com.hp.util.persistence.cassandra.entitymgr

Class EntityManager

java.lang.Object

com.hp.util.persistence.cassandra.entitymgr.EntityManager

public class EntityManager
extends Object

EntityManager is the persistence module that is responsible for all interactions with Cassandra database. It interfaces with the Dao at one end and with Astyanax Client for Cassandra at the other end.

The basic responsibility of EntityManager is to support CRUD operations. The other responsibilities include creation of Column Families, supporting Astyanax operations and so on.

Author:

Nachiket Abhyankar, Sugesh Chandran

Constructor Summary

Constructors

Modifier	Constructor and Description
	EntityManager(ConnectionManager connManager) Constructor.
protected	EntityManager(com.netflix.astyanax.Keyspace keyspace)

Method Summary

Methods

Modifier and Type	Method and Description
<K extends Serializable,C extends Serializable & Comparable<C>> long	countColumns(com.netflix.astyanax.model.ColumnFamily<K,C> colFamily, K rowKey) countColumns(com.netflix.astyanax.model.ColumnFamily<K, C>, K) counts the number of columns in a given row of a given column family.
<K extends Serializable,C> int	countRows(com.netflix.astyanax.model.ColumnFamily<K,C> colFamily) countRows(ColumnFamily) retrieves a count of all rows in a given column family
static void	createColumnFamily(ColumnFamilyDefinition<?,?> cf) createColumnFamily(com.hp.util.persistence.cassandra.entitymgr.ColumnFamilyDefinition<?, ?>) creates a new Cassandra Column Family.This method is a single way to create a Cassandra Column Family in the DAO framework.
<K extends Serializable,C extends Serializable & Comparable<C>> void	delete(com.netflix.astyanax.model.ColumnFamily<K,C> columnFamily, K rowKey, ColumnName<C,?> columnName) Deletes a single column.
<K extends Serializable,C extends Serializable & Comparable<C>> void	deleteColumns(com.netflix.astyanax.model.ColumnFamily<K,C> columnFamily, K rowKey, Collection<ColumnName<C,?>> columnsNames) Deletes a collection of columns.
static void	dropColumnFamily(com.netflix.astyanax.model.ColumnFamily<?,?> cf) Drops a column family.
void	executeOperation() executeOperation() executes a Write Operation.
<I extends Serializable,K extends Serializable & Comparable<K>> CassandraStorable<I,K>	get(com.netflix.astyanax.model.ColumnFamily<I,K> cf, Provider<ColumnDecoder<K,?>,ColumnName<K,?>> decoderProvider, I id) get(com.netflix.astyanax.model.ColumnFamily<I, K>, com.hp.util.Provider<com.hp.util.persistence.cassandra.entitymgr.column.ColumnDecoder<K, ?>, com.hp.util.persistence.cassandra.entitymgr.column.ColumnName<K, ?>>, I) retrieves a row from a Cassandra Column Family.
<K extends Serializable,C extends Serializable & Comparable<C>> Collection<CassandraStorable<K,C>>	get(com.netflix.astyanax.model.ColumnFamily<K,C> colFamily, Collection<K> rows, Collection<ColumnName<C,?>> columns, Provider<ColumnDecoder<C,?>,ColumnName<C,?>> decoder) get(com.netflix.astyanax.model.ColumnFamily<I, K>, com.hp.util.Provider<com.hp.util.persistence.cassandra.entitymgr.column.ColumnDecoder<K, ?>, com.hp.util.persistence.cassandra.entitymgr.column.ColumnName<K, ?>>, I) retrieves a collection of rows with specified columns.
