From 41c184bc642b25f67fb1d8ee290f28805fa5a0b4 Mon Sep 17 00:00:00 2001
From: Fujii Masao <fujii@postgresql.org>
Date: Wed, 22 Jan 2020 11:56:34 +0900
Subject: [PATCH] Add GUC ignore_invalid_pages.
Detection of WAL records having references to invalid pages
during recovery causes PostgreSQL to raise a PANIC-level error,
aborting the recovery. Setting ignore_invalid_pages to on causes
the system to ignore those WAL records (but still report a warning),
and continue recovery. This behavior may cause crashes, data loss,
propagate or hide corruption, or other serious problems.
However, it may allow you to get past the PANIC-level error,
to finish the recovery, and to cause the server to start up.
Author: Fujii Masao
Reviewed-by: Michael Paquier
Discussion: https://www.postgresql.org/message-id/CAHGQGwHCK6f77yeZD4MHOnN+PaTf6XiJfEB+Ce7SksSHjeAWtg@mail.gmail.com
---
doc/src/sgml/config.sgml | 25 +++++++++++++++++++++++++
src/backend/access/transam/xlogutils.c | 9 +++++++--
src/backend/utils/misc/guc.c | 20 ++++++++++++++++++++
3 files changed, 52 insertions(+), 2 deletions(-)
diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml
index 3ccacd528b4..e07dc01e802 100644
--- a/doc/src/sgml/config.sgml
+++ b/doc/src/sgml/config.sgml
@@ -9950,6 +9950,31 @@ LOG: CleanUpLock: deleting: lock(0xb7acd844) id(24688,24696,0,0,0,1)
</listitem>
</varlistentry>
+ <varlistentry id="guc-ignore-invalid-pages" xreflabel="ignore_invalid_pages">
+ <term><varname>ignore_invalid_pages</varname> (<type>boolean</type>)
+ <indexterm>
+ <primary><varname>ignore_invalid_pages</varname> configuration parameter</primary>
+ </indexterm>
+ </term>
+ <listitem>
+ <para>
+ If set to <literal>off</literal> (the default), detection of
+ WAL records having references to invalid pages during
+ recovery causes <productname>PostgreSQL</productname> to
+ raise a PANIC-level error, aborting the recovery. Setting
+ <varname>ignore_invalid_pages</varname> to <literal>on</literal>
+ causes the system to ignore invalid page references in WAL records
+ (but still report a warning), and continue the recovery.
+ This behavior may <emphasis>cause crashes, data loss,
+ propagate or hide corruption, or other serious problems</emphasis>.
+ However, it may allow you to get past the PANIC-level error,
+ to finish the recovery, and to cause the server to start up.
+ The parameter can only be set at server start. It only has effect
+ during recovery or in standby mode.
+ </para>
+ </listitem>
+ </varlistentry>
+
<varlistentry id="guc-jit-debugging-support" xreflabel="jit_debugging_support">
<term><varname>jit_debugging_support</varname> (<type>boolean</type>)
<indexterm>
diff --git a/src/backend/access/transam/xlogutils.c b/src/backend/access/transam/xlogutils.c
index b55c3833703..b217ffa52ff 100644
--- a/src/backend/access/transam/xlogutils.c
+++ b/src/backend/access/transam/xlogutils.c
@@ -31,6 +31,9 @@
#include "utils/rel.h"
+/* GUC variable */
+bool ignore_invalid_pages = false;
+
/*
* During XLOG replay, we may see XLOG records for incremental updates of
* pages that no longer exist, because their relation was later dropped or
@@ -93,7 +96,8 @@ log_invalid_page(RelFileNode node, ForkNumber forkno, BlockNumber blkno,
if (reachedConsistency)
{
report_invalid_page(WARNING, node, forkno, blkno, present);
- elog(PANIC, "WAL contains references to invalid pages");
+ elog(ignore_invalid_pages ? WARNING : PANIC,
+ "WAL contains references to invalid pages");
}
/*
@@ -240,7 +244,8 @@ XLogCheckInvalidPages(void)
}
if (foundone)
- elog(PANIC, "WAL contains references to invalid pages");
+ elog(ignore_invalid_pages ? WARNING : PANIC,
+ "WAL contains references to invalid pages");
hash_destroy(invalid_page_tab);
invalid_page_tab = NULL;
diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c
index e44f71e9910..9f179a91295 100644
--- a/src/backend/utils/misc/guc.c
+++ b/src/backend/utils/misc/guc.c
@@ -123,6 +123,7 @@ extern int CommitSiblings;
extern char *default_tablespace;
extern char *temp_tablespaces;
extern bool ignore_checksum_failure;
+extern bool ignore_invalid_pages;
extern bool synchronize_seqscans;
#ifdef TRACE_SYNCSCAN
@@ -1172,6 +1173,25 @@ static struct config_bool ConfigureNamesBool[] =
false,
NULL, NULL, NULL
},
+ {
+ {"ignore_invalid_pages", PGC_POSTMASTER, DEVELOPER_OPTIONS,
+ gettext_noop("Continues recovery after an invalid pages failure."),
+ gettext_noop("Detection of WAL records having references to "
+ "invalid pages during recovery causes PostgreSQL to "
+ "raise a PANIC-level error, aborting the recovery. "
+ "Setting ignore_invalid_pages to true causes "
+ "the system to ignore invalid page references "
+ "in WAL records (but still report a warning), "
+ "and continue recovery. This behavior may cause "
+ "crashes, data loss, propagate or hide corruption, "
+ "or other serious problems. Only has an effect "
+ "during recovery or in standby mode."),
+ GUC_NOT_IN_SAMPLE
+ },
+ &ignore_invalid_pages,
+ false,
+ NULL, NULL, NULL
+ },
{
{"full_page_writes", PGC_SIGHUP, WAL_SETTINGS,
gettext_noop("Writes full pages to WAL when first modified after a checkpoint."),
--
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