Re: log messages for archive recovery progress

2012/01/11 19:56, Simon Riggs wrote:
> 2012/1/11 Euler Taveira de Oliveira<euler@timbira.com>:
>> On 08-01-2012 11:59, Satoshi Nagayasu / Uptime Technologies, LLC. wrote:
>>>> [2011-12-08 15:14:36 JST] 16758: LOG:  restored log file "000000080000000000000046" from archive
>>>> [2011-12-08 15:14:36 JST] 16758: LOG:  recoverying 000000080000000000000046
>>>> [2011-12-08 15:14:36 JST] 16758: LOG:  restored log file "000000080000000000000047" from archive
>>>> [2011-12-08 15:14:36 JST] 16758: LOG:  recoverying 000000080000000000000047
>>>> cp: cannot stat `/backups/archlog/000000080000000000000048': No such file or directory
>>>> [2011-12-08 15:14:37 JST] 16758: LOG:  could not restore file "000000080000000000000048" from archive
>>>> [2011-12-08 15:14:37 JST] 16758: LOG:  attempting to look into pg_xlog
>>>> [2011-12-08 15:14:37 JST] 16758: LOG:  recoverying 000000080000000000000048
>>>
>> What about just 'restored log file "000000080000000000000048" from pg_xlog'
>> instead of the last two messages? If you can't read from pg_xlog emit 'could
>> not restore file "000000080000000000000048" from pg_xlog'.
>
> Yes, simple is better.
>
> We already have a message if the file is not present, we just need one
> if we switch to using pg_xlog.
>
> Please look at this.

Thanks for a patch. I agree that simple is better.

However, I'm a bit afraid that it will confuse DBA if we use
"restored" under the pg_xlog replay context, because we have
already used "restored" that means a WAL file as successfully
"copied" (not "replayed") from archive directory into pg_xlog
directory under the archive recovery context.

So, to determine the status of copying WAL files from
archive directory, I think we can use "restored", or
"could not restore" on failure.

And to determine the status of replaying WAL files
in pg_xlog directory (even if a WAL is copied from archive),
we have to use "recover" or "replay".

I'll try to revise my proposed log messages again.

Thanks,
-- 
Satoshi Nagayasu <snaga@uptime.jp>
Uptime Technologies, LLC. http://www.uptime.jp