Oracle DataGuard奇怪的ORA-16494错误
Oracle数据库DataGuard数据无法同步，主库查询v$archive_dest出现ORA-16494错误。
数据库版本Oracle 12.1.0.2.0：
SQL> select * from v$version;BANNER
--------------------------------------------------------------------------------CON_ID
----------
Oracle Database 12c Enterprise Edition Release 12.1.0.2.0 - 64bit Production0PL/SQL Release 12.1.0.2.0 - Production0CORE 12.1.0.2.0 Production0BANNER
--------------------------------------------------------------------------------CON_ID
----------
TNS for 64-bit Windows: Version 12.1.0.2.0 - Production0NLSRTL Version 12.1.0.2.0 - Production0检查主库DG参数：
SQL> show parameter log_archive_configNAME TYPE VALUE
------------------------------------ ----------- ------------------------------
log_archive_config string DG_CONFIG=(orcl,orcladg)
SQL>
SQL> show parameter log_archive_dest_2NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
log_archive_dest_2 string SERVICE=orcladg LGWR ASYNC VALID_FOR=(ONLINE_LOGFILES,PRIMARY_ROLE) DB_UNIQUE_NAME=orcladg
log_archive_dest_20 string
log_archive_dest_21 string
log_archive_dest_22 string
log_archive_dest_23 string
log_archive_dest_24 string
log_archive_dest_25 string
log_archive_dest_26 string
log_archive_dest_27 stringNAME TYPE VALUE
------------------------------------ ----------- ------------------------------
log_archive_dest_28 string
log_archive_dest_29 string
SQL> show parameter service_namesNAME TYPE VALUE
------------------------------------ ----------- ------------------------------
service_names string orcl
SQL> show parameter uniqueNAME TYPE VALUE
------------------------------------ ----------- ------------------------------
db_unique_name string orcl
检查备库参数：
SQL> show parameter log_archive_configNAME TYPE VALUE
------------------------------------ ----------- ------------------------------
log_archive_config string DG_CONFIG=(orcl,orcladg)
SQL> show parameter log_archive_dest_2NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
log_archive_dest_2 string SERVICE=orcl LGWR ASYNC VALID_FOR=(ONLINE_LOGFILES,PRIMARY_ROLE) DB_UNIQUE_NAME=orcl
log_archive_dest_20 string
log_archive_dest_21 string
log_archive_dest_22 string
log_archive_dest_23 string
log_archive_dest_24 string
log_archive_dest_25 string
log_archive_dest_26 string
log_archive_dest_27 stringNAME TYPE VALUE
------------------------------------ ----------- ------------------------------
log_archive_dest_28 string
log_archive_dest_29 string
SQL> show parameter service_namesNAME TYPE VALUE
------------------------------------ ----------- ------------------------------
service_names string pdborcl
SQL> show parameter uniqueNAME TYPE VALUE
------------------------------------ ----------- ------------------------------
db_unique_name string orcladg
检查主备库之间的网络连通性
主库：
C:\Users\Administrator>tnsping orclTNS Ping Utility for 64-bit Windows: Version 12.1.0.2.0 - Production on 08-5月 -2023 22:42:27Copyright (c) 1997, 2014, Oracle. All rights reserved.已使用的参数文件:
