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From: Melih Mutlu <m.melihmutlu@gmail.com>
Date: Wed, 7 Dec 2022 14:07:11 +0300
Message-ID: 
 <CAGPVpCTkdaOyBLXB435VXq0RA1cHLFQut7BPm6t8D4dsdiEXZQ@mail.gmail.com>
Subject: Re: wake up logical workers after ALTER SUBSCRIPTION
To: Nathan Bossart <nathandbossart@gmail.com>
Cc: Thomas Munro <thomas.munro@gmail.com>,
	"Hayato Kuroda (Fujitsu)" <kuroda.hayato@fujitsu.com>,
	"pgsql-hackers@postgresql.org" <pgsql-hackers@postgresql.org>
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Hi,


> Actually, that's not quite right.  The sync worker will wake up the apply
> worker to change the state from SYNCDONE to READY.  AllTablesyncsReady()
> checks that all tables are READY, so we need to wake up all the workers
> when an apply worker changes the state to READY.  Each worker will then
> evaluate whether to restart for two_phase mode.
>

Right. I didn't think about the two phase case thoroughly. Waking up all
apply workers can help.

Do we also need to wake up all sync workers too? Even if not, I'm not
actually sure whether doing that would harm anything though.
Just asking since currently the patch wakes up all workers including sync
workers if any still exists.

Best,
--
Melih Mutlu
Microsoft

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<div dir=3D"ltr"><div class=3D"gmail_quote"><div>Hi,</div><div>=C2=A0</div>=
<blockquote class=3D"gmail_quote" style=3D"margin:0px 0px 0px 0.8ex;border-=
left:1px solid rgb(204,204,204);padding-left:1ex">Actually, that&#39;s not =
quite right.=C2=A0 The sync worker will wake up the apply<br>
worker to change the state from SYNCDONE to READY.=C2=A0 AllTablesyncsReady=
()<br>
checks that all tables are READY, so we need to wake up all the workers<br>
when an apply worker changes the state to READY.=C2=A0 Each worker will the=
n<br>
evaluate whether to restart for two_phase mode.<br></blockquote><div><br></=
div><div>Right. I didn&#39;t think about the two phase case=C2=A0thoroughly=
. Waking up all apply workers can help.<br></div><div><br></div><div>Do we =
also need to wake up all sync workers too? Even if not, I&#39;m not actuall=
y sure whether doing that would harm anything though.</div><div>Just asking=
 since currently the patch wakes up all workers including sync workers if a=
ny still exists.</div><div><br></div><div>Best,</div><div>--</div><div>Meli=
h Mutlu</div><div>Microsoft</div></div></div>

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