Unique GMH Assignment

(Type 692)

This section describes the transaction used to inform a remote external application of the unique QTRACS-assigned GMH (global message handle). This transaction is only relevant in a RI environment where the external application is on a machine remote from QTRACS.

When communicating via the RI there are rare occasions when remote services may not be available to external applications because the "link" (i.e. TCP/IP or remote RI process) is down. It is important that no forward messages are ever lost; therefore, when the RI link is down, messages are queued and sent at a later time. Normally, OMCRTMSG would return a unique GMH to the caller. However, when the link is down, and the 'transactional backup' is employed, a GMH cannot be immediately provided to the external application.

To solve this problem, a temporary LMH (local message handle) must be assigned by the OMCRTMSG requester (which runs on the non-QTRACS machine). This LMH may be stored within the requesting application. When the RI link returns to service, and the queued transaction is finally delivered to QTRACS, then a unique GMH is assigned.

Depending upon the setting of the Application ID field in the 601, 604, and 609 transactions, a 692 transaction may be returned to the external application. This transaction is used to resolve all occurrences of the temporary LMH to the unique QTRACS-generated GMH.

Unique GMH Assignment transaction format

From	To	Size	Type	Field Description
1	5	9	Packed	Local Message Handle (LMH)
6	8	3	Character	Transaction Type = 692
9	13	9	Packed	QTRACS Generated Global Message Handle (GMH)
14	20	7	Character	Reserved - returned as blanks

Unique GMH Assignment transaction field descriptions

Field	Description
Local Message Handle	This packed decimal field contains the local message handle. The local message handle (LMH) is a temporary number used to reference a specific transaction. A LMH is a number assigned by the OMCRTMSG requester that is unique to the system that generated it (a negative number ranging from -1 to -999,999,999).
Transaction Type	This is the code that identifies the transaction as a unique GMH assignment. It is a 3-character numeric field that will contain 692.
Global Message Handle	This packed decimal field contains a unique QTRACS generated global message handle. The global message handle (GMH) will forever more be used to reference this specific message.