Hi all,
I realized that pg_waldump doesn't show replication origin ID, LSN,
and timestamp of PREPARE TRANSACTION record. Commit 7b8a899bdeb
improved pg_waldump two years ago so that it reports the detail of
information of PREPARE TRANSACTION but ISTM that it overlooked showing
replication origin information. As far as I can see in the discussion
thread[1], there was no discussion on that. These are helpful when
diagnosing 2PC related issues on the subscriber side.
I've attached a patch to add replication origin information to
xact_desc_prepare().
Regards,
[1]
https://www.postgresql.org/message-id/CAHGQGwEvhASad4JJnCv%3D0dW2TJypZgW_Vpb-oZik2a3utCqcrA%40mail.gmail.com
--
Masahiko Sawada
EDB: https://www.enterprisedb.com/
From b37d5a8cd5b84eeb850bd7ddeb903024652f20d2 Mon Sep 17 00:00:00 2001
From: Masahiko Sawada <sawada.mshk@gmail.com>
Date: Mon, 6 Dec 2021 14:32:57 +0900
Subject: [PATCH] Make pg_waldump report replication origin ID, LSN, and
timestamp.
Commit 7b8a899bdeb made pg_waldump report the detail of information
about PREPARE TRANSACTION record, like global transaction
identifier. However, replication origin LSN and timestamp were not
reporeted. These are helpful when diagnosing 2PC-related troubles on
the subsciber side.
This commit makes xact_desc_prepare() report replication origin ID,
LSN, and timestamp.
---
src/backend/access/rmgrdesc/xactdesc.c | 12 ++++++++++--
1 file changed, 10 insertions(+), 2 deletions(-)
diff --git a/src/backend/access/rmgrdesc/xactdesc.c b/src/backend/access/rmgrdesc/xactdesc.c
index 4b0d10f073..ea3649d822 100644
--- a/src/backend/access/rmgrdesc/xactdesc.c
+++ b/src/backend/access/rmgrdesc/xactdesc.c
@@ -16,6 +16,7 @@
#include "access/transam.h"
#include "access/xact.h"
+#include "replication/origin.h"
#include "storage/sinval.h"
#include "storage/standbydefs.h"
#include "utils/timestamp.h"
@@ -329,7 +330,7 @@ xact_desc_abort(StringInfo buf, uint8 info, xl_xact_abort *xlrec)
}
static void
-xact_desc_prepare(StringInfo buf, uint8 info, xl_xact_prepare *xlrec)
+xact_desc_prepare(StringInfo buf, uint8 info, xl_xact_prepare *xlrec, RepOriginId origin_id)
{
xl_xact_parsed_prepare parsed;
@@ -345,6 +346,12 @@ xact_desc_prepare(StringInfo buf, uint8 info, xl_xact_prepare *xlrec)
standby_desc_invalidations(buf, parsed.nmsgs, parsed.msgs, parsed.dbId,
parsed.tsId, xlrec->initfileinval);
+
+ if (origin_id != InvalidRepOriginId)
+ appendStringInfo(buf, "; origin: node %u, lsn %X/%X, at %s",
+ origin_id,
+ LSN_FORMAT_ARGS(parsed.origin_lsn),
+ timestamptz_to_str(parsed.origin_timestamp));
}
static void
@@ -381,7 +388,8 @@ xact_desc(StringInfo buf, XLogReaderState *record)
{
xl_xact_prepare *xlrec = (xl_xact_prepare *) rec;
- xact_desc_prepare(buf, XLogRecGetInfo(record), xlrec);
+ xact_desc_prepare(buf, XLogRecGetInfo(record), xlrec,
+ XLogRecGetOrigin(record));
}
else if (info == XLOG_XACT_ASSIGNMENT)
{
--
2.24.3 (Apple Git-128)
