As Jonathan mentioned in his keynote at the Cassandra Summit, the thrift + php has some bugs and is maintainerless right now.
Is there anyone out there in the Cassandra community that is adept at PHP that could help out with the thrift + php work? It would benefit all who use Cassandra with PHP. Bryan Duxbury, a thrift developer/committer, said "if someone really wanted to have a go at making thrift php robust, i would assist them heavily." Please respond to this thread or ask Bryan in the channel.