Unable to complete request: one or more nodes were unavailable.

[Vivek Mishra]

Hi,
I am trying Cassandra light weight transaction support with Cassandra 2.0.4

cqlsh:twitter> create table user(user_id text primary key, namef text);
cqlsh:twitter> insert into user(user_id,namef) values('v','ff') if not
exists;

*Unable to complete request: one or more nodes were unavailable.*

Any suggestions?

-Vivek