Send-then-commit, sync level=confirm, NAK response

This send-then-commit flow assumes no synchronization for the transactions as they are processed by IMS.

The following figure shows a flow in which all transactions are confirmed as they are received (each message requests a response).

Figure 1. Send-then-commit, sync level=confirm (NAK response) flow
begin figure description. Diagram flow chart of Send-Then-Commit, Sync Level=Confirm (NAK Response) as described in surrounding text. end figure description.
The sample flow shown in the preceding figure assumes the following:
  • Commit mode 1 is specified in the state-data section of the message prefix.
  • The transaction pipe is not synchronized.
  • The synchronization level is specified as Confirm in the state-data section.
  • NAK can be replied to by either IMS Connect or a remote workstation before the check requested bit.
  • If the client forgets to send the NAK/ACK before it closes the socket, IMS Connect will send the NAK to IMS and it will cause a U0119 abend.