Re: standalone backend PANICs during recovery

On Tue, Aug 30, 2016 at 9:48 PM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
> Michael Paquier <michael(dot)paquier(at)gmail(dot)com> writes:
>> On Wed, Aug 24, 2016 at 5:07 PM, Bernd Helmle <mailings(at)oopsware(dot)de> wrote:
>>> That said, i'm okay if --single is not intended to bring up a hot standby.
>>> There are many other ways to debug such problems.
>
>> This patch is still on the CF app:
>> https://commitfest.postgresql.org/10/610/
>> Even after thinking about it, my opinion is still the same. Let's
>> prevent a standalone backend to start if it sees recovery.conf.
>> Attached is a patch and the CF entry is switched as ready for
>> committer to move on.
>
> Hm, StartupXLOG seems like a pretty random place to check that, especially
> since doing it there requires an extra stat() call. Why didn't you just
> make readRecoveryCommandFile() error out?

Well, the idea is to do the check before doing anything on PGDATA and
leave it intact, particularly the post-crash fsync().
--
Michael