<K extends Serializable,C extends Serializable & Comparable<C>> Collection<CassandraStorable<K,C>>	get(com.netflix.astyanax.model.ColumnFamily<K,C> colFamily, Collection<K> rowKeys, ColumnName<C,?> startColumn, ColumnName<C,?> endColumn, boolean reversed, int limit, Provider<ColumnDecoder<C,?>,ColumnName<C,?>> decoder) get(com.netflix.astyanax.model.ColumnFamily<I, K>, com.hp.util.Provider<com.hp.util.persistence.cassandra.entitymgr.column.ColumnDecoder<K, ?>, com.hp.util.persistence.cassandra.entitymgr.column.ColumnName<K, ?>>, I) retrieves a collection of specified rows and a specified range of columns in each row.
<K extends Serializable,C extends Serializable & Comparable<C>> Collection<CassandraStorable<K,C>>	get(com.netflix.astyanax.model.ColumnFamily<K,C> colFamily, Collection<K> rowKeys, Provider<ColumnDecoder<C,?>,ColumnName<C,?>> decoderProvider) get(com.netflix.astyanax.model.ColumnFamily<I, K>, com.hp.util.Provider<com.hp.util.persistence.cassandra.entitymgr.column.ColumnDecoder<K, ?>, com.hp.util.persistence.cassandra.entitymgr.column.ColumnName<K, ?>>, I) retrieves Cassandra multiple rows from a column family.
<K extends Serializable,C extends Serializable & Comparable<C>> Collection<CassandraStorable<K,C>>	get(com.netflix.astyanax.model.ColumnFamily<K,C> cf, ColumnName<C,?> column, boolean key, Provider<ColumnDecoder<C,?>,ColumnName<C,?>> decoder) get(com.netflix.astyanax.model.ColumnFamily<I, K>, com.hp.util.Provider<com.hp.util.persistence.cassandra.entitymgr.column.ColumnDecoder<K, ?>, com.hp.util.persistence.cassandra.entitymgr.column.ColumnName<K, ?>>, I) retrieves rows using index.
<K extends Serializable,C extends Serializable & Comparable<C>> Collection<CassandraStorable<K,C>>	get(com.netflix.astyanax.model.ColumnFamily<K,C> cf, ColumnName<C,?> column, int key, Provider<ColumnDecoder<C,?>,ColumnName<C,?>> decoder) get(com.netflix.astyanax.model.ColumnFamily<I, K>, com.hp.util.Provider<com.hp.util.persistence.cassandra.entitymgr.column.ColumnDecoder<K, ?>, com.hp.util.persistence.cassandra.entitymgr.column.ColumnName<K, ?>>, I) retrieves rows using index.
<K extends Serializable,C extends Serializable & Comparable<C>> Collection<CassandraStorable<K,C>>	get(com.netflix.astyanax.model.ColumnFamily<K,C> cf, ColumnName<C,?> column, String key, Provider<ColumnDecoder<C,?>,ColumnName<C,?>> decoder) get(com.netflix.astyanax.model.ColumnFamily<I, K>, com.hp.util.Provider<com.hp.util.persistence.cassandra.entitymgr.column.ColumnDecoder<K, ?>, com.hp.util.persistence.cassandra.entitymgr.column.ColumnName<K, ?>>, I) retrieves rows using index.
<K extends Serializable,C extends Serializable & Comparable<C>> CassandraStorable<K,C>	get(com.netflix.astyanax.model.ColumnFamily<K,C> colFamily, K rowKey, ByteBuffer startColumn, ByteBuffer endColumn, boolean reversed, int limit, Provider<ColumnDecoder<C,?>,ColumnName<C,?>> decoder) get(com.netflix.astyanax.model.ColumnFamily<I, K>, com.hp.util.Provider<com.hp.util.persistence.cassandra.entitymgr.column.ColumnDecoder<K, ?>, com.hp.util.persistence.cassandra.entitymgr.column.ColumnName<K, ?>>, I) is used to retrieve a range of pre-constructed columns.
<K extends Serializable,C extends Serializable & Comparable<C>> CassandraStorable<K,C>	get(com.netflix.astyanax.model.ColumnFamily<K,C> colFamily, K rowKey, com.netflix.astyanax.model.ByteBufferRange range, Provider<ColumnDecoder<C,?>,ColumnName<C,?>> decoder) get(com.netflix.astyanax.model.ColumnFamily<I, K>, com.hp.util.Provider<com.hp.util.persistence.cassandra.entitymgr.column.ColumnDecoder<K, ?>, com.hp.util.persistence.cassandra.entitymgr.column.ColumnName<K, ?>>, I) retrieves a list of columns based on a column range.
