Package org.apache.accumulo.core.client

Interface AccumuloClient

All Superinterfaces:

AutoCloseable

public interface AccumuloClient
extends AutoCloseable

Client connection to an Accumulo instance. Allows the user to request a scanner, deleter or writer for the instance as well as various objects that permit administrative operations. Enforces security on the client side by requiring user credentials.

Supports fluent API for creation. Various options can be provided to Accumulo.newClient() and when finished a call to build() will return the AccumuloClient object. For example:

 
 try (AccumuloClient client = Accumulo.newClient()
        .to(instanceName, zookeepers)
        .as(user, password).build())
 {
   // use the client
 }
 
 

If migrating code from Connector to AccumuloClient an important difference to consider is that AccumuloClient is closable and Connector is not. Connector uses static resources and therefore creating them is cheap. AccumuloClient attempts to clean up resources on close, so constantly creating them could perform worse than Connector. Therefore, it would be better to create an AccumuloClient and pass it around.

AccumuloClient objects are intended to be thread-safe, and can be used by multiple threads. However, care should be taken to ensure that the client is eventually closed, to clean up any resources in use in the client application when all threads are finished with the AccumuloClient object. Additionally, while the client itself is thread-safe, it is not necessarily true that all objects produced from the client (such as Scanners) are thread-safe.

Since:

2.0.0

See Also:

• Accumulo Client Documentation

Nested Class Summary

Nested Classes

Modifier and Type	Interface	Description
static interface	AccumuloClient.AuthenticationArgs<T>	Builder methods for authentication
static interface	AccumuloClient.ClientFactory<T>	Builds AccumuloClient or client Properties after all options have been specified
static interface	AccumuloClient.ConnectionOptions<T>	Build methods for connection options
static interface	AccumuloClient.FromOptions<T>
static interface	AccumuloClient.InstanceArgs<T>	Builder method for setting Accumulo instance and zookeepers
static interface	AccumuloClient.PropertyOptions<T>	Builder methods for creating AccumuloClient using properties
static interface	AccumuloClient.SaslOptions<T>	Build methods for SASL
static interface	AccumuloClient.SslOptions<T>	Build methods for SSL/TLS

Method Summary

Modifier and Type	Method	Description
void	close()	Cleans up any resources created by an AccumuloClient like threads and sockets.
BatchDeleter	createBatchDeleter(String tableName, Authorizations authorizations, int numQueryThreads)	Factory method to create BatchDeleter.
BatchDeleter	createBatchDeleter(String tableName, Authorizations authorizations, int numQueryThreads, BatchWriterConfig config)	Factory method to create BatchDeleter
BatchScanner	createBatchScanner(String tableName)	Factory method to create a BatchScanner with all of user's authorizations and the number of query threads configured when AccumuloClient was created.
BatchScanner	createBatchScanner(String tableName, Authorizations authorizations)	Factory method to create a BatchScanner connected to Accumulo.
BatchScanner	createBatchScanner(String tableName, Authorizations authorizations, int numQueryThreads)	Factory method to create a BatchScanner connected to Accumulo.
BatchWriter	createBatchWriter(String tableName)	Factory method to create a BatchWriter.
BatchWriter	createBatchWriter(String tableName, BatchWriterConfig config)	Factory method to create a BatchWriter connected to Accumulo.
ConditionalWriter	createConditionalWriter(String tableName)	Factory method to create a ConditionalWriter connected to Accumulo.
ConditionalWriter	createConditionalWriter(String tableName, ConditionalWriterConfig config)	Factory method to create a ConditionalWriter connected to Accumulo.
MultiTableBatchWriter	createMultiTableBatchWriter()	Factory method to create a Multi-Table BatchWriter.
MultiTableBatchWriter	createMultiTableBatchWriter(BatchWriterConfig config)	Factory method to create a Multi-Table BatchWriter connected to Accumulo.
Scanner	createScanner(String tableName)	Factory method to create a Scanner with all of the user's authorizations.
Scanner	createScanner(String tableName, Authorizations authorizations)	Factory method to create a Scanner connected to Accumulo.
InstanceOperations	instanceOperations()	Retrieves an InstanceOperations object to modify instance configuration.
NamespaceOperations	namespaceOperations()	Retrieves a NamespaceOperations object to perform namespace functions, such as create and delete.
Properties	properties()
ReplicationOperations	replicationOperations()	Deprecated.
SecurityOperations	securityOperations()	Retrieves a SecurityOperations object to perform user security operations, such as creating users.
TableOperations	tableOperations()	Retrieves a TableOperations object to perform table functions, such as create and delete.
String	whoami()	Get the current user for this AccumuloClient

Method Details

createBatchScanner

BatchScanner createBatchScanner(String tableName,
 Authorizations authorizations,
 int numQueryThreads)
                         throws TableNotFoundException

Factory method to create a BatchScanner connected to Accumulo.

