Event message MQMD (message descriptor)

The MQMD structure describes the information that accompanies the message data of an event message. For a full description of MQMD, including a description of the elementary datatype of each parameter, see the WebSphere MQ Application Programming Reference manual.

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, HP-UX, z/OS, Compaq NonStop Kernel, HP OpenVMS, i5/OS, Solaris, Linux, Windows, and all WebSphere MQ clients connected to these systems.
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: 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.
Priority
Description: Message priority.
Datatype: MQLONG.
Value:
MQPRI_PRIORITY_AS_Q_DEF
The priority is that of the event queue.
Persistence
Description: Message persistence.
Datatype: MQLONG.
Value:
MQPER_PERSISTENCE_AS_Q_DEF
The priority is that of the event queue.
MsgId
Description: Message identifier.
Datatype: MQBYTE24.
Value: A unique value generated by the queue manager.
CorrelId
Description: Correlation identifier.
Datatype: MQBYTE24.
Value:

For performance, queue manager, logger, channel, bridge, and SSL events:

MQCI_NONE
No correlation identifier is specified. This is for private queues only.
For such events on a shared queue, a nonzero correlation identifier is set. This parameter is set so that 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

For configuration and command events:

A unique nonzero correlation identifier
All messages relating to the same event have the same CorrelId.
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.