In my organisation, we have a Spark Thrift server setup with HTTP & SSL because there is an underlying assumption that the binary mode is not securely encrypted over the wire and thus may reveal credentials or sensitive query data.
I have Googled, scan read a research paper and looked at the Thrift protocol spec searching for a definitive answer, but to no avail. It seems that the sheer lack of mention on authentication and encryption means that it is expected to be taken care of by an encasing networking layer?
Is the assumption that a Spark Thrift server in binary mode is transmitting unencrypted or otherwise insecure data correct?