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help / color / mirror / Atom feedFrom: Shinya Kato <[email protected]>
To: Fujii Masao <[email protected]>
Cc: PostgreSQL Hackers <[email protected]>
Subject: Re: pg_stat_replication.*_lag sometimes shows NULL during active replication
Date: Thu, 26 Mar 2026 14:40:37 +0900
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On Thu, Mar 26, 2026, 00:30 Fujii Masao <[email protected]> wrote:
> On Wed, Mar 25, 2026 at 4:03 PM Shinya Kato <[email protected]>
> wrote:
> > Thanks for the updated patch. LGTM.
> >
> > Regarding the backpatch, I'd personally appreciate it if the walsender.c
> changes were backpatched to stable branches. As you noted, it don't fully
> solve the reported issue, but they do help reduce the cases where lag
> columns in pg_stat_replication unexpectedly become NULL.
> >
> > Even a partial mitigation in the back branches would be valuable for
> users running stable releases.
>
> +1
>
> I've split the changes into two patches.
>
> Patch 0001 fixes premature NULL lag reporting in walsender. I will commit
> it
> and backpatch it to all supported branches.
>
> Patch 0002 avoids sending duplicate WAL locations in standby status
> replies.
> I will commit this to master only.
>
Thanks, LGTM.
Best regards,
Shinya Kato
>
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Subject: Re: pg_stat_replication.*_lag sometimes shows NULL during active replication
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