Date: Tue, 16 Aug 2022 13:36:15 +0200
From: Christoph Berg <myon@debian.org>
To: Daniel Gustafsson <daniel@yesql.se>
Cc: PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Subject: Re: pg_receivewal and SIGTERM
Message-ID: <YvuBL1tvlSNiFQUB@msg.df7cb.de>
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	Daniel Gustafsson <daniel@yesql.se>,
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Re: Daniel Gustafsson
> Do you think pg_recvlogical should support SIGTERM as well?  (The signals which
> it does trap should be added to the documentation which just now says "until
> terminated by a signal" but that's a separate thing.)

Ack, that makes sense, added in the attached updated patch.

>  	pqsignal(SIGINT, sigint_handler);
> +	pqsignal(SIGTERM, sigint_handler);
> Tiny nitpick, I think we should rename sigint_handler to just sig_handler as it
> does handle more than sigint.

I went with sigexit_handler since pg_recvlogical has also a
sighup_handler and "sig_handler" would be confusing there.

Christoph

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	filename="0001-pg_receivewal-pg_recvlogical-Exit-cleanly-on-SIGTERM.patch"

From beb3bcb32a9eabf2bf83e259706f89ccdac276d3 Mon Sep 17 00:00:00 2001
From: Christoph Berg <myon@debian.org>
Date: Mon, 15 Aug 2022 14:29:43 +0200
Subject: [PATCH] pg_receivewal, pg_recvlogical: Exit cleanly on SIGTERM

In pg_receivewal, compressed output is only flushed on clean exits. The
reason to support SIGTERM here as well is that pg_receivewal might well
be running as a daemon, and systemd's default KillSignal is SIGTERM.

Since pg_recvlogical is also supposed to run as a daemon, teach it about
SIGTERM as well.
---
 doc/src/sgml/ref/pg_receivewal.sgml    | 8 +++++---
 src/bin/pg_basebackup/pg_receivewal.c  | 7 ++++---
 src/bin/pg_basebackup/pg_recvlogical.c | 7 ++++---
 3 files changed, 13 insertions(+), 9 deletions(-)

diff --git a/doc/src/sgml/ref/pg_receivewal.sgml b/doc/src/sgml/ref/pg_receivewal.sgml
index 4fe9e1a874..5f83ba1893 100644
--- a/doc/src/sgml/ref/pg_receivewal.sgml
+++ b/doc/src/sgml/ref/pg_receivewal.sgml
@@ -118,8 +118,9 @@ PostgreSQL documentation
 
   <para>
    In the absence of fatal errors, <application>pg_receivewal</application>
-   will run until terminated by the <systemitem>SIGINT</systemitem> signal
-   (<keycombo action="simul"><keycap>Control</keycap><keycap>C</keycap></keycombo>).
+   will run until terminated by the <systemitem>SIGINT</systemitem>
+   (<keycombo action="simul"><keycap>Control</keycap><keycap>C</keycap></keycombo>)
+   or <systemitem>SIGTERM</systemitem> signal.
   </para>
  </refsect1>
 
@@ -457,7 +458,8 @@ PostgreSQL documentation
 
   <para>
    <application>pg_receivewal</application> will exit with status 0 when
-   terminated by the <systemitem>SIGINT</systemitem> signal.  (That is the
+   terminated by the <systemitem>SIGINT</systemitem> or
+   <systemitem>SIGTERM</systemitem> signal.  (That is the
    normal way to end it.  Hence it is not an error.)  For fatal errors or
    other signals, the exit status will be nonzero.
   </para>
diff --git a/src/bin/pg_basebackup/pg_receivewal.c b/src/bin/pg_basebackup/pg_receivewal.c
index f064cff4ab..e2cf924017 100644
--- a/src/bin/pg_basebackup/pg_receivewal.c
+++ b/src/bin/pg_basebackup/pg_receivewal.c
@@ -673,13 +673,13 @@ StreamLog(void)
 }
 
 /*
- * When sigint is called, just tell the system to exit at the next possible
+ * When SIGINT/SIGTERM are caught, just tell the system to exit at the next possible
  * moment.
  */
 #ifndef WIN32
 
 static void
-sigint_handler(int signum)
+sigexit_handler(int signum)
 {
 	time_to_stop = true;
 }
@@ -932,7 +932,8 @@ main(int argc, char **argv)
 	 * if one is needed, in GetConnection.)
 	 */
 #ifndef WIN32
-	pqsignal(SIGINT, sigint_handler);
+	pqsignal(SIGINT, sigexit_handler);
+	pqsignal(SIGTERM, sigexit_handler);
 #endif
 
 	/*
diff --git a/src/bin/pg_basebackup/pg_recvlogical.c b/src/bin/pg_basebackup/pg_recvlogical.c
index 2a4c8b130a..363102cf85 100644
--- a/src/bin/pg_basebackup/pg_recvlogical.c
+++ b/src/bin/pg_basebackup/pg_recvlogical.c
@@ -650,11 +650,11 @@ error:
 #ifndef WIN32
 
 /*
- * When sigint is called, just tell the system to exit at the next possible
+ * When SIGINT/SIGTERM are caught, just tell the system to exit at the next possible
  * moment.
  */
 static void
-sigint_handler(int signum)
+sigexit_handler(int signum)
 {
 	time_to_abort = true;
 }
@@ -922,7 +922,8 @@ main(int argc, char **argv)
 	 * if one is needed, in GetConnection.)
 	 */
 #ifndef WIN32
-	pqsignal(SIGINT, sigint_handler);
+	pqsignal(SIGINT, sigexit_handler);
+	pqsignal(SIGTERM, sigexit_handler);
 	pqsignal(SIGHUP, sighup_handler);
 #endif
 
-- 
2.35.1


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