A reader, June 14, 2017 - 2:34 pm UTC
Good explaination
has no gap exist on primary database
Quanwen Zhao, June 15, 2017 - 11:26 am UTC
SYS@orcl28> select * from v$archive_gap;
no rows selected
But,I found alert.log file on standby database,there is a hint:
Error 12547 received logging on to the standby
FAL[client, USER]: Error 12547 connecting to orcl28 for fetching gap sequence
Tue May 09 12:27:20 2017
suddenly,I remember that primary database had hung on Tue May 09 11:16:23 2017,I have to restart it for restoring production business,
and scn or timestamp on primary and standby database now,
on primary:
SYS@orcl28> col current_scn for 99999999999;
SYS@orcl28> select current_scn from v$database;
CURRENT_SCN
------------
11542643440
SYS@orcl28> select scn_to_timestamp(11542643440) from dual;
SCN_TO_TIMESTAMP(11542643440)
---------------------------------------------------------------------------
14-JUN-17 02.44.23.000000000 PM
on standby:
SYS@standby28> col current_scn for 99999999999;
SYS@standby28> select current_scn from v$database;
CURRENT_SCN
------------
11335455434
SYS@standby28> select scn_to_timestamp(11335455434) from dual;
SCN_TO_TIMESTAMP(11335455434)
---------------------------------------------------------------------------
09-MAY-17 11.16.23.000000000 AM
and last sequence# applied on standby database:
SYS@standby28> SELECT max(sequence#) from v$archived_log where applied='YES';
MAX(SEQUENCE#)
--------------
18056
A reader, June 18, 2017 - 9:04 am UTC
Thanks,Connor! your link article.
But gap is really not existed,all no applied archived log files on standby database is all existed,and finally I want to cancel redo data apply for having a try(alter database recover managed standby database cancel,hang long times,and I've no idea,cancel this operation),then manual killed mrp process(mrp0),and startup redo data apply(alter database recover managed standby database using current logfile disconnect),now all no applied archived log files start to apply in order and output 'Media recovery .....18056....' in alert log file. I think it is mrp's problem!
Ghaith, May 09, 2018 - 8:43 am UTC
Thanks for answering, it was ver usefull, but I found these not applied
SEQUENCE# APPLIED FIRST_TIM NEXT_TIME COMPLETIO
--------- --------- --------- --------- ---------
56783 NO 30-NOV-17 30-NOV-17 14-DEC-17
56783 NO 30-NOV-17 30-NOV-17 18-DEC-17
59544 NO 11-JAN-18 11-JAN-18 14-JAN-18
61340 NO 10-JAN-18 10-JAN-18 14-JAN-18
64966 NO 08-MAY-18 08-MAY-18 08-MAY-18
when I try to export them I got this message
specification does not match any archived log in the repository, backup cancelled because there are no files to backup
what should I do now ?
May 10, 2018 - 6:12 am UTC
Sorry - you've given us no context here. Is this related to the original question? Or a new database ? Something else ?
We've got nothing to work with here.
FAL SERVER AND FAL CLIENT
JUSTIN RAJU, November 10, 2018 - 6:53 am UTC
Hi Cornor,
thanks for the answer i have one question if i have PRODUCTION(PRIMARY) say A (with service name A) and standby B (with service name B) then in the parameter file of Primary what would be my FAL SERVER AND FAL CLIENT
will it be
init.ora file of Primary
fal_client=A
fal_server=B
or vice a versa
November 26, 2018 - 11:43 am UTC
Primary = A, Standby = B
On the standby
fal_server=A
fal_client=B
On the primary
fal_server=B
fal_client=A
(which will be used for when the primary is in standby mode)
Gap Detection and Resolution
faroun, July 03, 2022 - 9:02 am UTC
can I ask you a question?
I have situation that my log gap gets resolve automatic and some times it can't get the log until I start copy the log manually and applied it
its occurred every 10 minutes
what can cause that?
July 05, 2022 - 12:24 am UTC
Lots of places to check (and lots of potential causes)
v$database
gv$recovery_progress
v$managed_standby
v$archived_log
v$standby_log
v$dataguard_stats
but best bet would be to get your alert logs from primary / standby and log an SR so we can see all of the details