public inbox for [email protected]
help / color / mirror / Atom feedFrom: Amul Sul <[email protected]>
To: Robert Haas <[email protected]>
Cc: Chao Li <[email protected]>
Cc: Jakub Wartak <[email protected]>
Cc: PostgreSQL Hackers <[email protected]>
Subject: Re: pg_waldump: support decoding of WAL inside tarfile
Date: Tue, 27 Jan 2026 17:36:34 +0530
Message-ID: <CAAJ_b94=gtCeUKkGPUmPj_2SwHV+PiXQ8Mx-1RqfYj3pP3OwpA@mail.gmail.com> (raw)
In-Reply-To: <CA+Tgmob=3POOO8st-v-fCjKCKREQ=+gs5_PBQnoFeNBdERfuEg@mail.gmail.com>
References: <CAAJ_b94bqdWN3h2J-PzzzQ2Npbwct5ZQHggn_QoYGhC2rn-=WQ@mail.gmail.com>
<CAAJ_b97PQjE4kFD8Qk6UvtLrfPMixw1nxBz0OP5Z2WB2B-uMxQ@mail.gmail.com>
<CAAJ_b97JA8ehy_UDddrnGwDt9HG5NmJq8ATtmeMqo7YD-=tLyQ@mail.gmail.com>
<CA+TgmoZjhWDG_AR1i+L1yss-wbuWvxrdRwSdVUUUnVPrJV2CnQ@mail.gmail.com>
<CAAJ_b94Uh+b41LQG45bZFK+i62EVvv972LiGWWWuR64=-64rTQ@mail.gmail.com>
<CA+TgmobF5c7ZcZHdEhqwNxGDZzWG2bDtpRaDtoVELWX_VHs_1A@mail.gmail.com>
<CAAJ_b94gK1np8d1h-2c1YoCccGXr4zspTa-FC7X_bfXZNz=-DA@mail.gmail.com>
<CA+TgmoayDY5b+bP1vRRN7A3xOP-=+tK13B2C1g-Xm1j4WTrT9Q@mail.gmail.com>
<CAAJ_b97JAF+Zuoh2FBO79hVwLeaBPwsbXw-fY+313a7LfRQ-Bg@mail.gmail.com>
<CA+Tgmoardk4VuthHc23vov+AVkhq7eT0mFUs-2ctAnP1uiTaog@mail.gmail.com>
<CAAJ_b959x5VjmLJFmN78r_QohQuuj=fde11VbbAOHn5TzgEzng@mail.gmail.com>
<CAAJ_b97_N+0sipFyq80n0jX-nKcjcQEMOSTVg8DsqkHR8dW_Sw@mail.gmail.com>
<CAKZiRmyDk5KqovS9Ez3iFHd+p-TChSt2QTtWkwJ5Ya-+4gg21g@mail.gmail.com>
<CAAJ_b956a+e8-HNEpeJ60ByFv7XJRqECPu3B0dozv0ChMRTPbQ@mail.gmail.com>
<CAAJ_b94f6sUDWiZY90O-t7SWWeSK0nMWT7AsydKkpAL90m0oMQ@mail.gmail.com>
<[email protected]>
<CAAJ_b94SEcBVJcsp0Y1-YvLqZWBHPQH4FhRzSJfaH_ah_eL_FQ@mail.gmail.com>
<CAAJ_b97nn9denP2SAjuXyjwbd3is-VnZVSkiRMJ-5YNiKfO9MA@mail.gmail.com>
<CA+Tgmob_DB9QHDOxnP7a5Y0yJdeGqY8YNi+uK_811y7cN4mxYA@mail.gmail.com>
<CAAJ_b97VUiP-DbLNe-ddq64J_RiB4ZcPgAjHkJH-0dbzgjR++A@mail.gmail.com>
<CA+TgmoYMtcZBaqy9r59eDapaDy3WOdepkFFURu9MV-x-kxEbKg@mail.gmail.com>
<CAAJ_b95FOeW38gw-3BLmpdnTWHFimopTvf=eTObYUbTOC0x8qg@mail.gmail.com>
<CA+Tgmob=3POOO8st-v-fCjKCKREQ=+gs5_PBQnoFeNBdERfuEg@mail.gmail.com>
On Mon, Jan 26, 2026 at 10:52 PM Robert Haas <[email protected]> wrote:
>
> On Fri, Jan 23, 2026 at 7:27 AM Amul Sul <[email protected]> wrote:
> > Another option I previously considered was adding the filtration logic
> > inside the archive streamer itself. However, since the very first read
> > is required to calculate the WAL segment size, the filter check cannot
> > be performed immediately. However, we could send a signal to the
> > archive streamer via privateInfo (e.g., a read_any_wal or
> > skip_wal_check boolean flag) to disable the filtration check until the
> > size is calculated. But that approach isn't very elegant; if the first
> > WAL page we read belongs to a segment we actually want to skip, we
> > would still have to run the filter check and handle the skip/removal
> > logic outside of the streamer (i.e., inside init_archive_reader()).
> > This would result in performing the same filtration check in two
> > different places.
>
> I mean, I don't really buy this logic. If the information added to
> privateInfo is "here's the LSN before which you can remove stuff," and
> it starts out initialized to 0/0, then the read of the first WAL page
> causes no problem at all, because nothing is before 0/0. After it gets
> updated to some non-zero value, the next call to
> astreamer_waldump_content() can handle discarding any data we don't
> need.
>
> IMHO, the best argument for keeping things are is that in some cases,
> that decision might result in a bit of delay in discarding old data,
> but I don't think that really matters. I think all that we care about
> is the peak memory utilization of an operation, and I don't think that
> an explicit signaling system should increase that at all.
>
> That said, I'm certainly willing to consider other ideas about how
> this can work. However, I feel strongly that the logic needs to be not
> only correct, but clear and well-explained. Setting cur_wal to NULL to
> make the astreamer skip without adequate comments doesn't meet that
> standard. Maybe with some better comments it's all right, but frankly
> I'm a bit skeptical. Right now, you're using whether or not cur_wal is
> NULL as a signal to skip data or not skip data. How is that better
> than passing down the LSN and TLI that you want to read next and
> letting the astreamer figure out what to do itself? It's a signaling
> mechanism either way, but it seems a lot easier to figure out whether
> we always keep the LSN and TLI updated properly than to figure out
> whether cur_wal is always NULL at exactly the right times.
>
I am not sure how to calculate the LSN of the very first page it reads
at this point, since we don't have the segment size yet. Furthermore,
the previous implementation using the segment number as the hash key
was incorrect, as extracting the segment number and TLI is impossible
without knowing the segment size, IIUC.
In the attached version, I am using the WAL segment name as the hash
key, which is much more straightforward. I have rewritten
read_archive_wal_page(), and it looks much cleaner than before. The
logic to discard irrelevant WAL files is still within
get_archive_wal_entry. I added an explanation for setting cur_wal to
NULL, which is now handled in the separate function I mentioned
previously.
Kindly have a look at the attached version; let me know if you are
still not happy with the current approach for filtering/discarding
irrelevant WAL segments. It isn't much different from the previous
version, but I have tried to keep it in a separate routine for better
code readability, with comments to make it easier to understand. I
also added a comment for ArchivedWALFile.
I have included your patch (removing WalSegSz) to the attached patch
set as 0001; all my subsequent patches are now bumped by one.
Regards,
Amul
Attachments:
[application/octet-stream] v11-0001-Remove-file-level-global-WalSegSz.patch (4.6K, 2-v11-0001-Remove-file-level-global-WalSegSz.patch)
download | inline diff:
From 7a06dc03d198fd6776d5afba44d1ea16ee715699 Mon Sep 17 00:00:00 2001
From: Robert Haas <[email protected]>
Date: Fri, 16 Jan 2026 08:35:14 -0500
Subject: [PATCH v11 1/9] Remove file-level global WalSegSz.
It's better style to pass the value around to just the places that
need it. This makes it easier to determine whether the value is
always properly initialized before use.
---
src/bin/pg_waldump/pg_waldump.c | 37 +++++++++++++++++----------------
1 file changed, 19 insertions(+), 18 deletions(-)
diff --git a/src/bin/pg_waldump/pg_waldump.c b/src/bin/pg_waldump/pg_waldump.c
index aae655966ef..f3446385d6a 100644
--- a/src/bin/pg_waldump/pg_waldump.c
+++ b/src/bin/pg_waldump/pg_waldump.c
@@ -39,7 +39,6 @@
static const char *progname;
-static int WalSegSz;
static volatile sig_atomic_t time_to_stop = false;
static const RelFileLocator emptyRelFileLocator = {0, 0, 0};
@@ -203,11 +202,11 @@ open_file_in_directory(const char *directory, const char *fname)
/*
* Try to find fname in the given directory. Returns true if it is found,
* false otherwise. If fname is NULL, search the complete directory for any
- * file with a valid WAL file name. If file is successfully opened, set the
- * wal segment size.
+ * file with a valid WAL file name. If file is successfully opened, set
+ * *WaSegSz to the WAL segment size.
*/
static bool
-search_directory(const char *directory, const char *fname)
+search_directory(const char *directory, const char *fname, int *WalSegSz)
{
int fd = -1;
DIR *xldir;
@@ -249,17 +248,17 @@ search_directory(const char *directory, const char *fname)
{
XLogLongPageHeader longhdr = (XLogLongPageHeader) buf.data;
- WalSegSz = longhdr->xlp_seg_size;
-
- if (!IsValidWalSegSize(WalSegSz))
+ if (!IsValidWalSegSize(longhdr->xlp_seg_size))
{
pg_log_error(ngettext("invalid WAL segment size in WAL file \"%s\" (%d byte)",
"invalid WAL segment size in WAL file \"%s\" (%d bytes)",
- WalSegSz),
- fname, WalSegSz);
+ longhdr->xlp_seg_size),
+ fname, longhdr->xlp_seg_size);
pg_log_error_detail("The WAL segment size must be a power of two between 1 MB and 1 GB.");
exit(1);
}
+
+ *WalSegSz = longhdr->xlp_seg_size;
}
else if (r < 0)
pg_fatal("could not read file \"%s\": %m",
@@ -286,21 +285,22 @@ search_directory(const char *directory, const char *fname)
* XLOGDIR /
* $PGDATA / XLOGDIR /
*
- * The valid target directory is returned.
+ * The valid target directory is returned, and *WalSegSz is set to the
+ * size of the WAL segment found in that directory.
*/
static char *
-identify_target_directory(char *directory, char *fname)
+identify_target_directory(char *directory, char *fname, int *WalSegSz)
{
char fpath[MAXPGPATH];
if (directory != NULL)
{
- if (search_directory(directory, fname))
+ if (search_directory(directory, fname, WalSegSz))
return pg_strdup(directory);
/* directory / XLOGDIR */
snprintf(fpath, MAXPGPATH, "%s/%s", directory, XLOGDIR);
- if (search_directory(fpath, fname))
+ if (search_directory(fpath, fname, WalSegSz))
return pg_strdup(fpath);
}
else
@@ -308,10 +308,10 @@ identify_target_directory(char *directory, char *fname)
const char *datadir;
/* current directory */
- if (search_directory(".", fname))
+ if (search_directory(".", fname, WalSegSz))
return pg_strdup(".");
/* XLOGDIR */
- if (search_directory(XLOGDIR, fname))
+ if (search_directory(XLOGDIR, fname, WalSegSz))
return pg_strdup(XLOGDIR);
datadir = getenv("PGDATA");
@@ -319,7 +319,7 @@ identify_target_directory(char *directory, char *fname)
if (datadir != NULL)
{
snprintf(fpath, MAXPGPATH, "%s/%s", datadir, XLOGDIR);
- if (search_directory(fpath, fname))
+ if (search_directory(fpath, fname, WalSegSz))
return pg_strdup(fpath);
}
}
@@ -801,6 +801,7 @@ main(int argc, char **argv)
XLogRecPtr first_record;
char *waldir = NULL;
char *errormsg;
+ int WalSegSz;
static struct option long_options[] = {
{"bkp-details", no_argument, NULL, 'b'},
@@ -1127,7 +1128,7 @@ main(int argc, char **argv)
pg_fatal("could not open directory \"%s\": %m", waldir);
}
- waldir = identify_target_directory(waldir, fname);
+ waldir = identify_target_directory(waldir, fname, &WalSegSz);
fd = open_file_in_directory(waldir, fname);
if (fd < 0)
pg_fatal("could not open file \"%s\"", fname);
@@ -1189,7 +1190,7 @@ main(int argc, char **argv)
}
}
else
- waldir = identify_target_directory(waldir, NULL);
+ waldir = identify_target_directory(waldir, NULL, &WalSegSz);
/* we don't know what to print */
if (!XLogRecPtrIsValid(private.startptr))
--
2.47.1
[application/octet-stream] v11-0002-Refactor-pg_waldump-Move-some-declarations-to-ne.patch (2.2K, 3-v11-0002-Refactor-pg_waldump-Move-some-declarations-to-ne.patch)
download | inline diff:
From 1e6d7f2ba4550eaedd6eb0fdcf309db2637a6a38 Mon Sep 17 00:00:00 2001
From: Amul Sul <[email protected]>
Date: Thu, 22 Jan 2026 10:28:32 +0530
Subject: [PATCH v11 2/9] Refactor: pg_waldump: Move some declarations to new
pg_waldump.h
This change prepares for a second source file in this directory to
support reading WAL from tar files. Common structures, declarations,
and functions are being exported through this include file so
they can be used in both files.
