Oracle-ADG 异常宕机 ORA error 484

2022-05-24T03:40:20.051697+08:00
Errors in file /oracle/db/diag/rdbms/orcl/orcl1/trace/orcl1_dia0_71862.trc  (incident=72169):
ORA-32701: Possible hangs up to hang ID=1 detected
Incident details in: /oracle/db/diag/rdbms/orcl/orcl1/incident/incdir_72169/orcl1_dia0_71862_i72169.trc
2022-05-24T03:40:22.228367+08:00
DIA0 Instance 1 requires instance termination due to a GLOBAL, HIGH confidence hang
     with ID=1.
     Hang Resolution Reason: Automatic hang resolution was performed to free a
    significant number of affected sessions.
     Requesting termination of instance 1.
2022-05-24T03:40:23.250839+08:00
LMHB (ospid: 71904): terminating the instance due to ORA error 484
2022-05-24T03:40:23.250955+08:00
Cause - 'KILL_INSTANCE: GCR has been requested to terminate the instance.
LMHB (ospid: 71904) is terminating the instance.
'
2022-05-24T03:40:23.368962+08:00
System state dump requested by (instance=1, osid=71904 (LMHB)), summary=[abnormal instance termination]. error - 'Instance is terminating.
'
System State dumped to trace file /oracle/db/diag/rdbms/orcl/orcl1/trace/orcl1_diag_71839.trc
2022-05-24T03:40:23.798445+08:00
ORA-1092 : opitsk aborting process
2022-05-24T03:40:25.112157+08:00
License high water mark = 113
2022-05-24T03:40:26.105553+08:00
Dumping diagnostic data in directory=[cdmp_20220524034023], requested by (instance=1, osid=71904 (LMHB)), summary=[abnormal instance termination].
2022-05-24T03:40:27.561905+08:00
Instance terminated by LMHB, pid = 71904
2022-05-24T03:40:27.653964+08:00
Warning: 2 processes are still attacheded to shmid 63:
 (size: 2097152 bytes, creator pid: 71629, last attach/detach pid: 71836)
2022-05-24T03:40:28.112903+08:00
USER(prelim) (ospid: 147165): terminating the instance
2022-05-24T03:40:28.113566+08:00
Instance terminated by USER(prelim), pid = 147165

trace 文件命中：

*** 2022-05-24T03:40:20.053110+08:00
Resolvable Hangs in the System
                      Root       Chain Total               Hang               
   Hang Hang          Inst Root  #hung #hung  Hang   Hang  Resolution         
     ID Type Status   Num  Sess   Sess  Sess  Conf   Span  Action             
  ----- ---- -------- ---- ----- ----- ----- ------ ------ -------------------
      1 HANG RSLNPEND    1  4448     5     5   HIGH GLOBAL Terminate Process  
  Hang Resolution Reason: Automatic hang resolution was performed to free a
    significant number of affected sessions.
 
  Inst  Sess   Ser             Proc  Wait    Wait 
   Num    ID    Num      OSPID  Name Time(s) Event
  ----- ------ ----- --------- ----- ------- -----
      2   3366 18920     99479    FG     148 DFS lock handle
      2   3308 34538     99476    FG     149 DFS lock handle
      2   3251 57562     99461    FG     149 DFS lock handle
      2   3194 54189     99458    FG     149 DFS lock handle
      1   4448 36446    107256  CTWR     149 not in wait

由于配置了从ADG备库端进行RMAN备份，而且开启了 block change tracking， 导致该问题。

解决方案：

SQL> alter system set "_bct_mrp_timeout"=5 scope=both sid='*';

命中note：RMAN Backup of Standby Database with BCT Terminates the Instance (Doc ID 2821958.1)