Change DG to the maximum protection mode, reporting ORA-03113: end-of-fileoncommunicationchanne

ORA-03113: end-of-fileoncommunicationc

When I adjusted Data Guard to maximum protection, I encountered the following problem: end-of-file on communication c

When you adjusted Data Guard to maximum protection, you encountered the following problem: end-of-file on communication channel.
The execution process is as follows:

SQL> alter database set standby database to maximize PROTECTION;
Alter database set standby database to maximize PROTECTION
*
ERROR at line 1:
ORA-01126: database must be mounted in this instance and not open in any instance
SQL> shutdown immediate
Database closed.
Database dismounted.
Oracle instance shut down.
SQL> startup mount
ORACLE instance started.
Total System Global Area 390070272 bytes
Fixed Size 2021024 bytes
Variable Size 142608736 bytes
Database Buffers 243269632 bytes
Redo Buffers 2170880 bytes
Database mounted.
SQL> alter database set standby database to maximize PROTECTION;
Database altered.
SQL> select PROTECTION_MODE, OPEN_MODE, DB_UNIQUE_NAME, DATABASE_ROLE, SWITCHOVER_STATUS from v $ database;
PROTECTION_MODE OPEN_MODE DB_UNIQUE_NAME DATABASE_ROLE SWITCHOVER_STATUS
------------------------------------------------------------------------------------------------
MAXIMUM PROTECTION MOUNTED WENDING PRIMARY TO STANDBY
SQL> alter database open;
Alter database open
*
ERROR at line 1:
ORA-03113: end-of-file on communication channel

Analysis log:
[Oracle @ dg1 bdump] $ tail-10f alert_WENDING.log
LGWR: Destination LOG_ARCHIVE_DEST_1 is not serviced by LGWR
LGWR: Minimum of 1 synchronous standby database required
Sat Jan 4 23:05:16 2014
Errors in file/u01/oracle/admin/ORCLDB/bdump/wending_lgwr_10086.trc:
ORA-16072: a minimum of one standby database destination is required
Sat Jan 4 23:05:16 2014
Errors in file/u01/oracle/admin/ORCLDB/bdump/wending_lgwr_10086.trc:
ORA-16072: a minimum of one standby database destination is required
LGWR: terminating instance due to error 16072.
Instance terminated by LGWR, pid = 10086

In fact, the first step is to query the log_archive_dest parameter, check whether the synchronization method and affrem are set, and then whether the standy log is added, after all this is done, check the logs.
The problem may be solved after the first check is completed.
By the way, another method is to enable FLASHBACK_ON;
Enable FLASHBACK_ON.
SQL> select FLASHBACK_ON from v $ database;
FLASHBACK_ON
------------------
NO
SQL> alter database flashback on;
Database altered.

Add standy redolog
[Oracle @ dg2 ~] $ Sqlplus/as sysdba
SQL * Plus: Release 10.2.0.1.0-Production on Sun Jan 5 01:00:35 2014
Copyright (c) 1982,200 5, Oracle. All rights reserved.
Connected:
Oracle Database 10g Enterprise Edition Release 10.2.0.1.0-64bit Production
With the Partitioning, OLAP and Data Mining options
SQL> alter database add standby logfile group 4 ('/u01/oracle/oradata/ORCLDB/stdby_redo04.log') size 50 M;
Database altered.
SQL> alter database add standby logfile group 5 ('/u01/oracle/oradata/ORCLDB/stdby_redo05.log') size 50 M;
Database altered.
SQL> alter database add standby logfile group 6 ('/u01/oracle/oradata/ORCLDB/stdby_redo06.log') size 50 M;
Database altered.

[Oracle @ dg1 bdump] $ sqlplus/as sysdba
SQL * Plus: Release 10.2.0.1.0-Production on Sun Jan 5 01:10:32 2014
Copyright (c) 1982,200 5, Oracle. All rights reserved.
Connected:
Oracle Database 10g Enterprise Edition Release 10.2.0.1.0-64bit Production
With the Partitioning, OLAP and Data Mining options
SQL> alter database set standby database to maximize PROTECTION;
Alter database set standby database to maximize PROTECTION
*
ERROR at line 1:
ORA-01126: database must be mounted in this instance and not open in any instance
SQL> shutdown immediate
Database closed.
Database dismounted.
ORACLE instance shut down.
SQL> startup mount
ORACLE instance started.
Total System Global Area 390070272 bytes
Fixed Size 2021024 bytes
Variable Size 142608736 bytes
Database Buffers 243269632 bytes
Redo Buffers 2170880 bytes
Database mounted.
SQL> alter database set standby database to maximize PROTECTION;
Database altered.
SQL> select PROTECTION_MODE, OPEN_MODE, DB_UNIQUE_NAME, DATABASE_ROLE, SWITCHOVER_STATUS from v $ database;
PROTECTION_MODE OPEN_MODE DB_UNIQUE_NAME DATABASE_ROLE SWITCHOVER_STATUS
------------------------------------------------------------------------------------------------
MAXIMUM PROTECTION MOUNTED WENDING PRIMARY TO STANDBY