/* Streaming asynchronously on streamExector_ threads. */
EncryptionOptions encryption = DatabaseDescriptor.getEncryptionOptions();
if (encryption != null && encryption.internode_encryption == EncryptionOptions.InternodeEncryption.all)
streamExecutor_.execute(new SSLFileStreamTask(header, to));
else
streamExecutor_.execute(new FileStreamTask(header, to));
}