---
src/bin/pg_waldump/pg_waldump.c | 9 +--------
src/bin/pg_waldump/pg_waldump.h | 25 +++++++++++++++++++++++++
2 files changed, 26 insertions(+), 8 deletions(-)
create mode 100644 src/bin/pg_waldump/pg_waldump.h
diff --git a/src/bin/pg_waldump/pg_waldump.c b/src/bin/pg_waldump/pg_waldump.c
index f3446385d6a..4b7411a6498 100644
--- a/src/bin/pg_waldump/pg_waldump.c
+++ b/src/bin/pg_waldump/pg_waldump.c
@@ -29,6 +29,7 @@
#include "common/logging.h"
#include "common/relpath.h"
#include "getopt_long.h"
+#include "pg_waldump.h"
#include "rmgrdesc.h"
#include "storage/bufpage.h"
@@ -43,14 +44,6 @@ static volatile sig_atomic_t time_to_stop = false;
static const RelFileLocator emptyRelFileLocator = {0, 0, 0};
-typedef struct XLogDumpPrivate
-{
- TimeLineID timeline;
- XLogRecPtr startptr;
- XLogRecPtr endptr;
- bool endptr_reached;
-} XLogDumpPrivate;
-
typedef struct XLogDumpConfig
{
/* display options */
diff --git a/src/bin/pg_waldump/pg_waldump.h b/src/bin/pg_waldump/pg_waldump.h
new file mode 100644
index 00000000000..b88543856e5
--- /dev/null
+++ b/src/bin/pg_waldump/pg_waldump.h
@@ -0,0 +1,25 @@
+/*-------------------------------------------------------------------------
+ *
+ * pg_waldump.h - decode and display WAL
+ *
+ * Copyright (c) 2026, PostgreSQL Global Development Group
+ *
+ * IDENTIFICATION
+ * src/bin/pg_waldump/pg_waldump.h
+ *-------------------------------------------------------------------------
+ */
+#ifndef PG_WALDUMP_H
+#define PG_WALDUMP_H
+
+#include "access/xlogdefs.h"
+
+/* Contains the necessary information to drive WAL decoding */
+typedef struct XLogDumpPrivate
+{
+ TimeLineID timeline;
+ XLogRecPtr startptr;
+ XLogRecPtr endptr;
+ bool endptr_reached;
+} XLogDumpPrivate;
+
+#endif /* end of PG_WALDUMP_H */
--
2.47.1
[application/octet-stream] v11-0003-Refactor-pg_waldump-Separate-logic-used-to-calcu.patch (2.4K, 4-v11-0003-Refactor-pg_waldump-Separate-logic-used-to-calcu.patch)
download | inline diff:
From 1ead3c07617cdf6357ea05296c5e81229c631564 Mon Sep 17 00:00:00 2001
From: Amul Sul <[email protected]>
Date: Thu, 22 Jan 2026 10:38:16 +0530
Subject: [PATCH v11 3/9] Refactor: pg_waldump: Separate logic used to
calculate the required read size.
This refactoring prepares the codebase for an upcoming patch that will
support reading WAL from tar files. The logic for calculating the
required read size has been updated to handle both normal WAL files
and WAL files located inside a tar archive.
---
src/bin/pg_waldump/pg_waldump.c | 43 +++++++++++++++++++++++----------
1 file changed, 30 insertions(+), 13 deletions(-)
diff --git a/src/bin/pg_waldump/pg_waldump.c b/src/bin/pg_waldump/pg_waldump.c
index 4b7411a6498..958a71a01cf 100644
--- a/src/bin/pg_waldump/pg_waldump.c
+++ b/src/bin/pg_waldump/pg_waldump.c
@@ -326,6 +326,32 @@ identify_target_directory(char *directory, char *fname, int *WalSegSz)
return NULL; /* not reached */
}
+/*
+ * Returns the size in bytes of the data to be read. Returns -1 if the end
+ * point has already been reached.
+ */
+static inline int
+required_read_len(XLogDumpPrivate *private, XLogRecPtr targetPagePtr,
+ int reqLen)
+{
+ int count = XLOG_BLCKSZ;
+
+ if (XLogRecPtrIsValid(private->endptr))
+ {
+ if (targetPagePtr + XLOG_BLCKSZ <= private->endptr)
+ count = XLOG_BLCKSZ;
+ else if (targetPagePtr + reqLen <= private->endptr)
+ count = private->endptr - targetPagePtr;
+ else
+ {
+ private->endptr_reached = true;
+ return -1;
+ }
+ }
+
+ return count;
+}
+
/* pg_waldump's XLogReaderRoutine->segment_open callback */
static void
WALDumpOpenSegment(XLogReaderState *state, XLogSegNo nextSegNo,
@@ -383,21 +409,12 @@ WALDumpReadPage(XLogReaderState *state, XLogRecPtr targetPagePtr, int reqLen,
XLogRecPtr targetPtr, char *readBuff)
{
XLogDumpPrivate *private = state->private_data;
- int count = XLOG_BLCKSZ;
+ int count = required_read_len(private, targetPagePtr, reqLen);
WALReadError errinfo;
- if (XLogRecPtrIsValid(private->endptr))
- {
- if (targetPagePtr + XLOG_BLCKSZ <= private->endptr)
- count = XLOG_BLCKSZ;
- else if (targetPagePtr + reqLen <= private->endptr)
- count = private->endptr - targetPagePtr;
- else
- {
- private->endptr_reached = true;
- return -1;
- }
- }
+ /* Bail out if the count to be read is not valid */
+ if (count < 0)
+ return -1;
if (!WALRead(state, readBuff, targetPagePtr, count, private->timeline,
&errinfo))
--
2.47.1
[application/octet-stream] v11-0004-Refactor-pg_waldump-Restructure-TAP-tests.patch (5.6K, 5-v11-0004-Refactor-pg_waldump-Restructure-TAP-tests.patch)
download | inline diff:
From 1230820381263aaf109abb142e1e613ca2bd0cc9 Mon Sep 17 00:00:00 2001
From: Amul Sul <[email protected]>
Date: Thu, 22 Jan 2026 11:06:05 +0530
Subject: [PATCH v11 4/9] Refactor: pg_waldump: Restructure TAP tests.
Restructured tests that do not have a WAL file argument to run within
a loop, facilitating their re-execution for decoding WAL from tar
archives.
== NOTE ==
This is not intended to be committed separately. It can be merged
with the next patch, which is the main patch implementing this
feature.
---
src/bin/pg_waldump/t/001_basic.pl | 123 ++++++++++++++++--------------
1 file changed, 67 insertions(+), 56 deletions(-)
diff --git a/src/bin/pg_waldump/t/001_basic.pl b/src/bin/pg_waldump/t/001_basic.pl
index 5db5d20136f..3288fadcf48 100644
--- a/src/bin/pg_waldump/t/001_basic.pl
+++ b/src/bin/pg_waldump/t/001_basic.pl
@@ -198,28 +198,6 @@ command_like(
],
qr/./,
'runs with start and end segment specified');
-command_fails_like(
- [ 'pg_waldump', '--path' => $node->data_dir ],
- qr/error: no start WAL location given/,
- 'path option requires start location');
-command_like(
- [
- 'pg_waldump',
- '--path' => $node->data_dir,
- '--start' => $start_lsn,
- '--end' => $end_lsn,
- ],
- qr/./,
- 'runs with path option and start and end locations');
-command_fails_like(
- [
- 'pg_waldump',
- '--path' => $node->data_dir,
- '--start' => $start_lsn,
- ],
- qr/error: error in WAL record at/,
- 'falling off the end of the WAL results in an error');
-
command_like(
[
'pg_waldump', '--quiet',
@@ -227,15 +205,6 @@ command_like(
],
qr/^$/,
'no output with --quiet option');
-command_fails_like(
- [
- 'pg_waldump', '--quiet',
- '--path' => $node->data_dir,
- '--start' => $start_lsn
- ],
- qr/error: error in WAL record at/,
- 'errors are shown with --quiet');
-
# Test for: Display a message that we're skipping data if `from`
# wasn't a pointer to the start of a record.
@@ -272,7 +241,6 @@ sub test_pg_waldump
my $result = IPC::Run::run [
'pg_waldump',
- '--path' => $node->data_dir,
'--start' => $start_lsn,
'--end' => $end_lsn,
@opts
@@ -288,38 +256,81 @@ sub test_pg_waldump
my @lines;
-@lines = test_pg_waldump;
-is(grep(!/^rmgr: \w/, @lines), 0, 'all output lines are rmgr lines');
+my @scenarios = (
+ {
+ 'path' => $node->data_dir
+ });
-@lines = test_pg_waldump('--limit' => 6);
-is(@lines, 6, 'limit option observed');
+for my $scenario (@scenarios)
+{
+ my $path = $scenario->{'path'};
-@lines = test_pg_waldump('--fullpage');
-is(grep(!/^rmgr:.*\bFPW\b/, @lines), 0, 'all output lines are FPW');
+ SKIP:
+ {
+ command_fails_like(
+ [ 'pg_waldump', '--path' => $path ],
+ qr/error: no start WAL location given/,
+ 'path option requires start location');
+ command_like(
+ [
+ 'pg_waldump',
+ '--path' => $path,
+ '--start' => $start_lsn,
+ '--end' => $end_lsn,
+ ],
+ qr/./,
+ 'runs with path option and start and end locations');
+ command_fails_like(
+ [
+ 'pg_waldump',
+ '--path' => $path,
+ '--start' => $start_lsn,
+ ],
+ qr/error: error in WAL record at/,
+ 'falling off the end of the WAL results in an error');
-@lines = test_pg_waldump('--stats');
-like($lines[0], qr/WAL statistics/, "statistics on stdout");
-is(grep(/^rmgr:/, @lines), 0, 'no rmgr lines output');
+ command_fails_like(
+ [
+ 'pg_waldump', '--quiet',
+ '--path' => $path,
+ '--start' => $start_lsn
+ ],
+ qr/error: error in WAL record at/,
+ 'errors are shown with --quiet');
-@lines = test_pg_waldump('--stats=record');
-like($lines[0], qr/WAL statistics/, "statistics on stdout");
-is(grep(/^rmgr:/, @lines), 0, 'no rmgr lines output');
+ @lines = test_pg_waldump('--path' => $path);
+ is(grep(!/^rmgr: \w/, @lines), 0, 'all output lines are rmgr lines');
-@lines = test_pg_waldump('--rmgr' => 'Btree');
-is(grep(!/^rmgr: Btree/, @lines), 0, 'only Btree lines');
+ @lines = test_pg_waldump('--path' => $path, '--limit' => 6);
+ is(@lines, 6, 'limit option observed');
-@lines = test_pg_waldump('--fork' => 'init');
-is(grep(!/fork init/, @lines), 0, 'only init fork lines');
+ @lines = test_pg_waldump('--path' => $path, '--fullpage');
+ is(grep(!/^rmgr:.*\bFPW\b/, @lines), 0, 'all output lines are FPW');
-@lines = test_pg_waldump(
- '--relation' => "$default_ts_oid/$postgres_db_oid/$rel_t1_oid");
-is(grep(!/rel $default_ts_oid\/$postgres_db_oid\/$rel_t1_oid/, @lines),
- 0, 'only lines for selected relation');
+ @lines = test_pg_waldump('--path' => $path, '--stats');
+ like($lines[0], qr/WAL statistics/, "statistics on stdout");
+ is(grep(/^rmgr:/, @lines), 0, 'no rmgr lines output');
-@lines = test_pg_waldump(
- '--relation' => "$default_ts_oid/$postgres_db_oid/$rel_i1a_oid",
- '--block' => 1);
-is(grep(!/\bblk 1\b/, @lines), 0, 'only lines for selected block');
+ @lines = test_pg_waldump('--path' => $path, '--stats=record');
+ like($lines[0], qr/WAL statistics/, "statistics on stdout");
+ is(grep(/^rmgr:/, @lines), 0, 'no rmgr lines output');
+ @lines = test_pg_waldump('--path' => $path, '--rmgr' => 'Btree');
+ is(grep(!/^rmgr: Btree/, @lines), 0, 'only Btree lines');
+
+ @lines = test_pg_waldump('--path' => $path, '--fork' => 'init');
+ is(grep(!/fork init/, @lines), 0, 'only init fork lines');
+
+ @lines = test_pg_waldump('--path' => $path,
+ '--relation' => "$default_ts_oid/$postgres_db_oid/$rel_t1_oid");
+ is(grep(!/rel $default_ts_oid\/$postgres_db_oid\/$rel_t1_oid/, @lines),
+ 0, 'only lines for selected relation');
+
+ @lines = test_pg_waldump('--path' => $path,
+ '--relation' => "$default_ts_oid/$postgres_db_oid/$rel_i1a_oid",
+ '--block' => 1);
+ is(grep(!/\bblk 1\b/, @lines), 0, 'only lines for selected block');
+ }
+}
done_testing();
--
2.47.1
[application/octet-stream] v11-0005-pg_waldump-Add-support-for-archived-WAL-decoding.patch (39.3K, 6-v11-0005-pg_waldump-Add-support-for-archived-WAL-decoding.patch)
download | inline diff:
From 60a31941765d31420e62b77dcc607973823521e7 Mon Sep 17 00:00:00 2001
From: Amul Sul <[email protected]>
Date: Tue, 27 Jan 2026 15:44:09 +0530
Subject: [PATCH v11 5/9] pg_waldump: Add support for archived WAL decoding.
pg_waldump can now accept the path to a tar archive containing WAL
files and decode them. This feature was added primarily for
pg_verifybackup, which previously disabled WAL parsing for
tar-formatted backups.
Note that this patch requires that the WAL files within the archive be
in sequential order; an error will be reported otherwise. The next
patch is planned to remove this restriction.
