Oracle-DG,12c pdb创建测试

一、需求，测试12c DG 新建、删除PDB是否导致DG连通性中断

有同事之前沟通过说，搭建完成12c dg之后，由于新建、删除维护PDB，从而导致DG的中断，本篇博客对使用这种场景进行模拟测试，达到学习目的。

二、测试

2.1  主库新建一个pdb

SQL> CREATE PLUGGABLE DATABASE ypdb1 ADMIN USER ypdb1 IDENTIFIED BY oracle
 FILE_NAME_CONVERT =('/picclife/app/oracle/oradata/orcl/pdbseed','/picclife/app/oracle/oradata/orcl/ypdb1');
SQL> select file_name from cdb_data_files where con_id=4;
FILE_NAME
----------------------------------------------------------------
/picclife/app/oracle/oradata/orcl/ypdb1/system01.dbf
/picclife/app/oracle/oradata/orcl/ypdb1/sysaux01.dbf
/picclife/app/oracle/oradata/orcl/ypdb1/undotbs01.dbf


db_file_name_convert                
/picclife/app/oracle/oradata/orcl/pdbseed/, /picclife/app/oracle/oradata/orcldg/pdbseeddg/,
/picclife/app/oracle/oradata/orcl/c11pdb/, /picclife/app/oracle/oradata/orcldg/c11pdbdg/, 
/picclife/app/oracle/oradata/orcl/, /picclife/app/oracle/oradata/orcldg/
$ pwd
/picclife/app/oracle/oradata/orcldg/ypdb1
SYS@c12>select file_name from cdb_data_files where con_id=4;
FILE_NAME
-------------------------------------------------------------------------------------
/picclife/app/oracle/oradata/orcldg/ypdb1/system01.dbf
/picclife/app/oracle/oradata/orcldg/ypdb1/sysaux01.dbf
/picclife/app/oracle/oradata/orcldg/ypdb1/undotbs01.dbf

测试确认无异常，DG同步OK ！
也就是说DG 配置好完善的convert参数的情况下，会根据主库的路径自动进行转换。
例如本例中，将主库的orcl =>dg 转换为orcldg 
然而PDB的名称ypdb1在搭建dg时没有，因此没有配置这个路径的转换？ 那么Oracle是如何做的，没转换就默认dg也使用这个目录！
并且新建pdb时，oracle自动在主库新建了这个文件目录，dg也同样如此！

2.2 测试pdb删除

primary drop pdb ok
 select con_id,pdb_name,status from cdb_pdbs;
 alter pluggable database YPDB1 close;
 drop pluggable database YPDB1 including datafiles;
 
standby 
MRP0: Background Media Recovery terminated with error 65112
2021-04-20T09:24:00.069282+08:00
Errors in file /picclife/app/oracle/diag/rdbms/orcldg/c12/trace/c12_mrp0_58401.trc:
ORA-65112: 未在备用数据库的所有实例上关闭可插入数据库 YPDB1
Managed Standby Recovery not using Real Time Apply
Recovery interrupted!
Standby recovery stopped due to failure in applying recovery marker (opcode 17.35).
Datafiles are recovered to a consistent state at change 1895988 but controlfile is ahead at change 1895993.
Database remains open for continuous queries. Please continue recovery.
2021-04-20T09:24:00.127559+08:00
Errors in file /picclife/app/oracle/diag/rdbms/orcldg/c12/trace/c12_mrp0_58401.trc:
ORA-65112: 未在备用数据库的所有实例上关闭可插入数据库 YPDB1
2021-04-20T09:24:00.127647+08:00
MRP0: Background Media Recovery process shutdown (c12)

SYS@c12> alter pluggable database YPDB1 close;
SYS@c12>show pdbs
    CON_ID CON_NAME                       OPEN MODE  RESTRICTED
---------- ------------------------------ ---------- ----------
         2 PDB$SEED                       READ ONLY  NO
         3 C11PDB                         READ ONLY  NO
         4 YPDB1                          MOUNTED
recover managed standby database using current logfile disconnect;

确认删除正常！

那么对于PDB 的12c dg convert 参数有什么需要注意的事项？

与11g一样，只要是主库与备库路径不修改，可以不配置dg convert参数；
只要涉及路径不一致的，都进行转换！  

如果由于参数配置不正确，导致dg路径不一致，与11g处理类似，重新修改调整dg convert参数，完成路径转换的目的！

另外一个需要注意的是！  主库删除pdb,DG环境 PDB可能是read only状态，MRP进程应用drop pdb 报错，MRP进程abend,造成dg同步中断！


再次重新测试一遍PDB,新建、删除，此时dg 默认新建的pdb not open,因此主库再次删除时，dg 未报错！

发现另外一个可能会遇到的问题，主库删除pdb后，再次使用相同pdb名称新建pdb, dg库可能show pdbs看不到新建的pdb,并且切换容器也看不到要重启！！！
小伙伴们是不是惊呆了？？？重启大法宝