APAR status
Closed as program error.
Error description
An IBM MQ Managed File Transfer agent is configured to run a SourceTransferStartExit at the start of every managed transfer. The design of the SourceTransferStartExit means that it only expects to be run once for each managed transfer. If the exit detects that it is has been run more than once for a managed transfer, the exit returns an ResultCode of CANCEL. Very occasionally, the SourceTransferStartExit is run twice for the same managed transfer. This causes the exit to return a CANCEL ResultCode, which results in the managed transfer being marked as "Failed".
Local fix
n/a
Problem summary
**************************************************************** USERS AFFECTED: This issue affects users of IBM MQ Managed File Transfer who have agents configured to run SourceTransferStartExits at the beginning of managed transfers. Platforms affected: MultiPlatform **************************************************************** PROBLEM DESCRIPTION: When a source agent receives a managed transfer request, it performs the following steps: - Resolve the transfer item specification into a list of transfer items (files or messages) to transfer. - Run any SourceTransferStartExits. - Run any preSource programs or commands. - Contact the destination agent for the managed transfer, and perform the transfer negotiation. A destination agent can only act as the destination agent for a certain number of managed transfers at any one time. This is specified by the agent property "maxDestinationTransfers". If it is already acting as the destination agent for this number of managed transfers when it receives a new transfer negotiation request, it sends a reply back to the source agent indicating that it is currently too busy to participate in the new managed transfer. When the source agent receives this reply, it puts the managed transfer into a WaitingForDestinationCapacity state, and adds it to its backlog. After the time period specified by the agent property "senderTransferRetryInterval" has elapsed, the source agent resumes the managed transfer and sends a new transfer negotiation request to the destination agent again, to see if it is now able to participate in it. Now, in this situation, the source agent would incorrectly run any SourceTransferStartExits before contacting the destination agent for a second time. Depending on the design of the SourceTransferStartExit, this could result in unexpected behaviour.
Problem conclusion
To resolve this issue, MQ Managed File Transfer has been updated so that source agents only run SourceTransferStartExits before they send the initial transfer negotiation request message to a destination agent. If the managed transfer subsequently goes into a WaitingForDestinationCapacity state (because the destination agent is already participating in its maximum number of destination transfers), then the source agent will not re-run any SourceTransferStartExits prior to sending the subsequent transfer negotiation requests. --------------------------------------------------------------- The fix is targeted for delivery in the following PTFs: Version Maintenance Level v9.1 LTS 9.1.0.7 v9.2 LTS 9.2.0.2 The latest available MQ maintenance can be obtained from 'WebSphere MQ Recommended Fixes' http://www-1.ibm.com/support/docview.wss?rs=171&uid=swg27006037 If the maintenance level is not yet available information on its planned availability can be found in 'WebSphere MQ Planned Maintenance Release Dates' http://www-1.ibm.com/support/docview.wss?rs=171&uid=swg27006309 ---------------------------------------------------------------
Temporary fix
Comments
APAR Information
APAR number
IT33894
Reported component name
IBM MQ MFT V9.1
Reported component ID
5724H7272
Reported release
910
Status
CLOSED PER
PE
NoPE
HIPER
NoHIPER
Special Attention
NoSpecatt / Xsystem
Submitted date
2020-08-13
Closed date
2020-10-09
Last modified date
2020-10-09
APAR is sysrouted FROM one or more of the following:
APAR is sysrouted TO one or more of the following:
Fix information
Fixed component name
IBM MQ MFT V9.1
Fixed component ID
5724H7272
Applicable component levels
[{"Line of Business":{"code":"LOB45","label":"Automation"},"Business Unit":{"code":"BU053","label":"Cloud & Data Platform"},"Product":{"code":"SSYHRD","label":"IBM MQ"},"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"910"}]
Document Information
Modified date:
10 October 2020