---
doc/src/sgml/ref/pg_waldump.sgml | 8 +-
src/bin/pg_waldump/Makefile | 7 +-
src/bin/pg_waldump/archive_waldump.c | 615 +++++++++++++++++++++++++++
src/bin/pg_waldump/meson.build | 4 +-
src/bin/pg_waldump/pg_waldump.c | 235 +++++++---
src/bin/pg_waldump/pg_waldump.h | 44 ++
src/bin/pg_waldump/t/001_basic.pl | 84 +++-
src/tools/pgindent/typedefs.list | 3 +
8 files changed, 925 insertions(+), 75 deletions(-)
create mode 100644 src/bin/pg_waldump/archive_waldump.c
diff --git a/doc/src/sgml/ref/pg_waldump.sgml b/doc/src/sgml/ref/pg_waldump.sgml
index ce23add5577..d004bb0f67e 100644
--- a/doc/src/sgml/ref/pg_waldump.sgml
+++ b/doc/src/sgml/ref/pg_waldump.sgml
@@ -141,13 +141,17 @@ PostgreSQL documentation
<term><option>--path=<replaceable>path</replaceable></option></term>
<listitem>
<para>
- Specifies a directory to search for WAL segment files or a
- directory with a <literal>pg_wal</literal> subdirectory that
+ Specifies a tar archive or a directory to search for WAL segment files
+ or a directory with a <literal>pg_wal</literal> subdirectory that
contains such files. The default is to search in the current
directory, the <literal>pg_wal</literal> subdirectory of the
current directory, and the <literal>pg_wal</literal> subdirectory
of <envar>PGDATA</envar>.
</para>
+ <para>
+ If a tar archive is provided, its WAL segment files must be in
+ sequential order; otherwise, an error will be reported.
+ </para>
</listitem>
</varlistentry>
diff --git a/src/bin/pg_waldump/Makefile b/src/bin/pg_waldump/Makefile
index 4c1ee649501..aabb87566a2 100644
--- a/src/bin/pg_waldump/Makefile
+++ b/src/bin/pg_waldump/Makefile
@@ -3,6 +3,9 @@
PGFILEDESC = "pg_waldump - decode and display WAL"
PGAPPICON=win32
+# make these available to TAP test scripts
+export TAR
+
subdir = src/bin/pg_waldump
top_builddir = ../../..
include $(top_builddir)/src/Makefile.global
@@ -10,13 +13,15 @@ include $(top_builddir)/src/Makefile.global
OBJS = \
$(RMGRDESCOBJS) \
$(WIN32RES) \
+ archive_waldump.o \
compat.o \
pg_waldump.o \
rmgrdesc.o \
xlogreader.o \
xlogstats.o
-override CPPFLAGS := -DFRONTEND $(CPPFLAGS)
+override CPPFLAGS := -DFRONTEND -I$(libpq_srcdir) $(CPPFLAGS)
+LDFLAGS_INTERNAL += -L$(top_builddir)/src/fe_utils -lpgfeutils
RMGRDESCSOURCES = $(sort $(notdir $(wildcard $(top_srcdir)/src/backend/access/rmgrdesc/*desc*.c)))
RMGRDESCOBJS = $(patsubst %.c,%.o,$(RMGRDESCSOURCES))
diff --git a/src/bin/pg_waldump/archive_waldump.c b/src/bin/pg_waldump/archive_waldump.c
new file mode 100644
index 00000000000..0b8352ff6e8
--- /dev/null
+++ b/src/bin/pg_waldump/archive_waldump.c
@@ -0,0 +1,615 @@
+/*-------------------------------------------------------------------------
+ *
+ * archive_waldump.c
+ * A generic facility for reading WAL data from tar archives via archive
+ * streamer.
+ *
+ * Portions Copyright (c) 2026, PostgreSQL Global Development Group
+ *
+ * IDENTIFICATION
+ * src/bin/pg_waldump/archive_waldump.c
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#include "postgres_fe.h"
+
+#include <unistd.h>
+
+#include "access/xlog_internal.h"
+#include "common/hashfn.h"
+#include "common/logging.h"
+#include "fe_utils/simple_list.h"
+#include "pg_waldump.h"
+
+/*
+ * How many bytes should we try to read from a file at once?
+ */
+#define READ_CHUNK_SIZE (128 * 1024)
+
+/*
+ * Hash entry representing a WAL segment retrieved from the archive.
+ *
+ * While WAL segments are typically read sequentially, individual entries
+ * maintain their own buffers for the following reasons:
+ *
+ * 1. Boundary Handling: The archive streamer provides a continuous byte
+ * stream. A single streaming chunk may contain the end of one WAL segment
+ * and the start of the next. Separate buffers allow us to easily
+ * partition and track these bytes by their respective segments.
+ *
+ * 2. Out-of-Order Support: Dedicated buffers simplify logic if segments
+ * are ever archived or retrieved out of sequence.
+ *
+ * To minimize the memory footprint, entries and their associated buffers are
+ * freed immediately once consumed. Since pg_waldump does not request the same
+ * bytes twice, a segment is discarded as soon as it moves past it.
+ */
+typedef struct ArchivedWALFile
+{
+ uint32 status; /* hash status */
+ const char *fname; /* hash key: WAL segment name */
+
+ StringInfo buf;
+
+ int total_read; /* total size of a WAL read from archive */
+} ArchivedWALFile;
+
+static uint32 hash_string_pointer(const char *s);
+#define SH_PREFIX ArchivedWAL
+#define SH_ELEMENT_TYPE ArchivedWALFile
+#define SH_KEY_TYPE const char *
+#define SH_KEY fname
+#define SH_HASH_KEY(tb, key) hash_string_pointer(key)
+#define SH_EQUAL(tb, a, b) (strcmp(a, b) == 0)
+#define SH_SCOPE static inline
+#define SH_RAW_ALLOCATOR pg_malloc0
+#define SH_DECLARE
+#define SH_DEFINE
+#include "lib/simplehash.h"
+
+typedef struct astreamer_waldump
+{
+ astreamer base;
+ XLogDumpPrivate *privateInfo;
+} astreamer_waldump;
+
+static ArchivedWALFile *get_archive_wal_entry(const char *fname,
+ XLogDumpPrivate *privateInfo,
+ int WalSegSz);
+static int read_archive_file(XLogDumpPrivate *privateInfo, Size count);
+
+static astreamer *astreamer_waldump_new(XLogDumpPrivate *privateInfo);
+static void astreamer_waldump_content(astreamer *streamer,
+ astreamer_member *member,
+ const char *data, int len,
+ astreamer_archive_context context);
+static void astreamer_waldump_finalize(astreamer *streamer);
+static void astreamer_waldump_free(astreamer *streamer);
+
+static bool member_is_wal_file(astreamer_waldump *mystreamer,
+ astreamer_member *member,
+ char **fname);
+
+static const astreamer_ops astreamer_waldump_ops = {
+ .content = astreamer_waldump_content,
+ .finalize = astreamer_waldump_finalize,
+ .free = astreamer_waldump_free
+};
+
+/*
+ * Returns true if the given file is a tar archive and outputs its compression
+ * algorithm.
+ */
+bool
+is_archive_file(const char *fname, pg_compress_algorithm *compression)
+{
+ int fname_len = strlen(fname);
+ pg_compress_algorithm compress_algo;
+
+ /* Now, check the compression type of the tar */
+ if (fname_len > 4 &&
+ strcmp(fname + fname_len - 4, ".tar") == 0)
+ compress_algo = PG_COMPRESSION_NONE;
+ else if (fname_len > 4 &&
+ strcmp(fname + fname_len - 4, ".tgz") == 0)
+ compress_algo = PG_COMPRESSION_GZIP;
+ else if (fname_len > 7 &&
+ strcmp(fname + fname_len - 7, ".tar.gz") == 0)
+ compress_algo = PG_COMPRESSION_GZIP;
+ else if (fname_len > 8 &&
+ strcmp(fname + fname_len - 8, ".tar.lz4") == 0)
+ compress_algo = PG_COMPRESSION_LZ4;
+ else if (fname_len > 8 &&
+ strcmp(fname + fname_len - 8, ".tar.zst") == 0)
+ compress_algo = PG_COMPRESSION_ZSTD;
+ else
+ return false;
+
+ *compression = compress_algo;
+
+ return true;
+}
+
+/*
+ * Initializes the tar archive reader, creates a hash table for WAL entries,
+ * checks for existing valid WAL segments in the archive file and retrieves the
+ * segment size, and sets up filters for relevant entries.
+ */
+void
+init_archive_reader(XLogDumpPrivate *privateInfo, const char *waldir,
+ int *WalSegSz, pg_compress_algorithm compression)
+{
+ int fd;
+ astreamer *streamer;
+ ArchivedWALFile *entry = NULL;
+ XLogLongPageHeader longhdr;
+
+ /* Open tar archive and store its file descriptor */
+ fd = open_file_in_directory(waldir, privateInfo->archive_name);
+
+ if (fd < 0)
+ pg_fatal("could not open file \"%s\"", privateInfo->archive_name);
+
+ privateInfo->archive_fd = fd;
+
+ streamer = astreamer_waldump_new(privateInfo);
+
+ /* Before that we must parse the tar archive. */
+ streamer = astreamer_tar_parser_new(streamer);
+
+ /* Before that we must decompress, if archive is compressed. */
+ if (compression == PG_COMPRESSION_GZIP)
+ streamer = astreamer_gzip_decompressor_new(streamer);
+ else if (compression == PG_COMPRESSION_LZ4)
+ streamer = astreamer_lz4_decompressor_new(streamer);
+ else if (compression == PG_COMPRESSION_ZSTD)
+ streamer = astreamer_zstd_decompressor_new(streamer);
+
+ privateInfo->archive_streamer = streamer;
+
+ /* Hash table storing WAL entries read from the archive */
+ privateInfo->archive_wal_htab = ArchivedWAL_create(16, NULL);
+
+ /*
+ * Verify that the archive contains valid WAL files and fetch WAL segment
+ * size
+ */
+ while (entry == NULL || entry->buf->len < XLOG_BLCKSZ)
+ {
+ if (read_archive_file(privateInfo, XLOG_BLCKSZ) == 0)
+ pg_fatal("could not find WAL in \"%s\" archive",
+ privateInfo->archive_name);
+
+ entry = privateInfo->cur_file;
+ }
+
+ /* Set WalSegSz if WAL data is successfully read */
+ longhdr = (XLogLongPageHeader) entry->buf->data;
+
+ if (!IsValidWalSegSize(longhdr->xlp_seg_size))
+ {
+ pg_log_error(ngettext("invalid WAL segment size in WAL file from archive \"%s\" (%d byte)",
+ "invalid WAL segment size in WAL file from archive \"%s\" (%d bytes)",
+ longhdr->xlp_seg_size),
+ privateInfo->archive_name, longhdr->xlp_seg_size);
+ pg_log_error_detail("The WAL segment size must be a power of two between 1 MB and 1 GB.");
+ exit(1);
+ }
+
+ *WalSegSz = longhdr->xlp_seg_size;
+
+ /*
+ * With the WAL segment size available, we can now initialize the
+ * dependent start and end segment numbers.
+ */
+ Assert(!XLogRecPtrIsInvalid(privateInfo->startptr));
+ XLByteToSeg(privateInfo->startptr, privateInfo->startSegNo, *WalSegSz);
+
+ if (XLogRecPtrIsInvalid(privateInfo->endptr))
+ privateInfo->endSegNo = UINT64_MAX;
+ else
+ XLByteToSeg(privateInfo->endptr, privateInfo->endSegNo, *WalSegSz);
+}
+
+/*
+ * Release the archive streamer chain and close the archive file.
+ */
+void
+free_archive_reader(XLogDumpPrivate *privateInfo)
+{
+ /*
+ * NB: Normally, astreamer_finalize() is called before astreamer_free() to
+ * flush any remaining buffered data or to ensure the end of the tar
+ * archive is reached. However, when decoding a WAL file, once we hit the
+ * end LSN, any remaining WAL data in the buffer or the tar archive's
+ * unreached end can be safely ignored.
+ */
+ astreamer_free(privateInfo->archive_streamer);
+
+ /* Close the file. */
+ if (close(privateInfo->archive_fd) != 0)
+ pg_log_error("could not close file \"%s\": %m",
+ privateInfo->archive_name);
+}
+
+/*
+ * Copies WAL data from astreamer to readBuff; if unavailable, fetches more
+ * from the tar archive via astreamer.
+ */
+int
+read_archive_wal_page(XLogDumpPrivate *privateInfo, XLogRecPtr targetPagePtr,
+ Size count, char *readBuff, int WalSegSz)
+{
+ char *p = readBuff;
+ Size nbytes = count;
+ XLogRecPtr recptr = targetPagePtr;
+ XLogSegNo segno;
+ char fname[MAXFNAMELEN];
+ ArchivedWALFile *entry;
+
+ /* Identify the segment and locate its entry in the archive hash */
+ XLByteToSeg(targetPagePtr, segno, WalSegSz);
+ XLogFileName(fname, privateInfo->timeline, segno, WalSegSz);
+ entry = get_archive_wal_entry(fname, privateInfo, WalSegSz);
+
+ while (nbytes > 0)
+ {
+ char *buf = entry->buf->data;
+ int bufLen = entry->buf->len;
+ XLogRecPtr endPtr;
+ XLogRecPtr startPtr;
+
+ /* Calculate the LSN range currently residing in the buffer */
+ XLogSegNoOffsetToRecPtr(segno, entry->total_read, WalSegSz, endPtr);
+ startPtr = endPtr - bufLen;
+
+ /*
+ * Copy the requested WAL record if it exists in the buffer.
+ */
+ if (bufLen > 0 && startPtr <= recptr && recptr < endPtr)
+ {
+ int copyBytes;
+ int offset = recptr - startPtr;
+
+ /*
+ * Given startPtr <= recptr < endPtr and a total buffer size
+ * 'bufLen', the offset (recptr - startPtr) will always be less
+ * than 'bufLen'.
