Archives Not Applying On Standby Database

Archives Not Applying On Standby Database

Due to abnormal network outage for 10-12 hrs my standby database was behaving abnormally.

All the archives are moving properly from Primary node to DR. But it was not being applied.

Then we checked the gap using below command, and there were no gap.
select * from v$archive_gap;

Then we checked maximum sequence upto which archives had applied.
select THREAD#,max(SEQUENCE#),APPLIED from v$archived_log where APPLIED='YES' group by thread#,applied;

It showed sequence of 10 hrs old.It means my archives had not been applied for 10 hrs.

It means MRP process is hanged. Now we need to do manually recovery. We cancelled the recovery,
ALTER DATABASE RECOVER MANAGED STANDBY DATABASE CANCEL;

But our session got hanged. We waited for 20min but unluckily no progress.

Then we down our database by shutdown immediate command.Even it also got hanged.

Finally, we abnormally shutdown our database by shutdown abort and did manual recovery.

a) shutdown abort;

b) startup nomount;

c) alter database mount standby database;

--Manual recovery:

d) RECOVER AUTOMATIC FROM '/ora_arch/archivelog' STANDBY DATABASE UNTIL CANCEL;

e) alter database recover cancel;
--Manual recovery completed successfully

Now put the database in recovery mode.

ALTER DATABASE RECOVER MANAGED STANDBY DATABASE DISCONNECT FROM SESSION;

But unfortunately at the same time one more problem encountered.When i checked  gap,
SQL> select * from v$archive_gap;

THREAD# LOW_SEQUENCE# HIGH_SEQUENCE#
---------- ------------- --------------
2          4470           4470

There was a gap of only 1 archive of node 2. We waited for 50 min but there is no progress.Then we manually registered that archive.

alter database register or replace logfile '/ora_arch/arch_2_4470_718297972.arc';

Finally,there was no gap and even archives were applying normally.