db2LogReadAPI calls from Q replication application can get into
an endless loop causing the Qrep application to hang. This can
happen sporadically.
db2diag.log will contain the following entries repeating again
and again.
2015-05-20-14.01.18.285472-240 I271643A578 LEVEL: Info
PID : 19202154 TID : 61953 PROC :
db2sysc 0
INSTANCE: qatyesam NODE : 000 DB :
TYESQA
APPHDL : 0-44156 APPID: *N0.qatyesam.150520174257
AUTHID : QATYESAM HOSTNAME: tyesqdb1
EDUID : 61953 EDUNAME: db2shred.0 (TYESQA) 0
FUNCTION: DB2 UDB, recovery manager, sqlpshrEdu, probe:14000
DATA #1 : <preformatted>
Merging LFR scan flags after processing 16 pages.
Ping extent flags: 842
Pong extent flags: 3
Merged flags: 843
2015-05-20-14.01.18.767259-240 E272222A860 LEVEL: Info
PID : 19202154 TID : 70984 PROC :
db2sysc 0
INSTANCE: qatyesam NODE : 000 DB :
TYESQA
HOSTNAME: tyesqdb1
EDUID : 70984 EDUNAME: db2lfr.0 (TYESQA) 0
FUNCTION: DB2 UDB, recovery manager, sqlplfrFMReadLog,
probe:3381
DATA #1 : SQLPLFR_SCAN_ID, PD_TYPE_SQLPLFR_SCAN_ID, 8 bytes
LFR Scan Num = 5322255
LFR Scan Caller's EDUID = 61953
MESSAGE : LFR is scanning for pong page.
DATA #2 : SQLPG_EXTENT_NUM, PD_TYPE_SQLPG_EXTENT_NUM, 4 bytes
14140
DATA #3 : unsigned integer, 4 bytes
50804
DATA #4 : unsigned integer, 8 bytes
0
DATA #5 : unsigned integer, 8 bytes
18446744073709551615
DATA #6 : unsigned integer, 8 bytes
3688661893825
DATA #7 : unsigned integer, 4 bytes
64000
DATA #8 : unsigned integer, 8 bytes
3688868962372
2015-05-20-14.01.19.439104-240 E273083A860 LEVEL: Info
PID : 19202154 TID : 70984 PROC :
db2sysc 0
INSTANCE: qatyesam NODE : 000 DB :
TYESQA
HOSTNAME: tyesqdb1
EDUID : 70984 EDUNAME: db2lfr.0 (TYESQA) 0
FUNCTION: DB2 UDB, recovery manager, sqlplfrFMReadLog,
probe:3381
DATA #1 : SQLPLFR_SCAN_ID, PD_TYPE_SQLPLFR_SCAN_ID, 8 bytes
LFR Scan Num = 5322271
LFR Scan Caller's EDUID = 61953
MESSAGE : LFR is scanning for pong page.
DATA #2 : SQLPG_EXTENT_NUM, PD_TYPE_SQLPG_EXTENT_NUM, 4 bytes
14140
DATA #3 : unsigned integer, 4 bytes
51109
DATA #4 : unsigned integer, 8 bytes
0
DATA #5 : unsigned integer, 8 bytes
18446744073709551615
DATA #6 : unsigned integer, 8 bytes
3688661893825
DATA #7 : unsigned integer, 4 bytes
64000
DATA #8 : unsigned integer, 8 bytes
3688870205098
2015-05-20-14.01.19.446427-240 I273944A811 LEVEL: Info
PID : 19202154 TID : 70984 PROC :
db2sysc 0
INSTANCE: qatyesam NODE : 000 DB :
TYESQA
HOSTNAME: tyesqdb1
EDUID : 70984 EDUNAME: db2lfr.0 (TYESQA) 0
FUNCTION: DB2 UDB, recovery manager, sqlplfrDoScanNext,
probe:2415
DATA #1 : SQLPLFR_SCAN_ID, PD_TYPE_SQLPLFR_SCAN_ID, 8 bytes
LFR Scan Num = 5322271
LFR Scan Caller's EDUID = 61953
MESSAGE : Current buffer has 0 pages, EOL set here.
DATA #2 : String, 73 bytes
Mapping lfrScanNextFlagsOut from current buffer to the client
LFR buffer.
DATA #3 : String, 57 bytes
Client buffer flags (before mapping) / Next buffer flags:
DATA #4 : Hex integer, 8 bytes
0x0000000000000042
DATA #5 : Hex integer, 8 bytes
0x0000000000000043
2015-05-20-14.01.19.449400-240 I274756A578 LEVEL: Info
PID : 19202154 TID : 61953 PROC :
db2sysc 0
INSTANCE: qatyesam NODE : 000 DB :
TYESQA
APPHDL : 0-44156 APPID: *N0.qatyesam.150520174257
AUTHID : QATYESAM HOSTNAME: tyesqdb1
EDUID : 61953 EDUNAME: db2shred.0 (TYESQA) 0
FUNCTION: DB2 UDB, recovery manager, sqlpshrEdu, probe:14000
DATA #1 : <preformatted>
Merging LFR scan flags after processing 16 pages.
Ping extent flags: 842
Pong extent flags: 3
Merged flags: 843
+++++++++++++++++++++++++
Application snapshot will incorrect show the application status
as UOW waiting. db2trc will show the looping as follows in
the t.flw file.
1041462 | | | | | | | | | | | sqlpshrLogMergeIteration entry
[eduid 27118 eduname db2agent]
1041463 | | | | | | | | | | | | sqlorest entry [eduid 27118
eduname db2agent]
1041464 | | | | | | | | | | | | sqlorest data [probe 10]
1041480 | | | | | | | | | | | | sqlorest exit
1041481 | | | | | | | | | | | | pdLogEvRecEx entry [eduid
27118 eduname db2agent]
1041482 | | | | | | | | | | | | | pdIsDiagLevelOk entry
[eduid 27118 eduname db2agent]
1041483 | | | | | | | | | | | | | pdIsDiagLevelOk data
[probe 10]
1041484 | | | | | | | | | | | | | pdIsDiagLevelOk data
[probe 20]
1041485 | | | | | | | | | | | | | pdIsDiagLevelOk data
[probe 500]
1041486 | | | | | | | | | | | | | pdIsDiagLevelOk exit
1041487 | | | | | | | | | | | | pdLogEvRecEx exit
1041488 | | | | | | | | | | | sqlpshrLogMergeIteration exit
<== Start of loop till the end of the trace
1041489 | | | | | | | | | | | sqlpshrCheckIfReadyToMerge
entry [eduid 27118 eduname db2agent]
1041490 | | | | | | | | | | | sqlpshrCheckIfReadyToMerge
exit
1041491 | | | | | | | | | | | sqlpshrLogMergeIteration entry
[eduid 27118 eduname db2agent]
1041492 | | | | | | | | | | | | sqlorest entry [eduid 27118
eduname db2agent]
1041493 | | | | | | | | | | | | sqlorest data [probe 10]
1041494 | | | | | | | | | | | | sqlorest exit
1041495 | | | | | | | | | | | sqlpshrLogMergeIteration exit
1041496 | | | | | | | | | | | sqlpshrCheckIfReadyToMerge
entry [eduid 27118 eduname db2agent]
1041497 | | | | | | | | | | | sqlpshrCheckIfReadyToMerge
exit
1041498 | | | | | | | | | | | sqlpshrLogMergeIteration entry
[eduid 27118 eduname db2agent]
1041499 | | | | | | | | | | | | sqlorest entry [eduid 27118
eduname db2agent]
1041500 | | | | | | | | | | | | sqlorest data [probe 10] |
