Commit Graph

1736 Commits

Author SHA1 Message Date
John Naylor 7beda87b6a Fix grammar in error message
While at it, make ellipses formatting consistent when describing SQL statements.

Ekaterina Kiryanova and Alexander Lakhin

Reviewed by myself and Álvaro Herrera
Discussion: https://www.postgresql.org/message-id/eed5cec0-a542-53da-6a5e-7789c6ed9817%40postgrespro.ru
Backpatch only the grammar fix to v15
2022-09-15 11:40:17 +07:00
Tom Lane 0a20ff54f5 Split up guc.c for better build speed and ease of maintenance.
guc.c has grown to be one of our largest .c files, making it
a bottleneck for compilation.  It's also acquired a bunch of
knowledge that'd be better kept elsewhere, because of our not
very good habit of putting variable-specific check hooks here.
Hence, split it up along these lines:

* guc.c itself retains just the core GUC housekeeping mechanisms.
* New file guc_funcs.c contains the SET/SHOW interfaces and some
  SQL-accessible functions for GUC manipulation.
* New file guc_tables.c contains the data arrays that define the
  built-in GUC variables, along with some already-exported constant
  tables.
* GUC check/assign/show hook functions are moved to the variable's
  home module, whenever that's clearly identifiable.  A few hard-
  to-classify hooks ended up in commands/variable.c, which was
  already a home for miscellaneous GUC hook functions.

To avoid cluttering a lot more header files with #include "guc.h",
I also invented a new header file utils/guc_hooks.h and put all
the GUC hook functions' declarations there, regardless of their
originating module.  That allowed removal of #include "guc.h"
from some existing headers.  The fallout from that (hopefully
all caught here) demonstrates clearly why such inclusions are
best minimized: there are a lot of files that, for example,
were getting array.h at two or more levels of remove, despite
not having any connection at all to GUCs in themselves.

There is some very minor code beautification here, such as
renaming a couple of inconsistently-named hook functions
and improving some comments.  But mostly this just moves
code from point A to point B and deals with the ensuing
needs for #include adjustments and exporting a few functions
that previously weren't exported.

Patch by me, per a suggestion from Andres Freund; thanks also
to Michael Paquier for the idea to invent guc_funcs.c.

Discussion: https://postgr.es/m/587607.1662836699@sss.pgh.pa.us
2022-09-13 11:11:45 -04:00
Peter Eisentraut 45b1a67a0f pg_clean_ascii(): escape bytes rather than lose them
Rather than replace each unprintable byte with a '?' character, replace
it with a hex escape instead. The API now allocates a copy rather than
modifying the input in place.

Author: Jacob Champion <jchampion@timescale.com>
Discussion: https://www.postgresql.org/message-id/CAAWbhmgsvHrH9wLU2kYc3pOi1KSenHSLAHBbCVmmddW6-mc_=w@mail.gmail.com
2022-09-13 16:10:44 +02:00
David Rowley 8b26769bc4 Fix an assortment of improper usages of string functions
In a similar effort to f736e188c and 110d81728, fixup various usages of
string functions where a more appropriate function is available and more
fit for purpose.

These changes include:

1. Use cstring_to_text_with_len() instead of cstring_to_text() when
   working with a StringInfoData and the length can easily be obtained.
2. Use appendStringInfoString() instead of appendStringInfo() when no
   formatting is required.
3. Use pstrdup(...) instead of psprintf("%s", ...)
4. Use pstrdup(...) instead of psprintf(...) (with no formatting)
5. Use appendPQExpBufferChar() instead of appendPQExpBufferStr() when the
   length of the string being appended is 1.
6. appendStringInfoChar() instead of appendStringInfo() when no formatting
   is required and string is 1 char long.
7. Use appendPQExpBufferStr(b, .) instead of appendPQExpBuffer(b, "%s", .)
8. Don't use pstrdup when it's fine to just point to the string constant.

