IT05246: A SESSION'S RSTCB->SID CAN BE SET TO 0 WHICH CAN LEAD TO ROLLBACK ASSERT

APAR status

• Closed as program error.

Error description

• A timing problem between a session that is ending and another
  session that is just starting can lead
  to the new session's rstcb->sid  being set to 0.
  
  Largely, this may go unnoticed, but it can lead to rollback
  assertions like below when two sessions are
  running DML on the same data page
  
  16:48:05  Log record (OLDRSAM:HINSERT) failed, partnum 0x200043
  rowid 0x107 iserrno 126
  16:48:05  logundo: type 41, iserrno 126
  16:48:05
  16:48:05  IBM Informix Dynamic Server Version 12.10.F
  Software Serial Number RDS#N000000
  
  16:48:05  Assert Failed: Rollback error 126
  16:48:05   Who: Session(191, informix@host, 29944, 0x4523d038)
                  Thread(257, sqlexec, 451fce08, 8)
                  File: rstrans.c Line: 3167
  16:48:05   Results: Log record (OLDRSAM:HDELETE) in log 2,
  offset 0x1b73388 was not rolled back
  16:48:05   Action: Use 'onlog' to view the transaction and
  repair manually.
  16:48:05  Raw hex dump of stack located in
  /tmp/af.4e90f15.rawstk
  16:48:05  Stack for thread: 257 sqlexec
  
   base: 0x0000000049770000
    len:   102400
     pc: 0x0000000001aab7bc
    tos: 0x0000000049786f60
  state: running
     vp: 8
  
  0x0000000001aab7bc (oninit) afstack
  0x0000000001aa9a1c (oninit) afhandler
  0x0000000001aa8ca4 (oninit) affail_interface
  0x0000000000f4a54a (oninit) logundo
  0x00000000011ce850 (oninit) rlogm_undo
  0x0000000000f45f12 (oninit) rollback
  0x0000000000f44800 (oninit) rsrollback
  0x00000000011a64f3 (oninit) isrollback
  0x0000000000838a9f (oninit) sqisrollback
  0x00000000007d90d6 (oninit) sqrollback
  0x0000000000729bd2 (oninit) aud_sqrollback
  0x0000000000b88a0b (oninit) sql_rollback
  0x0000000000b886fe (oninit) sq_rollback
  0x0000000000cb14f6 (oninit) sqmain
  0x0000000001be802d (oninit) listen_verify
  0x0000000001be7079 (oninit) spawn_thread
  
  or I have seen another assertion like:
  
  16:59:06  Log record (OLDRSAM:HDELETE) failed, partnum 0x1001d5
  rowid 0x10a iserrno 126
  16:59:06  logundo: type 40, iserrno 126
  16:59:06
  16:59:06  IBM Informix Dynamic Server Version 12.10.F
  Software Serial Number RDS#N000000
  
  16:59:06  Assert Failed: Rollback error 126
  16:59:06   Who: Session(190, informix@host, 9084, 0x4523d388)
                  Thread(256, sqlexec, 451fd6e8, 8)
                  File: rstrans.c Line: 3167
  16:59:06   Results: Log record (OLDRSAM:HINSERT) in log 2,
  offset 0x1be6688 was not rolled back
  16:59:06   Action: Use 'onlog' to view the transaction and
  repair manually.
  16:59:06  Raw hex dump of stack located in
  /tmp/af.4e811aa.rawstk
  16:59:06  Stack for thread: 256 sqlexec
  
  0x0000000001aab7bc (oninit) afstack
  0x0000000001aa9a1c (oninit) afhandler
  0x0000000001aa8ca4 (oninit) affail_interface
  0x0000000000f4a54a (oninit) logundo
  0x00000000011ce850 (oninit) rlogm_undo
  0x0000000000f45f12 (oninit) rollback
  0x0000000000f44800 (oninit) rsrollback
  0x00000000011a64f3 (oninit) isrollback
  0x0000000000838a9f (oninit) sqisrollback
  0x00000000007d90d6 (oninit) sqrollback
  0x0000000000729bd2 (oninit) aud_sqrollback
  0x0000000000b88a0b (oninit) sql_rollback
  0x0000000000b886fe (oninit) sq_rollback
  0x0000000000cb14f6 (oninit) sqmain
  
  16:59:06  slotdelete: row already deleted
  16:59:06  slotdelete: bad rowid 10a in partnum 1001d5
  16:59:06  page 1
  page             addr             chksum slots flag type
  frptr frcnt next     prev     stamp
  0x5a315000       1:236523         d924   22    1    DATA
  1155  1149  0        0        279241
  slot ptr   len   flg value
  1    24    87    0
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED:                                              *
  * ALL DB USers                                                 *
  ****************************************************************
  * PROBLEM DESCRIPTION:                                         *
  * See Error Description                                        *
  ****************************************************************
  * RECOMMENDATION:                                              *
  * Update to IDS-12.10.xC5                                      *
  ****************************************************************
  

Problem conclusion

• Problem Fixed In IDS-12.10.xC5
  

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

  INFORMIX SERVER

• Fixed component ID

  5725A3900

Applicable component levels

• RC10 PSY

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