Back-end transaction initiation
The back-end transaction is initiated either by an attach header received from the partner system or by a transaction identifier included in the incoming data, and is started with the session as its principal facility.
Initially, the back-end transaction should determine the convid from EIBTRMID. This is not strictly necessary because the session is the back-end transaction’s principal facility making the CONVID parameter optional for DTP commands on this conversation. However, the convid is very useful for audit trails. Also, if the back-end transaction is involved in more than one conversation, then always specifying the convid will improve program readability and problem determination. Figure 1 shows a back-end transaction that does obtain the convid.
It is possible that the back-end transaction may fail to start. This will result in the front-end transaction abending. When this happens, message DFHIR3783 contains the reason for the error.