Subject: Re: [BUG] non archived WAL removed during production crash recovery
To: Jehan-Guillaume de Rorthais <jgdr@dalibo.com>,
 Kyotaro Horiguchi <horikyota.ntt@gmail.com>
Cc: pgsql-bugs@lists.postgresql.org, michael@paquier.xyz
References: <d0ef12c5-7e36-b9b3-c8ea-2e98d69d1317@oss.nttdata.com>
 <20200401181735.11100908@firost>
 <20200402.130443.1791362864704140391.horikyota.ntt@gmail.com>
 <20200402.130734.613319908534820379.horikyota.ntt@gmail.com>
 <20200402150234.278ae845@firost>
From: Fujii Masao <masao.fujii@oss.nttdata.com>
Message-ID: <d3e7d129-21ab-b98c-4b24-7a50db84ee3f@oss.nttdata.com>
Date: Thu, 2 Apr 2020 23:58:00 +0900
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On 2020/04/02 22:02, Jehan-Guillaume de Rorthais wrote:
> On Thu, 02 Apr 2020 13:07:34 +0900 (JST)
> Kyotaro Horiguchi <horikyota.ntt@gmail.com> wrote:
> 
>> Sorry, it was quite ambiguous.
>>
>> At Thu, 02 Apr 2020 13:04:43 +0900 (JST), Kyotaro Horiguchi
>> <horikyota.ntt@gmail.com> wrote in
>>> At Wed, 1 Apr 2020 18:17:35 +0200, Jehan-Guillaume de Rorthais
>>> <jgdr@dalibo.com> wrote in
>>>> Please, find in attachment a patch implementing this.
>>>
>>> The patch partially reintroduces the issue the patch have
>>> fixed. Specifically a standby running a crash recovery wrongly marks a
>>> WAL file as ".ready" if it is extant in pg_wal without accompanied by
>>> .ready file.
>>
>> The patch partially reintroduces the issue the commit 78ea8b5daa have
>> fixed. Specifically a standby running a crash recovery wrongly marks a
>> WAL file as ".ready" if it is extant in pg_wal without accompanied by
>> .ready file.
> 
> As far as I understand StartupXLOG(), NOT_IN_RECOVERY and IN_CRASH_RECOVERY are
> only set for production clusters, not standby ones.

DB_IN_CRASH_RECOVERY can be set even in standby mode. For example,
if you start the standby from the cold backup of the primary,
since InArchiveRecovery is false at the beginning of the recovery,
DB_IN_CRASH_RECOVERY is set in that moment. But then after all the valid
WAL in pg_wal have been replayed, InArchiveRecovery is set to true and
DB_IN_ARCHIVE_RECOVERY is set.

Regards,

-- 
Fujii Masao
Advanced Computing Technology Center
Research and Development Headquarters
NTT DATA CORPORATION