On 2021-Sep-03, Tom Lane wrote:
> "=?UTF-8?B?6JSh5qKm5aifKOeOiuS6jik=?=" <mengjuan....@alibaba-inc.com> writes:
> > I want to share a patch with you, in which I add a guc parameter
> > 'enable_send_stop' to enable set the value of SendStop in postmaster.c more
> > conveniently. SendStop enable postmaster to send SIGSTOP rather than
> > SIGQUIT to its children when some backend dumps core, and this variable is
> > originally set with -T parameter when start postgres, which is inconvenient
> > to control in some scenarios.
>
> TBH, I'd sooner rip out SendStop, and simplify the related postmaster
> logic.
I wrote a patch to do that in 2012, after this exchange:
https://postgr.es/m/1333124720-sup-6...@alvh.no-ip.org
I obviously doesn't apply at all anymore, but the thing that prevented
me from sending it was I couldn't find what the mentioned feature was
that would cause all backends to dump core at the time of a crash.
So it seemed to me that we would be ripping out a feature I had used,
with no replacement.
(It applies cleanly on top of 36b7e3da17bc.)
--
Álvaro Herrera 39°49'30"S 73°17'W — https://www.EnterpriseDB.com/
"Cuando no hay humildad las personas se degradan" (A. Christie)
>From d8198f6ad6c814c03c486bcce696fda912393405 Mon Sep 17 00:00:00 2001
From: Alvaro Herrera <alvhe...@alvh.no-ip.org>
Date: Wed, 23 May 2012 22:18:21 -0400
Subject: [PATCH] Remove -T postmaster option
This used to tell postmaster to send SIGSTOP instead of SIGQUIT in case
of trouble, with the intent of letting a hypothetical PG hacker collect
core dumps from every backends by attaching a debugger to them, one by
one. This has long been superseded by the ability of current operating
systems to dump core of several processes simultaneously.
---
src/backend/postmaster/postmaster.c | 52 +++++++++--------------------
1 file changed, 16 insertions(+), 36 deletions(-)
diff --git a/src/backend/postmaster/postmaster.c b/src/backend/postmaster/postmaster.c
index eeea933b19..bf6166caf4 100644
--- a/src/backend/postmaster/postmaster.c
+++ b/src/backend/postmaster/postmaster.c
@@ -187,7 +187,6 @@ static char ExtraOptions[MAXPGPATH];
* shared data structures. (Reinit is currently dead code, though.)
*/
static bool Reinit = true;
-static int SendStop = false;
/* still more option variables */
bool EnableSSL = false;
@@ -544,7 +543,7 @@ PostmasterMain(int argc, char *argv[])
* tcop/postgres.c (the option sets should not conflict) and with the
* common help() function in main/main.c.
*/
- while ((opt = getopt(argc, argv, "A:B:bc:C:D:d:EeFf:h:ijk:lN:nOo:Pp:r:S:sTt:W:-:")) != -1)
+ while ((opt = getopt(argc, argv, "A:B:bc:C:D:d:EeFf:h:ijk:lN:nOo:Pp:r:S:st:W:-:")) != -1)
{
switch (opt)
{
@@ -654,16 +653,6 @@ PostmasterMain(int argc, char *argv[])
SetConfigOption("log_statement_stats", "true", PGC_POSTMASTER, PGC_S_ARGV);
break;
- case 'T':
-
- /*
- * In the event that some backend dumps core, send SIGSTOP,
- * rather than SIGQUIT, to all its peers. This lets the wily
- * post_hacker collect core dumps from everyone.
- */
- SendStop = true;
- break;
-
case 't':
{
const char *tmp = get_stats_option_name(optarg);
@@ -2704,9 +2693,7 @@ HandleChildCrash(int pid, int exitstatus, const char *procname)
* to commit hara-kiri.
*
* SIGQUIT is the special signal that says exit without proc_exit
- * and let the user know what's going on. But if SendStop is set
- * (-s on command line), then we send SIGSTOP instead, so that we
- * can get core dumps from all backends by hand.
