PH52115: CICS DOES NOT CLEAN UP SOCKET CONTROL BLOCKS WHEN AIO_CANCEL REQUEST COMPLETES WITH AIORV=2 LEADING MAXSOCKETS LIMIT BE REACHED.

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• CICS has used BPX1AIO to issue an AIO_CANCEL to cancel an
  outstanding async receive on a socket. When the cancel completes
  with a AIORV=2 CICS does not clean up the socket control blocks
  correctly and the CICS socket object is then left in a state
  where it believes IO is active resulting in the MAXSOCKETS limit
  being reached eventually.
  

Local fix

• N/A
  

Problem summary

• ****************************************************************
  * USERS AFFECTED: All CICS users                               *
  ****************************************************************
  * PROBLEM DESCRIPTION: After many failed attempts to acquire   *
  *                      IPIC connections, CICS issues message   *
  *                      DFHSO0126 An attempt to create a socket *
  *                      has failed because the MAXSOCKETS       *
  *                      limit has been reached.                 *
  ****************************************************************
  Attempts were made to acquire some IPIC connections but these
  failed with capex exceptions. AIO_CANCEL requests to cancel the
  outstanding receives failed with AIO_NOTCANCELED (2). After this
  happened repeatedly, the MAXSOCKETS limit was reached and CICS
  started issuing DFHSO0126 messages.
  

Problem conclusion

• CICS has been updated to ensure we clean up the socket
  correctly if we receive a AIORV=2 (AIO_NOTCANCELED).
  

Temporary fix

Comments

APAR Information

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

  PH50022

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

  UI90711

Modules/Macros

• DFHSOAD  DFHSOCK  DFHSODM  DFHSODUF DFHSOIS  DFHSOL   DFHSOLI
  DFHSOLS  DFHSOLX  DFHSOLX6 DFHSOM01 DFHSOM02 DFHSOM03 DFHSOPL
  DFHSORD  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  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 UI90711

     UP23/02/25 P F302

Fix is available

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