Calling ‘MQINQ’ in COBOL to Get Queue Details See How

Here’s an example of COBOL to get queue details using MQINQ. MQ-series is IBM middle-ware product that helps integrate heterogeneous interfaces. Don’t worry. I’ll help you with how to use this and show you how to use this.

What are Queue Attributes?

MQINQ provides queue attributes. The below table tells you the list of attributes of a Queue.

Attribute	Data Type	Description
ALTERATION_DATE	Character12	Date definition last changed
ALTERATION_TIME	Character8	Time definition was last changed
BACKOUT_REQ_Q_NAME	Character48	Excessive backout requeue name
BACKOUT_THRESHOLD	Numeric	Backout threshold
BASE_Q_NAME	Character48	Name of queue to which alias resolves
CF_STRUC_NAME	Character12	Coupling-facility structure name (z/OS only)
CLUSTER_NAME	Character48	Name of cluster to which queue belongs
CLUSTER_NAMELIST	Character48	Name of namelist containing names of clusters to which queue belongs
CLUSTER_WORKLOAD_DATA	Character32	User data for cluster workload exit
CLUSTER_WORKLOAD_LENGTH	Numeric	Maximum length of message data passed to cluster workload exit
CREATION_DATE	Character12	Queue creation date
CREATION_TIME	Character8	Queue creation time
CURRENT_Q_DEPTH	Numeric	Number of messages on queue
DEF_BIND	Numeric	Default binding
DEF_INPUT_OPEN_OPTION	Numeric	Default open-for-input option
DEF_PERSISTENCE	Numeric	Default message persistence
DEF_PRIORITY	Numeric	Default message priority
DEF_XMIT_Q_NAME	Character48	Default transmission queue name
DEFINITION_TYPE	Numeric	Queue definition type
EXPIRY_INTERVAL	Numeric	Interval between scans for expired messages (z/OS only)
HARDEN_GET_BACKOUT	Numeric	Whether to harden backout count
IGQ_PUT_AUTHORITY	Numeric	Intra-group queuing put authority (z/OS only)
IGQ_USER_ID	Character12	Intra-group queuing agent user ID (z/OS only)
INDEX_TYPE	Numeric	Index type (z/OS only)
INHIBIT_GET	Numeric	Whether get operations are allowedThis output type is not supported on z/OS.
INHIBIT_PUT	Numeric	Whether put operations are allowed
INITIATION_Q_NAME	Character48	Initiation queue name
INTRA_GROUP_QUEUING	Numeric	Intra-group queuing support (z/OS only)
MAX_MSG_LENGTH	Numeric	Maximum message length
MAX_Q_DEPTH	Numeric	Maximum number of messages allowed on queue
MSG_DELIVERY_SEQUENCE	Numeric	Whether message priority is relevant
OPEN_INPUT_COUNT	Numeric	Number of CALL MQOPEN routines that have the queue open for input
OPEN_OUTPUT_COUNT	Numeric	Number of CALL MQOPEN routines that have the queue open for output
PROCESS_NAME	Character32	Name of process definition
Q_DEPTH_HIGH_EVENT	Numeric	Control attribute for queue depth high eventsThis output type is not supported on z/OS.
Q_DEPTH_HIGH_LIMIT	Numeric	High limit for queue depthThis output type is not supported on z/OS.
Q_DEPTH_LOW_EVENT	Numeric	Control attribute for queue depth low eventsThis output type is not supported on z/OS.
Q_DEPTH_LOW_LIMIT	Numeric	Low limit for queue depthThis output type is not supported on z/OS.
Q_DEPTH_MAX_EVENT	Numeric	Control attribute for queue depth max eventsThis output type is not supported on z/OS.
Q_DESC	Character64	Queue description
Q_NAME	Character48	Queue name
Q_SERVICE_INTERVAL	Numeric	Limit for queue service intervalThis output type is not supported on z/OS.
Q_SERVICE_INTERVAL_EVENT	Numeric	Control for queue service interval eventsThis output type is not supported on z/OS.
Q_TYPE	Numeric	Queue type
QSG_DISP	Numeric	Queue-sharing group disposition (z/OS only)
QSG_NAME	Character4	Name of queue-sharing group (z/OS only)
REMOTE_Q_MGR_NAME	Character48	Name of remote queue manager
REMOTE_Q_NAME	Character48	Name of remote queue as known on remote queue manager
RETENTION_INTERVAL	Numeric	Queue retention interval
SCOPE	Numeric	Queue definition scopeThis output type is not supported on z/OS.
SHAREABILITY	Numeric	Whether queue can be shared
STORAGE_CLASS	Character8	Storage class for queue (z/OS only)
TRIGGER_CONTROL	Numeric	Trigger control
TRIGGER_DATA	Character64	Trigger data
TRIGGER_DEPTH	Numeric	Trigger depth
TRIGGER_MSG_PRIORITY	Numeric	Threshold message priority for triggers
TRIGGER_TYPE	Numeric	Trigger type
USAGE	Numeric	Usage
XMIT_Q_NAME	Character48	Default transmission queue name

In total, attributes of four objects you’ll get when you call MQINQ. Below is the list (Queues, Namelists, Process definitions, and Queue Manager).

Table 1 MQINQ attribute selectors for queues
Table 2 MQINQ attribute selectors for namelists
Table 3 MQINQ attribute selectors for process definitions
Table 4 MQINQ attribute selectors for the queue manager

How to Get Queue Depth? (Number of Messages in a Queue)

First, you need to make MQINQ standard call. If successful, you will get queue attributes. Here’s more on MQINQ.

COBOL Sample Logic to CALL MQINQ

If this call is successful, you’ll get queue attributes.

*
*    Inquire about the attributes.
*
     CALL 'MQINQ' USING W02-HCONN,
                        W02-HOBJ,
                        W02-SELECTORCOUNT,
                        W02-SELECTORS-TABLE, /* Here stores all the info*/
                        W02-INTATTRCOUNT,
                        W02-INTATTRS-TABLE,
                        W02-CHARATTRLENGTH,
                        W02-CHARATTRS,
                        W02-COMPCODE,
                        W02-REASON.
*
* Test the output from the inquiry:
*
* - If the completion code is not OK, display an error
*   message showing the completion and reason codes
*
* - Otherwise, move the correct attribute status into
*   the relevant screen map fields
*
     IF W02-COMPCODE NOT = MQCC-OK
        MOVE 'MQINQ'       TO M01-MSG4-OPERATION
        MOVE W02-COMPCODE  TO M01-MSG4-COMPCODE
        MOVE W02-REASON    TO M01-MSG4-REASON
        MOVE M01-MESSAGE-4 TO M00-MESSAGE
*
     ELSE
*       Process the changes.
        ⋮
           END-IF.
        ⋮

After executing the above logic, you’ll get data into the selectors-Table. From it, you can get the ‘Q depth’ value, which ( CURRENT_Q_DEPTH ) tells the number of messages in a Queue.

References