<K extends Serializable,C extends Serializable & Comparable<C>> CassandraStorable<K,C>	get(com.netflix.astyanax.model.ColumnFamily<K,C> colFamily, K rowKey, Collection<ColumnName<C,?>> columns, Provider<ColumnDecoder<C,?>,ColumnName<C,?>> decoder) get(com.netflix.astyanax.model.ColumnFamily<I, K>, com.hp.util.Provider<com.hp.util.persistence.cassandra.entitymgr.column.ColumnDecoder<K, ?>, com.hp.util.persistence.cassandra.entitymgr.column.ColumnName<K, ?>>, I) is used for reading a non-contiguous set of columns from the database.
<K extends Serializable,C extends Serializable & Comparable<C>> CassandraStorable<K,C>	get(com.netflix.astyanax.model.ColumnFamily<K,C> colFamily, K rowKey, ColumnName<C,?> startColumn, ColumnName<C,?> endColumn, boolean reversed, int limit, Provider<ColumnDecoder<C,?>,ColumnName<C,?>> decoder) get(com.netflix.astyanax.model.ColumnFamily<I, K>, com.hp.util.Provider<com.hp.util.persistence.cassandra.entitymgr.column.ColumnDecoder<K, ?>, com.hp.util.persistence.cassandra.entitymgr.column.ColumnName<K, ?>>, I) is used to retrieve a range of simple columns.
<K extends Serializable,C extends Serializable & Comparable<C>> MarkPage<Column<C,?>>	get(com.netflix.astyanax.model.ColumnFamily<K,C> colFamily, K rowKey, MarkPageRequest<C> request, com.netflix.astyanax.serializers.CompositeRangeBuilder range, Provider<ColumnDecoder<C,?>,ColumnName<C,?>> decoder)
<K extends Serializable,C extends Serializable & Comparable<C>> MarkPage<Column<C,?>>	get(com.netflix.astyanax.model.ColumnFamily<K,C> colFamily, K rowKey, MarkPageRequest<C> request, Provider<ColumnDecoder<C,?>,ColumnName<C,?>> decoder)
<K extends Serializable,C extends Serializable & Comparable<C>> CassandraStorable<K,C>	get(com.netflix.astyanax.model.ColumnFamily<K,C> colFamily, K rowKey, Provider<ColumnDecoder<C,?>,ColumnName<C,?>> decoder, ColumnName<C,?>... columnNames) get(com.netflix.astyanax.model.ColumnFamily<I, K>, com.hp.util.Provider<com.hp.util.persistence.cassandra.entitymgr.column.ColumnDecoder<K, ?>, com.hp.util.persistence.cassandra.entitymgr.column.ColumnName<K, ?>>, I) retrieves a set of non-contiguous columns as per the user request.
<K extends Serializable,C extends Serializable & Comparable<C>> Collection<CassandraStorable<K,C>>	get(com.netflix.astyanax.model.ColumnFamily<K,C> colFamily, Provider<ColumnDecoder<C,?>,ColumnName<C,?>> decoder) get(com.netflix.astyanax.model.ColumnFamily<I, K>, com.hp.util.Provider<com.hp.util.persistence.cassandra.entitymgr.column.ColumnDecoder<K, ?>, com.hp.util.persistence.cassandra.entitymgr.column.ColumnName<K, ?>>, I) retrieves all rows of a given Column Family.
<I extends Serializable,K extends Serializable & Comparable<K>> void	prepareDeleteMutation(com.netflix.astyanax.model.ColumnFamily<I,K> colFamily, I rowKey, Collection<ColumnName<K,?>> colNames)
<K extends Serializable,C> void	prepareDeleteMutation(com.netflix.astyanax.model.ColumnFamily<K,C> colFamily, K id) prepareDeleteMutation(com.netflix.astyanax.model.ColumnFamily<K, C>, K) creates a delete Mutation and adds it to the MutationBatch.
<I extends Serializable,K extends Serializable & Comparable<K>,P extends Storable<I>> void	prepareMutation(com.netflix.astyanax.model.ColumnFamily<I,K> colFamily, P storable) prepareMutation(com.netflix.astyanax.model.ColumnFamily<I, K>, P) creates a write mutation and adds it to the MutationBatch.
static void	setKeySpace(com.netflix.astyanax.Keyspace keyspace)
static void	truncateColumnFamily(com.netflix.astyanax.model.ColumnFamily<?,?> cf) Deletes all data from a column family.

