PH60291: DFHAC2236 ABEND AITC DFHMIRS CAN OCCUR AFTER RECEIVING MANY DFHSO1002 UNABLE TO DETERMINE THE SECURE STAT 24/03/26 PTF PECHANGE

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• You are running CICS TS 5.6 and the region has been up for 6
  days.
  
  This region processes incoming socket connections and also DPLs
  from other regions.
  On the 6th day, mirror tasks start abending with code AITC that
  indicates an unexpected response from the Recovery Manager
  domain.
  
  Looking at the Link Summary in the RM domain of A dump taken at
  the time of the AITC,  abend showed over 60,000 SOCK client
  
  entries, Link id- SOCKLINK. Here is a sample of this:
  
  
  Link     Owning     Client Client   Remote      Link
  Token    UOW Addr   Name   Token    Access Id   Id
  
  0173000E address   SOCK   01040025 DEFAULT     SOCKLINK
  01720011 address   SOCK   01030032 DEFAULT     SOCKLINK
  01760001 address   SOCK   01040027 DEFAULT     SOCKLINK
  01750004 address   SOCK   01040029 DEFAULT     SOCKLINK
  
  Here are the CICS trace entries for the mirror task leading up
  to the AITC abend:
  RM 0301 RMLN  ENTRY SET_LINK              00000000,UNNECESSARY
  RM 0302 RMLN  EXIT  SET_LINK/EXCEPTION    LINK_UNKNOWN
  AP 2000 PCPG  ENTRY ABEND
  AP 0741 ABAB  ENTRY CREATE_ABEND_RECORD   DFHMIRS,AITC
  
  Looking back at the messages in MSGUSR for the previous 6 days,
  we found thousands of messages related to sockets.  Here is
  
  an example:
  
  DFHSO1002 CICS is unable to determine the secure state of a new
  
           connection received on ATTLSAWARE
  DFHSO1002 CICS is unable to determine the secure state of a new
           connection received on ATTLSAWARE
           TCPIPSERVICE service from client IP address ..
  
           UNIX System Services values returned are
           bpx_return_value( -1 ), bpx_return_code( 1,124 ), and
           bpx_reason_code( X'77B77221' ).
  
  Return code 1124 means ENOTCONN- the client has closed the
  connection.
  In the CICS Trace, here are examples of the exception trace
  entries for our main listener task CSOL:
  00004 SL    SO 0E1C SOUS  *EXC* GETSOCKNAME_FAILURE
                            RETURN_VALUE(-1) RETURN_CODE(1124)
  00004 SL    SO 0E1C SOUS  *EXC* GETSOCKNAME_FAILURE
                            RETURN_VALUE(-1) RETURN_CODE(1124)
  00004 SL    SO 0CAB SOLS  *EXC* SIOCTTLSCTL_ERROR
                            RETURN_VALUE(-1) RETURN_CODE(1124)
  
  
  After the GETSOCKNAME ends with the client has disconnected,
  CICS is not cleaning up the RM link for the socket and not
  freemaining the buffer obtained from subpool ASYNC4K.
  
  Additional symptoms: KIXREVDAM
  REASON_CODE 749B0000 AT-TLS aware LINK TOKEN  ADD_LINK
  client name SOCK disconnect socket
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED: All CICS users                               *
  ****************************************************************
  * PROBLEM DESCRIPTION: DFHAC2236 ABEND AITC DFHMIRS can occur  *
  *                      after receiving many DFHSO1002 due to   *
  *                      build up of RM_link tokens and async4k  *
  *                      buffers.                                *
  ****************************************************************
  When a new connection arrives in CICS on an ATTLSAWARE
  TCPIPSERVICE, CICS obtains information related to the connection
  to store in its control blocks. If CICS finds that the
  connection has been closed, DFHSOLS cleans up the control blocks
  associated with the socket, but fails to delete the RM_LINK and
  doesn't delete the async4k buffer.
  
  This results in a build up of RM Link tokens and aysnc4k
  buffers and many DFHSO1002 messages in the error log leading to
  AITC abend that indicates an unexpected response from the
  Recovery Manager domain.
  

Problem conclusion

• UI90660 UI90518 UI83806 UI93699
  
  DFHSOLS has been changed to relinquish the RM_LINK and freemain
  the async4k buffer when cleaning up the control blocks.
  

Temporary fix

Comments

APAR Information

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

  PH59944

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

  UI96387

Modules/Macros

• DFHLEPTS DFHMESOC DFHMESOE DFHMESOK DFHSOAD  DFHSOCK  DFHSODM
  DFHSODS  DFHSODUF DFHSOGH@ DFHSOHN  DFHSOIS  DFHSOL   DFHSOLI
  DFHSOLS  DFHSOLX  DFHSOLX6 DFHSOM01 DFHSOM02 DFHSOM03 DFHSONT
  DFHSOPL  DFHSORD  DFHSORL  DFHSORM  DFHSOS00 DFHSOS01 DFHSOS02
  DFHSOS03 DFHSOS04 DFHSOS05 DFHSOS06 DFHSOS07 DFHSOS08 DFHSOS09
  DFHSOS10 DFHSOS11 DFHSOS12 DFHSOS13 DFHSOS14 DFHSOS15 DFHSOS16
  DFHSOS17 DFHSOS18 DFHSOS19 DFHSOS20 DFHSOS21 DFHSOS22 DFHSOS23
  DFHSOSE  DFHSOSES DFHSOSK  DFHSOSM  DFHSOST  DFHSOTB  DFHSOTI
  DFHSOTRI DFHSOUE  DFHSOXM
  

Fix information

• Fixed component name

  CICS TS Z/OS V6

• Fixed component ID

  5655YA100

Applicable component levels

• R400 PSY UI96387

     UP24/04/06 P F404 {

Fix is available

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