+ */
+ Assert(offset < bufLen);
+
+ copyBytes = Min(nbytes, bufLen - offset);
+ memcpy(p, buf + offset, copyBytes);
+
+ /* Update state for read */
+ recptr += copyBytes;
+ nbytes -= copyBytes;
+ p += copyBytes;
+ }
+ else
+ {
+ /*
+ * pg_waldump may request to re-read the currently active page,
+ * but never a page older than the current one. Therefore, any
+ * fully consumed WAL data preceding the current page can be
+ * safely discarded.
+ */
+ resetStringInfo(entry->buf);
+
+ /*
+ * Push back the partial page data for the current page to the
+ * buffer, ensuring it remains full page available for re-reading
+ * if requested.
+ */
+ if (p > readBuff)
+ {
+ Assert((count - nbytes) > 0);
+ appendBinaryStringInfo(entry->buf, readBuff, count - nbytes);
+ }
+
+ /*
+ * Now, fetch more data; raise an error if it's not the current
+ * segment being read by the archive streamer or if reading of the
+ * archived file has finished.
+ */
+ if (privateInfo->cur_file != entry ||
+ read_archive_file(privateInfo, READ_CHUNK_SIZE) == 0)
+ pg_fatal("could not read file \"%s\" from archive \"%s\": read %lld of %lld",
+ fname, privateInfo->archive_name,
+ (long long int) count - nbytes,
+ (long long int) nbytes);
+ }
+ }
+
+ /*
+ * Should have either have successfully read all the requested bytes or
+ * reported a failure before this point.
+ */
+ Assert(nbytes == 0);
+
+ /*
+ * NB: We return the fixed value provided as input. Although we could
+ * return a boolean since we either successfully read the WAL page or
+ * raise an error, but the caller expects this value to be returned. The
+ * routine that reads WAL pages from the physical WAL file follows the
+ * same convention.
+ */
+ return count;
+}
+
+/*
+ * Clears the buffer of a WAL entry that is being ignored. This frees up memory
+ * and prevents the accumulation of irrelevant WAL data. Additionally,
+ * conditionally setting cur_file within privateinfo to NULL ensures the
+ * archive streamer skips unnecessary copy operations
+ */
+void
+free_archive_wal_entry(const char *fname, XLogDumpPrivate *privateInfo)
+{
+ ArchivedWALFile *entry;
+
+ entry = ArchivedWAL_lookup(privateInfo->archive_wal_htab, fname);
+
+ if (entry == NULL)
+ return;
+
+ /* Destroy the buffer */
+ destroyStringInfo(entry->buf);
+ entry->buf = NULL;
+
+ /* Set cur_file to NULL if it matches the entry being ignored */
+ if (privateInfo->cur_file == entry)
+ privateInfo->cur_file = NULL;
+
+ ArchivedWAL_delete_item(privateInfo->archive_wal_htab, entry);
+}
+
+/*
+ * Returns the archived WAL entry from the hash table if it exists. Otherwise,
+ * it invokes the routine to read the archived file, which then populates the
+ * entry in the hash table if that WAL exists in the archive.
+ */
+static ArchivedWALFile *
+get_archive_wal_entry(const char *fname, XLogDumpPrivate *privateInfo,
+ int WalSegSz)
+{
+ ArchivedWALFile *entry = NULL;
+ XLogSegNo segno;
+ TimeLineID timeline;
+
+ /* Search hash table */
+ entry = ArchivedWAL_lookup(privateInfo->archive_wal_htab, fname);
+
+ if (entry != NULL)
+ return entry;
+
+ /* Get segment number for faster comparison than string-based names */
+ XLogFromFileName(fname, &timeline, &segno, WalSegSz);
+
+ /* Needed WAL yet to be decoded from archive, do the same */
+ while (1)
+ {
+ XLogSegNo curSegNo;
+ TimeLineID curSegTimeline;
+
+ /* Fetch more data */
+ if (read_archive_file(privateInfo, READ_CHUNK_SIZE) == 0)
+ break; /* archive file ended */
+
+ /*
+ * Either, here for the first time, or the archived streamer is
+ * reading a non-WAL file or an irrelevant WAL file.
+ */
+ if (privateInfo->cur_file == NULL)
+ continue;
+
+ entry = privateInfo->cur_file;
+
+ /*
+ * Ignore if the timeline is different or the current segment is not
+ * the desired one.
+ */
+ XLogFromFileName(entry->fname, &curSegTimeline, &curSegNo, WalSegSz);
+ if (privateInfo->timeline != curSegTimeline ||
+ privateInfo->startSegNo > curSegNo ||
+ privateInfo->endSegNo < curSegNo ||
+ segno > curSegNo)
+ {
+ free_archive_wal_entry(entry->fname, privateInfo);
+ continue;
+ }
+
+ /* Found the required entry */
+ if (curSegNo == segno)
+ return entry;
+
+ /* WAL segments must be archived in order */
+ pg_log_error("WAL files are not archived in sequential order");
+ pg_log_error_detail("Expecting segment number " UINT64_FORMAT " but found " UINT64_FORMAT ".",
+ segno, curSegNo);
+ exit(1);
+ }
+
+ /* Requested WAL segment not found */
+ pg_fatal("could not find file \"%s\" in archive", fname);
+}
+
+/*
+ * Reads the archive file and passes it to the archive streamer for
+ * decompression.
+ */
+static int
+read_archive_file(XLogDumpPrivate *privateInfo, Size count)
+{
+ int rc;
+ char *buffer;
+
+ buffer = pg_malloc(READ_CHUNK_SIZE * sizeof(uint8));
+
+ rc = read(privateInfo->archive_fd, buffer, count);
+ if (rc < 0)
+ pg_fatal("could not read file \"%s\": %m",
+ privateInfo->archive_name);
+
+ /*
+ * Decompress (if required), and then parse the previously read contents
+ * of the tar file.
+ */
+ if (rc > 0)
+ astreamer_content(privateInfo->archive_streamer, NULL,
+ buffer, rc, ASTREAMER_UNKNOWN);
+ pg_free(buffer);
+
+ return rc;
+}
+
+/*
+ * Create an astreamer that can read WAL from a tar file.
+ */
+static astreamer *
+astreamer_waldump_new(XLogDumpPrivate *privateInfo)
+{
+ astreamer_waldump *streamer;
+
+ streamer = palloc0(sizeof(astreamer_waldump));
+ *((const astreamer_ops **) &streamer->base.bbs_ops) =
+ &astreamer_waldump_ops;
+
+ streamer->privateInfo = privateInfo;
+
+ return &streamer->base;
+}
+
+/*
+ * Main entry point of the archive streamer for reading WAL data from a tar
+ * file. If a member is identified as a valid WAL file, a hash entry is created
+ * for it, and its contents are copied into that entry's buffer, making them
+ * accessible to the decoding routine.
+ */
+static void
+astreamer_waldump_content(astreamer *streamer, astreamer_member *member,
+ const char *data, int len,
+ astreamer_archive_context context)
+{
+ astreamer_waldump *mystreamer = (astreamer_waldump *) streamer;
+ XLogDumpPrivate *privateInfo = mystreamer->privateInfo;
+
+ Assert(context != ASTREAMER_UNKNOWN);
+
+ switch (context)
+ {
+ case ASTREAMER_MEMBER_HEADER:
+ {
+ char *fname = NULL;
+ ArchivedWALFile *entry;
+ bool found;
+
+ pg_log_debug("reading \"%s\"", member->pathname);
+
+ if (!member_is_wal_file(mystreamer, member, &fname))
+ break;
+
+ entry = ArchivedWAL_insert(privateInfo->archive_wal_htab,
+ fname, &found);
+
+ /*
+ * Shouldn't happen, but if it does, simply ignore the
+ * duplicate WAL file.
+ */
+ if (found)
+ {
+ pg_log_warning("ignoring duplicate WAL file found in archive: \"%s\"",
+ member->pathname);
+ break;
+ }
+
+ entry->buf = makeStringInfo();
+ privateInfo->cur_file = entry;
+ }
+ break;
+
+ case ASTREAMER_MEMBER_CONTENTS:
+ if (privateInfo->cur_file)
+ {
+ appendBinaryStringInfo(privateInfo->cur_file->buf, data, len);
+ privateInfo->cur_file->total_read += len;
+ }
+ break;
+
+ case ASTREAMER_MEMBER_TRAILER:
+ privateInfo->cur_file = NULL;
+ break;
+
+ case ASTREAMER_ARCHIVE_TRAILER:
+ break;
+
+ default:
+ /* Shouldn't happen. */
+ pg_fatal("unexpected state while parsing tar file");
+ }
+}
+
+/*
+ * End-of-stream processing for an astreamer_waldump stream.
+ */
+static void
+astreamer_waldump_finalize(astreamer *streamer)
+{
+ Assert(streamer->bbs_next == NULL);
+}
+
+/*
+ * Free memory associated with a astreamer_waldump stream.
+ */
+static void
+astreamer_waldump_free(astreamer *streamer)
+{
+ Assert(streamer->bbs_next == NULL);
+ pfree(streamer);
+}
+
+/*
+ * Returns true if the archive member name matches the WAL naming format. If
+ * successful, it also outputs the WAL segment name.
+ */
+static bool
+member_is_wal_file(astreamer_waldump *mystreamer, astreamer_member *member,
+ char **fname)
+{
+ int pathlen;
+ char *filename;
+
+ /* We are only interested in normal files. */
+ if (member->is_directory || member->is_link)
+ return false;
+
+ pathlen = strlen(member->pathname);
+ if (pathlen < XLOG_FNAME_LEN)
+ return false;
+
+ /* WAL files from the top-level or pg_wal directory will be decoded */
+ if (pathlen > XLOG_FNAME_LEN &&
+ strncmp(member->pathname, XLOGDIR, strlen(XLOGDIR)) != 0)
+ return false;
+
+ /* WAL file could be with full path */
+ filename = member->pathname + (pathlen - XLOG_FNAME_LEN);
+ if (!IsXLogFileName(filename))
+ return false;
+
+ *fname = pnstrdup(filename, XLOG_FNAME_LEN);
+
+ return true;
+}
+
+/*
+ * Helper function for filemap hash table.
+ */
+static uint32
+hash_string_pointer(const char *s)
+{
+ unsigned char *ss = (unsigned char *) s;
+
+ return hash_bytes(ss, strlen(s));
+}
diff --git a/src/bin/pg_waldump/meson.build b/src/bin/pg_waldump/meson.build
index 633a9874bb5..a93bd947ca2 100644
--- a/src/bin/pg_waldump/meson.build
+++ b/src/bin/pg_waldump/meson.build
@@ -1,6 +1,7 @@
# Copyright (c) 2022-2026, PostgreSQL Global Development Group
pg_waldump_sources = files(
+ 'archive_waldump.c',
'compat.c',
'pg_waldump.c',
'rmgrdesc.c',
@@ -18,7 +19,7 @@ endif
pg_waldump = executable('pg_waldump',
pg_waldump_sources,
- dependencies: [frontend_code, lz4, zstd],
+ dependencies: [frontend_code, lz4, zstd, libpq],
c_args: ['-DFRONTEND'], # needed for xlogreader et al
kwargs: default_bin_args,
)
@@ -29,6 +30,7 @@ tests += {
'sd': meson.current_source_dir(),
'bd': meson.current_build_dir(),
'tap': {
+ 'env': {'TAR': tar.found() ? tar.full_path() : ''},
'tests': [
't/001_basic.pl',
't/002_save_fullpage.pl',
diff --git a/src/bin/pg_waldump/pg_waldump.c b/src/bin/pg_waldump/pg_waldump.c
index 958a71a01cf..3cd279caded 100644
--- a/src/bin/pg_waldump/pg_waldump.c
+++ b/src/bin/pg_waldump/pg_waldump.c
@@ -176,7 +176,7 @@ split_path(const char *path, char **dir, char **fname)
*
* return a read only fd
*/
-static int
+int
open_file_in_directory(const char *directory, const char *fname)
{
int fd = -1;
@@ -440,6 +440,63 @@ WALDumpReadPage(XLogReaderState *state, XLogRecPtr targetPagePtr, int reqLen,
return count;
}
+/*
+ * pg_waldump's XLogReaderRoutine->segment_open callback to support dumping WAL
+ * files from tar archives.
+ */
+static void
+TarWALDumpOpenSegment(XLogReaderState *state, XLogSegNo nextSegNo,
+ TimeLineID *tli_p)
+{
+ /* No action needed */
+}
+
+/*
+ * pg_waldump's XLogReaderRoutine->segment_close callback.
+ */
+static void
+TarWALDumpCloseSegment(XLogReaderState *state)
+{
+ /* No action needed */
+}
+
+/*
+ * pg_waldump's XLogReaderRoutine->page_read callback to support dumping WAL
+ * files from tar archives.
+ */
+static int
+TarWALDumpReadPage(XLogReaderState *state, XLogRecPtr targetPagePtr, int reqLen,
+ XLogRecPtr targetPtr, char *readBuff)
+{
+ XLogDumpPrivate *private = state->private_data;
+ int count = required_read_len(private, targetPagePtr, reqLen);
+ int WalSegSz = state->segcxt.ws_segsize;
+ XLogSegNo nextSegNo;
+
+ /* Bail out if the count to be read is not valid */
+ if (count < 0)
+ return -1;
+
+ /*
+ * If the target page is in a different segment, free the buffer space
+ * occupied by the previous segment data. Since pg_waldump never requests
+ * the same WAL bytes twice, moving to a new segment implies the previous
+ * buffer's data and that segment will not be needed again.
+ */
+ nextSegNo = state->seg.ws_segno;
+ if (!XLByteInSeg(targetPagePtr, nextSegNo, WalSegSz))
+ {
+ char fname[MAXFNAMELEN];
+
+ XLogFileName(fname, state->seg.ws_tli, nextSegNo, WalSegSz);
+ free_archive_wal_entry(fname, private);
+ }
+
+ /* Read the WAL page from the archive streamer */
+ return read_archive_wal_page(private, targetPagePtr, count, readBuff,
+ WalSegSz);
+}
+
/*
* Boolean to return whether the given WAL record matches a specific relation
* and optionally block.
