问题：

客户环境12.2 dg备库环境，定时清理归档脚本并未正常清理归档日志文件。

观察日志可以发现存在如下信息

RMAN-08137: WARNING: archived log not deleted, needed for standby or upstream capture process .

一般情况下，如果在备库环境或者主库环境，配置归档清理测量后，DG环境未应用归档将不允许删除。

本次排查RMAN清理归档策略默认，且无法删除的归档日志在DG视图v$archived_log 中applied列为YES

匹配MOS

RMAN-08137 while Deleting Archived Logs from Standby (文档 ID 2169282.1)

CAUSE

log_archive_dest_2 on standby which points to primary database was deferred :

log_archive_dest_2 <SERVICE_NAME> ASYNC NOAFFIRM valid_for=(online_logfile,primary_role) db_unique_name=<SERVICE_NAME>
log_archive_dest_state_2= DEFER

This is functionality change in Oracle12c with fix of <bug 16082541>:  RMAN DELETES ARCHIVELOGS WHICH HAVE NOT BEEN APPLIED TO A DEFERRED STANDBY

SOLUTION

1.  Enable the destination:

SQL>alter system set log_archive_dest_state_2 = ENABLE;

Once destination 2 is enabled , then Please run the archivelog deletion command on standby from RMAN .

NOTE:  There is no harm in enabling the log_archive_dest_2 on standby , redo will be transported only when standby becomes primary.

2.  If the destination should not be considered, unset the destination rather setting it's state to DEFER.  

 

实际情况发现，DG配置远程归档参数，指向主库，且远程归档线程状态为DEFER,按照文档提示，修改为ENABLE后，手工执行归档清理脚本后正常。