Methods inherited from class java.lang.Object

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

Constructor Detail

EntityManager

public EntityManager(ConnectionManager connManager)

Constructor. It takes the Keyspace Configuration and prepares an Astyanax Mutation batch ready for doing any Mutation. This is applicable only for Write Operations. For Reads, we prepare a query using the Astyanax Keyspace object.

Parameters:

connManager - The Connection Manager object that contains all relevant keyspace/database configuration.

EntityManager

protected EntityManager(com.netflix.astyanax.Keyspace keyspace)

Method Detail

setKeySpace

public static void setKeySpace(com.netflix.astyanax.Keyspace keyspace)

createColumnFamily

public static void createColumnFamily(ColumnFamilyDefinition<?,?> cf)
                               throws PersistenceConnException

createColumnFamily(com.hp.util.persistence.cassandra.entitymgr.ColumnFamilyDefinition<?, ?>) creates a new Cassandra Column Family.This method is a single way to create a Cassandra Column Family in the DAO framework.

Any DAO that needs to create a Column Family needs to follow these steps. 1. Define a Column Family Definition with the following parameters. a. Column Family Name b. Key Validator - This is the data type of the Row Key/Primary Key c. Default Validator - This is the Default data type of Column Value. If the column validators are not specified, Cassandra will use Default validator to validate the inserted values. d. Comparator - This is the data type of the Column Name. In Cassandra, a Column is a Tuple(Column Name, Column Value, Timestamp). Each have their own data types. The Comparator validates the inserted column name and also sorts columns in ascending order. e. Secondary Indexes - These are Cassandra Native Secondary Indexes. They should have a validator, index name and index type defined. Index Type is always "KEYS" because thats the only type of secondary index that is natively supported. Validator is the same as described above. Index name is generally the name of the column. f. CF Meta data - Every column in a static column family is known at the data modelling time. These columns have their own data type and hence a validator. This can be specified in the column definition as well. 2. The Column Family Definition should be passed down to this method.

Parameters:

cf - ColumnFamily Definition that contains enough information to create a column family in cassandra.

Throws:

PersistenceConnException - If Astyanax is unable to create a column family it throws a ConnectionException and should be handled in the upper layers.

dropColumnFamily

public static void dropColumnFamily(com.netflix.astyanax.model.ColumnFamily<?,?> cf)
                             throws PersistenceConnException

Drops a column family.

Parameters:

cf - column family to drop.

Throws:

PersistenceConnException - if errors occur while executing the operation.

truncateColumnFamily

public static void truncateColumnFamily(com.netflix.astyanax.model.ColumnFamily<?,?> cf)
                                 throws PersistenceConnException

Deletes all data from a column family.

Parameters:

cf - column family to truncate.

Throws:

PersistenceConnException - if errors occur while executing the operation.

prepareDeleteMutation

public <K extends Serializable,C> void prepareDeleteMutation(com.netflix.astyanax.model.ColumnFamily<K,C> colFamily,
                                                    K id)

prepareDeleteMutation(com.netflix.astyanax.model.ColumnFamily<K, C>, K) creates a delete Mutation and adds it to the MutationBatch. The dao calls this method repetatively for every row that needs to be deleted. This helps to delete all rows in a single batch operation.

Parameters:

colFamily - The column family that needs to be operated on.

id - The Row Key of the row that needs to be deleted.

prepareDeleteMutation

public <I extends Serializable,K extends Serializable & Comparable<K>> void prepareDeleteMutation(com.netflix.astyanax.model.ColumnFamily<I,K> colFamily,
                                                                                        I rowKey,
                                                                                        Collection<ColumnName<K,?>> colNames)

prepareMutation

public <I extends Serializable,K extends Serializable & Comparable<K>,P extends Storable<I>> void prepareMutation(com.netflix.astyanax.model.ColumnFamily<I,K> colFamily,
                                                                                                        P storable)

prepareMutation(com.netflix.astyanax.model.ColumnFamily<I, K>, P) creates a write mutation and adds it to the MutationBatch. The dao calls this method repetatively for each row that needs to be written. Also, rows of different column families can be added to the same MutationBatch. This helps in keeping the Commit Log in a stable condition. Should there be a failure, the log is replayed. try { //TODO : Support Paging return null; //return convertToStorable(result, decoder); } catch (ConnectionException e) { throw new RuntimeException(e); }

Parameters:

colFamily - Column family to which a row needs to be written.

storable - This is a Cassandra row that needs to be written.

get

public <I extends Serializable,K extends Serializable & Comparable<K>> CassandraStorable<I,K> get(com.netflix.astyanax.model.ColumnFamily<I,K> cf,
                                                                                        Provider<ColumnDecoder<K,?>,ColumnName<K,?>> decoderProvider,
                                                                                        I id)
                                                                                    throws PersistenceConnException

get(com.netflix.astyanax.model.ColumnFamily<I, K>, com.hp.util.Provider<com.hp.util.persistence.cassandra.entitymgr.column.ColumnDecoder<K, ?>, com.hp.util.persistence.cassandra.entitymgr.column.ColumnName<K, ?>>, I) retrieves a row from a Cassandra Column Family. The fetched row is identified by the supplied Row Key/Primary key from the DAO.

