APAR status
Closed as program error.
Error description
The DISPLAY CHSTATUS(CHANNEL_NAME) shows an '*' for the MCAUSER instead of the correct userid to which it is set.
Local fix
The USERSRC() value on the rule can be changed to USERSRC(MAP) (which is the default value) and then set the MCAUSER parameter on the rule to the same value as the CLNTUSER(). For example, instead of setting the rule with the command: SET CHLAUTH('My.Channel.SVC') TYPE(USERMAP) CLNTUSER('User123') USERSRC(CHANNEL) CHCKCLNT(REQUIRED) ACTION(REPLACE) you use the following command instead : SET CHLAUTH('My.Channel.SVC') TYPE(USERMAP) CLNTUSER('User123') MCAUSER('User123') CHCKCLNT(REQUIRED) ACTION(REPLACE)
Problem summary
**************************************************************** USERS AFFECTED: This issue affects users of WebSphere MQ V8 and IBM MQ V9 who use multiplexed channels together with the queue manager setting ChlauthEarlyAdopt=y. Platforms affected: MultiPlatform **************************************************************** PROBLEM DESCRIPTION: The DISPLAY CHSTATUS(CHANNEL_NAME) shows an '*' for the MCAUSER instead of the correct userid to which it is set. A race condition occurs in channel initialisation caused at a point where the channel status is progressing through a sequence of states. Normally, the MCAUSER in the channel status is temporarily set to the user defined on the channel (e.g. NOACCESS), then later updated to the correct (adopted) user id (e.g. User123). We see the problematic case when multiple conversations are starting concurrently. There is a timing window when a conversation has set MCAUSER status to the temporary user (NOACCESS) and another conversation begins. When this happens, MQ compares the conversation userid with the userid in channel status, realizes they are different and incorrectly sets the overall MCAUSER for the channel status to "*".
Problem conclusion
The MQ channel code has been modified to ensure the MCAUSER in the channel status is updated correctly when this timing condition arises. --------------------------------------------------------------- The fix is targeted for delivery in the following PTFs: Version Maintenance Level v8.0 8.0.0.9 v9.0 CD 9.0.5 v9.0 LTS 9.0.0.3 The latest available 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
IT22180
Reported component name
WMQ BASE MULTIP
Reported component ID
5724H7251
Reported release
800
Status
CLOSED PER
PE
NoPE
HIPER
NoHIPER
Special Attention
NoSpecatt / Xsystem
Submitted date
2017-08-28
Closed date
2017-10-31
Last modified date
2017-10-31
APAR is sysrouted FROM one or more of the following:
APAR is sysrouted TO one or more of the following:
PI89616
Fix information
Fixed component name
WMQ BASE MULTIP
Fixed component ID
5724H7251
Applicable component levels
R800 PSY
UP
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Document Information
Modified date:
31 October 2017