DB2 FOR LUW / DB2FORLUW / B10 - DB2

Import is using the SYSIBMADM.DBCFG interface to get config
parameter values from all partitions just in case the db config
is not the same on all partitions in DPF environment , so the
selecting from SYSIBMADM.DBCFG broadcast the request to all
nodes to get data. When all nodes got the request, they all need
to access GLFH file each will acquire latch and then lock the
file.  When multiple concurrent Import all query at the same
time, this may cause massive contention on the same file lock,
and db2 may hang there .

we will see repeat invoking of statement like :
SELECT SUBSTR(value, 1, 20) FROM SYSIBMADM.DBCFG WHERE name =
CAST('decflt_rounding'    AS VARCHAR(15))

Also we can see from  db2pd -api that both last sql statement
and current sql statment is same selecting from SYSIBMAMD.DBCFG

 AnchID StmtUID    NumEnv     NumVar     NumRef     NumExe
Text
873    1087       1          1          364        364
SELECT SUBSTR(value, 1, 20) FROM SYSIBMADM.DBCFG WHERE name =
CAST('decflt_rounding'    AS VARCHAR(15))
621    7502       1          1          366        366
SELECT VALUE FROM SYSIBMADM.DBCFG WHERE NAME =
'varchar2_compat'

The stack will be like :


_syscall6(0xfffffffcec3ebb20,0xffffffff7eaa91f0,0x2,0xffffffffff
ffffff,0xfffffffcec3eb9c4,0x1002f4360) + 0x20

__pos4obj_unlink(0xfffffffcec3ebb20,0xffffffff7eaa91f0,0x2,0xfff
fffffffffffff,0xfffffffcec3eb9c4,0x1002f4360) + 0x24
  sem_open(0xfffffffcec3ebb20,0x0,0x0,0x1593d4,0x0,0x0) + 0x3dc

__1cSOSSHIPCSemaphoreExGcreate6MkpknbCOSSIPCSemaphoreExCreatePar
am__I_(0xfffffffcec3ec0d8,0xfffffffcec3ec0a8,0x0,0x4b5400,0xffff
ffffffffffff,0xfffffffcec3ebb21) + 0x250

__1cVsqlnlsGetCCInfoFromCC6FL_pknPsqlnls_cc_table__(0xfffffffcec
3ecf98,0x0,0x40001,0xfffffffcec3ec218,0x1b0,0xfffffffcec3ec0d8)
+ 0x3a50

sqloNLCKUnlock(0xfffffffcec3ecf98,0xfffffffcec3fffff,0x4f40634,0
x3632800,0x40001,0x40000) + 0x244

__1cMSQdDLP_GLFH_CBGunlock6M_i_(0xfffffffcec3ecf70,0xffffffff665
7d870,0x4e07f4c,0x18800000,0x40000,0x3632b28) + 0x80

__1cOsqlpgCloseGLFH6FpnMSQdDLP_GLFH_CB__i_(0xfffffffcec3ecf70,0x
0,0x4e192dc,0x3632800,0xffffffff62f4ad48,0x40000) + 0xe4

__1cTsqlpBuildParmsNoDPS6FpknIsqeAgent_pkc4iIIpIII5pnNSQdDLP_LH_
PARMS__i_(0x0,0xfffffffcec3f3168,0x201752861,0x1,0x3,0xfffffffce
c3effc8) + 0x694

__1cIsqlpglhu6FpknIsqeAgent_pkc4iIIpIII5pnNSQdDLP_LH_PARMS__i_(0
x0,0x201752861,0x0,0x0,0xfffffffcec3f3ec0,0x0) + 0x580

__1cIsqlfgtlp6FIpvpI1pkcpc_i_(0x2,0x0,0xfffffffcec3f3ec4,0xfffff
ffcec3f3ec0,0x201752861,0xfffffffcec3f3fec) + 0x12c

__1cYsqlfInitDbCfgParamForGet6Fpc00kipnLdb2CfgParam_pnKsqlf_dbcf
d_pnFsqlca_ipnQsqeLocalDatabase__i_(0xfffffffcfdb0bff0,0x0,0x70,
0xffffffff60a1c0b5,0x1000,0x201752968) + 0x350

__1cMsqlfGetDbCfg6FpnQsqeLocalDatabase_pnGdb2Cfg_ipnFsqlca__i_(0
x201750080,0xfffffffcec3fc318,0x201752861,0x202899368,0x40000,0x
0) + 0x96c

__1cQsqlrwGetDBConfig6FpnIsqlrr_cb_pnUsqlrwGetDBConfigArgs_ppvpl
_i_(0xffffffff7516a420,0xffffffff365623f0,0xfffffffcec3fc4f8,0xf
ffffffcec3fc4f0,0x0,0x0) + 0x128

__1cbEsqlrwGetWLMTableFunctionResult6FpnIsqlrr_cb_pnUsqlrw_rpc_t
f_request_ppvplb_i_(0xffffffff7516a420,0xffffffff365623f0,0xffff
fffcec3fc4f8,0xfffffffcec3fc4f0,0xffffffff5e882bb0,0x70) +
0x48c

****************************************************************
* USERS AFFECTED:                                              *
* ALL                                                          *
****************************************************************
* PROBLEM DESCRIPTION:                                         *
* See Error Description                                        *
****************************************************************
* RECOMMENDATION:                                              *
* Upgrade to Db2 11.1 Mod 4 Fixpack 5 or higher                *
****************************************************************

Reduce the IMPORT concurrency

not known / see Local fix

forerunner  : IT25793 
follow-up : 

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

20.11.2018
16.01.2020
16.01.2020