PH67553: When a CICS TS 5.6 region uses a CICS TS 6.2 version of DFHDTSVC, Data Table accesses work but uses more CPU than normal.

APAR status

• Closed as program error.

Error description

• At CICS TS 6.1 and below, DFHDTSVC is downward compatible, and
  it is shipped in SDFHLINK. At CICS TS 6.1 and below, when there
  are multiple releases of CICS in the same LPAR, it makes sense
  to put the highest release of SDFHLINK in LNKLST or LPA.  All
  releases of CICS could then use highest version of DFHDTSVC.
  Starting with CICS TS 6.2, that is no longer the case.
  
  CICS TS 6.2 makes a change to DFHDTSVC that makes it no longer
  downward compatible with prior releases.  As such, CICS TS 6.2
  ships DFHDTSVC in SDFHAUTH.   Prior releases of CICS should not
  use the CICS TS 6.2 version of DFHDTSVC.
  
  If a CICS TS 6.1 (or lower) CICS region loads and uses a CICS TS
  6.2 (or higher) version of DFHDTSVC, Data Tables accesses still
  work, but they do not work efficiently.   Read requests do not
  access the loaded data table directly.   All requests, including
  Reads, are function shipped to the owning FOR.  This causes lots
  more CSMI tasks in the FOR, and more overall CPU used.  There is
  no message warning that a CICS TS 6.1 (or lower) CICS region is
  incorrectly using a CICS TS 6.2 (or higher) version of DFHDTSVC.
  
  
  There needs to be a message warning of this mistake.
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED: All CICS Users.                              *
  ****************************************************************
  * PROBLEM DESCRIPTION: When planning to upgrade to CICS TS 6.2 *
  *                      or higher, remote file control requests *
  *                      against Data Table files will be        *
  *                      function shipped if the wrong version   *
  *                      of DFHDTSVC is used.                    *
  ****************************************************************
  Prior to CICS TS 6.2, DFHDTSVC was backwards compatible for
  upgrade purposes and was stored in the LPA. Due to the changes
  made in CICS TS 6.2, DFHDTSVC was moved to the SDFHAUTH library
  so it would not be used by lower level versions of CICS when
  upgrade planning.
  
  If the CICS TS 6.2 SDFHAUTH library is placed in the DFHRPL
  concatenation before the lower level CICS's SDFHLINK library,
  then the lower level CICS release will use the CICS TS 6.2
  version of DFHDTSVC.
  
  The consequence of this is that all remote data table file
  control requests will be function shipped to the FOR rather
  than taking advantage of Data Table Services.
  

Problem conclusion

• DFHFCDTS has been altered to issue new error message
  DFHFC0432 to state that the wrong version of DFHDTSVC is being
  used by CICS TS and that all remote data table file control
  requests will be function shipped.
  
  New Message DFHFC0432 has been added to the CICS TS for z/OS 5.6
  Documentation site.
  
  DFHFC04032 E applid Shared access to remote data tables cannot
  be provided by this CICS system because the version of DFHDTSVC
  being used is incompatible with this release.
  
  Explanation
  CICS is about to issue a file control request against a remote
  data table but cannot do so because the version of DFHDTSVC
  being used is incompatible with this release.  This will prevent
  this CICS system being able to access the data table using
  cross memory services, so the file control request will be
  function shipped.
  
  System Action
  Processing continues with remote data table file control
  requests being function shipped. This will result in a
  performance degradation.
  
  Message DFHFC0432 will be reissued if any subsequent request is
  made to read or browse a remote data table. However, message
  DFHFC0432 is not issued more often than once an hour.
  
  User Response
  The CICS system should be pointed at the correct version of
  DFHDTSVC. DFHDTSVC supplied with CICS TS V6.2 is not backwards
  compatible.
  
  Module
  DFHFCDTS
  
  XMEOUT parameters/Message inserts
  1. applid
  
  Destination
  Console
  
  Applicable releases
  5.6
  

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:

  PH69960 UO08824

Modules/Macros

• DFHAMFC  DFHAMPFI DFHAPSM  DFHAPTR5 DFHBRNS  DFHDMPCA DFHDMRM
  DFHDTLA  DFHDTLX  DFHEDFX  DFHEIFC  DFHEIQCF DFHEIQDN DFHEIQDS
  DFHEIQMS DFHEIQSA DFHEIUOW DFHESE   DFHFCAT  DFHFCBD  DFHFCBU
  DFHFCCA  DFHFCDL  DFHFCDN  DFHFCDO  DFHFCDR  DFHFCDTS DFHFCDTX
  DFHFCDU  DFHFCDUF DFHFCDW  DFHFCDY  DFHFCES  DFHFCFL  DFHFCFR
  DFHFCFS  DFHFCIN1 DFHFCIN2 DFHFCIR  DFHFCL   DFHFCLF  DFHFCLJ
  DFHFCLJ1 DFHFCM   DFHFCMT  DFHFCN   DFHFCNQ  DFHFCOR  DFHFCQI
  DFHFCQR  DFHFCQS  DFHFCQT  DFHFCQU  DFHFCQX  DFHFCRC  DFHFCRC2
  DFHFCRD  DFHFCRF  DFHFCRL  DFHFCRN  DFHFCRO  DFHFCRP  DFHFCRR
  DFHFCRS  DFHFCRV  DFHFCSD  DFHFCSDS DFHFCST  DFHFCU   DFHFCVC
  DFHFCVR  DFHFCVS  DFHFCXDF DFHFRDUF DFHISFS  DFHMEFAC DFHMEFAE
  DFHMEFAK DFHMIRS  DFHSTFC  DFHSTLS  DFHSTP   DFHW2FI  DFHW2FR
  DFHXFP   DFHXFQ   DFHXFRM  DFHXFX
  

Fix information

• Fixed component name

  CICS TS Z/OS V5

• Fixed component ID

  5655Y0400

Applicable component levels