I (David) did find other cases of #8 but opted to use #4 instead as I
wasn't certain enough that applying #8 was ok (e.g in hba.c)

Author: Ranier Vilela, David Rowley
Discussion: https://postgr.es/m/CAApHDvo2j2+RJBGhNtUz6BxabWWh2Jx16wMUMWKUjv70Ver1vg@mail.gmail.com
2022-09-06 13:19:44 +12:00
Tom Lane 1c1294be71 Prevent long-term memory leakage in autovacuum launcher.
get_database_list() failed to restore the caller's memory context,
instead leaving current context set to TopMemoryContext which is
how CommitTransactionCommand() leaves it.  The callers both think
they are using short-lived contexts, for the express purpose of
not having to worry about cleaning up individual allocations.
The net effect therefore is that supposedly short-lived allocations
could accumulate indefinitely in the launcher's TopMemoryContext.

Although this has been broken for a long time, it seems we didn't
have any obvious memory leak here until v15's rearrangement of the
stats logic.  I (tgl) am not entirely convinced that there's no
other leak at all, though, and we're surely at risk of adding one
in future back-patched fixes.  So back-patch to all supported
branches, even though this may be only a latent bug in pre-v15.

Reid Thompson

Discussion: https://postgr.es/m/972a4e12b68b0f96db514777a150ceef7dcd2e0f.camel@crunchydata.com
2022-08-31 16:23:35 -04:00
Tom Lane 7fed801135 Clean up inconsistent use of fflush().
More than twenty years ago (79fcde48b), we hacked the postmaster
to avoid a core-dump on systems that didn't support fflush(NULL).
We've mostly, though not completely, hewed to that rule ever since.
But such systems are surely gone in the wild, so in the spirit of
cleaning out no-longer-needed portability hacks let's get rid of
multiple per-file fflush() calls in favor of using fflush(NULL).

Also, we were fairly inconsistent about whether to fflush() before
popen() and system() calls.  While we've received no bug reports
about that, it seems likely that at least some of these call sites
are at risk of odd behavior, such as error messages appearing in
an unexpected order.  Rather than expend a lot of brain cells
figuring out which places are at hazard, let's just establish a
uniform coding rule that we should fflush(NULL) before these calls.
A no-op fflush() is surely of trivial cost compared to launching
a sub-process via a shell; while if it's not a no-op then we likely
need it.

Discussion: https://postgr.es/m/2923412.1661722825@sss.pgh.pa.us
2022-08-29 13:55:41 -04:00
David Rowley 3e0fff2e68 More -Wshadow=compatible-local warning fixes
In a similar effort to f01592f91, here we're targetting fixing the
warnings where we've deemed the shadowing variable to serve a close enough
purpose to the shadowed variable just to reuse the shadowed version and
not declare the shadowing variable at all.

By my count, this takes the warning count from 106 down to 71.

Author: Justin Pryzby
Discussion: https://postgr.es/m/20220825020839.GT2342@telsasoft.com
2022-08-26 02:35:40 +12:00
Michael Paquier 701ac2cb1f Remove initialization of MyClientConnectionInfo at backend startup
This stuff should be already initialized at process startup, so adding
this extra step is confusing for no gain.

Per gripe from Tom Lane and Jacob Champion.

Discussion: https://postgr.es/m/bbf2b922-4ff7-5c30-e3ef-2a8bdcdd1116@timescale.com
2022-08-24 19:19:00 +09:00
Michael Paquier d951052a9e Allow parallel workers to retrieve some data from Port
This commit moves authn_id into a new global structure called
ClientConnectionInfo (mapping to a MyClientConnectionInfo for each
backend) which is intended to hold all the client information that
should be shared between the backend and any of its parallel workers,
access for extensions and triggers being the primary use case.  There is
no need to push all the data of Port to the workers, and authn_id is
quite a generic concept so using a separate structure provides the best
balance (the name of the structure has been suggested by Robert Haas).

While on it, and per discussion as this would be useful for a potential
SYSTEM_USER that can be accessed through parallel workers, a second
field is added for the authentication method, copied directly from
Port.

ClientConnectionInfo is serialized and restored using a new parallel
key and a structure tracks the length of the authn_id, making the
addition of more fields straight-forward.

