When you see the error message "DTM9034: Unsupported reconnect request" it means that the Teradata client application has lost connectivity to Hyper-Q and is trying to reconnect to the session it was previously connected to. Hyper-Q responds with the error code indicating to the client that the session it seeks to reconnect to is invalid. For security reasons, each client session is associated with a dedicated session to the downstream database and authentication is performed directly against the downstream database. Upon loss of connectivity to the client, Hyper-Q tears down the corresponding session to the downstream database (and vice versa).
To retry the transaction, open a new connection from the client and resubmit the transaction that was interrupted by the connectivity loss.
In case of frequent occurrence of connectivity loss between the client application and Hyper-Q, check firewalls and routers between client and Hyper-Q for settings that drop idle TCP connections or filter out TCP keepalive message.