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

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 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