The problem was caused by a hanging nanosleep system call (an OS bug):
23976: ora_pr00_DB
00007ffed4b76eba nanosleep (7fffbfff8a90, 7fffbfff8aa0)
000000000afedcdc sltrusleep () + 6c
000000001899e10b kcrm_logmgr_idle_action () + 26b
000000001899d985 kcrm_wait_for_reply () + 55
0000000018ed883d krd_move_influx () + 44d
0000000018ed94f9 krdsoclean () + 599
000000001917708d krr_do_media_recovery () + 16bbd
0000000018eaa45b krddmr () + c7b
0000000018eebd1d krd_logmerger_driver () + 1a6d
000000001909f280 krp_slave_main () + bc0
000000000c12f49b ksvrdp_int () + 94b
000000000abbb283 opirip () + 263
0000000009e055eb opidrv () + 24b
0000000009e05307 sou2o () + 97
0000000009e050cf opimai_real () + 9f
0000000009e04c66 ssthrdmain () + 266
0000000009e049d7 main () + a7
000000000b4c237b ???????? ()
Best regards,
Nenad
From: Noveljic Nenad
Sent: Dienstag, 20. Oktober 2020 15:49
To: 'ORACLE-L' <oracle-l@xxxxxxxxxxxxx>
Subject: RE: pr00 hanging in "parallel recovery control message reply"
I've managed to capture the last x$trace entries before the recovery hung.
select pname,function,file_loc,event,section,data from x$trace t, v$process p
where p.pid = t.pid and p.pname like '%PR%' order by time ;
PNAME FUNCTION FILE_LOC EVENT SECTION DATA
----- ---------- ------------ ------ ----------
--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
...
PR0O kslwtectx ksl2.c@3485<mailto:ksl2.c@3485> 10005 KSL WAIT
END [latch free] 1610768712/0x60026148 325/0x145 0/0x0 wait_id=26219
seq_num=26220 snap_id=1
PR0O kslwtectx ksl2.c@3493<mailto:ksl2.c@3493> 10005 KSL WAIT
END wait times (usecs) - snap=297, exc=297, tot=297
PR0O kslwtbctx ksl2.c@3342<mailto:ksl2.c@3342> 10005 KSL WAIT
BEG [latch free] 1610768712/0x60026148 325/0x145 0/0x0 wait_id=26220
seq_num=26221 snap_id=1
PR0O kslwtectx ksl2.c@3493<mailto:ksl2.c@3493> 10005 KSL WAIT
END wait times (usecs) - snap=54, exc=54, tot=54
PR0O kslwtectx ksl2.c@3485<mailto:ksl2.c@3485> 10005 KSL WAIT
END [latch free] 1610768712/0x60026148 325/0x145 0/0x0 wait_id=26220
seq_num=26221 snap_id=1
PR21 kslwtectx ksl2.c@3485<mailto:ksl2.c@3485> 10005 KSL WAIT
END [latch free] 1610768712/0x60026148 325/0x145 0/0x0 wait_id=26402
seq_num=26403 snap_id=1
PR21 kslwtectx ksl2.c@3493<mailto:ksl2.c@3493> 10005 KSL WAIT
END wait times (usecs) - snap=438, exc=438, tot=438
PR0X kslwtectx ksl2.c@3485<mailto:ksl2.c@3485> 10005 KSL WAIT
END [latch free] 1610768712/0x60026148 325/0x145 0/0x0 wait_id=26501
seq_num=26502 snap_id=1
PR0X kslwtectx ksl2.c@3493<mailto:ksl2.c@3493> 10005 KSL WAIT
END wait times (usecs) - snap=464, exc=464, tot=464
PR07 kslwtbctx ksl2.c@3342<mailto:ksl2.c@3342> 10005 KSL WAIT
BEG [latch: messages] 1610659696/0x6000b770 53/0x35 0/0x0 wait_id=26874
seq_num=26875 snap_id=1
PR07 kslwtectx ksl2.c@3485<mailto:ksl2.c@3485> 10005 KSL WAIT
END [latch: messages] 1610659696/0x6000b770 53/0x35 0/0x0 wait_id=26874
seq_num=26875 snap_id=1
