From 4bfbb58801e9d2a0e0ab8320dd95bc850a0a397b Mon Sep 17 00:00:00 2001
From: Kyotaro Horiguchi <horikyota.ntt@gmail.com>
Date: Fri, 24 Dec 2021 12:52:07 +0900
Subject: [PATCH v3 1/2] Make a message on process termination more dscriptive

The message at process termination due to slot limit doesn't provide
the reason. In the major scenario the message is followed by another
message about slot invalidatation, which shows the detail for the
termination.  However the second message is missing if the slot is
temporary one.

Augment the first message with the reason same as the second message.

Backpatch through to 13 where the message was introduced.

Reported-by: Alex Enachioaie <alex@altmetric.com>
Author: Kyotaro Horiguchi <horikyota.ntt@gmail.com>
Reviewed-by: Ashutosh Bapat <ashutosh.bapat.oss@gmail.com>
Reviewed-by: Bharath Rupireddy <bharath.rupireddyforpostgres@gmail.com>
Discussion: https://www.postgresql.org/message-id/17327-89d0efa8b9ae6271%40postgresql.org
Backpatch-through: 13
---
 src/backend/replication/slot.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/src/backend/replication/slot.c b/src/backend/replication/slot.c
index 90ba9b417d..0ceac3a54d 100644
--- a/src/backend/replication/slot.c
+++ b/src/backend/replication/slot.c
@@ -1253,8 +1253,9 @@ InvalidatePossiblyObsoleteSlot(ReplicationSlot *s, XLogRecPtr oldestLSN,
 			if (last_signaled_pid != active_pid)
 			{
 				ereport(LOG,
-						(errmsg("terminating process %d to release replication slot \"%s\"",
-								active_pid, NameStr(slotname))));
+						(errmsg("terminating process %d to release replication slot \"%s\" because its restart_lsn %X/%X exceeds max_slot_wal_keep_size",
+								active_pid, NameStr(slotname),
+								LSN_FORMAT_ARGS(restart_lsn))));
 
 				(void) kill(active_pid, SIGTERM);
 				last_signaled_pid = active_pid;
-- 
2.27.0

