MQMD (message descriptor)

 

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The MQMD structure describes the information that accompanies the message data of an event message. For an event message, the MQMD structure contains these values:

StrucId

Description:	Structure identifier.
Datatype:	MQCHAR4.
Value:	MQMD_STRUC_ID

Version

Description:	Structure version number.
Datatype:	MQLONG.
Values:	MQMD_VERSION_1 Version-1 message descriptor structure, supported in all environments. MQMD_VERSION_2 Version-2 message descriptor structure, supported on AIX(R), DOS client, HP-UX, OS/2(R), OS/400, Solaris, Windows NT client and Windows platforms.

Report

Description:	Options for report messages.
Datatype:	MQLONG.
Value:	MQRO_NONE No reports required.

MsgType

Description:	Indicates type of message.
Datatype:	MQLONG.
Value:	MQMT_DATAGRAM.

Expiry

Description:	Message lifetime.
Datatype:	MQLONG.
Value:	MQEI_UNLIMITED The message does not have an expiry time.

Feedback

Description:	Feedback or reason code.
Datatype:	MQLONG.
Value:	MQFB_NONE.

Encoding

Description:	Numeric encoding of message data.
Datatype:	MQLONG.
Value:	MQENC_NATIVE.

CodedCharSetId

Description:	Character set identifier of event message data.
Datatype:	MQLONG.
Value:	MQCCSI_Q_MQR Coded character set ID (CCSID) of the queue manager generating the event.

Format

Description:	Format name of message data.
Datatype:	MQCHAR8.
Value:	MQFMT_EVENT Event message. For the C programming language, the constant MQFMT_EVENT_ARRAY is also defined; this has the same value as MQFMT_EVENT, but is an array of characters not a string.

Priority

Description:	Message priority.
Datatype:	MQLONG.
Value:	MQPRI_PRIORITY_AS_Q_DEF Default priority of the event queue, if it is a local queue, or its local definition at the queue manager generating the event.

Persistence

Description:	Message persistence.
Datatype:	MQLONG.
Value:	MQPER_PERSISTENCE_AS_Q_DEF Default persistence of the event queue, if it is a local queue, or its local definition at the queue manager generating the event.

MsgId

Description:	Message identifier.
Datatype:	MQBYTE24.
Initial value:	MQMI_NONE.
Valid values:	A unique value generated by the queue manager.

CorrelId

Description:	Correlation identifier.
Datatype:	MQBYTE24.
Initial value:	MQCI_NONE.
Valid values:	MQCI_NONE No correlation identifier is specified. This is for local queues only. For shared queues: a nonzero correlation identifier is set. For events on a shared queue, this parameter is set, so you can track multiple event messages from different queue managers. The characters are specified below: 1-4 Product identifier ('CSQ ') 5-8 Queue-sharing group name 9 Queue manager identifier 10-17 Time stamp 18-24 Nulls

BackoutCount

Description:	Backout counter.
Datatype:	MQLONG.
Value:	0.

ReplyToQ

Description:	Name of reply queue.
Datatype:	MQCHAR48.
Values:	Blank.

ReplyToQMgr

Description:	Name of reply queue manager.
Datatype:	MQCHAR48.
Value:	The queue manager name at the originating system.

UserIdentifier

Description:	Identifies the application that originated the message.
Datatype:	MQCHAR12.
Value:	Blank.

AccountingToken

Description:	Accounting token that allows an application to charge for work done as a result of the message.
Datatype:	MQBYTE32.
Value:	MQACT_NONE.

ApplIdentityData

Description:	Application data relating to identity.
Datatype:	MQCHAR32.
Values:	Blank.

PutApplType

Description:	Type of application that put the message.
Datatype:	MQLONG.
Value:	MQAT_QMGR Queue-manager-generated message.

PutApplName

Description:	Name of application that put the message.
Datatype:	MQCHAR28.
Value:	The queue manager name at the originating system.

PutDate

Description:	Date when message was put.
Datatype:	MQCHAR8.
Value:	As generated by the queue manager.

PutTime

Description:	Time when message was put.
Datatype:	MQCHAR8.
Value:	As generated by the queue manager.

ApplOriginData

Description:	Application data relating to origin.
Datatype:	MQCHAR4.
Value:	Blank.

Note: If Version is MQMD_VERSION_2, the following additional fields are present:

GroupId

Description:	Identifies to which message group or logical message the physical message belongs.
Datatype:	MQBYTE24.
Value:	MQGI_NONE No group identifier specified.

MsgSeqNumber

Description:	Sequence number of logical message within group.
Datatype:	MQLONG.
Value:	1.

Offset

Description:	Offset of data in physical message from start of logical message.
Datatype:	MQLONG.
Value:	0.

MsgFlags

Description:	Message flags that specify attributes of the message or control its processing.
Datatype:	MQLONG.
Value:	MQMF_NONE.

OriginalLength

Description:	Length of original message.
Datatype:	MQLONG.
Value:	MQOL_UNDEFINED.