Cassandra::Simple Perl Module - Easy to use, Perl oriented client interface to Apache Cassandra.
Cassandra::Simple
version 0.2
Easy to use, Perl oriented client interface to Apache Cassandra.
This module attempts to abstract the underlying Thrift methods as much as possible to allow any Perl developer a small learning curve when using Cassandra.
my ($keyspace, $column_family) = qw/simple simple/;
my $conn = Cassandra::Simple->new(keyspace => $keyspace,);
$conn->create_column_family( column_family => $column_family);
$conn->insert(column_family => $column_family, key => 'KeyA', columns => { 'ColumnA' => 'AA' , 'ColumnB' => 'AB' } );
$conn->get(column_family => $column_family, key => 'KeyA');
$conn->get(column_family => $column_family, key => 'KeyA', columns => [ qw/ColumnA/ ]);
$conn->get(column_family => $column_family, key => 'KeyA', column_count => 1, column_reversed => 1);
$conn->batch_insert(column_family => $column_family, rows => { 'KeyB' => [ [ 'ColumnA' => 'BA' ] , [ 'ColumnB' => 'BB' ] ], 'KeyC' => [ [ 'ColumnA' => 'CA' ] , [ 'ColumnD' => 'CD' ] ] });
$conn->multiget(column_family => $column_family, 'keys' => [qw/KeyA KeyC/]);
$conn->get_range(column_family => $column_family, start => 'KeyA', finish => 'KeyB', column_count => 1 );
$conn->get_range(column_family => $column_family);
$conn->get_indexed_slices(column_family => $column_family, expression_list => [ [ 'ColumnA' => 'BA' ] ]);
$conn->remove(column_family => $column_family, 'keys' => [ 'KeyA' ], columns => [ 'ColumnA' ]);
$conn->remove(column_family => $column_family, 'keys' => [ 'KeyA' ]);
$conn->remove(column_family => $column_family);
$conn->get_count(column_family => $column_family, key => 'KeyA');
$conn->multiget_count(column_family => $column_family, 'keys' => [ 'KeyB', 'KeyC' ]);
Arguments:
column_family, key, columns, column_start, column_finish, column_count, column_reversed, super_column, consistency_level
Returns an HASH of the form { column => value, column => value }
Arguments:
column_family, keys, columns, column_start, column_finish, column_count, column_reversed, super_column, consistency_level
Returns an HASH of the form { key => { column => value, column => value }, key => { column => value, column => value } }
Arguments:
column_family, key, columns, column_start, column_finish, super_column, consistency_level
Returns the count as an int
Arguments:
column_family, keys, columns, column_start, column_finish, super_column, consistency_level
Returns a mapping of key -> count
Arguments:
column_family, start, finish, columns, column_start, column_finish, column_reversed, column_count, row_count, super_column, consistency_level
Returns an HASH of the form { key => { column => value, column => value }, key => { column => value, column => value } }
Arguments:
column_family, expression_list, start, row_count, columns, column_start, column_finish, column_reversed, column_count, consistency_level
The expression_list is an ARRAYREF of ARRAYREF containing $column[, $operator], $value. $operator can be '=', '<', '>', '<=' or '>='.
Returns an HASH of the form { key => { column => value, column => value }, key => { column => value, column => value } }
Arguments:
column_family, key, columns, timestamp, ttl, consistency_level
The $columns is an HASHREF of the form { column => value, column => value }
Arguments:
column_family, key, columns, timestamp, ttl, consistency_level
The $columns is an HASH of the form { super_column => { column => value, column => value } }
Arguments:
column_family, rows, timestamp, ttl, consistency_level
$rows is an HASH of the form { key => { column => value , column => value }, key => { column => value , column => value } }
Arguments:
column_family, key, column, value, super_column, consistency_level
Increment or decrement counter $column by $value. $value is 1 by default.
Arguments:
column_family, rows, consistency_level
$rows is an HASH of the form { key => { column => value , column => value }, key => { column => value , column => value } }
Remove counter $column on $key.
Arguments:
column_family, key, column, super_column, consistency_level_write
Arguments:
column_family, keys, columns, super_column, write_consistency_level
$keys is a key or an ARRAY of keys to be deleted.
A removal whitout keys truncates the whole column_family.
The timestamp used for remove is returned.
Arguments:
Returns an HASH of { column_family_name => column_family_type } where column family type is either Standard or Super
Arguments:
keyspace, column_family,
cfdef
cfdef is any Column Family Definition option (column_type, comparator_type, etc.).
Arguments:
keyspace, strategy, strategy_options
Arguments:
Arguments:
keyspace
Arguments:
keyspace, column_family, columns, validation_class
Creates an index on $columns of $column_family. $columns is an ARRAY of column names to be indexed. $validation_class only applies when $column doesn't yet exist, and even then it is optional (defaults to BytesType).
Arguments:
keyspace
Lists the addresses of all nodes on the cluster associated with the keyspace <$keyspace>.
Bugs should be reported on github at https://github.com/fmgoncalves/p5-cassandra-simple.
Thrift Type Checking and Packing/Unpacking
The defined types (or defaults) for each column family are known and should therefore be complied with. Introducing Composite Types has forcefully introduced this functionality to an extent, but there should be a refactoring to make this ubiquitous to the client.
Error Handling
Exceptions raised when calling Cassandra code should be reported in error form with appropriate description.
Unit Tests
Sort of done in the examples folder https://github.com/fmgoncalves/p5-cassandra-simple/tree/master/examples
Tombstones
get, get_range and get_indexed_slices should probably filter out tombstones, even if it means returning less than the requested count. Ideally it would retry until it got enough results.
Methods
The following are Thrift methods left unimplemented.
Not all of these will be implemented, since some aren't useful to the common developer.
Priority will be given to live schema updating methods.
describe_cluster_name
string describe_cluster_name()
describe_keyspace
KsDef describe_keyspace(string keyspace)
describe_partitioner
string describe_partitioner()
describe_snitch
string describe_snitch()
describe_version
string describe_version()
system_drop_column_family
string system_drop_column_family(ColumnFamily column_family)
Implementation loosely based on Cassandra::Lite.
http://search.cpan.org/~gslin/Cassandra-Lite-0.0.4/lib/Cassandra/Lite.pm
API based on Pycassa.
Filipe Gonçalves <the.wa.syndrome@gmail.com>
This software is copyright (c) 2012 by Filipe Gonçalves.
This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.