Commit Graph

26 Commits

Author SHA1 Message Date
Nathan Bossart c627d944e6 Add built-in ERROR handling for archive callbacks.
Presently, the archiver process restarts when an archive callback
ERRORs.  To avoid this, archive module authors can use sigsetjmp(),
manage a memory context, etc., but that requires a lot of extra
code that will likely look roughly the same between modules.  This
commit adds basic archive callback ERROR handling to pgarch.c so
that module authors won't ordinarily need to worry about this.
While this built-in handler attempts to clean up anything that an
archive module could conceivably have left behind, it is possible
that some modules are doing unexpected things that require
additional cleanup.  Module authors should be sure to do any extra
required cleanup in a PG_CATCH block within the archiving callback.

The archiving callback is now called in a short-lived memory
context that the archiver process resets between invocations.  If a
module requires longer-lived storage, it must maintain its own
memory context.

Thanks to these changes, the basic_archive module can be greatly
simplified.

Suggested-by: Andres Freund
Reviewed-by: Andres Freund, Yong Li
Discussion: https://postgr.es/m/20230217215624.GA3131134%40nathanxps13
2024-04-02 22:28:11 -05:00
Nathan Bossart 2c29e7fc95 Add macro for customizing an archiving WARNING message.
Presently, if an archive module's check_configured_cb callback
returns false, a generic WARNING message is emitted, which
unfortunately provides no actionable details about the reason why
the module is not configured.  This commit introduces a macro that
archive module authors can use to add a DETAIL line to this WARNING
message.

Co-authored-by: Tung Nguyen
Reviewed-by: Daniel Gustafsson, Álvaro Herrera
Discussion: https://postgr.es/m/4109578306242a7cd5661171647e11b2%40oss.nttdata.com
2024-03-04 15:41:42 -06:00
Bruce Momjian 29275b1d17 Update copyright for 2024
Reported-by: Michael Paquier

Discussion: https://postgr.es/m/ZZKTDPxBBMt3C0J9@paquier.xyz

Backpatch-through: 12
2024-01-03 20:49:05 -05:00
Michael Paquier 27f7f81e4c basic_archive: Fix comments related to NO_INSTALLCHECK
These comments incorrectly referred to shared_preload_libraries as being
required for the test to work.

Thinko in commit c68a183990.

Author: Bharath Rupireddy
Discussion: https://postgr.es/m/CALj2ACXpjFDiXf-L7AARQ4ppuxiDYSKZjyZb=wOa+cgg0zuWAw@mail.gmail.com
2023-12-20 08:39:54 +09:00
Tom Lane 0245f8db36 Pre-beta mechanical code beautification.
Run pgindent, pgperltidy, and reformat-dat-files.

This set of diffs is a bit larger than typical.  We've updated to
pg_bsd_indent 2.1.2, which properly indents variable declarations that
have multi-line initialization expressions (the continuation lines are
now indented one tab stop).  We've also updated to perltidy version
20230309 and changed some of its settings, which reduces its desire to
add whitespace to lines to make assignments etc. line up.  Going
forward, that should make for fewer random-seeming changes to existing
code.

Discussion: https://postgr.es/m/20230428092545.qfb3y5wcu4cm75ur@alvherre.pgsql
2023-05-19 17:24:48 -04:00
Michael Paquier 35739b87dc Redesign archive modules
A new callback named startup_cb, called shortly after a module is
loaded, is added.  This makes possible the initialization of any
additional state data required by a module.  This initial state data can
be saved in a ArchiveModuleState, that is now passed down to all the
callbacks that can be defined in a module.  With this design, it is
possible to have a per-module state, aimed at opening the door to the
support of more than one archive module.

The initialization of the callbacks is changed so as
_PG_archive_module_init() does not anymore give in input a
ArchiveModuleCallbacks that a module has to fill in with callback
definitions.  Instead, a module now needs to return a const
ArchiveModuleCallbacks.

