pg_recvlogical use of SIGHUP

Started by Dave Cramerabout 8 years ago4 messageshackers
Beta feature

Hackorum builds and tests every patch posted to the lists, not only commitfest submissions. This is Hackorum's own CI rather than the PostgreSQL project's, and it is still under testing - please report anything that looks wrong.

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You can run a PostgreSQL built from this patch straight from Docker, with no checkout and no build:

docker run --rm -p 5432:5432 ghcr.io/hackorum-dev/postgres-patch:t39011
psql -h localhost -U postgres

Built from patchset v4 (message #4), September 20, 2026 at 12:56 PM.

Every patchset is also pushed to a branch of our PostgreSQL fork, so you can check out the same tree CI built. Without a PostgreSQL checkout:

git clone --branch t39011_4 https://github.com/hackorum-dev/postgres.git

In a checkout you already have, add the fork once:

git remote add hackorum https://github.com/hackorum-dev/postgres.git

then, for this patchset and every later one:

git fetch hackorum t39011_4 && git checkout t39011_4

Patchset v4 (message #4) is on t39011_4

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#1Dave Cramer
pg@fastcrypt.com

There is some undocumented (nothing in the docs) code that allows for
closing reopening the output file for pg_recvlogical.

Since this doesn't change the name of the file in the process I'm wondering
how one might actually use this "feature" ?

I could see it being useful if we were to be able to change the file name
and create a new file based on some form of template ?

Am I missing something ?

Dave Cramer

#2Andres Freund
andres@anarazel.de
In reply to: Dave Cramer (#1)
Re: pg_recvlogical use of SIGHUP

Hi,

On 2018-07-06 13:49:37 -0400, Dave Cramer wrote:

There is some undocumented (nothing in the docs) code that allows for
closing reopening the output file for pg_recvlogical.

Since this doesn't change the name of the file in the process I'm wondering
how one might actually use this "feature" ?

You can rename the file, then sighup, no? Renaming while the file is
open will continue to write into the renamed file, but sighup'ing will
use the original name.

Greetings,

Andres Freund

#3Dave Cramer
pg@fastcrypt.com
In reply to: Andres Freund (#2)
Re: pg_recvlogical use of SIGHUP

On 6 July 2018 at 14:11, Andres Freund <andres@anarazel.de> wrote:

Hi,

On 2018-07-06 13:49:37 -0400, Dave Cramer wrote:

There is some undocumented (nothing in the docs) code that allows for
closing reopening the output file for pg_recvlogical.

Since this doesn't change the name of the file in the process I'm

wondering

how one might actually use this "feature" ?

You can rename the file, then sighup, no? Renaming while the file is
open will continue to write into the renamed file, but sighup'ing will
use the original name.

That is the missing piece, thanks!
I'll prepare a patch for the docs

Dave Cramer

#4Dave Cramer
pg@fastcrypt.com
In reply to: Dave Cramer (#3)
Re: pg_recvlogical use of SIGHUP

On 6 July 2018 at 14:11, Andres Freund <andres@anarazel.de> wrote:

Hi,

On 2018-07-06 13:49:37 -0400, Dave Cramer wrote:

There is some undocumented (nothing in the docs) code that allows for
closing reopening the output file for pg_recvlogical.

Since this doesn't change the name of the file in the process I'm

wondering

how one might actually use this "feature" ?

You can rename the file, then sighup, no? Renaming while the file is
open will continue to write into the renamed file, but sighup'ing will
use the original name.

That is the missing piece, thanks!
I'll prepare a patch for the docs

See attached patch.

Attachments:

t39011_4
pg_recvlogical.patchapplication/octet-stream; name=pg_recvlogical.patchDownload+6-2