PH53754: DTIMOUT DOES NOT TAKE EFFECT WHEN THE OPTIMIZED ATTACH MECHANISM IS USED TO HANDLE INBOUND HTTP REQUESTS

APAR status

• Closed as program error.

Error description

• A http client made a request and as a result the optimized
  attach mechanism was used and the task received the incoming
  data as part of its initialization. In this instance the
  client only sent a portion of the expected data and as a
  result the CICS task remained in a socket receive wait
  pending the arrival of the rest of it. DTIMOUT was set to
  60 seconds but didn't take effect and the task remained in
  the wait indefinitely.
  
  By design DTIMOUT does not take effect during task
  initialization as it is purge protected. This APAR will
  change that behaviour so that if the optimized attach
  mechanism is being used the DTIMOUT value will be used as
  an explicit timeout on the wait.
  
  For reference, the kernel stack for a task that is using the
  optimized task and is stuck in a socket receive wait should
  show the following module flow :
  
  DFHXTMA -> DFHWBXM (BIND_XM_CLIENT) -> DFHWBSR
  (RECEIVE ) -> DFHSOCK (RECEIVE_SOCK -> TCP_RECEIVE)
  -> DFHSOS07 -> DFHDSSR -> POP_TASK
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED: All CICS users.                              *
  ****************************************************************
  * PROBLEM DESCRIPTION: DTIMOUT value has no effect when        *
  *                      optimised attach is used for HTTP       *
  *                      requests.                               *
  ****************************************************************
  When a DTIMOUT is set for the optimised attach mechanism no
  timeout will occur when the elapsed time surpasses the DTIMOUT
  value. Instead, CICS will continue to handle the HTTP request as
  if no DTIMOUT value is set.
  

Problem conclusion

• CICS has been changed so that the DTIMOUT value will have
  effect when the optimised attach method is used as well.
  

Temporary fix

Comments

APAR Information

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

  PH52637

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

  UI91679

Modules/Macros

• DFHWBA   DFHWBA1  DFHWBAP  DFHWBAPF DFHWBBLI DFHWBDM  DFHWBDUF
  DFHWBENV DFHWBPA  DFHWBPW  DFHWBSO  DFHWBSR  DFHWBTRI DFHWBTTA
  DFHWBXM  DFHWBXN
  

Fix information

• Fixed component name

  CICS TS Z/OS V6

• Fixed component ID

  5655YA100

Applicable component levels

• R400 PSY UI91679

     UP23/05/04 P F305