@@ -777,8 +834,8 @@ usage(void)
printf(_(" -F, --fork=FORK only show records that modify blocks in fork FORK;\n"
" valid names are main, fsm, vm, init\n"));
printf(_(" -n, --limit=N number of records to display\n"));
- printf(_(" -p, --path=PATH directory in which to find WAL segment files or a\n"
- " directory with a ./pg_wal that contains such files\n"
+ printf(_(" -p, --path=PATH tar archive or a directory in which to find WAL segment files or\n"
+ " a directory with a ./pg_wal that contains such files\n"
" (default: current directory, ./pg_wal, $PGDATA/pg_wal)\n"));
printf(_(" -q, --quiet do not print any output, except for errors\n"));
printf(_(" -r, --rmgr=RMGR only show records generated by resource manager RMGR;\n"
@@ -810,8 +867,11 @@ main(int argc, char **argv)
XLogRecord *record;
XLogRecPtr first_record;
char *waldir = NULL;
+ char *walpath = NULL;
char *errormsg;
int WalSegSz;
+ bool is_archive = false;
+ pg_compress_algorithm compression;
static struct option long_options[] = {
{"bkp-details", no_argument, NULL, 'b'},
@@ -943,7 +1003,7 @@ main(int argc, char **argv)
}
break;
case 'p':
- waldir = pg_strdup(optarg);
+ walpath = pg_strdup(optarg);
break;
case 'q':
config.quiet = true;
@@ -1107,10 +1167,20 @@ main(int argc, char **argv)
goto bad_argument;
}
- if (waldir != NULL)
+ if (walpath != NULL)
{
+ /* validate path points to tar archive */
+ if (is_archive_file(walpath, &compression))
+ {
+ char *fname = NULL;
+
+ split_path(walpath, &waldir, &fname);
+
+ private.archive_name = fname;
+ is_archive = true;
+ }
/* validate path points to directory */
- if (!verify_directory(waldir))
+ else if (!verify_directory(walpath))
{
pg_log_error("could not open directory \"%s\": %m", waldir);
goto bad_argument;
@@ -1128,6 +1198,17 @@ main(int argc, char **argv)
int fd;
XLogSegNo segno;
+ /*
+ * If a tar archive is passed using the --path option, all other
+ * arguments become unnecessary.
+ */
+ if (is_archive)
+ {
+ pg_log_error("unnecessary command-line arguments specified with tar archive (first is \"%s\")",
+ argv[optind]);
+ goto bad_argument;
+ }
+
split_path(argv[optind], &directory, &fname);
if (waldir == NULL && directory != NULL)
@@ -1138,69 +1219,77 @@ main(int argc, char **argv)
pg_fatal("could not open directory \"%s\": %m", waldir);
}
- waldir = identify_target_directory(waldir, fname, &WalSegSz);
- fd = open_file_in_directory(waldir, fname);
- if (fd < 0)
- pg_fatal("could not open file \"%s\"", fname);
- close(fd);
-
- /* parse position from file */
- XLogFromFileName(fname, &private.timeline, &segno, WalSegSz);
-
- if (!XLogRecPtrIsValid(private.startptr))
- XLogSegNoOffsetToRecPtr(segno, 0, WalSegSz, private.startptr);
- else if (!XLByteInSeg(private.startptr, segno, WalSegSz))
+ if (fname != NULL && is_archive_file(fname, &compression))
{
- pg_log_error("start WAL location %X/%08X is not inside file \"%s\"",
- LSN_FORMAT_ARGS(private.startptr),
- fname);
- goto bad_argument;
+ private.archive_name = fname;
+ is_archive = true;
}
-
- /* no second file specified, set end position */
- if (!(optind + 1 < argc) && !XLogRecPtrIsValid(private.endptr))
- XLogSegNoOffsetToRecPtr(segno + 1, 0, WalSegSz, private.endptr);
-
- /* parse ENDSEG if passed */
- if (optind + 1 < argc)
+ else
{
- XLogSegNo endsegno;
-
- /* ignore directory, already have that */
- split_path(argv[optind + 1], &directory, &fname);
-
+ waldir = identify_target_directory(waldir, fname, &WalSegSz);
fd = open_file_in_directory(waldir, fname);
if (fd < 0)
pg_fatal("could not open file \"%s\"", fname);
close(fd);
/* parse position from file */
- XLogFromFileName(fname, &private.timeline, &endsegno, WalSegSz);
+ XLogFromFileName(fname, &private.timeline, &segno, WalSegSz);
- if (endsegno < segno)
- pg_fatal("ENDSEG %s is before STARTSEG %s",
- argv[optind + 1], argv[optind]);
+ if (!XLogRecPtrIsValid(private.startptr))
+ XLogSegNoOffsetToRecPtr(segno, 0, WalSegSz, private.startptr);
+ else if (!XLByteInSeg(private.startptr, segno, WalSegSz))
+ {
+ pg_log_error("start WAL location %X/%08X is not inside file \"%s\"",
+ LSN_FORMAT_ARGS(private.startptr),
+ fname);
+ goto bad_argument;
+ }
- if (!XLogRecPtrIsValid(private.endptr))
- XLogSegNoOffsetToRecPtr(endsegno + 1, 0, WalSegSz,
- private.endptr);
+ /* no second file specified, set end position */
+ if (!(optind + 1 < argc) && !XLogRecPtrIsValid(private.endptr))
+ XLogSegNoOffsetToRecPtr(segno + 1, 0, WalSegSz, private.endptr);
- /* set segno to endsegno for check of --end */
- segno = endsegno;
- }
+ /* parse ENDSEG if passed */
+ if (optind + 1 < argc)
+ {
+ XLogSegNo endsegno;
+ /* ignore directory, already have that */
+ split_path(argv[optind + 1], &directory, &fname);
- if (!XLByteInSeg(private.endptr, segno, WalSegSz) &&
- private.endptr != (segno + 1) * WalSegSz)
- {
- pg_log_error("end WAL location %X/%08X is not inside file \"%s\"",
- LSN_FORMAT_ARGS(private.endptr),
- argv[argc - 1]);
- goto bad_argument;
+ fd = open_file_in_directory(waldir, fname);
+ if (fd < 0)
+ pg_fatal("could not open file \"%s\"", fname);
+ close(fd);
+
+ /* parse position from file */
+ XLogFromFileName(fname, &private.timeline, &endsegno, WalSegSz);
+
+ if (endsegno < segno)
+ pg_fatal("ENDSEG %s is before STARTSEG %s",
+ argv[optind + 1], argv[optind]);
+
+ if (!XLogRecPtrIsValid(private.endptr))
+ XLogSegNoOffsetToRecPtr(endsegno + 1, 0, WalSegSz,
+ private.endptr);
+
+ /* set segno to endsegno for check of --end */
+ segno = endsegno;
+ }
+
+
+ if (!XLByteInSeg(private.endptr, segno, WalSegSz) &&
+ private.endptr != (segno + 1) * WalSegSz)
+ {
+ pg_log_error("end WAL location %X/%08X is not inside file \"%s\"",
+ LSN_FORMAT_ARGS(private.endptr),
+ argv[argc - 1]);
+ goto bad_argument;
+ }
}
}
- else
- waldir = identify_target_directory(waldir, NULL, &WalSegSz);
+ else if (!is_archive)
+ waldir = identify_target_directory(walpath, NULL, &WalSegSz);
/* we don't know what to print */
if (!XLogRecPtrIsValid(private.startptr))
@@ -1212,12 +1301,37 @@ main(int argc, char **argv)
/* done with argument parsing, do the actual work */
/* we have everything we need, start reading */
- xlogreader_state =
- XLogReaderAllocate(WalSegSz, waldir,
- XL_ROUTINE(.page_read = WALDumpReadPage,
- .segment_open = WALDumpOpenSegment,
- .segment_close = WALDumpCloseSegment),
- &private);
+ if (is_archive)
+ {
+ /*
+ * A NULL WAL directory indicates that the archive file is located in
+ * the current working directory of the pg_waldump execution
+ */
+ if (waldir == NULL)
+ waldir = pg_strdup(".");
+
+ /* Set up for reading tar file */
+ init_archive_reader(&private, waldir, &WalSegSz, compression);
+
+ /* Routine to decode WAL files in tar archive */
+ xlogreader_state =
+ XLogReaderAllocate(WalSegSz, waldir,
+ XL_ROUTINE(.page_read = TarWALDumpReadPage,
+ .segment_open = TarWALDumpOpenSegment,
+ .segment_close = TarWALDumpCloseSegment),
+ &private);
+ }
+ else
+ {
+ /* Routine to decode WAL files */
+ xlogreader_state =
+ XLogReaderAllocate(WalSegSz, waldir,
+ XL_ROUTINE(.page_read = WALDumpReadPage,
+ .segment_open = WALDumpOpenSegment,
+ .segment_close = WALDumpCloseSegment),
+ &private);
+ }
+
if (!xlogreader_state)
pg_fatal("out of memory while allocating a WAL reading processor");
@@ -1326,6 +1440,9 @@ main(int argc, char **argv)
XLogReaderFree(xlogreader_state);
+ if (is_archive)
+ free_archive_reader(&private);
+
return EXIT_SUCCESS;
bad_argument:
diff --git a/src/bin/pg_waldump/pg_waldump.h b/src/bin/pg_waldump/pg_waldump.h
index b88543856e5..e98a20152da 100644
--- a/src/bin/pg_waldump/pg_waldump.h
+++ b/src/bin/pg_waldump/pg_waldump.h
@@ -12,6 +12,11 @@
#define PG_WALDUMP_H
#include "access/xlogdefs.h"
+#include "fe_utils/astreamer.h"
+
+/* Forward declaration */
+struct ArchivedWALFile;
+struct ArchivedWAL_hash;
/* Contains the necessary information to drive WAL decoding */
typedef struct XLogDumpPrivate
@@ -20,6 +25,45 @@ typedef struct XLogDumpPrivate
XLogRecPtr startptr;
XLogRecPtr endptr;
bool endptr_reached;
+
+ /* Fields required to read WAL from archive */
+ char *archive_name; /* Tar archive name */
+ int archive_fd; /* File descriptor for the open tar file */
+
+ astreamer *archive_streamer;
+
+ /* What the archive streamer is currently reading */
+ struct ArchivedWALFile *cur_file;
+
+ /*
+ * Hash table of all WAL files that the archive stream has read, including
+ * the one currently in progress.
+ */
+ struct ArchivedWAL_hash *archive_wal_htab;
+
+ /*
+ * Although these values can be easily derived from startptr and endptr,
+ * doing so repeatedly for each archived member would be inefficient, as
+ * it would involve recalculating and filtering out irrelevant WAL
+ * segments.
+ */
+ XLogSegNo startSegNo;
+ XLogSegNo endSegNo;
} XLogDumpPrivate;
+extern int open_file_in_directory(const char *directory, const char *fname);
+
+extern bool is_archive_file(const char *fname,
+ pg_compress_algorithm *compression);
+extern void init_archive_reader(XLogDumpPrivate *privateInfo,
+ const char *waldir, int *WalSegSz,
+ pg_compress_algorithm compression);
+extern void free_archive_reader(XLogDumpPrivate *privateInfo);
+extern int read_archive_wal_page(XLogDumpPrivate *privateInfo,
+ XLogRecPtr targetPagePtr,
+ Size count, char *readBuff,
+ int WalSegSz);
+extern void free_archive_wal_entry(const char *fname,
+ XLogDumpPrivate *privateInfo);
+
#endif /* end of PG_WALDUMP_H */
diff --git a/src/bin/pg_waldump/t/001_basic.pl b/src/bin/pg_waldump/t/001_basic.pl
index 3288fadcf48..13567fbdba1 100644
--- a/src/bin/pg_waldump/t/001_basic.pl
+++ b/src/bin/pg_waldump/t/001_basic.pl
@@ -3,10 +3,13 @@
use strict;
use warnings FATAL => 'all';
+use Cwd;
use PostgreSQL::Test::Cluster;
use PostgreSQL::Test::Utils;
use Test::More;
+my $tar = $ENV{TAR};
+
program_help_ok('pg_waldump');
program_version_ok('pg_waldump');
program_options_handling_ok('pg_waldump');
@@ -235,7 +238,7 @@ command_like(
sub test_pg_waldump
{
local $Test::Builder::Level = $Test::Builder::Level + 1;
- my @opts = @_;
+ my ($path, @opts) = @_;
my ($stdout, $stderr);
@@ -243,6 +246,7 @@ sub test_pg_waldump
'pg_waldump',
'--start' => $start_lsn,
'--end' => $end_lsn,
+ '--path' => $path,
@opts
],
'>' => \$stdout,
@@ -254,11 +258,50 @@ sub test_pg_waldump
return @lines;
}
-my @lines;
+# Create a tar archive, sorting the file order
+sub generate_archive
+{
+ my ($archive, $directory, $compression_flags) = @_;
+
+ my @files;
+ opendir my $dh, $directory or die "opendir: $!";
+ while (my $entry = readdir $dh) {
+ # Skip '.' and '..'