Parameters:

tableName - the name of the table to query

authorizations - A set of authorization labels that will be checked against the column visibility of each key in order to filter data. The authorizations passed in must be a subset of the accumulo user's set of authorizations. If the accumulo user has authorizations (A1, A2) and authorizations (A2, A3) are passed, then an exception will be thrown.

numQueryThreads - the number of concurrent threads to spawn for querying

Returns:

BatchScanner object for configuring and querying

Throws:

TableNotFoundException - when the specified table doesn't exist

createBatchScanner

BatchScanner createBatchScanner(String tableName,
 Authorizations authorizations)
                         throws TableNotFoundException

Factory method to create a BatchScanner connected to Accumulo. This method uses the number of query threads configured when AccumuloClient was created. If none were configured, defaults will be used.

Parameters:

tableName - the name of the table to query

authorizations - A set of authorization labels that will be checked against the column visibility of each key in order to filter data. The authorizations passed in must be a subset of the accumulo user's set of authorizations. If the accumulo user has authorizations (A1, A2) and authorizations (A2, A3) are passed, then an exception will be thrown.

Returns:

BatchScanner object for configuring and querying

Throws:

TableNotFoundException - when the specified table doesn't exist

createBatchScanner

BatchScanner createBatchScanner(String tableName)
                         throws TableNotFoundException,
AccumuloSecurityException,
AccumuloException

Factory method to create a BatchScanner with all of user's authorizations and the number of query threads configured when AccumuloClient was created. If no query threads were configured, defaults will be used.

Parameters:

tableName - the name of the table to query

Returns:

BatchScanner object for configuring and querying

Throws:

TableNotFoundException - when the specified table doesn't exist

AccumuloSecurityException

AccumuloException

createBatchDeleter

BatchDeleter createBatchDeleter(String tableName,
 Authorizations authorizations,
 int numQueryThreads,
 BatchWriterConfig config)
                         throws TableNotFoundException

Factory method to create BatchDeleter

Parameters:

tableName - the name of the table to query and delete from

authorizations - A set of authorization labels that will be checked against the column visibility of each key in order to filter data. The authorizations passed in must be a subset of the accumulo user's set of authorizations. If the accumulo user has authorizations (A1, A2) and authorizations (A2, A3) are passed, then an exception will be thrown.

numQueryThreads - the number of concurrent threads to spawn for querying

config - configuration used to create batch writer. This config takes precedence. Any unset values will be merged with config set when the AccumuloClient was created. If no config was set during AccumuloClient creation, BatchWriterConfig defaults will be used.

Returns:

BatchDeleter object for configuring and deleting

Throws:

TableNotFoundException

createBatchDeleter

BatchDeleter createBatchDeleter(String tableName,
 Authorizations authorizations,
 int numQueryThreads)
                         throws TableNotFoundException

Factory method to create BatchDeleter. This method uses BatchWriterConfig set when AccumuloClient was created. If none was set, BatchWriterConfig defaults will be used.

Parameters:

tableName - the name of the table to query and delete from

authorizations - A set of authorization labels that will be checked against the column visibility of each key in order to filter data. The authorizations passed in must be a subset of the accumulo user's set of authorizations. If the accumulo user has authorizations (A1, A2) and authorizations (A2, A3) are passed, then an exception will be thrown.

numQueryThreads - the number of concurrent threads to spawn for querying

Returns:

BatchDeleter object

Throws:

TableNotFoundException - if table not found

createBatchWriter

BatchWriter createBatchWriter(String tableName,
 BatchWriterConfig config)
                       throws TableNotFoundException

Factory method to create a BatchWriter connected to Accumulo.

Parameters:

tableName - the name of the table to insert data into

config - configuration used to create batch writer. This config will take precedence. Any unset values will be merged with the config set when the AccumuloClient was created. If no config was set during AccumuloClient creation, BatchWriterConfig defaults will be used.

