Summary results of IMS transactions and commands

The following figure summarizes the results of IMS transactions that a client submits under various processing conditions using a synchronized tpipe.

The summarization differentiates recoverable sequence numbers of zero and non-zero, and shows the differences between recoverable and unrecoverable transactions for commit modes 0 and 1 for both the zero and non-zero sequence.

In the tables, CM0 indicates a commit-then-send (commit mode 0) transaction and CM1 indicates a send-then-commit (commit mode 1) transaction.

Table 1. Results of IMS transactions using a synchronized Tpipe
Recoverable sequence number	CM0 recoverable transaction	CM0 unrecoverable transaction	CM1 recoverable transaction	CM1 unrecoverable transaction
0 (zero)	Client receives ACK message. Output is recoverable, and no input/output recoverable sequence is updated.	Client receives ACK message. Output is not recoverable and no input/output recoverable sequence number is updated.	Client receives NAK message with sense code X'001C'.	Client receives NAK message with sense code X'001C'.
Not 0 (zero)	If the recoverable sequence number is valid, client receives ACK message. If it is not valid, client receives NAK message with sense code X'001F'. Transaction and output are recoverable.	Client receives NAK message with sense code X'0023'. Client should set recoverable sequence number to 0 (zero).	Client receives NAK message with sense code X'001C'.	Client receives NAK message with sense code X'001C'.

The following table summarizes the results of IMS transactions that a client submits under various processing conditions using a nonsynchronized tpipe. The summarization differentiates recoverable sequence numbers of zero and non-zero, and shows the differences between recoverable and unrecoverable transactions for commit modes 0 and 1 for both the zero and non-zero sequence.

Table 2. Results of IMS transactions using a nonsynchronized Tpipe
Recoverable sequence number	CM0 recoverable transaction	CM0 unrecoverable transaction	CM1 recoverable transaction	CM1 unrecoverable transaction
0 (zero)	Client receives ACK message. Transaction and output are recoverable.	Client receives ACK message. Transaction and output are not recoverable.	Client receives ACK message. Transaction and output are not recoverable.	Client receives ACK message. Transaction and output are not recoverable.
Not 0 (zero)	Client receives NAK message with sense code X'0023'. Client should set recoverable sequence number to 0 (zero).	Client receives NAK message with sense code X'0023'. Client should set recoverable sequence number to 0 (zero).	Client receives NAK message with sense code X'0023'. Client should set recoverable sequence number to 0 (zero).	Client receives NAK message with sense code X'0023'. Client should set recoverable sequence number to 0 (zero).

The following table summarizes the results of commands that a client issues under various processing conditions using a synchronized tpipe or a nonsynchronized tpipe. The summarization differentiates recoverable sequence numbers of zero and non-zero, and shows the differences between commit modes 0 and 1 for both synchronized and nonsynchronized tpipes.

Table 3. Results of commands that a client issues
Recoverable sequence number	Synchronized tpipe with CM0	Synchronized tpipe with CM1	Nonsynchronized tpipe with CM0	Nonsynchronized tpipe with CM1
0 (zero)	Client receives ACK message. Command output is recoverable and output recoverable sequence number is updated.	Client receives NAK message with sense code X'001C'.	Client receives ACK message. Output is not recoverable.	Client receives ACK message. Output is not recoverable.
Not 0 (zero)	Client receives NAK message with sense code X'0023'. Client should set recoverable sequence number to 0 (zero).	Client receives NAK message with sense code X'001C'.	Client receives NAK message with sense code X'0023'. Client should set recoverable sequence number to 0 (zero).	Client receives NAK message with sense code X'0023'. Client should set recoverable sequence number to 0 (zero).