Feedback-ID: i0fe9450f:Fastmail
Date: Thu, 11 Sep 2025 08:28:35 +0900
From: Michael Paquier <michael@paquier.xyz>
To: Kouber Saparev <kouber@gmail.com>
Cc: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>,
	pgsql-hackers@lists.postgresql.org
Subject: Re: BF mamba failure
Message-ID: <aMIJozPEP5OLI3Yj@paquier.xyz>
References: <Zw8MRH2ks_BgLTa-@paquier.xyz>
 <Zw+RPPRDK+L2W480@ip-10-97-1-34.eu-west-3.compute.internal>
 <ZxCRku2jk8Jz0sTU@paquier.xyz>
 <ZzWs6_pKr8DgEAvs@paquier.xyz>
 <ZzXL7WkzGyhxJljW@ip-10-97-1-34.eu-west-3.compute.internal>
 <ZzbR5Eu66lP9rt50@paquier.xyz>
 <CAN4RuQvYth942J2+FcLmJKgdpq6fE5eqyFvb_PuskxF2eL=Wzg@mail.gmail.com>
 <aJPiwtnsuh9yfFnz@paquier.xyz>
 <CAN4RuQt_Sr9h2NG0-fr7XSmU=DeHkzTeysCuOAWhWrkuhw8Puw@mail.gmail.com>
 <CAN4RuQs6ht4T7ph8NbxHZ+NmDmTrvczAxpyZmcqk+74tzsciuw@mail.gmail.com>
MIME-Version: 1.0
Content-Type: multipart/signed; micalg=pgp-sha512;
	protocol="application/pgp-signature"; boundary="qiJl9CAuOX0n6zCf"
Content-Disposition: inline
In-Reply-To: 
 <CAN4RuQs6ht4T7ph8NbxHZ+NmDmTrvczAxpyZmcqk+74tzsciuw@mail.gmail.com>
Archived-At: 
 <https://www.postgresql.org/message-id/aMIJozPEP5OLI3Yj%40paquier.xyz>
Precedence: bulk


--qiJl9CAuOX0n6zCf
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline

On Tue, Sep 09, 2025 at 04:07:45PM +0300, Kouber Saparev wrote:
> Yet again one of our replicas died. Should I file a bug report or
> something, what should we do in order to prevent it? Restart the database
> every month/week or so?...

I don't think we need another bug to report the same problem.  We are
aware that this may be an issue and that it is hard to track, the
problem is to find room to be able to investigate it, at this stage.

I may be able to come back to it soon-ishly, looking at how to trigger
any race condition.  The difficulty is to think how the current code
is able to reach this state, because we have a race condition at hand
in standbys.

As a start, are these failures only in the startup process?  Has the
startup process reached a consistent state when the problem happens
because the replay code is too eager at removing the stats entries?
Has it not reached a consistent state.  These could be useful hints to
extract a reproducible test case, looking for common patterns.

I'll ask around if I have seen cases like that in the user pool I have
an access to.
--
Michael

--qiJl9CAuOX0n6zCf
Content-Type: application/pgp-signature; name="signature.asc"

-----BEGIN PGP SIGNATURE-----
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=QQzO
-----END PGP SIGNATURE-----

--qiJl9CAuOX0n6zCf--