All the structure and callback definitions of archive modules are moved
into their own header, named archive_module.h, from pgarch.h.
Command-based archiving follows the same line, with a new set of files
named shell_archive.{c,h}.

There are a few more items that are under discussion to improve the
design of archive modules, like the fact that basic_archive calls
sigsetjmp() by itself to define its own error handling flow.  These will
be adjusted later, the changes done here cover already a good portion
of what has been discussed.

Any modules created for v15 will need to be adjusted to this new
design.

Author: Nathan Bossart
Reviewed-by: Andres Freund
Discussion: https://postgr.es/m/20230130194810.6fztfgbn32e7qarj@awork3.anarazel.de
2023-02-17 14:26:42 +09:00
Andres Freund 30b789eafe Remove uses of AssertVariableIsOfType() obsoleted by f2b73c8
Author: Nathan Bossart <nathandbossart@gmail.com>
Discussion: https://postgr.es/m/20230208172705.GA451849@nathanxps13
2023-02-08 21:06:46 -08:00
Michael Paquier 9aeff092c0 Revert "Rename contrib module basic_archive to basic_wal_module"
This reverts commit 0ad3c60, as per feedback from Tom Lane, Robert Haas
and Andres Freund.  The new name used for the module had little
support.

This moves back to basic_archive as module name, and we will likely use
that as template for recovery modules, as well.

Discussion: https://postgr.es/m/CA+TgmoYG5uGOp7DGFT5gzC1kKFWGjkLSj_wOQxGhfMcvVEiKGA@mail.gmail.com
2023-01-26 09:13:39 +09:00
Michael Paquier 0ad3c60caf Rename contrib module basic_archive to basic_wal_module
This rename is in preparation for the introduction of recovery modules,
where basic_wal_module will be used as a base template for the set of
callbacks introduced.  The former name did not really reflect all that.

Author: Nathan Bossart
Discussion: https://postgr.es/m/20221227192449.GA3672473@nathanxps13
2023-01-25 14:36:51 +09:00
Michael Paquier 2f31f405e1 Constify the arguments of copydir.h functions
This makes sure that the internal logic of these functions does not
attempt to change the value of the arguments constified, and it removes
one unconstify() in basic_archive.c.

Author: Nathan Bossart
Reviewed-by: Andrew Dunstan, Peter Eisentraut
Discussion: https://postgr.es/m/20230114231126.GA2580330@nathanxps13
2023-01-18 08:55:26 +09:00
Bruce Momjian c8e1ba736b Update copyright for 2023
Backpatch-through: 11
2023-01-02 15:00:37 -05:00
Andrew Dunstan 8284cf5f74 Add copyright notices to meson files
Discussion: https://postgr.es/m/222b43a5-2fb3-2c1b-9cd0-375d376c8246@dunslane.net
2022-12-20 07:54:39 -05:00
Andres Freund 3f0e786ccb meson: Add 'running' test setup, as a replacement for installcheck
To run all tests that support running against existing server:
$ meson test --setup running

To run just the main pg_regress tests against existing server:
$ meson test --setup running regress-running/regress

To ensure the 'running' setup continues to work, test it as part of the
freebsd CI task.

Discussion: https://postgr.es/m/CAH2-Wz=XDQcmLoo7RR_i6FKQdDmcyb9q5gStnfuuQXrOGhB2sQ@mail.gmail.com
2022-12-07 12:13:35 -08:00
Michael Paquier c68a183990 Fix calculation related to temporary WAL segment name in basic_archive
The file name used for its temporary destination, before renaming it to
the real deal, has been using a microseconds in a timestamp aimed to be
originally in milli-seconds.  This is harmless as this is aimed at being
a safeguard against name collisions (note MyProcPid in the name), but
let's be correct with the maths.

While on it, add a note in the module's makefile to document why
installcheck is not supported.