Parameters:

cf - The Column Family to read from.

decoderProvider - The Decoder Provider for all columns of the given column family. This decoder provider is customised for a CF and hence each CF needs to provide an implementation of DecoderProvider

id - The Row Key of the row to be read

Returns:

A single Cassandra Row.

Throws:

PersistenceConnException - If the connection to the DB cannot be established, this exception is thrown.

get

public <K extends Serializable,C extends Serializable & Comparable<C>> CassandraStorable<K,C> get(com.netflix.astyanax.model.ColumnFamily<K,C> colFamily,
                                                                                        K rowKey,
                                                                                        com.netflix.astyanax.model.ByteBufferRange range,
                                                                                        Provider<ColumnDecoder<C,?>,ColumnName<C,?>> decoder)
                                                                                    throws PersistenceConnException

get(com.netflix.astyanax.model.ColumnFamily<I, K>, com.hp.util.Provider<com.hp.util.persistence.cassandra.entitymgr.column.ColumnDecoder<K, ?>, com.hp.util.persistence.cassandra.entitymgr.column.ColumnName<K, ?>>, I) retrieves a list of columns based on a column range. It does not retrieve the entire row. This is a variation of the entire row read using Astyanax slice queries. This method is used for reading composite column slices.

Parameters:

colFamily - Column Family to retrieve data from

rowKey - The Row to retrieve columns from

range - The ByteBuffer slice Range

decoder - Decoder for the given column Family.

Returns:

Storable object with columns that satisfy the query

Throws:

PersistenceConnException - If the connection to the DB cannot be established, this exception is thrown

get

public <K extends Serializable,C extends Serializable & Comparable<C>> CassandraStorable<K,C> get(com.netflix.astyanax.model.ColumnFamily<K,C> colFamily,
                                                                                        K rowKey,
                                                                                        ColumnName<C,?> startColumn,
                                                                                        ColumnName<C,?> endColumn,
                                                                                        boolean reversed,
                                                                                        int limit,
                                                                                        Provider<ColumnDecoder<C,?>,ColumnName<C,?>> decoder)
                                                                                    throws PersistenceConnException

get(com.netflix.astyanax.model.ColumnFamily<I, K>, com.hp.util.Provider<com.hp.util.persistence.cassandra.entitymgr.column.ColumnDecoder<K, ?>, com.hp.util.persistence.cassandra.entitymgr.column.ColumnName<K, ?>>, I) is used to retrieve a range of simple columns. The order of retrieval and the size of the retrieved set can be specified in this method.

Parameters:

colFamily - Column Family to retrieve columns from

rowKey - Row key to lookup data columns

startColumn - First column in the range

endColumn - Last column in the range

reversed - True if the order should be reversed. Note that for reversed, startColumn should be greater than endColumn.

limit - Maximum number of columns to return

decoder - Decoder for the given column family.

Returns:

A Single Row with columns in the specified range

Throws:

PersistenceConnException - If the connection to the DB cannot be established, this exception is thrown

get

public <K extends Serializable,C extends Serializable & Comparable<C>> CassandraStorable<K,C> get(com.netflix.astyanax.model.ColumnFamily<K,C> colFamily,
                                                                                        K rowKey,
                                                                                        ByteBuffer startColumn,
                                                                                        ByteBuffer endColumn,
                                                                                        boolean reversed,
                                                                                        int limit,
                                                                                        Provider<ColumnDecoder<C,?>,ColumnName<C,?>> decoder)
                                                                                    throws PersistenceConnException

get(com.netflix.astyanax.model.ColumnFamily<I, K>, com.hp.util.Provider<com.hp.util.persistence.cassandra.entitymgr.column.ColumnDecoder<K, ?>, com.hp.util.persistence.cassandra.entitymgr.column.ColumnName<K, ?>>, I) is used to retrieve a range of pre-constructed columns. This method is used for retrieving composite columns bounded by a start and a end. The order can be reversed and the size of columns can be limited to a certain number of columns.

Parameters:

colFamily - Column Family to retrieve data from

rowKey - Row Key to look up

startColumn - First Column in the Composite Column Range

endColumn - Last Column in the Composite Column Range

reversed - True if the order needs to be reversed. For reversed, startColumn should be greater than endColumn

limit - The maximum number of columns to retrieve.

decoder - Column Decoder for the Column Family.

