IT24846: DBMS_SQL.OPEN_CURSOR CAUSES MEMORY LEAK IN KRCBH POOL

APAR status

• Closed as program error.

Error description

• When running a procedure containing following DBMS_SQL system
  module calls, db2pd -dbptnmem shows that DBMS set grows.
  
  CALL DBMS_SQL.OPEN_CURSOR(v_curid);
  CALL DBMS_SQL.PARSE(v_curid, v_sql, DBMS_SQL.native);
  CALL DBMS_SQL.EXECUTE(v_curid, v_status);
  CALL DBMS_SQL.CLOSE_CURSOR(v_curid);
  
  The db2pd -memblocks indicates memory blocks for the system
  routines allocated in the krcbh heap keeps increasing as below:
  
  $ db2pd -memblock dbms 69 sort
  
  Memory blocks in DBMS set for pool 69.
  
  Memory blocks sorted by size for krcbh pool: (PoolID: 69,
  SecondID: 0, PoolAddr: 0x00000002000033A8)
  PoolID     PoolName   TotalSize(Bytes)     TotalCount LOC   File
  
  69         krcbh      1333344136           22727093   3010
  907928531
  69         krcbh      6291456              1          1798
  698130716
  69         krcbh      101968               1          1608
  698130716
  69         krcbh      66800                1          5470
  698130716
  69         krcbh      16400                1          5641
  1507598115
  69         krcbh      4304                 1          1407
  698130716
  69         krcbh      1280                 10         470
  2296446861
  69         krcbh      856                  1          8502
  698130716
  69         krcbh      552                  1          1999
  698130716
  69         krcbh      80                   1          1973
  698130716
  69         krcbh      16                   1          1957
  698130716
  Total size for krcbh pool: 1339827848 bytes (PoolID: 69,
  SecondID: 0, PoolAddr: 0x00000002000033A8)
  
  Note: the LOC can slightly vary depending on the fixpack and/or
  platform.
  

Local fix

• Please disconnect the application which called
  DBMS_SQL.OPEN_CURSOR.
  

Problem summary

• ****************************************************************
  * USERS AFFECTED:                                              *
  * Users using DBMS_SQL system                                  *
  * module                                                       *
  ****************************************************************
  * PROBLEM DESCRIPTION:                                         *
  * See Error Description                                        *
  ****************************************************************
  * RECOMMENDATION:                                              *
  * Upgrade to Db2 v11.1 m4fp4                                   *
  ****************************************************************
  

Problem conclusion

• Problem first fixed in v11.1 m4fp4
  

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:

Fix information

• Fixed component name

  DB2 FOR LUW

• Fixed component ID

  DB2FORLUW

Applicable component levels

• RB10 PSY

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