Returns:

BatchWriter object for configuring and writing data to

Throws:

TableNotFoundException

createBatchWriter

BatchWriter createBatchWriter(String tableName)
                       throws TableNotFoundException

Factory method to create a BatchWriter. This method uses BatchWriterConfig set when AccumuloClient was created. If none was set, BatchWriterConfig defaults will be used.

Parameters:

tableName - the name of the table to insert data into

Returns:

BatchWriter object

Throws:

TableNotFoundException - if table not found

createMultiTableBatchWriter

MultiTableBatchWriter createMultiTableBatchWriter(BatchWriterConfig config)

Factory method to create a Multi-Table BatchWriter connected to Accumulo. Multi-table batch writers can queue data for multiple tables. Also data for multiple tables can be sent to a server in a single batch. It's an efficient way to ingest data into multiple tables from a single process.

Parameters:

config - configuration used to create multi-table batch writer. This config will take precedence. Any unset values will be merged with the config set when the AccumuloClient was created. If no config was set during AccumuloClient creation, BatchWriterConfig defaults will be used.

Returns:

MultiTableBatchWriter object for configuring and writing data to

createMultiTableBatchWriter

MultiTableBatchWriter createMultiTableBatchWriter()

Factory method to create a Multi-Table BatchWriter. This method uses BatchWriterConfig set when AccumuloClient was created. If none was set, BatchWriterConfig defaults will be used.

Returns:

MultiTableBatchWriter object

createScanner

Scanner createScanner(String tableName,
 Authorizations authorizations)
               throws TableNotFoundException

Factory method to create a Scanner connected to Accumulo.

Parameters:

tableName - the name of the table to query data from

authorizations - A set of authorization labels that will be checked against the column visibility of each key in order to filter data. The authorizations passed in must be a subset of the accumulo user's set of authorizations. If the accumulo user has authorizations (A1, A2) and authorizations (A2, A3) are passed, then an exception will be thrown.

Returns:

Scanner object for configuring and querying data with

Throws:

TableNotFoundException - when the specified table doesn't exist

See Also:

• IsolatedScanner

createScanner

Scanner createScanner(String tableName)
               throws TableNotFoundException,
AccumuloSecurityException,
AccumuloException

Factory method to create a Scanner with all of the user's authorizations.

Parameters:

tableName - the name of the table to query data from

Returns:

Scanner object for configuring and querying data with

Throws:

TableNotFoundException - when the specified table doesn't exist

AccumuloSecurityException

AccumuloException

See Also:

• IsolatedScanner

createConditionalWriter

ConditionalWriter createConditionalWriter(String tableName,
 ConditionalWriterConfig config)
                                   throws TableNotFoundException

Factory method to create a ConditionalWriter connected to Accumulo.

Parameters:

tableName - the name of the table to query data from

config - configuration used to create conditional writer

Returns:

ConditionalWriter object for writing ConditionalMutations

Throws:

TableNotFoundException - when the specified table doesn't exist

createConditionalWriter

ConditionalWriter createConditionalWriter(String tableName)
                                   throws TableNotFoundException

Factory method to create a ConditionalWriter connected to Accumulo.

Parameters:

tableName - the name of the table to query data from

Returns:

ConditionalWriter object for writing ConditionalMutations

Throws:

TableNotFoundException - when the specified table doesn't exist

Since:

2.1.0

whoami

String whoami()

Get the current user for this AccumuloClient

Returns:

the user name

tableOperations

TableOperations tableOperations()

Retrieves a TableOperations object to perform table functions, such as create and delete.

Returns:

an object to manipulate tables

namespaceOperations

NamespaceOperations namespaceOperations()

Retrieves a NamespaceOperations object to perform namespace functions, such as create and delete.

Returns:

an object to manipulate namespaces

securityOperations

SecurityOperations securityOperations()

Retrieves a SecurityOperations object to perform user security operations, such as creating users.

Returns:

an object to modify users and permissions

instanceOperations

InstanceOperations instanceOperations()

Retrieves an InstanceOperations object to modify instance configuration.

Returns:

an object to modify instance configuration

replicationOperations

@Deprecated(since="2.1.0")
ReplicationOperations replicationOperations()

Deprecated.

Retrieves a ReplicationOperations object to manage replication configuration.

Returns:

an object to modify replication configuration

properties

Properties properties()

Returns:

All Properties used to create client except 'auth.token'

close

void close()

Cleans up any resources created by an AccumuloClient like threads and sockets. Anything created from this client will likely not work after calling this method. For example a Scanner created using this client will likely fail after close is called.

Specified by:

close in interface AutoCloseable