+ next if $entry eq '.' || $entry eq '..';
+ push @files, $entry;
+ }
+ closedir $dh;
+
+ @files = sort @files;
+
+ # move into the WAL directory before archiving files
+ my $cwd = getcwd;
+ chdir($directory) || die "chdir: $!";
+ command_ok([$tar, $compression_flags, $archive, @files]);
+ chdir($cwd) || die "chdir: $!";
+}
+
+my $tmp_dir = PostgreSQL::Test::Utils::tempdir_short();
my @scenarios = (
{
- 'path' => $node->data_dir
+ 'path' => $node->data_dir,
+ 'is_archive' => 0,
+ 'enabled' => 1
+ },
+ {
+ 'path' => "$tmp_dir/pg_wal.tar",
+ 'compression_method' => 'none',
+ 'compression_flags' => '-cf',
+ 'is_archive' => 1,
+ 'enabled' => 1
+ },
+ {
+ 'path' => "$tmp_dir/pg_wal.tar.gz",
+ 'compression_method' => 'gzip',
+ 'compression_flags' => '-czf',
+ 'is_archive' => 1,
+ 'enabled' => check_pg_config("#define HAVE_LIBZ 1")
});
for my $scenario (@scenarios)
@@ -267,6 +310,19 @@ for my $scenario (@scenarios)
SKIP:
{
+ skip "tar command is not available", 3
+ if !defined $tar;
+ skip "$scenario->{'compression_method'} compression not supported by this build", 3
+ if !$scenario->{'enabled'} && $scenario->{'is_archive'};
+
+ # create pg_wal archive
+ if ($scenario->{'is_archive'})
+ {
+ generate_archive($path,
+ $node->data_dir . '/pg_wal',
+ $scenario->{'compression_flags'});
+ }
+
command_fails_like(
[ 'pg_waldump', '--path' => $path ],
qr/error: no start WAL location given/,
@@ -298,38 +354,42 @@ for my $scenario (@scenarios)
qr/error: error in WAL record at/,
'errors are shown with --quiet');
- @lines = test_pg_waldump('--path' => $path);
+ my @lines;
+ @lines = test_pg_waldump($path);
is(grep(!/^rmgr: \w/, @lines), 0, 'all output lines are rmgr lines');
- @lines = test_pg_waldump('--path' => $path, '--limit' => 6);
+ @lines = test_pg_waldump($path, '--limit' => 6);
is(@lines, 6, 'limit option observed');
- @lines = test_pg_waldump('--path' => $path, '--fullpage');
+ @lines = test_pg_waldump($path, '--fullpage');
is(grep(!/^rmgr:.*\bFPW\b/, @lines), 0, 'all output lines are FPW');
- @lines = test_pg_waldump('--path' => $path, '--stats');
+ @lines = test_pg_waldump($path, '--stats');
like($lines[0], qr/WAL statistics/, "statistics on stdout");
is(grep(/^rmgr:/, @lines), 0, 'no rmgr lines output');
- @lines = test_pg_waldump('--path' => $path, '--stats=record');
+ @lines = test_pg_waldump($path, '--stats=record');
like($lines[0], qr/WAL statistics/, "statistics on stdout");
is(grep(/^rmgr:/, @lines), 0, 'no rmgr lines output');
- @lines = test_pg_waldump('--path' => $path, '--rmgr' => 'Btree');
+ @lines = test_pg_waldump($path, '--rmgr' => 'Btree');
is(grep(!/^rmgr: Btree/, @lines), 0, 'only Btree lines');
- @lines = test_pg_waldump('--path' => $path, '--fork' => 'init');
+ @lines = test_pg_waldump($path, '--fork' => 'init');
is(grep(!/fork init/, @lines), 0, 'only init fork lines');
- @lines = test_pg_waldump('--path' => $path,
+ @lines = test_pg_waldump($path,
'--relation' => "$default_ts_oid/$postgres_db_oid/$rel_t1_oid");
is(grep(!/rel $default_ts_oid\/$postgres_db_oid\/$rel_t1_oid/, @lines),
0, 'only lines for selected relation');
- @lines = test_pg_waldump('--path' => $path,
+ @lines = test_pg_waldump($path,
'--relation' => "$default_ts_oid/$postgres_db_oid/$rel_i1a_oid",
'--block' => 1);
is(grep(!/\bblk 1\b/, @lines), 0, 'only lines for selected block');
+
+ # Cleanup.
+ unlink $path if $scenario->{'is_archive'};
}
}
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index ddbe4c64971..c322001e076 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -144,6 +144,8 @@ ArchiveOpts
ArchiveShutdownCB
ArchiveStartupCB
ArchiveStreamState
+ArchivedWALFile
+ArchivedWAL_hash
ArchiverOutput
ArchiverStage
ArrayAnalyzeExtraData
@@ -3504,6 +3506,7 @@ astreamer_recovery_injector
astreamer_tar_archiver
astreamer_tar_parser
astreamer_verify
+astreamer_waldump
astreamer_zstd_frame
auth_password_hook_typ
autovac_table
--
2.47.1
[application/octet-stream] v11-0006-pg_waldump-Remove-the-restriction-on-the-order-o.patch (13.4K, 7-v11-0006-pg_waldump-Remove-the-restriction-on-the-order-o.patch)
download | inline diff:
From 1baf6ee367d5e73222a7f3be7afdce0b273d586e Mon Sep 17 00:00:00 2001
From: Amul Sul <[email protected]>
Date: Tue, 27 Jan 2026 15:38:34 +0530
Subject: [PATCH v11 6/9] pg_waldump: Remove the restriction on the order of
archived WAL files.
With previous patch, pg_waldump would stop decoding if WAL files were
not in the required sequence. With this patch, decoding will now
continue. Any WAL file that is out of order will be written to a
temporary location, from which it will be read later. Once a temporary
file has been read, it will be removed.
---
doc/src/sgml/ref/pg_waldump.sgml | 8 +-
src/bin/pg_waldump/archive_waldump.c | 173 ++++++++++++++++++++++++---
src/bin/pg_waldump/pg_waldump.c | 35 +++++-
src/bin/pg_waldump/pg_waldump.h | 3 +
src/bin/pg_waldump/t/001_basic.pl | 3 +-
5 files changed, 200 insertions(+), 22 deletions(-)
diff --git a/doc/src/sgml/ref/pg_waldump.sgml b/doc/src/sgml/ref/pg_waldump.sgml
index d004bb0f67e..27adf77755c 100644
--- a/doc/src/sgml/ref/pg_waldump.sgml
+++ b/doc/src/sgml/ref/pg_waldump.sgml
@@ -149,8 +149,12 @@ PostgreSQL documentation
of <envar>PGDATA</envar>.
</para>
<para>
- If a tar archive is provided, its WAL segment files must be in
- sequential order; otherwise, an error will be reported.
+ If a tar archive is provided and its WAL segment files are not in
+ sequential order, those files will be written to a temporary directory
+ named starting with <filename>waldump_tmp</filename>. This directory will be
+ created inside the directory specified by the <envar>TMPDIR</envar>
+ environment variable if it is set; otherwise, it will be created within
+ the same directory as the tar archive.
</para>
</listitem>
</varlistentry>
diff --git a/src/bin/pg_waldump/archive_waldump.c b/src/bin/pg_waldump/archive_waldump.c
index 0b8352ff6e8..b524fdad37f 100644
--- a/src/bin/pg_waldump/archive_waldump.c
+++ b/src/bin/pg_waldump/archive_waldump.c
@@ -17,6 +17,7 @@
#include <unistd.h>
#include "access/xlog_internal.h"
+#include "common/file_perm.h"
#include "common/hashfn.h"
#include "common/logging.h"
#include "fe_utils/simple_list.h"
@@ -27,6 +28,9 @@
*/
#define READ_CHUNK_SIZE (128 * 1024)
+/* Temporary exported WAL file directory */
+char *TmpWalSegDir = NULL;
+
/*
* Hash entry representing a WAL segment retrieved from the archive.
*
@@ -51,6 +55,7 @@ typedef struct ArchivedWALFile
const char *fname; /* hash key: WAL segment name */
StringInfo buf;
+ bool tmpfile_exists; /* spill file exists? */
int total_read; /* total size of a WAL read from archive */
} ArchivedWALFile;
@@ -78,6 +83,11 @@ static ArchivedWALFile *get_archive_wal_entry(const char *fname,
XLogDumpPrivate *privateInfo,
int WalSegSz);
static int read_archive_file(XLogDumpPrivate *privateInfo, Size count);
+static void setup_tmpwal_dir(const char *waldir);
+static void cleanup_tmpwal_dir_atexit(void);
+
+static FILE *prepare_tmp_write(const char *fname);
+static void perform_tmp_write(const char *fname, StringInfo buf, FILE *file);
static astreamer *astreamer_waldump_new(XLogDumpPrivate *privateInfo);
static void astreamer_waldump_content(astreamer *streamer,
@@ -134,7 +144,9 @@ is_archive_file(const char *fname, pg_compress_algorithm *compression)
/*
* Initializes the tar archive reader, creates a hash table for WAL entries,
* checks for existing valid WAL segments in the archive file and retrieves the
- * segment size, and sets up filters for relevant entries.
+ * segment size, and sets up filters for relevant entries. It also configures a
+ * temporary directory for out-of-order WAL data and registers an exit callback
+ * to clean up temporary files.
*/
void
init_archive_reader(XLogDumpPrivate *privateInfo, const char *waldir,
@@ -210,6 +222,13 @@ init_archive_reader(XLogDumpPrivate *privateInfo, const char *waldir,
privateInfo->endSegNo = UINT64_MAX;
else
XLByteToSeg(privateInfo->endptr, privateInfo->endSegNo, *WalSegSz);
+
+ /*
+ * Setup temporary directory to store WAL segments and set up an exit
+ * callback to remove it upon completion.
+ */
+ setup_tmpwal_dir(waldir);
+ atexit(cleanup_tmpwal_dir_atexit);
}
/*
@@ -358,6 +377,17 @@ free_archive_wal_entry(const char *fname, XLogDumpPrivate *privateInfo)
destroyStringInfo(entry->buf);
entry->buf = NULL;
+ /* Remove temporary file if any */
+ if (entry->tmpfile_exists)
+ {
+ char fpath[MAXPGPATH];
+
+ snprintf(fpath, MAXPGPATH, "%s/%s", TmpWalSegDir, fname);
+
+ if (unlink(fpath) == 0)
+ pg_log_debug("removed file \"%s\"", fpath);
+ }
+
/* Set cur_file to NULL if it matches the entry being ignored */
if (privateInfo->cur_file == entry)
privateInfo->cur_file = NULL;
@@ -369,6 +399,9 @@ free_archive_wal_entry(const char *fname, XLogDumpPrivate *privateInfo)
* Returns the archived WAL entry from the hash table if it exists. Otherwise,
* it invokes the routine to read the archived file, which then populates the
* entry in the hash table if that WAL exists in the archive.
+ * If the archive streamer happens to be reading a
+ * WAL from archive file that is not currently needed, that WAL data is written
+ * to a temporary file.
*/
static ArchivedWALFile *
get_archive_wal_entry(const char *fname, XLogDumpPrivate *privateInfo,
@@ -377,6 +410,7 @@ get_archive_wal_entry(const char *fname, XLogDumpPrivate *privateInfo,
ArchivedWALFile *entry = NULL;
XLogSegNo segno;
TimeLineID timeline;
+ FILE *write_fp = NULL;
/* Search hash table */
entry = ArchivedWAL_lookup(privateInfo->archive_wal_htab, fname);
@@ -393,19 +427,29 @@ get_archive_wal_entry(const char *fname, XLogDumpPrivate *privateInfo,
XLogSegNo curSegNo;
TimeLineID curSegTimeline;
+ /*
+ * The WAL file entry currently being processed may change during
+ * archive streamer execution. Therefore, maintain a local variable to
+ * reference the previous entry, ensuring that any remaining data in
+ * its buffer is successfully flushed to the temporary file before
+ * switching to the next WAL entry.
+ */
+ entry = privateInfo->cur_file;
+
/* Fetch more data */
- if (read_archive_file(privateInfo, READ_CHUNK_SIZE) == 0)
- break; /* archive file ended */
+ if (entry == NULL || entry->buf->len == 0)
+ {
+ if (read_archive_file(privateInfo, READ_CHUNK_SIZE) == 0)
+ break; /* archive file ended */
+ }
/*
* Either, here for the first time, or the archived streamer is
* reading a non-WAL file or an irrelevant WAL file.
*/
- if (privateInfo->cur_file == NULL)
+ if (entry == NULL)
continue;
- entry = privateInfo->cur_file;
-
/*
* Ignore if the timeline is different or the current segment is not
* the desired one.
@@ -413,8 +457,7 @@ get_archive_wal_entry(const char *fname, XLogDumpPrivate *privateInfo,
XLogFromFileName(entry->fname, &curSegTimeline, &curSegNo, WalSegSz);
if (privateInfo->timeline != curSegTimeline ||
privateInfo->startSegNo > curSegNo ||
- privateInfo->endSegNo < curSegNo ||
- segno > curSegNo)
+ privateInfo->endSegNo < curSegNo)
{
free_archive_wal_entry(entry->fname, privateInfo);
continue;
@@ -424,11 +467,32 @@ get_archive_wal_entry(const char *fname, XLogDumpPrivate *privateInfo,
if (curSegNo == segno)
return entry;
- /* WAL segments must be archived in order */
- pg_log_error("WAL files are not archived in sequential order");
- pg_log_error_detail("Expecting segment number " UINT64_FORMAT " but found " UINT64_FORMAT ".",
- segno, curSegNo);
- exit(1);
+ /*
+ * Archive streamer is currently reading a file that isn't the one
+ * asked for, but it's required in the future. It should be written to
+ * a temporary location for retrieval when needed.
+ */
+
+ /* Create a temporary file if one does not already exist */
+ if (!entry->tmpfile_exists)
+ {
+ write_fp = prepare_tmp_write(entry->fname);
+ entry->tmpfile_exists = true;
+ }
+
+ /* Flush data from the buffer to the file */
+ perform_tmp_write(entry->fname, entry->buf, write_fp);
+ resetStringInfo(entry->buf);
+
+ /*
+ * The change in the current segment entry indicates that the reading
+ * of this file has ended.