Author: Nathan Bossart
Reviewed-by: Bharath Rupireddy
Discussion: https://postgr.es/m/20221014044106.GA1673343@nathanxps13
Backpatch-through: 15
2022-10-17 11:40:14 +09:00
Andres Freund 902ab2fcef meson: Add windows resource files
The generated resource files aren't exactly the same ones as the old
buildsystems generate. Previously "InternalName" and "OriginalFileName" were
mostly wrong / not set (despite being required), but that was hard to fix in
at least the make build. Additionally, the meson build falls back to a
"auto-generated" description when not set, and doesn't set it in a few cases -
unlikely that anybody looks at these descriptions in detail.

Author: Andres Freund <andres@anarazel.de>
Author: Nazir Bilal Yavuz <byavuz81@gmail.com>
Reviewed-by: Peter Eisentraut <peter.eisentraut@enterprisedb.com>
2022-10-05 09:56:05 -07:00
Andres Freund e6927270cd meson: Add initial version of meson based build system
Autoconf is showing its age, fewer and fewer contributors know how to wrangle
it. Recursive make has a lot of hard to resolve dependency issues and slow
incremental rebuilds. Our home-grown MSVC build system is hard to maintain for
developers not using Windows and runs tests serially. While these and other
issues could individually be addressed with incremental improvements, together
they seem best addressed by moving to a more modern build system.

After evaluating different build system choices, we chose to use meson, to a
good degree based on the adoption by other open source projects.

We decided that it's more realistic to commit a relatively early version of
the new build system and mature it in tree.

This commit adds an initial version of a meson based build system. It supports
building postgres on at least AIX, FreeBSD, Linux, macOS, NetBSD, OpenBSD,
Solaris and Windows (however only gcc is supported on aix, solaris). For
Windows/MSVC postgres can now be built with ninja (faster, particularly for
incremental builds) and msbuild (supporting the visual studio GUI, but
building slower).

Several aspects (e.g. Windows rc file generation, PGXS compatibility, LLVM
bitcode generation, documentation adjustments) are done in subsequent commits
requiring further review. Other aspects (e.g. not installing test-only
extensions) are not yet addressed.

When building on Windows with msbuild, builds are slower when using a visual
studio version older than 2019, because those versions do not support
MultiToolTask, required by meson for intra-target parallelism.

The plan is to remove the MSVC specific build system in src/tools/msvc soon
after reaching feature parity. However, we're not planning to remove the
autoconf/make build system in the near future. Likely we're going to keep at
least the parts required for PGXS to keep working around until all supported
versions build with meson.

Some initial help for postgres developers is at
https://wiki.postgresql.org/wiki/Meson

With contributions from Thomas Munro, John Naylor, Stone Tickle and others.

Author: Andres Freund <andres@anarazel.de>
Author: Nazir Bilal Yavuz <byavuz81@gmail.com>
Author: Peter Eisentraut <peter@eisentraut.org>
Reviewed-By: Peter Eisentraut <peter.eisentraut@enterprisedb.com>
Discussion: https://postgr.es/m/20211012083721.hvixq4pnh2pixr3j@alap3.anarazel.de
2022-09-21 22:37:17 -07:00
Michael Paquier 12c254c99f Tweak detail and hint messages to be consistent with project policy
Detail and hint messages should be full sentences and should end with a
period, but some of the messages newly-introduced in v15 did not follow
that.

Author: Justin Pryzby
Reviewed-by: Álvaro Herrera
Discussion: https://postgr.es/m/20220719120948.GF12702@telsasoft.com
Backpatch-through: 15
2022-07-20 09:50:12 +09:00
Andres Freund fd4bad1655 Remove now superfluous declarations of dlsym()ed symbols.
The prior commit declared them centrally.

