IBM Support

IT36036: Using MQ REST API Gateway to administer remote queue manager canresult in MQWB0000E Error.

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APAR status

  • Closed as program error.

Error description

  • Using MQ REST API Gateway to administer remote queue manager can
    result in MQWB0000E Error.
    
    Response returned:
    
    {
    "error": [{
    "action": "Use the message from the exception to resolve the
    problem if possible. If necessary, seek assistance from IBM
    support.",
    "completionCode": 0,  "explanation": "An exception was thrown
    which is not otherwise handled.",
    "message": "MQWB0000E: An unexpected exception 'rest'
    occurred.",
    "msgId": "MQWB0000E",
    "reasonCode": 0,
    "type": "cmd"
    }]
    }
    

Local fix

Problem summary

  • ****************************************************************
    USERS AFFECTED:
    This affects users of the IBM MQ administrative REST API
    gateway.
    
    
    Platforms affected:
    MultiPlatform
    
    ****************************************************************
    PROBLEM DESCRIPTION:
    When using the IBM MQ administrative REST API gateway, under
    heavy load it was possible for two or more threads processing a
    REST request to attempt to initialize the same internal object
    at the same time. If this happened, the following error response
    would be returned
    
    {
    "error": [{
    "action": "Use the message from the exception to resolve the
    problem if possible. If necessary, seek assistance from IBM
    support.",
    "completionCode": 0,  "explanation": "An exception was thrown
    which is not otherwise handled.",
    "message": "MQWB0000E: An unexpected exception 'rest'
    occurred.",
    "msgId": "MQWB0000E",
    "reasonCode": 0,
    "type": "cmd"
    }]
    }
    0
    
    In addition to this, the MQ web server would generate an FDC.
    The contents of the FDC would be similar to the following
    example:
    
    Level:      ***unknown***
    Time:       13/10/2020 01:24:14:394 BST
    Thread:     61 (Default Executor-thread-10)
    Class:      com.ibm.mq.restapi.mappers.GenericExceptionMapper
    Method:     toResponse
    Probe:      FFDC_001
    Cause:      java.lang.NullPointerException
    java.lang.NullPointerException
     at
    com.ibm.mq.restapi.attributes.interfaces.PCFAttribute.getValueAs
    StringFromPOJO(PCFAttribute.java:952)
     at
    com.ibm.mq.rest.v1.resource.MQQueueResource.createQueue(MQQueueR
    esource.java:1526)
     at sun.reflect.GeneratedMethodAccessor12.invoke(Unknown Source)
     at
    sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethod
    AccessorImpl.java:55)
    

Problem conclusion

  • The REST API has been changed to ensure that only one thread
    initializes the same internal object at a time. This prevents
    unexpected exception and FDC being generated.
    
    ---------------------------------------------------------------
    The fix is targeted for delivery in the following PTFs:
    
    Version    Maintenance Level
    v9.2 LTS   9.2.0.3
    v9.x CD    9.2.3
    
    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

    IT36036

  • Reported component name

    MQ BASE V9.2

  • Reported component ID

    5724H7281

  • Reported release

    920

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt / Xsystem

  • Submitted date

    2021-02-25

  • Closed date

    2021-04-21

  • Last modified date

    2021-04-21

  • 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

    MQ BASE V9.2

  • Fixed component ID

    5724H7281

Applicable component levels

[{"Line of Business":{"code":"LOB36","label":"IBM Automation"},"Business Unit":{"code":"BU053","label":"Cloud & Data Platform"},"Product":{"code":"SSYHRD","label":"IBM MQ"},"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"920"}]

Document Information

Modified date:
22 April 2021