DB2 FOR LUW / DB2FORLUW / 970 - DB2

There is a very small time frame that a deadlatch (latch waiting 
loop, similar to deadlock) might happen between two agent 
processes if they are performing dynamic SQL compile. 
The following conditions concurrence will probably lead to 
deadlatch. 
 
- the two applications involved must be compiling the same 
statement. 
- the statement includes a reference to a procedure, function or 
method. 
- the two agent processes are performing any dynamic SQL compile 
(which includes PREPARE or EXECUTE IMMEDIATE). 
 
 
The deadlatch scenario can be described as follow. 
Process A is holding latch SQLO_LT_sqlra_cached_stmt__latch and 
waiting latch SQLO_LT_sqlra_cached_env__latch. 
While another process B is holding and waiting latch conversely. 
This type of deadlatch will cause some applications hang. 
The latch holding and waiting information can be obtained in 
trap files. 
 
Here is an example for this deadlatch: 
 
pid     process name     holding latch name 
waiting latch name 
------- ---------------- -------------------------------- 
-------------------------------- 
1111111 db2agent (SAMPL) SQLO_LT_sqlra_cached_stmt__latch 
SQLO_LT_sqlra_cached_env__latch 
2222222 db2agent (SAMPL) SQLO_LT_sqlra_cached_env__latch 
SQLO_LT_sqlra_cached_stmt__latch 
 
 
Here is a possible stack trace of pid 1111111: 
========================= 
sqloXlatchConflict 
sqloXlatchAIX 
sqlra_find_var_var 
sqlra_find_var 
sqlra_get_var 
sqlrr_prepare 
sqljs_ddm_prpsqlstt 
sqljsParseRdbAccessed 
sqljsParse 
========================= 
 
 
Here is a possible stack trace of pid 2222222: 
================================ 
sqloXlatchConflict 
sqloXlatchAIX 
sqlra_compare_env_routine_auths 
sqlra_compare_env_routine_auths 
sqlra_hash_loc_env 
sqlra_cache_ins_env 
sqlra_find_var_env 
sqlra_find_var 
sqlra_get_var 
sqlrr_prepare 
sqljs_ddm_prpsqlstt 
sqljsParseRdbAccessed 
sqljsParse 
================================

**************************************************************** 
* USERS AFFECTED:                                              * 
* any                                                          * 
**************************************************************** 
* PROBLEM DESCRIPTION:                                         * 
* presents as a hang                                           * 
**************************************************************** 
* RECOMMENDATION:                                              * 
* upgrade to DB2 for LUW v97 fp1                               * 
****************************************************************

DB2 Version 9.7 Fix Pack 1 for Linux, UNIX, and Windows
 DB2 Version 9.7 Fix Pack 2 for Linux, UNIX, and Windows
 DB2 Version 9.7 Fix Pack 3 for Linux, UNIX, and Windows
 DB2 Version 9.7 Fix Pack 3a for Linux, UNIX, and Windows
 DB2 Version 9.7 Fix Pack 4 for Linux, UNIX, and Windows
 DB2 Version 9.7 Fix Pack 5 for Linux, UNIX, and Windows
 DB2 Version 9.7 Fix Pack 7 for Linux, UNIX, and Windows
 DB2 Version 9.7 Fix Pack 9a for Linux, UNIX, and Windows
 DB2 Version 9.7 Fix Pack 6 for Linux, UNIX, and Windows
 DB2 Version 9.7 Fix Pack 8 for Linux, UNIX, and Windows
 DB2 Version 9.7 Fix Pack 9 for Linux, UNIX, and Windows
 DB2 Version 9.7 Fix Pack 10 for Linux, UNIX, and Windows
 

fixed in DB2 for LUW v97 fp1

keiner bekannt / siehe Local-Fix

Datum - Problem gemeldet    :
Datum - Problem geschlossen :
Datum - der letzten Änderung:

22.10.2009
18.02.2010
18.02.2010

9.7.FP1