Returns:

A Single row with the columns requested.

Throws:

PersistenceConnException - If the connection to the DB cannot be established, this exception is thrown

get

public <K extends Serializable,C extends Serializable & Comparable<C>> CassandraStorable<K,C> get(com.netflix.astyanax.model.ColumnFamily<K,C> colFamily,
                                                                                        K rowKey,
                                                                                        Provider<ColumnDecoder<C,?>,ColumnName<C,?>> decoder,
                                                                                        ColumnName<C,?>... columnNames)
                                                                                    throws PersistenceConnException

get(com.netflix.astyanax.model.ColumnFamily<I, K>, com.hp.util.Provider<com.hp.util.persistence.cassandra.entitymgr.column.ColumnDecoder<K, ?>, com.hp.util.persistence.cassandra.entitymgr.column.ColumnName<K, ?>>, I) retrieves a set of non-contiguous columns as per the user request. This method expects a set of columns to read.

Parameters:

colFamily - Column Family to retrieve data from

rowKey - Row Key to look up data

decoder - The Column Decoder for the Column Family

columnNames - The set of Columns to be read

Returns:

A single row with requested columns with values.

Throws:

PersistenceConnException - If the connection to the DB cannot be established, this exception is thrown

get

public <K extends Serializable,C extends Serializable & Comparable<C>> CassandraStorable<K,C> get(com.netflix.astyanax.model.ColumnFamily<K,C> colFamily,
                                                                                        K rowKey,
                                                                                        Collection<ColumnName<C,?>> columns,
                                                                                        Provider<ColumnDecoder<C,?>,ColumnName<C,?>> decoder)
                                                                                    throws PersistenceConnException

get(com.netflix.astyanax.model.ColumnFamily<I, K>, com.hp.util.Provider<com.hp.util.persistence.cassandra.entitymgr.column.ColumnDecoder<K, ?>, com.hp.util.persistence.cassandra.entitymgr.column.ColumnName<K, ?>>, I) is used for reading a non-contiguous set of columns from the database.

Parameters:

colFamily - Column Family to retrieve data from

rowKey - Row Key to lookup a row

columns - Collection of Columns to read

decoder - Decoder for the Column Family

Returns:

A Single Row consisting of the columns specified *

Throws:

PersistenceConnException - If the connection to the DB cannot be established, this exception is thrown

get

public <K extends Serializable,C extends Serializable & Comparable<C>> Collection<CassandraStorable<K,C>> get(com.netflix.astyanax.model.ColumnFamily<K,C> colFamily,
                                                                                                    Collection<K> rowKeys,
                                                                                                    Provider<ColumnDecoder<C,?>,ColumnName<C,?>> decoderProvider)
                                                                                                throws PersistenceConnException

get(com.netflix.astyanax.model.ColumnFamily<I, K>, com.hp.util.Provider<com.hp.util.persistence.cassandra.entitymgr.column.ColumnDecoder<K, ?>, com.hp.util.persistence.cassandra.entitymgr.column.ColumnName<K, ?>>, I) retrieves Cassandra multiple rows from a column family. This method is generally used to get the final result set in a read operation with filters.

Parameters:

colFamily - Column Family to read from

rowKeys - The collection of rowKeys to read from

decoderProvider - Decoder Provider for each column of this column family

Returns:

A list of records from the Column Family

Throws:

PersistenceConnException - If the connection to the DB cannot be established, this exception is thrown

get

public <K extends Serializable,C extends Serializable & Comparable<C>> Collection<CassandraStorable<K,C>> get(com.netflix.astyanax.model.ColumnFamily<K,C> colFamily,
                                                                                                    Collection<K> rows,
                                                                                                    Collection<ColumnName<C,?>> columns,
                                                                                                    Provider<ColumnDecoder<C,?>,ColumnName<C,?>> decoder)
                                                                                                throws PersistenceConnException

get(com.netflix.astyanax.model.ColumnFamily<I, K>, com.hp.util.Provider<com.hp.util.persistence.cassandra.entitymgr.column.ColumnDecoder<K, ?>, com.hp.util.persistence.cassandra.entitymgr.column.ColumnName<K, ?>>, I) retrieves a collection of rows with specified columns. This method expects a set of Rows and a set of Columns to be read from the Database. This method improves the read response time as it does not read the entire row for each row key specified.