+ * and let the user know what's going on.
*
* We could exclude dead_end children here, but at least in the
* SIGSTOP case it seems better to include them.
@@ -2715,9 +2702,8 @@ HandleChildCrash(int pid, int exitstatus, const char *procname)
{
ereport(DEBUG2,
(errmsg_internal("sending %s to process %d",
- (SendStop ? "SIGSTOP" : "SIGQUIT"),
- (int) bp->pid)));
- signal_child(bp->pid, (SendStop ? SIGSTOP : SIGQUIT));
+ "SIGQUIT", (int) bp->pid)));
+ signal_child(bp->pid, SIGQUIT);
}
}
}
@@ -2729,9 +2715,8 @@ HandleChildCrash(int pid, int exitstatus, const char *procname)
{
ereport(DEBUG2,
(errmsg_internal("sending %s to process %d",
- (SendStop ? "SIGSTOP" : "SIGQUIT"),
- (int) StartupPID)));
- signal_child(StartupPID, (SendStop ? SIGSTOP : SIGQUIT));
+ "SIGQUIT", (int) StartupPID)));
+ signal_child(StartupPID, SIGQUIT);
}
/* Take care of the bgwriter too */
@@ -2741,9 +2726,8 @@ HandleChildCrash(int pid, int exitstatus, const char *procname)
{
ereport(DEBUG2,
(errmsg_internal("sending %s to process %d",
- (SendStop ? "SIGSTOP" : "SIGQUIT"),
- (int) BgWriterPID)));
- signal_child(BgWriterPID, (SendStop ? SIGSTOP : SIGQUIT));
+ "SIGQUIT", (int) BgWriterPID)));
+ signal_child(BgWriterPID, SIGQUIT);
}
/* Take care of the checkpointer too */
@@ -2753,9 +2737,8 @@ HandleChildCrash(int pid, int exitstatus, const char *procname)
{
ereport(DEBUG2,
(errmsg_internal("sending %s to process %d",
- (SendStop ? "SIGSTOP" : "SIGQUIT"),
- (int) CheckpointerPID)));
- signal_child(CheckpointerPID, (SendStop ? SIGSTOP : SIGQUIT));
+ "SIGQUIT", (int) CheckpointerPID)));
+ signal_child(CheckpointerPID, SIGQUIT);
}
/* Take care of the walwriter too */
@@ -2765,9 +2748,8 @@ HandleChildCrash(int pid, int exitstatus, const char *procname)
{
ereport(DEBUG2,
(errmsg_internal("sending %s to process %d",
- (SendStop ? "SIGSTOP" : "SIGQUIT"),
- (int) WalWriterPID)));
- signal_child(WalWriterPID, (SendStop ? SIGSTOP : SIGQUIT));
+ "SIGQUIT", (int) WalWriterPID)));
+ signal_child(WalWriterPID, SIGQUIT);
}
/* Take care of the walreceiver too */
@@ -2777,9 +2759,8 @@ HandleChildCrash(int pid, int exitstatus, const char *procname)
{
ereport(DEBUG2,
(errmsg_internal("sending %s to process %d",
- (SendStop ? "SIGSTOP" : "SIGQUIT"),
- (int) WalReceiverPID)));
- signal_child(WalReceiverPID, (SendStop ? SIGSTOP : SIGQUIT));
+ "SIGQUIT", (int) WalReceiverPID)));
+ signal_child(WalReceiverPID, SIGQUIT);
}
/* Take care of the autovacuum launcher too */
@@ -2789,9 +2770,8 @@ HandleChildCrash(int pid, int exitstatus, const char *procname)
{
ereport(DEBUG2,
(errmsg_internal("sending %s to process %d",
- (SendStop ? "SIGSTOP" : "SIGQUIT"),
- (int) AutoVacPID)));
- signal_child(AutoVacPID, (SendStop ? SIGSTOP : SIGQUIT));
+ "SIGQUIT", (int) AutoVacPID)));
+ signal_child(AutoVacPID, SIGQUIT);
}
/*
--
2.30.2
