Cassandra: Request did not complete within rpc_timeout
From the EOFException I take it that your problem is not the rpc_timeout but a corrupt data file. And it seams that Cassandra is not properly handling the exception and never returns the error to the piece of server code that "holds" your client connection and waits for data to send back to the client. Thus the timeout.

You could try and run nodetool repair &lt;your_keyspace&gt;. Maybe it is able to fix the corrupted data file. If not, try to drop the keyspace and restore it again.

To answer your question. The timeouts are set in the cassandra.yaml file in the config directory of your cassandra installation on each node.