Author: Andres Freund <andres@anarazel.de>
Reviewed-By: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/20211101020311.av6hphdl6xbjbuif@alap3.anarazel.de
2022-07-17 17:29:32 -07:00
Michael Paquier dac1ff3090 Replace durable_rename_excl() by durable_rename(), take two
durable_rename_excl() attempts to avoid overwriting any existing files
by using link() and unlink(), and it falls back to rename() on some
platforms (aka WIN32), which offers no such overwrite protection.  Most
callers use durable_rename_excl() just in case there is an existing
file, but in practice there shouldn't be one (see below for more
details).

Furthermore, failures during durable_rename_excl() can result in
multiple hard links to the same file.  As per Nathan's tests, it is
possible to end up with two links to the same file in pg_wal after a
crash just before unlink() during WAL recycling.  Specifically, the test
produced links to the same file for the current WAL file and the next
one because the half-recycled WAL file was re-recycled upon restarting,
leading to WAL corruption.

This change replaces all the calls of durable_rename_excl() to
durable_rename().  This removes the protection against accidentally
overwriting an existing file, but some platforms are already living
without it and ordinarily there shouldn't be one.  The function itself
is left around in case any extensions are using it.  It will be removed
on HEAD via a follow-up commit.

Here is a summary of the existing callers of durable_rename_excl() (see
second discussion link at the bottom), replaced by this commit.  First,
basic_archive used it to avoid overwriting an archive concurrently
created by another server, but as mentioned above, it will still
overwrite files on some platforms.  Second, xlog.c uses it to recycle
past WAL segments, where an overwrite should not happen (origin of the
change at f0e37a8) because there are protections about the WAL segment
to select when recycling an entry.  The third and last area is related
to the write of timeline history files.  writeTimeLineHistory() will
write a new timeline history file at the end of recovery on promotion,
so there should be no such files for the same timeline.
What remains is writeTimeLineHistoryFile(), that can be used in parallel
by a WAL receiver and the startup process, and some digging of the
buildfarm shows that EEXIST from a WAL receiver can happen with an error
of "could not link file \"pg_wal/xlogtemp.NN\" to \"pg_wal/MM.history\",
which would cause an automatic restart of the WAL receiver as it is
promoted to FATAL, hence this should improve the stability of the WAL
receiver as rename() would overwrite an existing TLI history file
already fetched by the startup process at recovery.

This is a bug fix, but knowing the unlikeliness of the problem involving
one or more crashes at an exceptionally bad moment, no backpatch is
done.  Also, I want to be careful with such changes (aaa3aed did the
opposite of this change by removing HAVE_WORKING_LINK so as Windows
would do a link() rather than a rename() but this was not
concurrent-safe).  A backpatch could be revisited in the future.  This
is the second time this change is attempted, ccfbd92 being the first
one, but this time no assertions are added for the case of a TLI history
file written concurrently by the WAL receiver or the startup process
because we can expect one to exist (some of the TAP tests are able to
trigger with a proper timing).

Author: Nathan Bossart
Reviewed-by: Robert Haas, Kyotaro Horiguchi, Michael Paquier
Discussion: https://postgr.es/m/20220407182954.GA1231544@nathanxps13
Discussion: https://postgr.es/m/Ym6GZbqQdlalSKSG@paquier.xyz
2022-07-05 10:16:12 +09:00
Tom Lane 23e7b38bfe Pre-beta mechanical code beautification.
Run pgindent, pgperltidy, and reformat-dat-files.
I manually fixed a couple of comments that pgindent uglified.
2022-05-12 15:17:30 -04:00
Peter Eisentraut 9700b250c5 Formatting and punctuation improvements in sample configuration files 2022-05-10 21:15:56 +02:00
Michael Paquier 55b5686511 Revert recent changes with durable_rename_excl()
This reverts commits 2c902bb and ccfbd92.  Per buildfarm members
kestrel, rorqual and calliphoridae, the assertions checking that a TLI
history file should not exist when created by a WAL receiver have been
failing, and switching to durable_rename() over durable_rename_excl()
would cause the newest TLI history file to overwrite the existing one.
We need to think harder about such cases, so revert the new logic for
now.