Author: Jacob Champion
Reviewed-by: Bertrand Drouvot, Stephen Frost, Robert Haas, Tom Lane,
Michael Paquier, Julien Rouhaud
Discussion: https://postgr.es/m/793d990837ae5c06a558d58d62de9378ab525d83.camel@vmware.com
2022-08-24 12:57:13 +09:00
Tom Lane 4ee6740167 Doc: prefer sysctl to /proc/sys in docs and comments.
sysctl is more portable than Linux's /proc/sys file tree, and
often easier to use too.  That's why most of our docs refer to
sysctl when talking about how to adjust kernel parameters.
Bring the few stragglers into line.

Discussion: https://postgr.es/m/361175.1661187463@sss.pgh.pa.us
2022-08-23 10:15:06 -04:00
Andres Freund 1bdd54e662 Remove redundant call to pgstat_report_wal()
pgstat_report_stat() will be called before shutdown so an explicit call to
pgstat_report_wal() just before shutdown is redundant.

This likely was not redundant before 5891c7a8ed, but now it clearly is.

Author: Melanie Plageman <melanieplageman@gmail.com>
Reviewed-by: Andres Freund <andres@anarazel.de>
Discussion: https://www.postgresql.org/message-id/CAAKRu_aaq33UnG4TXq3S-OSXGWj1QGf0sU%2BECH4tNwGFNERkZA%40mail.gmail.com
2022-08-22 20:25:42 -07:00
Thomas Munro f558088285 Remove HAVE_UNIX_SOCKETS.
Since HAVE_UNIX_SOCKETS is now defined unconditionally, remove the macro
and drop a small amount of dead code.

The last known systems not to have them (as far as I know at least) were
QNX, which we de-supported years ago, and Windows, which now has them.

If a new OS ever shows up with the POSIX sockets API but without working
AF_UNIX, it'll presumably still be able to compile the code, and fail at
runtime with an unsupported address family error.  We might want to
consider adding a HINT that you should turn off the option to use it if
your network stack doesn't support it at that point, but it doesn't seem
worth making the relevant code conditional at compile time.

Also adjust a couple of places in the docs and comments that referred to
builds without Unix-domain sockets, since there aren't any.  Windows
still gets a special mention in those places, though, because we don't
try to use them by default there yet.

Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Reviewed-by: Andres Freund <andres@anarazel.de>
Reviewed-by: Peter Eisentraut <peter.eisentraut@enterprisedb.com>
Discussion: https://postgr.es/m/CA%2BhUKG%2BL_3brvh%3D8e0BW_VfX9h7MtwgN%3DnFHP5o7X2oZucY9dg%40mail.gmail.com
2022-08-14 08:46:53 +12:00
Thomas Munro 7e50b4e3c5 Remove configure probe for sys/select.h.
<sys/select.h> is in SUSv3 and every targeted Unix system has it.
Provide an empty header in src/include/port/win32 so that we can
include it unguarded even on Windows.

Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/CA%2BhUKG%2BL_3brvh%3D8e0BW_VfX9h7MtwgN%3DnFHP5o7X2oZucY9dg%40mail.gmail.com
2022-08-14 00:09:47 +12:00
Robert Haas 34dffa0224 Fix non-specific error message.
"something has gone wrong" is not helpful. Make this elog()
consistent with the other one in the same function.

Discussion: http://postgr.es/m/CA+Tgmoa_AZ2jUWSA_noiqOqnxBaWDR+t3bHjSygZi6+wqDBCXQ@mail.gmail.com
2022-08-11 14:12:11 -04:00
Michael Paquier 47ab1ac822 Use hba_file/ident_file GUCs rather than pg_hba.conf/pg_ident.conf in logs
This is particularly useful when log_min_messages is set to FATAL, so as
one can know which file was not getting loaded whether hba_file or
ident_file are set to some non-default values.  If using the default
values of these GUC parameters, the same reports are generated.

This commit changes the load (startup) and reload (SIGHUP) messages.

Author: Julien Rouhaud
Discussion: https://postgr.es/m/20220223045959.35ipdsvbxcstrhya@jrouhaud
2022-08-05 09:37:12 +09:00
Fujii Masao 756e221db6 Reduce overhead of renaming archive status files.
Presently, archive status files are durably renamed from .ready to
.done to indicate that a file has been archived.  Persisting this
rename to disk accounts for a significant amount of the overhead
associated with archiving.  While durably renaming the file
prevents re-archiving in most cases, archive commands and libraries
must already gracefully handle attempts to re-archive the last
archived file after a crash (e.g., a crash immediately after
archive_command exits but before the server renames the status
file).

