DB2 FOR LUW / DB2FORLUW / 910 - DB2

In routine sqm_evmon_ipc_iot::enq_msg the code tries to release 
the evmonQueueLatch even though the latch is not held.  The 
latch isn't being held because the event monitor was no longer 
in "execute" status and so bailed out. This would occur if the 
event monitor is stopped/ deactivated just as the event was 
being collected. 
 
APAR only applies to V91 and has already fixed in future 
releases. 
 
db2diag.log and call stack will show these entries 
--------------- 
2011-06-18-16.00.12.801624-420 I1255652A1562      LEVEL: Severe 
PID     : 177094               TID  : 1           PROC : 
db2agntp (PCMIS00I) 2 
INSTANCE: pdid334              NODE : 002         DB   : 
PCMIS00I 
APPHDL  : 7-1279               APPID: *N7.pdid334.110618225952 
AUTHID  : PDID334 
FUNCTION: DB2 UDB, SQO Latch Tracing, 
sqlo_xlatch::releaseConflict, probe:10 
DATA #1 : String, 27 bytes 
unlocking an unlatched lock 
DATA #2 : Pointer, 8 bytes 
0x078000000057876c 
DATA #3 : String, 111 bytes 
{ 
   lock          = { 0x00000000 [ unlocked ] } 
   identity      = sqm_evmon_ipc_iot::evmonQueueLatch (603) 
} 
DATA #4 : Hexdump, 8 bytes 
0x078000000057876C : 0000 0000 025B 0000 
.....[.. 
CALLSTCK: 
  [0] 0x0900000004AD1C54 sqloSpinLockReleaseConflict + 0xEC 
  [1] 0x09000000063EC9C0 
enq_msg__17sqm_evmon_ipc_iotFPC17sqm_evmon_iot_msg + 0x1A4 
  [2] 0x0900000004F66D5C 
flush_buffer__17sqm_evmon_ostreamFP14sqmEvmonBuffer + 0xC0 
  [3] 0x0900000004F65B64 write_data__17sqm_evmon_ostreamFPCcCUib 
+ 0x36C 
  [4] 0x0900000006506828 
log_event__9sqm_evmonFP16sqlm_header_infoP8sqledbcbCUiP18sqle_ma 
ster_app_cbCiT5 
+ 0x3AC 
  [5] 0x0900000006524FE4 
gen_conn_evt__13sqm_evmon_mgrFP18sqle_master_app_cbb + 0x380 
  [6] 0x0900000004B0062C 
sqleTermDbConnect__FP13sqle_agent_cbP8sqledbcbP5sqlcaP21sqleTerm 
ConnectStatus 
+ 0x17B8 
  [7] 0x09000000057DB864 
sqlesrsp__FP20sqle_agent_privatecbUcP5sqlcai + 0x598 
  [8] 0x0900000004B299A0 
sqleSecondaryStopUsing__FP13sqle_agent_cb + 0x12C 
  [9] 0x0900000004B29404 
sqleSubRequestRouter__FP13sqle_agent_cbPUiT2 + 0x668

DB2 PANIC, CRASHES INSTANCE WHEN BY MISTAKE TRYING TO RELEASE 
THE EVMONQUEUELATCH EVEN THOUGH LATCH IS NOT HELD.

1. explicitly activate your database 
and 
2. leave event monitor active to avoid hitting the problem

DB2 Version 9.1 Fix Pack 11  for Linux, UNIX and Windows
 DB2 Version 9.1 Fix Pack 12  for Linux, UNIX and Windows
 

Fixed in V91 FP11

1. explicitly activate your database 
and 
2. leave event monitor active to avoid hitting the problem

Date  - problem reported    :
Date  - problem closed      :
Date  - last modified       :

15.07.2011
22.12.2011
22.12.2011

9.1.FP11