PK79015: IMS DEDB FAST RECOVERY ENHANCEMENT IN SUPPORT OF IMS V9 APAR PK38102

Obtain the fix for this APAR.

APAR status

• Closed as new function.

Error description

• IMS DEDB Fast Recovery enhancement in support of IMS V9 APAR
  PK38012.
  
  Symptom is:
  Using SVSO MAS structure ( single structure multiple
  areas ) encounters a structure full condition during
  IXLCACHE READ_DATA. This is a valid condition, since
  the read-and-register operation requires structure storage.
  The normal IMS processing flow for this condition is to
  initiate a castout process and do the I/O from DASD.
  If, however, castout is already running ( DMACFLV2,DMACFVCO )
  then this is treated as an actual I/O error, which has bad
  consequences - all systems disconnect from the structure
  and close the area.
  This processing logic is undesirable. IMS should invoke
  castout and wait and retry the operation, not read from DASD,
  and if the error occurs while castout is already in progress,
  IMS should wait for castout completion and retry the operation.
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED: All IMS DEDB FAST RECOVERY Version 2         *
  *                 Release 2 (FMID=H1J2220) users who use the   *
  *                 Shared VSO AREA under Multiple AREA          *
  *                 Structure (MAS) environment in IMS V9, IMS   *
  *                 V10 or IMS V11.                              *
  ****************************************************************
  * PROBLEM DESCRIPTION: This APAR is DFR version for IMS V9     *
  *                      APAR PK38102, IMS V10 APAR PK53963 and  *
  *                      IMS V11.                                *
  *                      - PK38102 and PK53963                   *
  *                      SVSO READ ERROR ON STRUCTURE FULL       *
  *                      ( IXLRSNCODESTRFULL ) DURING CASTOUT    *
  *                      HANDLED AS PERMANENT ERROR.             *
  ****************************************************************
  * RECOMMENDATION: Apply the maintenance for this APAR.         *
  ****************************************************************
  - PK79015 for IMS DEDB Fast Recovery
  Customer using SVSO MAS structure ( single structure multiple
  areas ) encountered a structure full condition during
  IXLCACHE READ_DATA. This is a valid condition, since
  the read-and-register operation requires structure storage.
  If the error occurs, DFR treats the error as a read error.
  This is a valid error.
  But if data sharer exists, it may be possible to resolve
  the error by the data sharer.
  So DFR retries the operation and waits for resolving the error.
  

Problem conclusion

Temporary fix

Comments

• The following modules have been modified.
  (x = 9, A and B)
  
  DFRXRDDx - This module was changed so that when the CF structure
             full ( IXLRSNCODESTRFULL ) condition encountered,
             after 1 second wait, an attempt will be made to read
             the CF.
             If the structure full condition IXLRSNCODESTRFULL
             persist after 10 re-read attempts, read error return
             code is returned to the caller.
  

APAR Information

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

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

  UK43445

Modules/Macros

• DFRXRDDA DFRXRDDB DFRXRDD9
  

Fix information

• Fixed component name

  DEDB FAST RECOV

• Fixed component ID

  5655E3200

Applicable component levels

• R220 PSY UK43445

     UP09/01/30 P F901

Fix is available

• Select the PTF appropriate for your component level. You will be required to sign in. Distribution on physical media is not available in all countries.