RP/MSQ 5.0 (VMS)/MSQ 5.01 (VMS) - Pbm with [UN]AVAIL messages under specific conditions (Doc ID 778110.1)

Last updated on FEBRUARY 07, 2025

Applies to:

Goal

DESCRIPTION:
This is a MessageQ OpenVMS v.5 problem on message-based services, demonstrated by a testcase for reproduction.

In the Programmer's Guide, it says:
An application program registers to receive availability messages by sending a message of type AVAIL_REG to the local
Avail Server process. The Avail Server responds with a message of type AVAIL_REG_REPLY, acknowledging the notification
request.
After registration, the requestor immediately receives an AVAIL or UNAVAIL message indicating the current availability
of the target queue. Queue availability messages provide ongoing notification when a specific queue becomes attached
or detached and
***when a link is connected or lost.***
This happens under 'normal' conditions, but this escalation is focused on specific conditions where it does not happen
and would probably require a New Patch.

Specific conditions:
 - The first application (using reprod.program) attaches to a permanent queue on a group (# 2) : 2.194 (EXAMPLE_Q_2)
 - The second application (using reprod.program) attaches to a temporary queue on another group (# 201) : 201.202
 - The 2 groups may be on the same machine, are running and connected through cross-group link
 - But group 201 defines (in config file) link to group 2, and group 2 does not define link to group 201
 - The first application has registered (AVAIL_REG request) to local SBS in order to monitor 201.202
Then disconnecting cross-group link (MGR_UTILITY>Link Management>DC) from any of the 2 groups, prevents 2.194 to
receive MSG_TYPE_UNAVAIL message.

CONFIGURATION:
MessageQ 5.0
MessageQ 5.1

Solution

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