NAME

Net::Cassandra::Easy - Perlish interface to the Cassandra database

SYNOPSIS

  use Net::Cassandra::Easy;
  my $server = 'myserver';
  my $port = 'any port but default is 9160';

  $Net::Cassandra::Easy::DEBUG = 1; # to see the Thrift structures and other fun stuff

  # this will login() with no credentials so only AllowAllAuthenticator will work
  # the default Keyspace1 column families are used in these examples
  my $c = Net::Cassandra::Easy->new(server => $server, port => $port, keyspace => 'Standard1', credentials => { none => 1 });
  $c->connect();

  my $key = 'processes';

  my $result;

  # see test.pl for more examples, including insertions and deletions (with the mutate() call)

  $result = $c->get([$key], family => 'Super3', byoffset => { count => -1 }); # last supercolumn, e.g. "latest" in LongType with timestamps

  $result = $c->get([$key], family => 'Super3', byoffset => { count => 1 }); # first supercolumn, e.g. "earliest" in LongType with timestamps

  $result = $c->get([$key], family => 'Super3', byoffset => { start => 'abcdefgh', count => 1 }); # first supercolumn after the 8 bytes 'abcdefgh'

  $result = $c->get([$key], family => 'Super3', byoffset => { startlong => '100', finishlong => '101', count => 1 }); # first supercolumn after the Long (8 bytes) 100 and before the 8-byte Long 101, both Longs in a string so they will work in 32-bit Perl

  $result = $c->get([$key], family => 'Super3', byname => [qw/one two/ ]); # get two supercolumns by name

  $result = $c->get([$key], family => 'Super3', bylong => [0, 1, '10231024'); # get three supercolumns by name as an 8-byte Long (note the last one is a quoted string so it will work in 32-bit Perl)

  $result = $c->mutate([$key], family => 'Super3', insertions => { 'hello!!!' => { testing => 123 } } ]) # insert SuperColumn named 'hello!!!' with one Column

  $result = $c->mutate([$key], family => 'Super3', insertions => { Net::Cassandra::Easy::pack_decimal(0) => { testing => 123 } } ]) # insert SuperColumn named 0 (as a long with 8 bytes) with one Column

  $result = $c->mutate([$key], family => 'Super3', deletions => { byname => ['hello!!!'] } ]) # delete SuperColumn named 'hello!!!'

  $result = $c->mutate([$key], family => 'Super3', deletions => { bylong => [123] } ]) # delete SuperColumn named 123

  $result = $c->mutate([$key], family => 'Standard1', deletions => { standard => 1, byname => ['one', 'two'] } ]) # delete columns from a row in a non-super column family

  $result = $c->mutate([$key], family => 'Standard1', insertions => { testing => 123 } ]) # insert Columns into a non-super column family

  $result = $c->describe(, # describe the keyspace families

  $result = $c->keys(['Super3'], range => { start_key => 'z', end_key => 'a', count => 100} ]) # list keys from 'a' to 'z', max 100

  $result = $c->keys(['Super3'], range => { start_token => 0, end_token => 1, count => 100} ]) # list keys from token 0 to token 1, max 100

  # EXPERIMENTAL schema reconfiguration support, see test.pl for how it's used

  my $keyspace = 'Keyspace2';
  my $family = 'Super3';                        # this is a LongType super CF
  my $std_family = 'Standard1';         # this is a non-super CF (the STD family, yes, I get it, thank you)

  # this is used for the pre-test setup
  my $families = {
                  $std_family =>
                  {
                   column_type => 'Standard',
                   comparator_type => 'BytesType',
                   comment => 'none',
                   row_cache_size => 0,
                   key_cache_size => 200000,
                  },
                  $family =>
                  {
                   column_type => 'Super',
                   comparator_type => 'LongType',
                   subcomparator_type => 'BytesType',
                   comment => 'none',
                   row_cache_size => 0,
                   key_cache_size => 200000,
                  }
                 };

  eval
  {
    print "configuring a new keyspace $keyspace, but this may fail\n";
    my $c = Net::Cassandra::Easy->new(server => $server, port => $port, keyspace => $keyspace, credentials => { none => 1 });
    $c->connect();
    $c->configure(
                  insertions =>
                  {
                   $keyspace =>
                   {
                    strategy_class => 'org.apache.cassandra.locator.RackUnawareStrategy',
                    replication_factor => 1,
                    snitch_class => 'org.apache.cassandra.locator.EndPointSnitch',
                    families => $families,
                   }
                  }
                 );
  };

  eval
  {
    print "configuring just CFs @{[ join ',', sort keys %$families ]} in $keyspace, but this may also fail\n";
    my $c = Net::Cassandra::Easy->new(server => $server, port => $port, keyspace => $keyspace, credentials => { none => 1 });
    $c->connect();
    $c->configure(
                  insertions =>
                  {
                   $keyspace =>
                   {
                    families => $families,
                   }
                  }
                 );
  };

  print Dumper $result; # enjoy

DESCRIPTION

Net::Cassandra::Easy aims to simplify the basic interactions with the Cassandra database.

Under the covers it translates every request to the Thrift API. It will stay current with that API as much as possible; I participate in the Cassandra project and watch the mailing lists so any changes should be in Net::Cassandra::Easy quickly.

How is it better than Net::Cassandra?

Net::Cassandra::Easy tries to stay away from Thrift. Thus it's easier to use in my opinion, and when and if Cassandra starts using another API, e.g. Avro, Net::Cassandra::Easy will not change much.

How do the timestamps work?

Net::Cassandra::Easy uses microsecond-resolution timestamps (whatever Time::HiRes gives us, basically). You can override the timestamps with the timestamp initialization parameter, which takes a subroutine reference.

EXPORT

Nothing, it's all methods on the client object.

AUTHOR

Teodor Zlatanov <tzz@lifelogs.com>

THANKS

Mike Gallamore <mike.e.gallamore@googlemail.com>

SEE ALSO

perl(1).

perldoc Net::Cassandra