This change reduces the amount of overhead associated with
archiving by using rename() instead of durable_rename() to rename
the archive status files.  As a consequence, the server is more
likely to attempt to re-archive files after a crash, but as noted
above, archive commands and modules are already expected to handle
this.  It is also possible that the server will attempt to re-
archive files that have been removed or recycled, but the archiver
already handles this, too.

Author: Nathan Bossart
Reviewed-by: Kyotaro Horiguchi, Fujii Masao
Discussion: https://postgr.es/m/20220222011948.GA3850532@nathanxps13
2022-07-26 16:00:18 +09:00
Tom Lane b35617de37 Process session_preload_libraries within InitPostgres's transaction.
Previously we did this after InitPostgres, at a somewhat randomly chosen
place within PostgresMain.  However, since commit a0ffa885e doing this
outside a transaction can cause a crash, if we need to check permissions
while replacing a placeholder GUC.  (Besides which, a preloaded library
could itself want to do database access within _PG_init.)

To avoid needing an additional transaction start/end in every session,
move the process_session_preload_libraries call to within InitPostgres's
transaction.  That requires teaching the code not to call it when
InitPostgres is called from somewhere other than PostgresMain, since
we don't want session_preload_libraries to affect background workers.
The most future-proof solution here seems to be to add an additional
flag parameter to InitPostgres; fortunately, we're not yet very worried
about API stability for v15.

Doing this also exposed the fact that we're currently honoring
session_preload_libraries in walsenders, even those not connected to
any database.  This seems, at minimum, a POLA violation: walsenders
are not interactive sessions.  Let's stop doing that.

(All these comments also apply to local_preload_libraries, of course.)

Per report from Gurjeet Singh (thanks also to Nathan Bossart and Kyotaro
Horiguchi for review).  Backpatch to v15 where a0ffa885e came in.

Discussion: https://postgr.es/m/CABwTF4VEpwTHhRQ+q5MiC5ucngN-whN-PdcKeufX7eLSoAfbZA@mail.gmail.com
2022-07-25 10:27:43 -04:00
Andres Freund 950e64fa46 Use STDOUT/STDERR_FILENO in most of syslogger.
This fixes problems on windows when logging collector is used in a service,
failing with:
FATAL:  could not redirect stderr: Bad file descriptor

This is triggered by 76e38b37a5. The problem is that STDOUT/STDERR_FILENO
aren't defined on windows, which lead us to use _fileno(stdout) etc, but that
doesn't work if stdout/stderr are closed.

Author: Andres Freund <andres@anarazel.de>
Reported-By: Sandeep Thakkar <sandeep.thakkar@enterprisedb.com>
Message-Id: 20220520164558.ozb7lm6unakqzezi@alap3.anarazel.de (on pgsql-packagers)
Backpatch: 15-, where 76e38b37a5 came in
2022-07-18 17:22:11 -07:00
Tom Lane 5e692dcaca Remove postmaster.c's reset_shared() wrapper function.
reset_shared just invokes CreateSharedMemoryAndSemaphores, so let's
get rid of it and invoke that directly.  This removes a confusing
seeming-inconsistency between the postmaster's startup sequence
and the startup sequence used in standalone mode.

Nathan Bossart, reviewed by Pavel Borisov

Discussion: https://postgr.es/m/20220329221702.GA559657@nathanxps13
2022-07-16 12:26:35 -04:00
Robert Haas b0a55e4329 Change internal RelFileNode references to RelFileNumber or RelFileLocator.
We have been using the term RelFileNode to refer to either (1) the
integer that is used to name the sequence of files for a certain relation
within the directory set aside for that tablespace/database combination;
or (2) that value plus the OIDs of the tablespace and database; or
occasionally (3) the whole series of files created for a relation
based on those values. Using the same name for more than one thing is
confusing.

Replace RelFileNode with RelFileNumber when we're talking about just the
single number, i.e. (1) from above, and with RelFileLocator when we're
talking about all the things that are needed to locate a relation's files
on disk, i.e. (2) from above. In the places where we refer to (3) as
a relfilenode, instead refer to "relation storage".