Parameters:

colFamily - Column Family to read data

rows - A set of row keys to be read

columns - A set of columns to read in each row

decoder - Column decoder for the given Column Family

Returns:

A set of Rows with a set of specified columns

Throws:

PersistenceConnException - If the connection to the DB cannot be established, this exception is thrown

get

public <K extends Serializable,C extends Serializable & Comparable<C>> Collection<CassandraStorable<K,C>> get(com.netflix.astyanax.model.ColumnFamily<K,C> colFamily,
                                                                                                    Collection<K> rowKeys,
                                                                                                    ColumnName<C,?> startColumn,
                                                                                                    ColumnName<C,?> endColumn,
                                                                                                    boolean reversed,
                                                                                                    int limit,
                                                                                                    Provider<ColumnDecoder<C,?>,ColumnName<C,?>> decoder)
                                                                                                throws PersistenceConnException

get(com.netflix.astyanax.model.ColumnFamily<I, K>, com.hp.util.Provider<com.hp.util.persistence.cassandra.entitymgr.column.ColumnDecoder<K, ?>, com.hp.util.persistence.cassandra.entitymgr.column.ColumnName<K, ?>>, I) retrieves a collection of specified rows and a specified range of columns in each row.

Parameters:

colFamily - Column Family to retrieve data from

rowKeys - A set of row keys to read

startColumn - First column of the range in each row

endColumn - Last column of the range in each row

reversed - True if read is done in reverse order. In reverse order read, the start column should be greater than end column

limit - Maximum number of columns in the range.

decoder - Column decoder for the given Column Family

Returns:

A set of rows with the range of specified set of columns.

Throws:

PersistenceConnException - If the connection to the DB cannot be established, this exception is thrown

get

public <K extends Serializable,C extends Serializable & Comparable<C>> Collection<CassandraStorable<K,C>> get(com.netflix.astyanax.model.ColumnFamily<K,C> colFamily,
                                                                                                    Provider<ColumnDecoder<C,?>,ColumnName<C,?>> decoder)

get(com.netflix.astyanax.model.ColumnFamily<I, K>, com.hp.util.Provider<com.hp.util.persistence.cassandra.entitymgr.column.ColumnDecoder<K, ?>, com.hp.util.persistence.cassandra.entitymgr.column.ColumnName<K, ?>>, I) retrieves all rows of a given Column Family.

Parameters:

colFamily - Column Family to read all rows from

decoder - Column decoder for the given column family

Returns:

All rows of a given column family

get

public <K extends Serializable,C extends Serializable & Comparable<C>> MarkPage<Column<C,?>> get(com.netflix.astyanax.model.ColumnFamily<K,C> colFamily,
                                                                                       K rowKey,
                                                                                       MarkPageRequest<C> request,
                                                                                       Provider<ColumnDecoder<C,?>,ColumnName<C,?>> decoder)
                                                              throws com.netflix.astyanax.connectionpool.exceptions.ConnectionException

Throws:

com.netflix.astyanax.connectionpool.exceptions.ConnectionException

get

public <K extends Serializable,C extends Serializable & Comparable<C>> MarkPage<Column<C,?>> get(com.netflix.astyanax.model.ColumnFamily<K,C> colFamily,
                                                                                       K rowKey,
                                                                                       MarkPageRequest<C> request,
                                                                                       com.netflix.astyanax.serializers.CompositeRangeBuilder range,
                                                                                       Provider<ColumnDecoder<C,?>,ColumnName<C,?>> decoder)
                                                              throws com.netflix.astyanax.connectionpool.exceptions.ConnectionException

Throws:

com.netflix.astyanax.connectionpool.exceptions.ConnectionException

get

public <K extends Serializable,C extends Serializable & Comparable<C>> Collection<CassandraStorable<K,C>> get(com.netflix.astyanax.model.ColumnFamily<K,C> cf,
                                                                                                    ColumnName<C,?> column,
                                                                                                    boolean key,
                                                                                                    Provider<ColumnDecoder<C,?>,ColumnName<C,?>> decoder)
                                                                                                throws PersistenceConnException

get(com.netflix.astyanax.model.ColumnFamily<I, K>, com.hp.util.Provider<com.hp.util.persistence.cassandra.entitymgr.column.ColumnDecoder<K, ?>, com.hp.util.persistence.cassandra.entitymgr.column.ColumnName<K, ?>>, I) retrieves rows using index.

