. The string is assumed to use the platform's default charset.

Returns:

a new scanner builder for the table

newScanTokenBuilder

public KuduScanToken.KuduScanTokenBuilder newScanTokenBuilder(KuduTable table)

Creates a new KuduScanToken.KuduScanTokenBuilder for a particular table. Used for integrations with compute frameworks.

Parameters:

table - the table you intend to scan

Returns:

a new scan token builder for the table

close

public void close()
           throws KuduException

Analogous to shutdown().

Specified by:

close in interface AutoCloseable

Throws:

KuduException - if an error happens while closing the connections

shutdown

public void shutdown()
              throws KuduException

Performs a graceful shutdown of this instance.

Throws:

KuduException - if anything went wrong

exportAuthenticationCredentials

@InterfaceStability.Unstable
public byte[] exportAuthenticationCredentials()
                                                                    throws KuduException

Export serialized authentication data that may be passed to a different client instance and imported to provide that client the ability to connect to the cluster.

Throws:

KuduException

importAuthenticationCredentials

@InterfaceStability.Unstable
public void importAuthenticationCredentials(byte[] authnData)

Import data allowing this client to authenticate to the cluster. This will typically be used before making any connections to servers in the cluster. Note that, if this client has already been used by one user, this method cannot be used to switch authenticated users. Attempts to do so have undefined results, and may throw an exception.

Parameters:

authnData - then authentication data provided by a prior call to exportAuthenticationCredentials()

getDefaultOperationTimeoutMs

public long getDefaultOperationTimeoutMs()

Get the timeout used for operations on sessions and scanners.

Returns:

a timeout in milliseconds

getDefaultAdminOperationTimeoutMs

public long getDefaultAdminOperationTimeoutMs()

Get the timeout used for admin operations.

Returns:

a timeout in milliseconds

getMasterAddressesAsString

public String getMasterAddressesAsString()

Returns:

the list of master addresses, stringified using commas to separate them