MIME-Version: 1.0
References: <CALj2ACUBiRLHF7VYD-0nYVHSvVBSCQ_5OMbP4tE8Ys_rpvQ--A@mail.gmail.com>
 <Zg2DgfXorAXrC8lw@ip-10-97-1-34.eu-west-3.compute.internal>
 <CALj2ACXbUzp-9tixeUK_dws5k+ARJaXxj8cj9W3adA0XNUS4Hg@mail.gmail.com>
 <Zg+rvmqjL3DfbJdx@ip-10-97-1-34.eu-west-3.compute.internal>
 <CALj2ACW8SYiRL8vGAhez=FdrzxO0W5pVFvN8GF7yKCO8_c=QdQ@mail.gmail.com>
 <CAA4eK1+-ipXB+LuUiDNQ5L+sWJFpzK89k-Oc7xOG37AefrptoQ@mail.gmail.com>
 <CALj2ACWhTY9mRc7sOpuao=GGidRjCVXc0SNtJ_DNman4nh5CcQ@mail.gmail.com>
 <CALj2ACVY+Fd5vC0VjW=5VDK9mmt-Y+PDZxnBp8ngGAZc24Vv9g@mail.gmail.com>
 <CALj2ACX0FVrx9f0c2g19Rb-WAJhm3wdyttde3YQtkotL6bUveA@mail.gmail.com>
 <CALj2ACXQNGXokgx8APwdxrG4MHMF=cOz6XQtUL7EHua9oUfkgA@mail.gmail.com> <Zo2zMwVuMcB79OH2@nathan>
In-Reply-To: <Zo2zMwVuMcB79OH2@nathan>
From: Masahiko Sawada <sawada.mshk@gmail.com>
Date: Tue, 13 Aug 2024 06:32:45 +0900
Message-ID: <CAD21AoCpLHEcZzZmXiC0ZyAXfO0iV+eJoFB8i3+XDLV1ci9MFA@mail.gmail.com>
Subject: Re: Introduce XID age and inactive timeout based replication slot invalidation
To: Nathan Bossart <nathandbossart@gmail.com>
Cc: Bharath Rupireddy <bharath.rupireddyforpostgres@gmail.com>, 
	Amit Kapila <amit.kapila16@gmail.com>, Bertrand Drouvot <bertranddrouvot.pg@gmail.com>, 
	shveta malik <shveta.malik@gmail.com>, 
	PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
Archived-At: <https://www.postgresql.org/message-id/CAD21AoCpLHEcZzZmXiC0ZyAXfO0iV%2BeJoFB8i3%2BXDLV1ci9MFA%40mail.gmail.com>
Precedence: bulk

On Tue, Jul 9, 2024 at 3:01=E2=80=AFPM Nathan Bossart <nathandbossart@gmail=
.com> wrote:
>
> On Mon, Jun 24, 2024 at 11:30:00AM +0530, Bharath Rupireddy wrote:
> > 6) Vacuum command can't be run on the standby in recovery. So, to help
> > invalidate replication slots on the standby, I have for now let the
> > checkpointer also do the XID age based invalidation. I know
> > invalidating both in checkpointer and vacuum may not be a great idea,
> > but I'm open to thoughts.
>
> Hm.  I hadn't considered this angle.

Another idea would be to let the startup process do slot invalidation
when replaying a RUNNING_XACTS record. Since a RUNNING_XACTS record
has the latest XID on the primary, I think the startup process can
compare it to the slot-xmin, and invalidate slots which are older than
the age limit.

Regards,

--
Masahiko Sawada
Amazon Web Services: https://aws.amazon.com