Re: The Redo Hasn't Arrived Yet

From: Charlotte Hammond <"Charlotte>
Date: Wed, 20 May 2020 08:08:50 +0000 (UTC)
Message-ID: <119259469.1981778.1589962130810_at_mail.yahoo.com>



 Thanks Hemant,
I don't issue any commands myself to start the database - it is started by Oracle Restart automatically.  The problem does not occur all the time but is quite frequent.   One thing I've noticed is that it's only on databases using active data guard where this happens - we don't get the problem on regular standby. Unfortunately I don't have active data guard on any newer Oracle versions as the moment to compare with. Just to re-iterate - I'm not too concerned about it as an operational issues as we can workaround pretty easily - I'm just more curious about why it's happening! Thanks,Charlotte

    On Wednesday, May 20, 2020, 04:05:11 AM GMT+1, Hemant K Chitale <hemantkchitale_at_gmail.com> wrote:    

I just tested a 19c Standby database with SHUTDOWN ABORT wile transactions were in-flight. The active datafiles appear in V$RECOVER_FILE for some time after the startup.But I don't see the messages you present. What is the exact sequence of commands you issue to startup the standby database ?  At what point do these messages appear ?Do you have a 12c or higher standby that can be tested ?

Hemant K Chitale

Hemant K Chitale

On Tue, May 19, 2020 at 3:32 PM Charlotte Hammond <charlottejanehammond_at_yahoo.com> wrote:

 Thanks Hemant,
But what I don't understand is how datafiles could be updated when the redo hasn't arrived yet.   Surely the redo should *always* be ahead of any other file in the database? Thanks,Charlotte On Tuesday, May 19, 2020, 02:58:14 AM GMT+1, Hemant K Chitale <hemantkchitale_at_gmail.com> wrote:    

imho, while applying redo to a Standby, datafiles will , temporarily, be at inconsistent SCNs until a checkpoint is done to update all the headers consistent with the controlfile.An ABORT doesn't execute a checkpoint while an IMMEDIATE does do so.

Hemant K Chitale

On Mon, May 18, 2020 at 11:24 PM Charlotte Hammond <charlottejanehammond_at_yahoo.com> wrote:

 I agree - shutdown immediate would be better. It's kind of procedural - servers are being shutdown by a third party "at random" when not required to save on hosting costs - Oracle Restart is being used which uses shutdown abort when the host itself is going down (regardless of the shutdown mode specified for the resource).    Now, there are various ways this can be fixed but I'm really trying to understand WHY this is actually causing the problem below, so I can explain / motivate people to address it. Thanks!Charlotte

    On Monday, May 18, 2020, 03:38:39 PM GMT+1, Hemant K Chitale <hemantkchitale_at_gmail.com> wrote:  

 Why ABORT for the Standby ?
I use SHUTDOWN IMMEDIATE.
Hemant K Chitale
On Mon, 18 May 2020, 22:11 Charlotte Hammond, <dmarc-noreply_at_freelists.org> wrote:

Hello,
If we shutdown *abort* our Data Guard standbys (11.2.0.4 maximum performance with RTA), we occasionally get the errors below on restart ("redo hasn't arrived yet") Now this isn't a problem and is easy to fix - but I'm trying to understand WHY it happens:  How can the controlfile and/or datafile headers in the standby database be ahead of the available redo at the time of abort?i.e. What is different about crash recovery on a standby compared to a primary? Many thanks for any clarifications!
Charlotte

Mon May 18 07:03:53 2020Standby crash recovery failed to bring standby database to a consistentpoint because needed redo hasn't arrived yet.MRP: Wait timeout: thread 1 sequence# 0Standby Crash Recovery aborted due to error 16016.Errors in file /u01/app/oracle/diag/rdbms/dinmybs1/DINMYBS1/trace/DINMYBS1_ora_4660.trc:ORA-16016: archived log for thread 1 sequence# 1134 unavailableRecovery interrupted!Some recovered datafiles maybe left media fuzzyMedia recovery may continue but open resetlogs may failCompleted Standby Crash Recovery.Errors in file /u01/app/oracle/diag/rdbms/dinmybs1/DINMYBS1/trace/DINMYBS1_ora_4660.trc:ORA-10458: standby database requires recoveryORA-01196: file 1 is inconsistent due to a failed media recovery sessionORA-01110: data file 1: '+DATA/dinmybs1/datafile/system.268.1023746733'ORA-10458 signalled during: ALTER DATABASE OPEN /* db agent *//* {0:0:2} */...         

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Received on Wed May 20 2020 - 10:08:50 CEST

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