+ */
+ if (entry != privateInfo->cur_file && write_fp != NULL)
+ {
+ fclose(write_fp);
+ write_fp = NULL;
+ }
}
/* Requested WAL segment not found */
@@ -465,7 +529,88 @@ read_archive_file(XLogDumpPrivate *privateInfo, Size count)
}
/*
- * Create an astreamer that can read WAL from a tar file.
+ * Set up a temporary directory to temporarily store WAL segments.
+ */
+static void
+setup_tmpwal_dir(const char *waldir)
+{
+ char *template;
+
+ /*
+ * Use the directory specified by the TMPDIR environment variable. If it's
+ * not set, use the provided WAL directory to extract WAL file
+ * temporarily.
+ */
+ template = psprintf("%s/waldump_tmp-XXXXXX",
+ getenv("TMPDIR") ? getenv("TMPDIR") : waldir);
+ TmpWalSegDir = mkdtemp(template);
+
+ if (TmpWalSegDir == NULL)
+ pg_fatal("could not create directory \"%s\": %m", template);
+
+ canonicalize_path(TmpWalSegDir);
+
+ pg_log_debug("created directory \"%s\"", TmpWalSegDir);
+}
+
+/*
+ * Remove temporary directory at exit, if any.
+ */
+static void
+cleanup_tmpwal_dir_atexit(void)
+{
+ rmtree(TmpWalSegDir, true);
+}
+
+/*
+ * Create an empty placeholder file and return its handle.
+ */
+static FILE *
+prepare_tmp_write(const char *fname)
+{
+ char fpath[MAXPGPATH];
+ FILE *file;
+
+ snprintf(fpath, MAXPGPATH, "%s/%s", TmpWalSegDir, fname);
+
+ /* Create an empty placeholder */
+ file = fopen(fpath, PG_BINARY_W);
+ if (file == NULL)
+ pg_fatal("could not create file \"%s\": %m", fpath);
+
+#ifndef WIN32
+ if (chmod(fpath, pg_file_create_mode))
+ pg_fatal("could not set permissions on file \"%s\": %m",
+ fpath);
+#endif
+
+ pg_log_debug("temporarily exporting file \"%s\"", fpath);
+
+ return file;
+}
+
+/*
+ * Write buffer data to the given file handle.
+ */
+static void
+perform_tmp_write(const char *fname, StringInfo buf, FILE *file)
+{
+ Assert(file);
+
+ errno = 0;
+ if (buf->len > 0 && fwrite(buf->data, buf->len, 1, file) != 1)
+ {
+ /*
+ * If write didn't set errno, assume problem is no disk space
+ */
+ if (errno == 0)
+ errno = ENOSPC;
+ pg_fatal("could not write to file \"%s\": %m", fname);
+ }
+}
+
+/*
+ * Create an astreamer that can read WAL from tar file.
*/
static astreamer *
astreamer_waldump_new(XLogDumpPrivate *privateInfo)
diff --git a/src/bin/pg_waldump/pg_waldump.c b/src/bin/pg_waldump/pg_waldump.c
index 3cd279caded..6056a9c14e8 100644
--- a/src/bin/pg_waldump/pg_waldump.c
+++ b/src/bin/pg_waldump/pg_waldump.c
@@ -478,21 +478,46 @@ TarWALDumpReadPage(XLogReaderState *state, XLogRecPtr targetPagePtr, int reqLen,
return -1;
/*
- * If the target page is in a different segment, free the buffer space
- * occupied by the previous segment data. Since pg_waldump never requests
- * the same WAL bytes twice, moving to a new segment implies the previous
- * buffer's data and that segment will not be needed again.
+ * If the target page is in a different segment, free the buffer and/or
+ * temporary file disk space occupied by the previous segment's data.
+ * Since pg_waldump never requests the same WAL bytes twice, moving to a
+ * new segment implies the previous buffer's data and that segment will
+ * not be needed again.
+ *
+ * Afterward, check for the next required WAL segment's physical existence
+ * in the temporary directory first before invoking the archive streamer.
*/
nextSegNo = state->seg.ws_segno;
if (!XLByteInSeg(targetPagePtr, nextSegNo, WalSegSz))
{
char fname[MAXFNAMELEN];
+ if (state->seg.ws_file >= 0)
+ {
+ close(state->seg.ws_file);
+ state->seg.ws_file = -1;
+ }
+
XLogFileName(fname, state->seg.ws_tli, nextSegNo, WalSegSz);
free_archive_wal_entry(fname, private);
+
+ XLByteToSeg(targetPagePtr, nextSegNo, WalSegSz);
+ state->seg.ws_tli = private->timeline;
+ state->seg.ws_segno = nextSegNo;
+
+ /*
+ * If the next segment exists, open it and continue reading from there
+ */
+ XLogFileName(fname, state->seg.ws_tli, nextSegNo, WalSegSz);
+ state->seg.ws_file = open_file_in_directory(TmpWalSegDir, fname);
}
- /* Read the WAL page from the archive streamer */
+ /* Continue reading from the open WAL segment, if any */
+ if (state->seg.ws_file >= 0)
+ return WALDumpReadPage(state, targetPagePtr, count, targetPtr,
+ readBuff);
+
+ /* Otherwise, read the WAL page from the archive streamer */
return read_archive_wal_page(private, targetPagePtr, count, readBuff,
WalSegSz);
}
diff --git a/src/bin/pg_waldump/pg_waldump.h b/src/bin/pg_waldump/pg_waldump.h
index e98a20152da..13187802009 100644
--- a/src/bin/pg_waldump/pg_waldump.h
+++ b/src/bin/pg_waldump/pg_waldump.h
@@ -18,6 +18,9 @@
struct ArchivedWALFile;
struct ArchivedWAL_hash;
+/* Temporary directory */
+extern char *TmpWalSegDir;
+
/* Contains the necessary information to drive WAL decoding */
typedef struct XLogDumpPrivate
{
diff --git a/src/bin/pg_waldump/t/001_basic.pl b/src/bin/pg_waldump/t/001_basic.pl
index 13567fbdba1..68b0cdd29e5 100644
--- a/src/bin/pg_waldump/t/001_basic.pl
+++ b/src/bin/pg_waldump/t/001_basic.pl
@@ -7,6 +7,7 @@ use Cwd;
use PostgreSQL::Test::Cluster;
use PostgreSQL::Test::Utils;
use Test::More;
+use List::Util qw(shuffle);
my $tar = $ENV{TAR};
@@ -272,7 +273,7 @@ sub generate_archive
}
closedir $dh;
- @files = sort @files;
+ @files = shuffle @files;
# move into the WAL directory before archiving files
my $cwd = getcwd;
--
2.47.1
[application/octet-stream] v11-0007-pg_verifybackup-Delay-default-WAL-directory-prep.patch (1.7K, 8-v11-0007-pg_verifybackup-Delay-default-WAL-directory-prep.patch)
download | inline diff:
From a7d540d3dfde29630ed86103175c6293def31128 Mon Sep 17 00:00:00 2001
From: Amul Sul <[email protected]>
Date: Wed, 16 Jul 2025 14:47:43 +0530
Subject: [PATCH v11 7/9] pg_verifybackup: Delay default WAL directory
preparation.
We are not sure whether to parse WAL from a directory or an archive
until the backup format is known. Therefore, we delay preparing the
default WAL directory until the point of parsing. This delay is
harmless, as the WAL directory is not used elsewhere.
---
src/bin/pg_verifybackup/pg_verifybackup.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/src/bin/pg_verifybackup/pg_verifybackup.c b/src/bin/pg_verifybackup/pg_verifybackup.c
index f9f2d457f2f..ab01c4d003a 100644
--- a/src/bin/pg_verifybackup/pg_verifybackup.c
+++ b/src/bin/pg_verifybackup/pg_verifybackup.c
@@ -285,10 +285,6 @@ main(int argc, char **argv)
manifest_path = psprintf("%s/backup_manifest",
context.backup_directory);
- /* By default, look for the WAL in the backup directory, too. */
- if (wal_directory == NULL)
- wal_directory = psprintf("%s/pg_wal", context.backup_directory);
-
/*
* Try to read the manifest. We treat any errors encountered while parsing
* the manifest as fatal; there doesn't seem to be much point in trying to
@@ -368,6 +364,10 @@ main(int argc, char **argv)
if (context.format == 'p' && !context.skip_checksums)
verify_backup_checksums(&context);
+ /* By default, look for the WAL in the backup directory, too. */
+ if (wal_directory == NULL)
+ wal_directory = psprintf("%s/pg_wal", context.backup_directory);
+
/*
* Try to parse the required ranges of WAL records, unless we were told
* not to do so.
--
2.47.1
[application/octet-stream] v11-0008-pg_verifybackup-Rename-the-wal-directory-switch-.patch (5.9K, 9-v11-0008-pg_verifybackup-Rename-the-wal-directory-switch-.patch)
download | inline diff:
From 298182611c3e355cdb85ce48b725a1677096c2c7 Mon Sep 17 00:00:00 2001
From: Amul Sul <[email protected]>
Date: Tue, 25 Nov 2025 17:32:14 +0530
Subject: [PATCH v11 8/9] pg_verifybackup: Rename the wal-directory switch to
wal-path
With previous patches to pg_waldump can now decode WAL directly from
tar files. This means you'll be able to specify a tar archive path
instead of a traditional WAL directory.
To keep things consistent and more versatile, we should also
generalize the input switch for pg_verifybackup. It should accept
either a directory or a tar file path that contains WALs. This change
will also aligning it with the existing manifest-path switch naming.
== NOTE ==
The corresponding PO files require updating due to this change.
---
doc/src/sgml/ref/pg_verifybackup.sgml | 2 +-
src/bin/pg_verifybackup/pg_verifybackup.c | 22 +++++++++++-----------
src/bin/pg_verifybackup/t/007_wal.pl | 4 ++--
3 files changed, 14 insertions(+), 14 deletions(-)
diff --git a/doc/src/sgml/ref/pg_verifybackup.sgml b/doc/src/sgml/ref/pg_verifybackup.sgml
index 61c12975e4a..e9b8bfd51b1 100644
--- a/doc/src/sgml/ref/pg_verifybackup.sgml
+++ b/doc/src/sgml/ref/pg_verifybackup.sgml
@@ -261,7 +261,7 @@ PostgreSQL documentation
<varlistentry>
<term><option>-w <replaceable class="parameter">path</replaceable></option></term>
- <term><option>--wal-directory=<replaceable class="parameter">path</replaceable></option></term>
+ <term><option>--wal-path=<replaceable class="parameter">path</replaceable></option></term>
<listitem>
<para>
Try to parse WAL files stored in the specified directory, rather than
diff --git a/src/bin/pg_verifybackup/pg_verifybackup.c b/src/bin/pg_verifybackup/pg_verifybackup.c
index ab01c4d003a..3103d36f1b9 100644
--- a/src/bin/pg_verifybackup/pg_verifybackup.c
+++ b/src/bin/pg_verifybackup/pg_verifybackup.c
@@ -93,7 +93,7 @@ static void verify_file_checksum(verifier_context *context,
uint8 *buffer);
static void parse_required_wal(verifier_context *context,
char *pg_waldump_path,
- char *wal_directory);
+ char *wal_path);
static astreamer *create_archive_verifier(verifier_context *context,
char *archive_name,
Oid tblspc_oid,
@@ -126,7 +126,7 @@ main(int argc, char **argv)
{"progress", no_argument, NULL, 'P'},
{"quiet", no_argument, NULL, 'q'},
{"skip-checksums", no_argument, NULL, 's'},
- {"wal-directory", required_argument, NULL, 'w'},
+ {"wal-path", required_argument, NULL, 'w'},
{NULL, 0, NULL, 0}
};
@@ -135,7 +135,7 @@ main(int argc, char **argv)
char *manifest_path = NULL;
bool no_parse_wal = false;
bool quiet = false;
- char *wal_directory = NULL;
+ char *wal_path = NULL;
char *pg_waldump_path = NULL;
DIR *dir;
@@ -221,8 +221,8 @@ main(int argc, char **argv)
context.skip_checksums = true;
break;
case 'w':
- wal_directory = pstrdup(optarg);
- canonicalize_path(wal_directory);
+ wal_path = pstrdup(optarg);
+ canonicalize_path(wal_path);
break;
default:
/* getopt_long already emitted a complaint */
@@ -365,15 +365,15 @@ main(int argc, char **argv)
verify_backup_checksums(&context);
/* By default, look for the WAL in the backup directory, too. */
- if (wal_directory == NULL)
- wal_directory = psprintf("%s/pg_wal", context.backup_directory);
+ if (wal_path == NULL)
+ wal_path = psprintf("%s/pg_wal", context.backup_directory);
/*
* Try to parse the required ranges of WAL records, unless we were told
* not to do so.