C:\app\pdborcl\product\12.1.0\dbhome_1\network\admin\sqlnet.ora已使用 TNSNAMES 适配器来解析别名
尝试连接 (DESCRIPTION = (ADDRESS_LIST = (ADDRESS = (PROTOCOL = TCP)(HOST = WIN-VJ841V9N3PU)(PORT = 1521))) (CONNECT_DATA = (SERVER = DEDICATED) (SERVICE_NAME =
OK (20 毫秒)C:\Users\Administrator>tnsping orcladgTNS Ping Utility for 64-bit Windows: Version 12.1.0.2.0 - Production on 08-5月 -2023 22:42:39Copyright (c) 1997, 2014, Oracle. All rights reserved.已使用的参数文件:
C:\app\pdborcl\product\12.1.0\dbhome_1\network\admin\sqlnet.ora已使用 TNSNAMES 适配器来解析别名
尝试连接 (DESCRIPTION = (ADDRESS = (PROTOCOL = TCP)(HOST = 172.16.188.201)(PORT = 1521)) (CONNECT_DATA = (SERVER = DEDICATED) (SERVICE_NAME = pdborcl)))
OK (20 毫秒)
备库：
C:\Users\Administrator>tnsping orclTNS Ping Utility for 64-bit Windows: Version 12.1.0.2.0 - Production on 08-5月 -2023 22:42:27Copyright (c) 1997, 2014, Oracle. All rights reserved.已使用的参数文件:
C:\app\pdborcl\product\12.1.0\dbhome_1\network\admin\sqlnet.ora已使用 TNSNAMES 适配器来解析别名
尝试连接 (DESCRIPTION = (ADDRESS_LIST = (ADDRESS = (PROTOCOL = TCP)(HOST = WIN-VJ841V9N3PU)(PORT = 1521))) (CONNECT_DATA = (SERVER = DEDICATED) (SERVICE_NAME =
OK (20 毫秒)C:\Users\Administrator>tnsping orcladgTNS Ping Utility for 64-bit Windows: Version 12.1.0.2.0 - Production on 08-5月 -2023 22:42:39Copyright (c) 1997, 2014, Oracle. All rights reserved.已使用的参数文件:
C:\app\pdborcl\product\12.1.0\dbhome_1\network\admin\sqlnet.ora已使用 TNSNAMES 适配器来解析别名
尝试连接 (DESCRIPTION = (ADDRESS = (PROTOCOL = TCP)(HOST = 172.16.188.201)(PORT = 1521)) (CONNECT_DATA = (SERVER = DEDICATED) (SERVICE_NAME = pdborcl)))
OK (20 毫秒)
主备库之间网络是畅通的。
主库切换日志，查询v$archive_dest：
SQL> alter system switch logfile;系统已更改。
出现ORA-16494错误，该错误在网上找不到，而且MOS上也没有相关的记载。
再次检查备库，会不会是PDB模式的，而且有名为PDBORCL的PDB，导致主库通过tns直接连到了PDB中。
备库查询：
SQL> select con_id,name,open_mode from v$pdbs;CON_ID NAME OPEN_MODE
---------- ------------------------------ ----------2 PDB$SEED MOUNTED3 PDBORCL MOUNTED果然有个叫PDBORCL的PDB。
查看数据库的数据库名：
SQL> select name,open_mode,database_role from v$database;NAME OPEN_MODE DATABASE_ROLE
--------- -------------------- ----------------
ORCL MOUNTED PHYSICAL STANDBY
所以，如果想连到CDB中，应该将service_names指定为orcl，由于是备库，可设置为rzorcl或orclstd等，方便识别，但是一定要与PDBORCL不同名。
修改备库service_names
SQL> alter system set service_names='rzorcl';在修改主库和备库中tnsnames.ora文件中备库连接串中SERVICE=RZORCL。
再次尝试切换日志，错误消失。
系统已更改。SQL>
SQL>
SQL>
SQL> select error from v$archive_dest;ERROR
-----------------------------------------------------------------ERROR
-----------------------------------------------------------------ERROR
-----------------------------------------------------------------已选择 31 行。SQL>
再次查看备库日志接收情况：
SQL> select process,sequence#,block# from v$managed_standby;PROCESS SEQUENCE# BLOCK#
--------- ---------- ----------
ARCH 103988 43008
ARCH 0 0
ARCH 103987 4096
ARCH 103989 40960
MRP0 103990 29955
RFS 0 0
RFS 103990 29955
RFS 0 0
RFS 0 09 rows selected.
备库日志接收正常，问题解决。