Note that all the failures have been reported in the test
025_stuck_on_old_timeline.

Discussion: https://postgr.es/m/511362.1651116498@sss.pgh.pa.us
2022-04-28 13:08:16 +09:00
Michael Paquier ccfbd9287d Replace existing durable_rename_excl() calls with durable_rename()
durable_rename_excl() attempts to avoid overwriting any existing files
by using link() and unlink(), falling back to rename() on some platforms
(e.g., Windows where link() followed by unlink() is not concurrent-safe,
see 909b449).  Most callers of durable_rename_excl() use it just in case
there is an existing file, but it happens that for all of them we never
expect a target file to exist (WAL segment recycling, creation of
timeline history file and basic_archive).

basic_archive used durable_rename_excl() to avoid overwriting an archive
concurrently created by another server.  Now, there is a stat() call to
avoid overwriting an existing archive a couple of lines above, so note
that this change opens a small TOCTOU window in this module between the
stat() call and durable_rename().

Furthermore, as mentioned in the top comment of durable_rename_excl(),
this routine can result in multiple hard links to the same file and data
corruption, with two or more links to the same file in pg_wal/ if a
crash happens before the unlink() call during WAL recycling.
Specifically, this would produce links to the same file for the current
WAL file and the next one because the half-recycled WAL file was
re-recycled during crash recovery of a follow-up cluster restart.

This change replaces all calls to durable_rename_excl() with
durable_rename().  This removes the protection against accidentally
overwriting an existing file, but some platforms are already living
without it, and all those code paths never expect an existing file (a
couple of assertions are added to check after that, in case).

This is a bug fix, but knowing the unlikeliness of the problem involving
one of more crashes at an exceptionally bad moment, no backpatch is
done.  This could be revisited in the future.

Author: Nathan Bossart
Reviewed-by: Robert Haas, Kyotaro Horiguchi, Michael Paquier
Discussion: https://postgr.es/m/20220407182954.GA1231544@nathanxps13
2022-04-28 10:11:45 +09:00
Tom Lane 88103567cb Disallow setting bogus GUCs within an extension's reserved namespace.
Commit 75d22069e tried to throw a warning for setting a custom GUC whose
prefix belongs to a previously-loaded extension, if there is no such GUC
defined by the extension.  But that caused unstable behavior with
parallel workers, because workers don't necessarily load extensions and
GUCs in the same order their leader did.  To make that work safely, we
have to completely disallow the case.  We now actually remove any such
GUCs at the time of initial extension load, and then throw an error not
just a warning if you try to add one later.  While this might create a
compatibility issue for a few people, the improvement in error-detection
capability seems worth it; it's hard to believe that there's any good
use-case for choosing such GUC names.

This also un-reverts 5609cc01c (Rename EmitWarningsOnPlaceholders() to
MarkGUCPrefixReserved()), since that function's old name is now even
more of a misnomer.

Florin Irion and Tom Lane

Discussion: https://postgr.es/m/1902182.1640711215@sss.pgh.pa.us
2022-02-21 14:10:43 -05:00
Robert Haas 00c360a89c In basic_archive tests, insist on wal_level='replica'.
That's normally the default, but buildfarm member thorntail has
other ideas.

Nathan Bossart

Discussion: http://postgr.es/m/20220203212539.GA1082940@nathanxps13
2022-02-03 16:40:32 -05:00
Robert Haas 5ef1eefd76 Allow archiving via loadable modules.
Running a shell command for each file to be archived has a lot of
overhead and may not offer as much error checking as you want, or the
exact semantics that you want. So, offer the option to call a loadable
module for each file to be archived, rather than running a shell command.

Also, add a 'basic_archive' contrib module as an example implementation
that archives to a local directory.

Nathan Bossart, with a little bit of kibitzing by me.

Discussion: http://postgr.es/m/20220202224433.GA1036711@nathanxps13
2022-02-03 14:05:02 -05:00