PR07 kslwtectx ksl2.c@3493<mailto:ksl2.c@3493> 10005 KSL WAIT
END wait times (usecs) - snap=4, exc=4, tot=4
PR29 kslwtbctx ksl2.c@3342<mailto:ksl2.c@3342> 10005 KSL WAIT
BEG [latch free] 1610768712/0x60026148 325/0x145 0/0x0 wait_id=26605
seq_num=26606 snap_id=1
PR16 kslwtbctx ksl2.c@3342<mailto:ksl2.c@3342> 10005 KSL WAIT
BEG [latch free] 1610768712/0x60026148 325/0x145 0/0x0 wait_id=26767
seq_num=26768 snap_id=1
PR1Z kslwtbctx ksl2.c@3342<mailto:ksl2.c@3342> 10005 KSL WAIT
BEG [latch free] 1610768712/0x60026148 325/0x145 0/0x0 wait_id=26818
seq_num=26819 snap_id=1
PR29 kslwtectx ksl2.c@3485<mailto:ksl2.c@3485> 10005 KSL WAIT
END [latch free] 1610768712/0x60026148 325/0x145 0/0x0 wait_id=26605
seq_num=26606 snap_id=1
PR29 kslwtectx ksl2.c@3493<mailto:ksl2.c@3493> 10005 KSL WAIT
END wait times (usecs) - snap=148, exc=148, tot=148
PR16 kslwtectx ksl2.c@3485<mailto:ksl2.c@3485> 10005 KSL WAIT
END [latch free] 1610768712/0x60026148 325/0x145 0/0x0 wait_id=26767
seq_num=26768 snap_id=1
PR16 kslwtectx ksl2.c@3493<mailto:ksl2.c@3493> 10005 KSL WAIT
END wait times (usecs) - snap=237, exc=237, tot=237
PR1Z kslwtectx ksl2.c@3493<mailto:ksl2.c@3493> 10005 KSL WAIT
END wait times (usecs) - snap=280, exc=280, tot=280
PR1Z kslwtectx ksl2.c@3485<mailto:ksl2.c@3485> 10005 KSL WAIT
END [latch free] 1610768712/0x60026148 325/0x145 0/0x0 wait_id=26818
seq_num=26819 snap_id=1
PR00 kccwbp kcc.c@18381<mailto:kcc.c@18381> 10021
0115000000000000 0115000000000000 b06db40000000000
PR00 executed kccwbp (write to the control file).
This call has already finished when the recovery hung:
pstack 18229
18229: ora_pr00_DB
00007ffed487703a portfs (5, 4, 7fffbfff4840, 0, 5f5e100, 7fffbfff4860)
00000000061568bd sskgpwwait () + dd
00000000061564a3 skgpwwait () + c3
00000000063594ff ksliwat () + 9af
00000000063586ef kslwaitctx () + af
0000000015b6dd85 kcrm_wait_for_reply () + 125
0000000016368183 krr_do_media_recovery () + c183
00000000160935eb krddmr () + dab
00000000160dccd6 krd_logmerger_driver () + 7c6
00000000162a13cc krp_slave_main () + cac
00000000083b374d ksvrdp_int () + 81d
0000000006e84f47 opirip () + 257
00000000060a19d0 opidrv () + 160
00000000060a17e7 sou2o () + 97
00000000060a15b4 opimai_real () + a4
00000000060a110b ssthrdmain () + 26b
00000000060a0e79 main () + a9
00000000076f7784 ???????? ()
Three pr processes (PR1Z, PR16 and PR29) had contention on "active checkpoint
queue latch".
SQL> select addr,name from v$latch where addr like '%60026148' or addr like
'%6000B770' ;
ADDR NAME
----------------
----------------------------------------------------------------
000000006000B770 messages
0000000060026148 active checkpoint queue latch
PR07 allocated the message latch. Maybe its message got lost?
I’ve observed this problem on 19.5 and 19.7, but not on other releases.
Best regards,
Nenad
http://nenadnoveljic.com/blog/
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