*/
if (!no_parse_wal)
- parse_required_wal(&context, pg_waldump_path, wal_directory);
+ parse_required_wal(&context, pg_waldump_path, wal_path);
/*
* If everything looks OK, tell the user this, unless we were asked to
@@ -1198,7 +1198,7 @@ verify_file_checksum(verifier_context *context, manifest_file *m,
*/
static void
parse_required_wal(verifier_context *context, char *pg_waldump_path,
- char *wal_directory)
+ char *wal_path)
{
manifest_data *manifest = context->manifest;
manifest_wal_range *this_wal_range = manifest->first_wal_range;
@@ -1208,7 +1208,7 @@ parse_required_wal(verifier_context *context, char *pg_waldump_path,
char *pg_waldump_cmd;
pg_waldump_cmd = psprintf("\"%s\" --quiet --path=\"%s\" --timeline=%u --start=%X/%08X --end=%X/%08X\n",
- pg_waldump_path, wal_directory, this_wal_range->tli,
+ pg_waldump_path, wal_path, this_wal_range->tli,
LSN_FORMAT_ARGS(this_wal_range->start_lsn),
LSN_FORMAT_ARGS(this_wal_range->end_lsn));
fflush(NULL);
@@ -1376,7 +1376,7 @@ usage(void)
printf(_(" -P, --progress show progress information\n"));
printf(_(" -q, --quiet do not print any output, except for errors\n"));
printf(_(" -s, --skip-checksums skip checksum verification\n"));
- printf(_(" -w, --wal-directory=PATH use specified path for WAL files\n"));
+ printf(_(" -w, --wal-path=PATH use specified path for WAL files\n"));
printf(_(" -V, --version output version information, then exit\n"));
printf(_(" -?, --help show this help, then exit\n"));
printf(_("\nReport bugs to <%s>.\n"), PACKAGE_BUGREPORT);
diff --git a/src/bin/pg_verifybackup/t/007_wal.pl b/src/bin/pg_verifybackup/t/007_wal.pl
index 79087a1f6be..8ad2234453d 100644
--- a/src/bin/pg_verifybackup/t/007_wal.pl
+++ b/src/bin/pg_verifybackup/t/007_wal.pl
@@ -42,10 +42,10 @@ command_ok([ 'pg_verifybackup', '--no-parse-wal', $backup_path ],
command_ok(
[
'pg_verifybackup',
- '--wal-directory' => $relocated_pg_wal,
+ '--wal-path' => $relocated_pg_wal,
$backup_path
],
- '--wal-directory can be used to specify WAL directory');
+ '--wal-path can be used to specify WAL directory');
# Move directory back to original location.
rename($relocated_pg_wal, $original_pg_wal) || die "rename pg_wal back: $!";
--
2.47.1
[application/octet-stream] v11-0009-pg_verifybackup-enabled-WAL-parsing-for-tar-form.patch (9.9K, 10-v11-0009-pg_verifybackup-enabled-WAL-parsing-for-tar-form.patch)
download | inline diff:
From fc8da7124b665d32849e6eec401728ee58748788 Mon Sep 17 00:00:00 2001
From: Amul Sul <[email protected]>
Date: Tue, 25 Nov 2025 17:34:26 +0530
Subject: [PATCH v11 9/9] pg_verifybackup: enabled WAL parsing for tar-format
backup
Now that pg_waldump supports decoding from tar archives, we should
leverage this functionality to remove the previous restriction on WAL
parsing for tar-backed formats.
---
doc/src/sgml/ref/pg_verifybackup.sgml | 5 +-
src/bin/pg_verifybackup/pg_verifybackup.c | 66 +++++++++++++------
src/bin/pg_verifybackup/t/002_algorithm.pl | 4 --
src/bin/pg_verifybackup/t/003_corruption.pl | 4 +-
src/bin/pg_verifybackup/t/008_untar.pl | 5 +-
src/bin/pg_verifybackup/t/010_client_untar.pl | 5 +-
6 files changed, 50 insertions(+), 39 deletions(-)
diff --git a/doc/src/sgml/ref/pg_verifybackup.sgml b/doc/src/sgml/ref/pg_verifybackup.sgml
index e9b8bfd51b1..16b50b5a4df 100644
--- a/doc/src/sgml/ref/pg_verifybackup.sgml
+++ b/doc/src/sgml/ref/pg_verifybackup.sgml
@@ -36,10 +36,7 @@ PostgreSQL documentation
<literal>backup_manifest</literal> generated by the server at the time
of the backup. The backup may be stored either in the "plain" or the "tar"
format; this includes tar-format backups compressed with any algorithm
- supported by <application>pg_basebackup</application>. However, at present,
- <literal>WAL</literal> verification is supported only for plain-format
- backups. Therefore, if the backup is stored in tar-format, the
- <literal>-n, --no-parse-wal</literal> option should be used.
+ supported by <application>pg_basebackup</application>.
</para>
<para>
diff --git a/src/bin/pg_verifybackup/pg_verifybackup.c b/src/bin/pg_verifybackup/pg_verifybackup.c
index 3103d36f1b9..cc492728ae8 100644
--- a/src/bin/pg_verifybackup/pg_verifybackup.c
+++ b/src/bin/pg_verifybackup/pg_verifybackup.c
@@ -74,7 +74,9 @@ pg_noreturn static void report_manifest_error(JsonManifestParseContext *context,
const char *fmt,...)
pg_attribute_printf(2, 3);
-static void verify_tar_backup(verifier_context *context, DIR *dir);
+static void verify_tar_backup(verifier_context *context, DIR *dir,
+ char **base_archive_path,
+ char **wal_archive_path);
static void verify_plain_backup_directory(verifier_context *context,
char *relpath, char *fullpath,
DIR *dir);
@@ -83,7 +85,9 @@ static void verify_plain_backup_file(verifier_context *context, char *relpath,
static void verify_control_file(const char *controlpath,
uint64 manifest_system_identifier);
static void precheck_tar_backup_file(verifier_context *context, char *relpath,
- char *fullpath, SimplePtrList *tarfiles);
+ char *fullpath, SimplePtrList *tarfiles,
+ char **base_archive_path,
+ char **wal_archive_path);
static void verify_tar_file(verifier_context *context, char *relpath,
char *fullpath, astreamer *streamer);
static void report_extra_backup_files(verifier_context *context);
@@ -136,6 +140,8 @@ main(int argc, char **argv)
bool no_parse_wal = false;
bool quiet = false;
char *wal_path = NULL;
+ char *base_archive_path = NULL;
+ char *wal_archive_path = NULL;
char *pg_waldump_path = NULL;
DIR *dir;
@@ -327,17 +333,6 @@ main(int argc, char **argv)
pfree(path);
}
- /*
- * XXX: In the future, we should consider enhancing pg_waldump to read WAL
- * files from an archive.
- */
- if (!no_parse_wal && context.format == 't')
- {
- pg_log_error("pg_waldump cannot read tar files");
- pg_log_error_hint("You must use -n/--no-parse-wal when verifying a tar-format backup.");
- exit(1);
- }
-
/*
* Perform the appropriate type of verification appropriate based on the
* backup format. This will close 'dir'.
@@ -346,7 +341,7 @@ main(int argc, char **argv)
verify_plain_backup_directory(&context, NULL, context.backup_directory,
dir);
else
- verify_tar_backup(&context, dir);
+ verify_tar_backup(&context, dir, &base_archive_path, &wal_archive_path);
/*
* The "matched" flag should now be set on every entry in the hash table.
@@ -364,9 +359,28 @@ main(int argc, char **argv)
if (context.format == 'p' && !context.skip_checksums)
verify_backup_checksums(&context);
- /* By default, look for the WAL in the backup directory, too. */
+ /*
+ * By default, WAL files are expected to be found in the backup directory
+ * for plain-format backups. In the case of tar-format backups, if a
+ * separate WAL archive is not found, the WAL files are most likely
+ * included within the main data directory archive.
+ */
if (wal_path == NULL)
- wal_path = psprintf("%s/pg_wal", context.backup_directory);
+ {
+ if (context.format == 'p')
+ wal_path = psprintf("%s/pg_wal", context.backup_directory);
+ else if (wal_archive_path)
+ wal_path = wal_archive_path;
+ else if (base_archive_path)
+ wal_path = base_archive_path;
+ else
+ {
+ pg_log_error("WAL archive not found");
+ pg_log_error_hint("Specify the correct path using the option -w/--wal-path. "
+ "Or you must use -n/--no-parse-wal when verifying a tar-format backup.");
+ exit(1);
+ }
+ }
/*
* Try to parse the required ranges of WAL records, unless we were told
@@ -787,7 +801,8 @@ verify_control_file(const char *controlpath, uint64 manifest_system_identifier)
* close when we're done with it.
*/
static void
-verify_tar_backup(verifier_context *context, DIR *dir)
+verify_tar_backup(verifier_context *context, DIR *dir, char **base_archive_path,
+ char **wal_archive_path)
{
struct dirent *dirent;
SimplePtrList tarfiles = {NULL, NULL};
@@ -816,7 +831,8 @@ verify_tar_backup(verifier_context *context, DIR *dir)
char *fullpath;
fullpath = psprintf("%s/%s", context->backup_directory, filename);
- precheck_tar_backup_file(context, filename, fullpath, &tarfiles);
+ precheck_tar_backup_file(context, filename, fullpath, &tarfiles,
+ base_archive_path, wal_archive_path);
pfree(fullpath);
}
}
@@ -875,11 +891,13 @@ verify_tar_backup(verifier_context *context, DIR *dir)
*
* The arguments to this function are mostly the same as the
* verify_plain_backup_file. The additional argument outputs a list of valid
- * tar files.
+ * tar files, along with the full paths to the main archive and the WAL
+ * directory archive.
*/
static void
precheck_tar_backup_file(verifier_context *context, char *relpath,
- char *fullpath, SimplePtrList *tarfiles)
+ char *fullpath, SimplePtrList *tarfiles,
+ char **base_archive_path, char **wal_archive_path)
{
struct stat sb;
Oid tblspc_oid = InvalidOid;
@@ -918,9 +936,17 @@ precheck_tar_backup_file(verifier_context *context, char *relpath,
* extension such as .gz, .lz4, or .zst.
*/
if (strncmp("base", relpath, 4) == 0)
+ {
suffix = relpath + 4;
+
+ *base_archive_path = pstrdup(fullpath);
+ }
else if (strncmp("pg_wal", relpath, 6) == 0)
+ {
suffix = relpath + 6;
+
+ *wal_archive_path = pstrdup(fullpath);
+ }
else
{
/* Expected a <tablespaceoid>.tar file here. */
diff --git a/src/bin/pg_verifybackup/t/002_algorithm.pl b/src/bin/pg_verifybackup/t/002_algorithm.pl
index 0556191ec9d..edc515d5904 100644
--- a/src/bin/pg_verifybackup/t/002_algorithm.pl
+++ b/src/bin/pg_verifybackup/t/002_algorithm.pl
@@ -30,10 +30,6 @@ sub test_checksums
{
# Add switch to get a tar-format backup
push @backup, ('--format' => 'tar');
-
- # Add switch to skip WAL verification, which is not yet supported for
- # tar-format backups
- push @verify, ('--no-parse-wal');
}
# A backup with a bogus algorithm should fail.
diff --git a/src/bin/pg_verifybackup/t/003_corruption.pl b/src/bin/pg_verifybackup/t/003_corruption.pl
index b1d65b8aa0f..882d75d9dc2 100644
--- a/src/bin/pg_verifybackup/t/003_corruption.pl
+++ b/src/bin/pg_verifybackup/t/003_corruption.pl
@@ -193,10 +193,8 @@ for my $scenario (@scenario)
command_ok([ $tar, '-cf' => "$tar_backup_path/base.tar", '.' ]);
chdir($cwd) || die "chdir: $!";
- # Now check that the backup no longer verifies. We must use -n
- # here, because pg_waldump can't yet read WAL from a tarfile.
command_fails_like(
- [ 'pg_verifybackup', '--no-parse-wal', $tar_backup_path ],
+ [ 'pg_verifybackup', $tar_backup_path ],
$scenario->{'fails_like'},
"corrupt backup fails verification: $name");
diff --git a/src/bin/pg_verifybackup/t/008_untar.pl b/src/bin/pg_verifybackup/t/008_untar.pl
index ae67ae85a31..161c08c190d 100644
--- a/src/bin/pg_verifybackup/t/008_untar.pl
+++ b/src/bin/pg_verifybackup/t/008_untar.pl
@@ -47,7 +47,6 @@ my $tsoid = $primary->safe_psql(
SELECT oid FROM pg_tablespace WHERE spcname = 'regress_ts1'));
my $backup_path = $primary->backup_dir . '/server-backup';
-my $extract_path = $primary->backup_dir . '/extracted-backup';
my @test_configuration = (
{
@@ -123,14 +122,12 @@ for my $tc (@test_configuration)
# Verify tar backup.
$primary->command_ok(
[
- 'pg_verifybackup', '--no-parse-wal',
- '--exit-on-error', $backup_path,
+ 'pg_verifybackup', '--exit-on-error', $backup_path,
],
"verify backup, compression $method");
# Cleanup.
rmtree($backup_path);
- rmtree($extract_path);
}
}
diff --git a/src/bin/pg_verifybackup/t/010_client_untar.pl b/src/bin/pg_verifybackup/t/010_client_untar.pl
index 1ac7b5db75a..9670fbe4fda 100644
--- a/src/bin/pg_verifybackup/t/010_client_untar.pl
+++ b/src/bin/pg_verifybackup/t/010_client_untar.pl
@@ -32,7 +32,6 @@ print $jf $junk_data;
close $jf;
my $backup_path = $primary->backup_dir . '/client-backup';
-my $extract_path = $primary->backup_dir . '/extracted-backup';
my @test_configuration = (
{
@@ -137,13 +136,11 @@ for my $tc (@test_configuration)
# Verify tar backup.
$primary->command_ok(
[
- 'pg_verifybackup', '--no-parse-wal',
- '--exit-on-error', $backup_path,
+ 'pg_verifybackup', '--exit-on-error', $backup_path,
],
"verify backup, compression $method");
# Cleanup.
- rmtree($extract_path);
rmtree($backup_path);
}
}
--
2.47.1
view thread (8+ messages) latest in thread
reply
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Reply to all the recipients using the --to and --cc options:
reply via email
To: [email protected]
Cc: [email protected], [email protected], [email protected], [email protected], [email protected]
Subject: Re: pg_waldump: support decoding of WAL inside tarfile
In-Reply-To: <CAAJ_b94=gtCeUKkGPUmPj_2SwHV+PiXQ8Mx-1RqfYj3pP3OwpA@mail.gmail.com>
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
This inbox is served by agora; see mirroring instructions
for how to clone and mirror all data and code used for this inbox