PK17376: EYUXZ0910I CMAS STARTUP DEBUG MISNGBUF EXCEPTION DLST TSLG JOIN

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• EYUXZ0910I SVCDUMP issued by CMAS while other CMAS connection
  paths are changing and MASes are joining.  The SVCDUMP is from
  an LNMI Receive Link task.  The debug text is MisngBuf with
  Point Id 18.  The link buffer is for a TSLG (Topology Services
  List Get) request which is out of sequence.  The internal trace
  contains previous exception trace entries with debug text
  InvlDLST with Point Id 19 for the missing link buffers.  The
  COMGDLST contains invalid CMAS SYSIDs due to the sending CMAS
  changing paths to other CMASes while needing to send multiple
  buffers for the TSLG MAL data.
  .
  Additional Symptom(s) Search Keyword(s): CTRP CTSN_PCK_NUM
  COMGPSID_NUM COMGPSID_PCKTYPE_MIC middle-in-chain linkbuf
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED: All CICSPlex/SM V3R1M0 Users                 *
  ****************************************************************
  * PROBLEM DESCRIPTION: Various unpredictable errors may occur  *
  *                      when a CMAS is sending information to   *
  *                      another CMAS while in the process of    *
  *                      acquiring or terminating a direct or    *
  *                      indirect connection to one or more      *
  *                      additional CMASes.                      *
  *                                                              *
  *                      One possible symptom is an SVC dump     *
  *                      taken by the receiving CMAS.  The dump  *
  *                      title will be similar to the following: *
  *                                                              *
  *                        EYU0XZPT Dump,<cmasjobn>,<cmasname>,  *
  *                        <lpar>,CMAS,<tranid>,<tasknum>,TRAC,  *
  *                        EYU0CTRP,<date>,<time>                *
  *                                                              *
  *                      Examination of the auxtrace datasets    *
  *                      for the CMAS that requested the dump    *
  *                      will show an accompanying exception     *
  *                      trace issued by method EYU0CTRP (CTRP), *
  *                      with a debug text of "MisngBuf" and a   *
  *                      trace point ID of 18.  This will most   *
  *                      likely be preceded by at least one      *
  *                      additional exception trace issued by    *
  *                      method EYU0CTRD (CTRD), with a debug    *
  *                      text of "InvlDLST" and a trace point ID *
  *                      of 19.                                  *
  ****************************************************************
  * RECOMMENDATION: After applying the PTF that resolves this    *
  *                 APAR, all CMASes must be restarted.  Note    *
  *                 that the restarts do not need to occur at    *
  *                 the same time.                               *
  ****************************************************************
  When a CMAS sends information to  another CMAS, method EYU0CTST
  (CTST) calls method EYU0CPLC (CPLC) to retrieve the address of
  the destination list (DLST) which defines the path from the
  sending CMAS to the receiving CMAS.  CTST stores the address of
  the DLST in the Transport Services Source Block (EYURCTSR)
  section of the Transport Services Block (EYURCTSB) for the
  request, copies the DLST data into the communications buffer,
  and then the buffer is shipped to the receiving CMAS.  If the
  request requires additional buffers of data, CTST is recalled,
  retrieving the DLST address from the EYURCTSR and copying the
  DLST into each subsequent buffer.  When the last buffer for a
  request is formatted, the EYURCTSR is cleared.
  
  When a CMAS acquires or terminates a direct or indirect
  connection to another CMAS, method EYU0CPAG (CPAG) is called to
  rebuild all the DLSTs for the CMAS, since the addition or
  subtraction of a connection may result in changed paths between
  the CMAS and the other CMASes it is connected to.
  
  If after CTST places the address of a DLST into a EYURCTSR for a
  request and before CTST completes sending all buffers for the
  request, CPAG is called to rebuild the DLSTs, the address of the
  DLST in the EYURCTSR may be invalid, especially if the area has
  been reused for a different DLST.  This results in an invalid
  DLST being placed into a buffer.  When processing the buffer,
  CTRP running in the receiving CMAS will throw away the buffer
  and generate an "InvlDLST" trace.  If another CPAG call is made
  before the original request is complete, it is possible that the
  original DLST area will be reset.  This will result in the next
  buffer being shipped with the correct DLST, but since previous
  buffers were rejected with the "InvlDLST" trace, the current
  buffer will be rejected with the ""MisngBuf" trace and the
  accompanying dump.
  

