InvalidRequestException(why:Expected 8 or 0 byte long for date ) cassandra

Question

I'm new to Cassandra. I'm trying to create a column family with a composite key that contains longtype for timestamp. Here is the code:

Composite cs = new Composite(); 
cs.addComponent(id, StringSerializer.get());
cs.addComponent(tstamp, DateSerializer.get());
Mutator mutator  = HFactory.createMutator(keyspace, stringSerializer);
mutator.insert(id, cf.getName(), HFactory.createColumn(cs, id, CompositeSerializer.get(), StringSerializer.get()));
                 mutator.insert( id, cf.getName(), HFactory.createColumn("ipaddress", usrlog.getIpaddress()));
                 mutator.insert( id, cf.getName(), HFactory.createColumn("timestamp", tstamp.getTime(), StringSerializer.get(), LongSerializer.get()));
                 mutator.insert( id, cf.getName(), HFactory.createColumn("search_term", usrlog.getSearchterm()));
                 mutator.insert( id, cf.getName(), HFactory.createColumn("user_agent", usrlog.getUseragent()));

Answer 1

because you insert a wrong date.the lengh is not fit .