You have one what? I guess the "database management system developed by Facebook", right? You should be clear about that, this is not something "well known".
The review of the current, almost three years old, version of Net::Cassandra::Easy says "This might be a good module if it were updated, but this version is too old to be useful. It appears this module will not work with any version of Cassandra above 5.x." It's a little strange since the current version of Cassandra is 1.2.3, but I guess John meant 0.5.0. Especially since the docs of the module say "Net::Cassandra::Easy WILL NOT WORK WITH 0.6.x RELEASES OF Cassandra.".
Looks like there is no supported Perl interface to this database.
Enoch was right!
Enjoy the last years of Rome.