Looking into it further, I believe your issue is that you did not define the table with compact storage. Without that, CQL3 will treat every column as a composite (as is hinted in your stack trace where you see AbstractCompositeType is the cause of the error). Try changing your table definition as follows:
create table users ( id uuid primary key, firstname varchar, lastname varchar, password varchar, age int, email varchar) WITH COMPACT STORAGE and compaction = {'class' : 'LeveledCompactionStrategy' } From: Davide Anastasia <davide.anasta...@gmail.com<mailto:davide.anasta...@gmail.com>> Reply-To: "user@cassandra.apache.org<mailto:user@cassandra.apache.org>" <user@cassandra.apache.org<mailto:user@cassandra.apache.org>> Date: Friday, June 7, 2013 2:11 AM To: "user@cassandra.apache.org<mailto:user@cassandra.apache.org>" <user@cassandra.apache.org<mailto:user@cassandra.apache.org>> Subject: Re: Bulk loader with Cassandra 1.2.5 AbstractCompositeType.java