PH63454: URIMAP DNS caching cannot be disabled.

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• A HTTP status code of 404 is returned when a CICS server
  performs an outbound web request using URIMAP where the target
  host's IP address is cached but the target service is no longer
  running on the target CICS server.
  The service has been moved to another CICS server on a different
  IP address.
  Customer requires the ability to disable the URIMAP DNS Cache
  for server moves.
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED: All CICS users                               *
  ****************************************************************
  * PROBLEM DESCRIPTION: URIMAP DNS caching cannot be disabled.  *
  ****************************************************************
  CICS 6.1 introduced DNS caching for the hostname specified in
  URIMAPs. In APAR PH58715 a timeout of 60 seconds was introduced
  for IP address caching. CICS has continued to always make a new
  DNS lookup when a connection could not be established to a
  target IP address.
  However if a target service is moved from one IP address to
  another but the original IP address returns an HTTP response
  ( eg HTTP 404 ) then CICS will continue to use this IP address
  until the 60 seconds elapses.
  

Problem conclusion

• CICS has been updated to add a new feature toggle
  'com.ibm.cics.web.dnscache=true/false'.  The default is 'true'
  which means CICS will continue to cache IP addresses with a 60
  second timeout.
  
  In an environment where target services are moved from one IP
  address to another, but the first IP address continues to return
  HTTP responses (e.g. a HTTP 404), then by setting this toggle to
  'false' CICS will start using a new server as soon as the DNS is
  updated.  This would prevent CICS receiving a HTTP 404 response.
  
  Additionally, a new message, DFHWB1583 has been added to
  document when a DNS lookup detects that the IP address has
  changed from the one that was being currently used. The IBM
  Documentation for CICS TS 6.x will be updated to document this
  new feature toggle and message.
  

Temporary fix

Comments

• ×**** PE24/12/03 FIX IN ERROR. SEE APAR PH64388  FOR DESCRIPTION
  ×**** PE25/04/24 FIX IN ERROR. SEE APAR PH66288  FOR DESCRIPTION
  

APAR Information

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

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

  UI98907 UI98908

Modules/Macros

• DFHMEWBC DFHMEWBE DFHMEWBK DFHWBA   DFHWBA1  DFHWBAP  DFHWBAPF
  DFHWBBLI DFHWBBMS DFHWBCL  DFHWBDM  DFHWBDUF DFHWBENV DFHWBFM
  DFHWBIP  DFHWBLT  DFHWBPA  DFHWBQM  DFHWBRL  DFHWBRP  DFHWBSC
  DFHWBSO  DFHWBSR  DFHWBSV  DFHWBTC  DFHWBTCC DFHWBTRI DFHWBTTA
  DFHWBUE  DFHWBUR  DFHWBUX  DFHWBXM  DFHWBXN
  

Fix information

• Fixed component name

  CICS TS Z/OS V6

• Fixed component ID

  5655YA100

Applicable component levels

• R400 PSY UI98908

     UP24/11/05 P F411

• R500 PSY UI98907

     UP24/11/02 P F411

Fix is available

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