log_archive_dest_20? ? ? ? ? ? ? ? ? string? ? ?

log_archive_dest_21? ? ? ? ? ? ? ? ? string? ? ?

3、最大可用模式Maximum Availability Mode测试

当前从默认的最大性能切换到最大可用模式，首先需要满足将日志传输模式进行修改。

SQL> alter system set log_archive_dest_2='SERVICE=vlifesb sync affirm net_timeout=30 valid_for=(online_logfiles,primary_role) db_unique_name=vlifesb';

System altered

SQL> select dest_id, dest_name, TRANSMIT_MODE, ASYNC_BLOCKS, AFFIRM TYPE, VALID_NOW, VALID_TYPE, VALID_ROLE, DB_UNIQUE_NAME, NET_TIMEOUT from v$archive_dest where status<>'INACTIVE';

? DEST_ID DEST_NAME? ? ? ? ? ? TRANSMIT_MODE ASYNC_BLOCKS TYPE VALID_NOW? ? ? ? VALID_TYPE? ? ? VALID_ROLE? DB_UNIQUE_NAME? ? ? ? ? ? ? ? NET_TIMEOUT

---------- -------------------- ------------- ------------ ---- ---------------- --------------- ------------ ------------------------------ -----------

? ? ? ? 1 LOG_ARCHIVE_DEST_1? SYNCHRONOUS? ? ? ? ? ? ? 0 NO? YES? ? ? ? ? ? ? ALL_LOGFILES? ? ALL_ROLES? ? NONE? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? 0

? ? ? ? 2 LOG_ARCHIVE_DEST_2? PARALLELSYNC? ? ? ? ? ? 0 YES? YES? ? ? ? ? ? ? ONLINE_LOGFILE? PRIMARY_ROLE vlifesb? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? 30

此时，将保护模式使用alter database进行设置。

SQL> alter database set standby database to maximize availability;

Database altered

SQL> select name, open_mode, database_role, protection_mode from v$database;

NAME? ? ? OPEN_MODE? ? ? ? ? ? DATABASE_ROLE? ? PROTECTION_MODE

--------- -------------------- ---------------- --------------------

VLIFE? ? READ WRITE? ? ? ? ? PRIMARY? ? ? ? ? MAXIMUM AVAILABILITY

在切换动作的时候，主库日志情况如下：

Wed Oct 21 15:13:48 2015

alter database set standby database to maximize availability

Completed: alter database set standby database to maximize availability

Wed Oct 21 15:13:49 2015

Destination LOG_ARCHIVE_DEST_2 is UNSYNCHRONIZED –发现没有同步，需要补充。

******************************************************************

LGWR: Setting 'active' archival for destination LOG_ARCHIVE_DEST_2

******************************************************************

Wed Oct 21 15:13:49 2015

NSS2 started with pid=34, OS id=9186?

LGWR: Standby redo logfile selected to archive thread 1 sequence 82

LGWR: Standby redo logfile selected for thread 1 sequence 82 for destination LOG_ARCHIVE_DEST_2

Thread 1 advanced to log sequence 82 (LGWR switch)

? Current log# 3 seq# 82 mem# 0: /u01/app/oracle/oradata/VLIFE/onlinelog/o1_mf_3_c1kb1c24_.log

? Current log# 3 seq# 82 mem# 1: /u01/app/oracle/fast_recovery_area/VLIFE/onlinelog/o1_mf_3_c1kb1c43_.log

Wed Oct 21 15:13:53 2015

Archived Log entry 104 added for thread 1 sequence 81 ID 0xfad4f44b dest 1:

Wed Oct 21 15:13:54 2015

ARC3: Archive log rejected (thread 1 sequence 81) at host 'vlifesb'

FAL[server, ARC3]: FAL archive failed, see trace file.

ARCH: FAL archive failed. Archiver continuing

ORACLE Instance vlife - Archival Error. Archiver continuing.

Wed Oct 21 15:14:42 2015

Destination LOG_ARCHIVE_DEST_2 is SYNCHRONIZED

LGWR: Standby redo logfile selected to archive thread 1 sequence 83

LGWR: Standby redo logfile selected for thread 1 sequence 83 for destination LOG_ARCHIVE_DEST_2

Thread 1 advanced to log sequence 83 (LGWR switch)

? Current log# 1 seq# 83 mem# 0: /u01/app/oracle/oradata/VLIFE/onlinelog/o1_mf_1_c1kb19q4_.log

? Current log# 1 seq# 83 mem# 1: /u01/app/oracle/fast_recovery_area/VLIFE/onlinelog/o1_mf_1_c1kb19sb_.log

Wed Oct 21 15:14:42 2015

Archived Log entry 107 added for thread 1 sequence 82 ID 0xfad4f44b dest 1: