Hi all, 
I use pycassa and I want to store lists and tuples in cassandra by serializing them using MessagePack. Seems like custom data type is what I need. Here is data type I created:
##########################################
class MyListType(CassandraType):
    @staticmethod
    def pack(value):
        return msgpack.packb(value)

    @staticmethod
    def unpack(value):
        return msgpack.unpackb(value)
##########################################
Now I'm creating a new column family and use instance of this class in column_validation_classes but unsuccessful. It raises "InvalidRequestException: InvalidRequestException(why="Unable to find abstract-type class 'org.apache.cassandra.db.marshal.MyListType'")".

What I'm doing wrong? How to do it properly?
Thanks.
--
Vladimir Prudnikov