Re: Probable problem with pg_standby - Mailing list pgsql-hackers

From Detlef Ulherr
Subject Re: Probable problem with pg_standby
Date
Msg-id 4910489B.4000802@sun.com
Whole thread Raw
In response to Re: Probable problem with pg_standby  ("Fujii Masao" <masao.fujii@gmail.com>)
List pgsql-hackers
Fujii Masao wrote:
> On Tue, Nov 4, 2008 at 8:09 PM, Detlef Ulherr <Detlef.Ulherr@sun.com> wrote:
>   
>> All I did was forcing the primary in a recovery to generate a new timeline.
>> The installed version was 8.3.4, but the problem is the same with earlier
>> versions as well. It occurred in 8.2 also. this problem is reproducible all
>> the times. For my agent code I implemented a workaround which guarantees
>> that during a resilvering process the primary and the standby start at t the
>> same timeline. But my feeling is that the standby should go to the same
>> timeline as the primary when he receives the history file without
>> disruption, and by all means it should never stop the recovery unmotivated.
>> This will make a full synchronization necessary and in times of larger
>> databases, this may cause major downtimes.
>>     
>
> I agree with you only if normal archive recovery case (not specified
> recovery_target_xid/time). But, in point-in-time recovery case, the standby
> cannot continue to redo without stopping. DBA has to reconstruct the
> standby (get new online-backup with new timeline ID, locate it on the
> standby and restart recovery).
>
> Or, we should deal with normal archive recovery and point-in-time one
> separately?
>
> Regards,
>
>   
Agreed, a point in time recovery can send the primary behind the 
standby, but this should not happen with a normal archive recovery, so 
separating the two cases will be a big improvement. A meaningful error 
message in the log will help the poor dba, currently there is nothing in 
the standby's log. It just stops the recovery.

In my case it was a normal archive recovery, and definitely no point in 
time recovery.

Regards,

-- 

*****************************************************************************Detlef UlherrStaff Engineer
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