Event message MQMD (message descriptor)

The message descriptor for an event message contains information that a system monitoring application can use, such as the message type and format, and the date and time that the message was put on the event queue.

The information in the descriptor informs a system management application that the message type is MQMT_DATAGRAM, and the message format is MQFMT_EVENT.

Many of the fields in an event message contain fixed data, which is supplied by the queue manager that generated the message. The MQMD also specifies the name of the queue manager (truncated to 28 characters) that put the message.

For an event message, the MQMD structure contains the following values:

StrucId

Description:

Structure identifier.

Data type:

MQCHAR4.

Value:

MQMD_STRUC_ID

Version

Description:

Structure version number.

Data type:

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®, IBM® i, Solaris, Linux®, Windows, and all IBM MQ MQI clients connected to these systems.

Report

Description:

Options for report messages.

Data type:

MQLONG.

Value:

MQRO_NONE: No reports required.

MsgType

Description:

Indicates type of message.

Data type:

MQLONG.

Value:

MQMT_DATAGRAM.

Expiry

Description:

Message lifetime.

Data type:

MQLONG.

Value:

MQEI_UNLIMITED: The message does not have an expiry time.

Feedback

Description:

Feedback or reason code.

Data type:

MQLONG.

Value:

MQFB_NONE.

Encoding

Description:

Numeric encoding of message data.

Data type:

MQLONG.

Value:

MQENC_NATIVE.

CodedCharSetId

Description:

Character set identifier of event message data.

Data type:

MQLONG.

Value:

Coded character set ID (CCSID) of the queue manager generating the event.

Format

Description:

Format name of message data.

Data type:

MQCHAR8.

Value:

MQFMT_EVENT: Event message.

Priority

Description:

Message priority.

Data type:

MQLONG.

Value:

MQPRI_PRIORITY_AS_Q_DEF: The priority is that of the event queue.

Persistence

Description:

Message persistence.

Data type:

MQLONG.

Value:

MQPER_PERSISTENCE_AS_Q_DEF: The priority is that of the event queue.

MsgId

Description:

Message identifier.

Data type:

MQBYTE24.

Value:

A unique value generated by the queue manager.

CorrelId

Description:

Correlation identifier.

Data type:

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 in the following way:

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.

Data type:

MQLONG.

Value:

ReplyToQ

Description:

Name of reply queue.

Data type:

MQCHAR48.

Values:

Blank.

ReplyToQMgr

Description:

Name of reply queue manager.

Data type:

MQCHAR48.

Value:

The queue manager name at the originating system.

UserIdentifier

Description:

Identifies the application that originated the message.

Data type:

MQCHAR12.

Value:

Blank.

AccountingToken

Description:

Accounting token that allows an application to charge for work done as a result of the message.

Data type:

MQBYTE32.

Value:

MQACT_NONE.

ApplIdentityData

Description:

Application data relating to identity.

Data type:

MQCHAR32.

Values:

Blank.

PutApplType

Description:

Type of application that put the message.

Data type:

MQLONG.

Value:

MQAT_QMGR: Queue manager generated message.

PutApplName

Description:

Name of application that put the message.

Data type:

MQCHAR28.

Value:

The queue manager name at the originating system.

PutDate

Description:

Date when message was put.

Data type:

MQCHAR8.

Value:

As generated by the queue manager.

PutTime

Description:

Time when message was put.

Data type:

MQCHAR8.

Value:

As generated by the queue manager.

ApplOriginData

Description:

Application data relating to origin.

Data type:

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.

Data type:

MQBYTE24.

Value:

MQGI_NONE: No group identifier specified.

MsgSeqNumber

Description:

Sequence number of logical message within group.

Data type:

MQLONG.

Value:

Offset

Description:

Offset of data in physical message from start of logical message.

Data type:

MQLONG.

Value:

MsgFlags

Description:

Message flags that specify attributes of the message or control its processing.

Data type:

MQLONG.

Value:

MQMF_NONE.

OriginalLength

Description:

Length of original message.

Data type:

MQLONG.

Value:

MQOL_UNDEFINED.