Date: Mon, 12 Sep 2022 21:13:11 -0500
From: Justin Pryzby <pryzby@telsasoft.com>
To: Thomas Munro <thomas.munro@gmail.com>
Cc: Robert Haas <robertmhaas@gmail.com>,
	Aleksander Alekseev <aleksander@timescale.com>,
	pgsql-hackers@lists.postgresql.org,
	Michael Paquier <michael@paquier.xyz>
Subject: Re: Background writer and checkpointer in crash recovery
Message-ID: <20220913021311.GN31833@telsasoft.com>
References: 
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 <CA+hUKGKBngNkTLm1gSmosY6o-azfUvQxALaBSEOjs6KpKYQ9pg@mail.gmail.com>
 <162763450191.31964.15384962987091520173.pgcf@coridan.postgresql.org>
 <CA+Tgmoa9TsiRDQnTm20fMJjWD3W9Lm3kSS8VJJRXeFnoRw6k9g@mail.gmail.com>
 <CA+hUKGKiBnK9cB_NAxBOHJ7okw9p46F7ZmBP2FjpdTf5RJxS-g@mail.gmail.com>
 <CA+TgmoYxi_f14WW6osP61DYQinrVQLyFX1F38NZWHW9xJJmgNg@mail.gmail.com>
 <CA+hUKG+egXmO5GYhrhO5WgXziFeVMAE_uSVBEEBqsYh3Tid9fg@mail.gmail.com>
 <CA+hUKGK--es4iccyAcLrevOdz5Sns4u=nNXDG5nF_G3MaGPggg@mail.gmail.com>
 <20220912005443.GB31833@telsasoft.com>
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On Sun, Sep 11, 2022 at 07:54:43PM -0500, Justin Pryzby wrote:
> On Tue, Aug 03, 2021 at 02:19:22PM +1200, Thomas Munro wrote:
> > On Tue, Aug 3, 2021 at 9:52 AM Thomas Munro <thomas.munro@gmail.com> wrote:
> > > On Tue, Aug 3, 2021 at 1:17 AM Robert Haas <robertmhaas@gmail.com> wrote:
> > > > That's great. I just realized that this leaves us with identical
> > > > RequestCheckpoint() calls in two nearby places. Is there any reason
> > > > not to further simplify as in the attached?
> > >
> > > LGTM.
> > 
> > And pushed.
> 
> Gripe: this made the "ps" display worse than before.
> 
> 7ff23c6d2 Run checkpointer and bgwriter in crash recovery.
> 
> A couple years ago, I complained that during the end-of-recovery
> checkpoint, the "ps" display still said "recovering NNNNN", which made
> it look like it was stuck on a particular WAL file.
> 
> That led to commit df9274adf, which updated the startup process's "ps"
> to say "end-of-recovery checkpoint".
> 
> But since the start process no longer does the checkpoint, it still
> says:
> 
> postgres 19738 11433  5 19:33 ?        00:00:01 postgres: startup recovering 000000010000000C000000FB
> postgres 19739 11433  3 19:33 ?        00:00:00 postgres: checkpointer performing end-of-recovery checkpoint
> 
> That looks inconsistent.  It'd be better if the startup process's "ps"
> were cleared.

Like this, maybe.

It's similar to what I suggested to consider backpatching here:
https://www.postgresql.org/message-id/20201214032224.GA30237%40telsasoft.com

diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c
index 7a710e6490d..4bf8614d45f 100644
--- a/src/backend/access/transam/xlog.c
+++ b/src/backend/access/transam/xlog.c
@@ -5302,6 +5302,7 @@ StartupXLOG(void)
 	EndOfLogTLI = endOfRecoveryInfo->endOfLogTLI;
 	abortedRecPtr = endOfRecoveryInfo->abortedRecPtr;
 	missingContrecPtr = endOfRecoveryInfo->missingContrecPtr;
+	set_ps_display("");
 
 	/*
 	 * When recovering from a backup (we are in recovery, and archive recovery