Problem conclusion

• The parameter list (MAL - method argument list) for CPLC,
  EYUZCPLC, has been updated to allow a caller to request a copy
  of the DLST in CICS task storage, instead of the pointer to the
  DLST.  CPLC has been updated to recognize the new parm, and if
  it is specified, will issue a CICS getmain in task storage for
  the length of the DLST, copy the DLST into the task storage, and
  return the address of the task storage to its caller.  This copy
  is a private copy made available only to the caller, and will
  not be affected by subsequent CPAG calls.  CTST has been updated
  to request a copy of the DLST instead of the DLST pointer when
  calling CPLC.  CTST will place the address of the copy of the
  DLST into the EYURCTSR.  When CTST no longer needs the DLST, it
  will issue a CICS freemain to release the storage and will clear
  the address in the EYURCTSR.
  

Temporary fix

• FIX AVAILABLE BY PTF ONLY
  

Comments

• Various unpredictable errors may occur
  when a CMAS is sending information to
  another CMAS while in the process of
  acquiring or terminating a direct or
  indirect connection to one or more
  additional CMASes.
  
  One possible symptom is an SVC dump
  taken by the receiving CMAS.  The dump
  title will be similar to the following:
  
    EYU0XZPT Dump,<cmasjobn>,<cmasname>,
    <lpar>,CMAS,<tranid>,<tasknum>,TRAC,
    EYU0CTRP,<date>,<time>
  
  Examination of the auxtrace datasets
  for the CMAS that requested the dump
  will show an accompanying exception
  trace issued by method EYU0CTRP (CTRP),
  with a debug text of "MisngBuf" and a
  trace point ID of 18.  This will most
  likely be preceded by at least one
  additional exception trace issued by
  method EYU0CTRD (CTRD), with a debug
  text of "InvlDLST" and a trace point ID
  of 19.
  
  
  When a CMAS sends information to  another CMAS, method EYU0CTST
  (CTST) calls method EYU0CPLC (CPLC) to retrieve the address of
  the destination list (DLST) which defines the path from the
  sending CMAS to the receiving CMAS.  CTST stores the address of
  the DLST in the Transport Services Source Block (EYURCTSR)
  section of the Transport Services Block (EYURCTSB) for the
  request, copies the DLST data into the communications buffer,
  and then the buffer is shipped to the receiving CMAS.  If the
  request requires additional buffers of data, CTST is recalled,
  retrieving the DLST address from the EYURCTSR and copying the
  DLST into each subsequent buffer.  When the last buffer for a
  request is formatted, the EYURCTSR is cleared.
  
  When a CMAS acquires or terminates a direct or indirect
  connection to another CMAS, method EYU0CPAG (CPAG) is called to
  rebuild all the DLSTs for the CMAS, since the addition or
  subtraction of a connection may result in changed paths between
  the CMAS and the other CMASes it is connected to.
  
  If after CTST places the address of a DLST into a EYURCTSR for a
  request and before CTST completes sending all buffers for the
  request, CPAG is called to rebuild the DLSTs, the address of the
  DLST in the EYURCTSR may be invalid, especially if the area has
  been reused for a different DLST.  This results in an invalid
  DLST being placed into a buffer.  When processing the buffer,
  CTRP running in the receiving CMAS will throw away the buffer
  and generate an "InvlDLST" trace.  If another CPAG call is made
  before the original request is complete, it is possible that the
  original DLST area will be reset.  This will result in the next
  buffer being shipped with the correct DLST, but since previous
  buffers were rejected with the "InvlDLST" trace, the current
  buffer will be rejected with the ""MisngBuf" trace and the
  accompanying dump.
  
  
  The parameter list (MAL - method argument list) for CPLC,
  EYUZCPLC, has been updated to allow a caller to request a copy
  of the DLST in CICS task storage, instead of the pointer to the
  DLST.  CPLC has been updated to recognize the new parm, and if
  it is specified, will issue a CICS getmain in task storage for
  the length of the DLST, copy the DLST into the task storage, and
  return the address of the task storage to its caller.  This copy
  is a private copy made available only to the caller, and will
  not be affected by subsequent CPAG calls.  CTST has been updated
  to request a copy of the DLST instead of the DLST pointer when
  calling CPLC.  CTST will place the address of the copy of the
  DLST into the EYURCTSR.  When CTST no longer needs the DLST, it
  will issue a CICS freemain to release the storage and will clear
  the address in the EYURCTSR.
  

APAR Information

• APAR is sysrouted FROM one or more of the following:

  PK17440

• APAR is sysrouted TO one or more of the following:

  UK13566

Modules/Macros

•    EYUQCPLC EYURCPLC EYURCTSR EYUTRCOM EYUYCPLC
  EYUZCPLC EYU0CPLC EYU0CTST EYU9CMPU EYU9CMP3 EYU9CMP4 EYU9CMP5
  

Fix information

• Fixed component name

  CPSM CICS 3.1

• Fixed component ID

  5655M1501

Applicable component levels

• R100 PSY UK13566

     UP06/04/19 P F604

Fix is available

• Select the PTF appropriate for your component level. You will be required to sign in. Distribution on physical media is not available in all countries.