Parameters:

cf - Column Family from which to read rows

column - Column to determine secondary index

key - boolean key to search index

decoder - Column decoder for the given column family

Returns:

rows found in secondary index with key

Throws:

PersistenceConnException - If the connection to the DB cannot be established, this exception is thrown

get

public <K extends Serializable,C extends Serializable & Comparable<C>> Collection<CassandraStorable<K,C>> get(com.netflix.astyanax.model.ColumnFamily<K,C> cf,
                                                                                                    ColumnName<C,?> column,
                                                                                                    String key,
                                                                                                    Provider<ColumnDecoder<C,?>,ColumnName<C,?>> decoder)
                                                                                                throws PersistenceConnException

get(com.netflix.astyanax.model.ColumnFamily<I, K>, com.hp.util.Provider<com.hp.util.persistence.cassandra.entitymgr.column.ColumnDecoder<K, ?>, com.hp.util.persistence.cassandra.entitymgr.column.ColumnName<K, ?>>, I) retrieves rows using index.

Parameters:

cf - Column Family from which to read rows

column - Column to determine secondary index

key - string key to search index

decoder - Column decoder for the given column family

Returns:

rows found in secondary index with key

Throws:

PersistenceConnException - If the connection to the DB cannot be established, this exception is thrown

get

public <K extends Serializable,C extends Serializable & Comparable<C>> Collection<CassandraStorable<K,C>> get(com.netflix.astyanax.model.ColumnFamily<K,C> cf,
                                                                                                    ColumnName<C,?> column,
                                                                                                    int key,
                                                                                                    Provider<ColumnDecoder<C,?>,ColumnName<C,?>> decoder)
                                                                                                throws PersistenceConnException

get(com.netflix.astyanax.model.ColumnFamily<I, K>, com.hp.util.Provider<com.hp.util.persistence.cassandra.entitymgr.column.ColumnDecoder<K, ?>, com.hp.util.persistence.cassandra.entitymgr.column.ColumnName<K, ?>>, I) retrieves rows using index.

Parameters:

cf - Column Family from which to read rows

column - Column to determine secondary index

key - integer key to search index

decoder - Column decoder for the given column family

Returns:

rows found in secondary index with key

Throws:

PersistenceConnException - If the connection to the DB cannot be established, this exception is thrown

countColumns

public <K extends Serializable,C extends Serializable & Comparable<C>> long countColumns(com.netflix.astyanax.model.ColumnFamily<K,C> colFamily,
                                                                               K rowKey)
                  throws PersistenceConnException

countColumns(com.netflix.astyanax.model.ColumnFamily<K, C>, K) counts the number of columns in a given row of a given column family. countColumns(com.netflix.astyanax.model.ColumnFamily<K, C>, K) counts the number of columns in a given row of a given column family.

Parameters:

colFamily - The column family to read from

rowKey - The Row Key of the Column Family to count columns from.

Returns:

A count of columns that are present in the row

Throws:

PersistenceConnException - If the connection to the DB cannot be established, this exception is thrown

countRows

public <K extends Serializable,C> int countRows(com.netflix.astyanax.model.ColumnFamily<K,C> colFamily)
              throws PersistenceException

countRows(ColumnFamily) retrieves a count of all rows in a given column family

Parameters:

colFamily - Column Family to get the count from.

Returns:

Number of rows in the column family

Throws:

PersistenceException - A General Persistence Exception.

delete

public <K extends Serializable,C extends Serializable & Comparable<C>> void delete(com.netflix.astyanax.model.ColumnFamily<K,C> columnFamily,
                                                                         K rowKey,
                                                                         ColumnName<C,?> columnName)

Deletes a single column.

Parameters:

columnName - name of the column to delete.

rowKey - row key.

columnFamily - column family.

deleteColumns

public <K extends Serializable,C extends Serializable & Comparable<C>> void deleteColumns(com.netflix.astyanax.model.ColumnFamily<K,C> columnFamily,
                                                                                K rowKey,
                                                                                Collection<ColumnName<C,?>> columnsNames)

Deletes a collection of columns.

Parameters:

columnsNames - names of the columns to delete.

rowKey - row key.

columnFamily - column family.

executeOperation

public void executeOperation()
                      throws PersistenceConnException

executeOperation() executes a Write Operation.

Throws:

PersistenceConnException - If the connection to Database is not established, then this exception is thrown.