OA35627: XCF CONNECTIVITY NOT ESTABLISHED BETWEEN TWO VTAM NODES AFTER IPL OF ONE OF THE NODES

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• Two VTAM nodes have XCF connectivity.  One of the nodes is
  IPLed.  When the node restarts, the XCF connectivity is not
  restored.  If TCPIP is defined with DYNAMICXCF, the start of the
  XCF link will fail with messages:
  EZZ4308I ERROR: CODE=8010002B DURING ACTIVATION OF DEVICE
  HOSTxx.
  IST2187I XCF SEND FAILURE ON TRLE ISTTxxxx   MESSAGE TYPE: XID
  IST1684I RETURN CODE = 00000008 REASON CODE = 00000008
  IST314I END
  IST1504I XCF CONNECTION WITH NET.xxxxxx IS INOPERATIVE
  IST1501I XCF TOKEN = xxxxxxxxxxxxxxxx
  IST1578I DEVICE INOP DETECTED FOR ISTTxxxx BY ISTTSC8X CODE =
  010
  .
  A display of the ISTPxxxx PU will show state PDISC:
  IST075I NAME = ISTPxxxx         , TYPE = PU_T2
  IST486I STATUS= PDISC---X-, DESIRED STATE= RACTN
  .
  The XCF connectivity cannot be reestablished to the other VTAM
  node.
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED: All using XCF connections.                   *
  ****************************************************************
  * PROBLEM DESCRIPTION: XCF connection does not recover         *
  *                      after an IPL of one of the              *
  *                      sysplex nodes.  The XCF PU is hung      *
  *                      in PDISC or PFDSC state.                *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  The problem is summarized as follows:
  
  1) XCF is being used for connectivity in a sysplex.
  2) One of the sysplex nodes is IPLed.
  3) When the node is brought back up, all of the XCF
     connections are restored, except for one.
  4) On the node which was not IPLed, the XCF SNA PU
     was hung in PDISC state.
  5) If the operator tries to issue a V NET,INACT,ID=ISTPxxxx
     to force the PU down, it then hangs in PFDSC state.
  6) No traces were available to determine the exact point of
     failure.
  7) Internal control blocks from the dump revealed that
     a response to a CM_DEACT_REQ was not returned to the
     AHNCB PU PAB for processing.
  8) From code analysis, it was determined that when
     module IUTLLCS1 processes a CM_DEACT_REQ, if the
     SAP token resolution fails, the CM_DEACT_REQ was
     simply discarded.  This would leave the XCF PU
     hung in PDISC state forever.
  
  Although the reported problem was for an XCF connection, this
  problem could affect an AHHC/MPC connection in a similar
  manner.  The solution will correct both AHHC and XCF
  connections.
  

Problem conclusion

• IUTLLCS1 - Added code to send back a CM_DEACT_CNF when the SAP
             token resolution fails.
  ISTTSC9C - When processing a DISCONTACT RUPE in AHNCB_CODSP
             state, it will allow a second CM_DEACT_REQ to be
             sent to the Registration Manager (RM) PAB for
             processing.  Upon receipt of this flow, the RM PAB
             already has code to correctly post back
             a CM_DEACT_REQ in the event the SAP token
             resolution fails.  This new logic only executes
             if it has been at least 180 seconds from the
             time the initial CM_DEACT_REQ was sent.  It
             also only allows for one retry to cleanup the hung
             PU.
  ISTAHNCB - Defined two new fields in the AHNCB in support of
             the new DISCONTACT function processing.
  
             AHNCB_DSAP_SENT_IN_CODSP   BIT(1)
  
             AHNCB_CODSP_TOD            Fixed(32)
  ISTTSCMA,
  ISTTSC8E - Included for maintenance purposes.
  

Temporary fix

• *********
  * HIPER *
  *********
  

Comments

APAR Information

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

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

  UA59378 UA59379 UA59380

Modules/Macros

• ISTAHNCB ISTTSCMA ISTTSC8E ISTTSC9C IUTLLCS1
  

Fix information

• Fixed component name

  VTAM V4 MVS/ESA

• Fixed component ID

  569511701

Applicable component levels

• R1A0 PSY UA59378

     UP11/04/22 P F104 Ž

• R1B0 PSY UA59379

     UP11/04/22 P F104 Ž

• R1C0 PSY UA59380

     UP11/04/22 P F104 Ž

Fix is available

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