BUFLEN (10-digit signed integer) - input

Length of the message in BUFFER.

Zero is valid, and indicates that the message contains no application data. The upper limit for BUFLEN depends on various factors:

• If the destination queue is a shared queue, the upper limit is 63 KB (64 512 bytes).

• If the destination is a local queue or resolves to a local queue (but is not a shared queue), the upper limit depends on whether:

  • The local queue manager supports segmentation.

  • The sending application specifies the flag that allows the queue manager to segment the message. This flag is MFSEGA, and can be specified either in a version-2 MQMD, or in an MQMDE used with a version-1 MQMD.

  If both of these conditions are satisfied, BUFLEN cannot exceed 999 999 999 minus the value of the MDOFF field in MQMD. The longest logical message that can be put is therefore 999 999 999 bytes (when MDOFF is zero). However, resource constraints imposed by the operating system or environment in which the application is running may result in a lower limit.

  If one or both of the above conditions is not satisfied, BUFLEN cannot exceed the smaller of the queue's MaxMsgLength attribute and queue manager's MaxMsgLength attribute.

• If the destination is a remote queue or resolves to a remote queue, the conditions for local queues apply, but at each queue manager through which the message must pass in order to reach the destination queue; in particular:

  1. The local transmission queue used to store the message temporarily at the local queue manager

  2. Intermediate transmission queues (if any) used to store the message at queue managers on the route between the local and destination queue managers

  3. The destination queue at the destination queue manager

  The longest message that can be put is therefore governed by the most restrictive of these queues and queue managers.

  When a message is on a transmission queue, additional information resides with the message data, and this reduces the amount of application data that can be carried. In this situation it is recommended that LNMHD bytes be subtracted from the MaxMsgLength values of the transmission queues when determining the limit for BUFLEN.

  Note:

  Only failure to comply with condition 1 can be diagnosed synchronously (with reason code RC2030 or RC2031) when the message is put. If conditions 2 or 3 are not satisfied, the message is redirected to a dead-letter (undelivered-message) queue, either at an intermediate queue manager or at the destination queue manager. If this happens, a report message is generated if one was requested by the sender.