only grant select , but still can modify data

[rock zhang]

Hi All,

I want to create a readonly account, so i run the following command following: 
http://docs.datastax.com/en/cassandra/1.2/cassandra/security/security_config_native_authenticate_t.html

CREATE USER readonly WITH PASSWORD 'xxxx'  ;

GRANT SELECT ON ALL KEYSPACES TO readonly;

Then I login DevCenter  with readonly account , i still can modify the data, 
anyone knows why ?  Many thanks.

I set keyspace system_auth replica as 6 since i have 6 nodes. 


Thanks
Rock