Since there is a ton of SQL code in the world that knows about
pg_class.relfilenode, don't change the name of that column, or of other
SQL-facing things that derive their name from it.

On the other hand, do adjust closely-related internal terminology. For
example, the structure member names dbNode and spcNode appear to be
derived from the fact that the structure itself was called RelFileNode,
so change those to dbOid and spcOid. Likewise, various variables with
names like rnode and relnode get renamed appropriately, according to
how they're being used in context.

Hopefully, this is clearer than before. It is also preparation for
future patches that intend to widen the relfilenumber fields from its
current width of 32 bits. Variables that store a relfilenumber are now
declared as type RelFileNumber rather than type Oid; right now, these
are the same, but that can now more easily be changed.

Dilip Kumar, per an idea from me. Reviewed also by Andres Freund.
I fixed some whitespace issues, changed a couple of words in a
comment, and made one other minor correction.

Discussion: http://postgr.es/m/CA+TgmoamOtXbVAQf9hWFzonUo6bhhjS6toZQd7HZ-pmojtAmag@mail.gmail.com
Discussion: http://postgr.es/m/CA+Tgmobp7+7kmi4gkq7Y+4AM9fTvL+O1oQ4-5gFTT+6Ng-dQ=g@mail.gmail.com
Discussion: http://postgr.es/m/CAFiTN-vTe79M8uDH1yprOU64MNFE+R3ODRuA+JWf27JbhY4hJw@mail.gmail.com
2022-07-06 11:39:09 -04:00
Peter Eisentraut 02c408e21a Remove redundant null pointer checks before free()
Per applicable standards, free() with a null pointer is a no-op.
Systems that don't observe that are ancient and no longer relevant.
Some PostgreSQL code already required this behavior, so this change
does not introduce any new requirements, just makes the code more
consistent.

Discussion: https://www.postgresql.org/message-id/flat/dac5d2d0-98f5-94d9-8e69-46da2413593d%40enterprisedb.com
2022-07-03 11:47:15 +02:00
Tom Lane 7ab5b4eb48 Be more careful about GucSource for internally-driven GUC settings.
The original advice for hard-wired SetConfigOption calls was to use
PGC_S_OVERRIDE, particularly for PGC_INTERNAL GUCs.  However,
that's really overkill for PGC_INTERNAL GUCs, since there is no
possibility that we need to override a user-provided setting.
Instead use PGC_S_DYNAMIC_DEFAULT in most places, so that the
value will appear with source = 'default' in pg_settings and thereby
not be shown by psql's new \dconfig command.  The one exception is
that when changing in_hot_standby in a hot-standby session, we still
use PGC_S_OVERRIDE, because people felt that seeing that in \dconfig
would be a good thing.

Similarly use PGC_S_DYNAMIC_DEFAULT for the auto-tune value of
wal_buffers (if possible, that is if wal_buffers wasn't explicitly
set to -1), and for the typical 2MB value of max_stack_depth.

In combination these changes remove four not-very-interesting
entries from the typical output of \dconfig, all of which people
fingered as "why is that showing up?" in the discussion thread.

Discussion: https://postgr.es/m/3118455.1649267333@sss.pgh.pa.us
2022-06-08 13:26:18 -04:00
Robert Haas 4f2400cb3f Add a new shmem_request_hook hook.
Currently, preloaded libraries are expected to request additional
shared memory and LWLocks in _PG_init().  However, it is not unusal
for such requests to depend on MaxBackends, which won't be
initialized at that time.  Such requests could also depend on GUCs
that other modules might change.  This introduces a new hook where
modules can safely use MaxBackends and GUCs to request additional
shared memory and LWLocks.

Furthermore, this change restricts requests for shared memory and
LWLocks to this hook.  Previously, libraries could make requests
until the size of the main shared memory segment was calculated.
Unlike before, we no longer silently ignore requests received at
invalid times.  Instead, we FATAL if someone tries to request
additional shared memory or LWLocks outside of the hook.

Nathan Bossart and Julien Rouhaud

Discussion: https://postgr.es/m/20220412210112.GA2065815%40nathanxps13
Discussion: https://postgr.es/m/Yn2jE/lmDhKtkUdr@paquier.xyz
2022-05-13 09:31:06 -04:00
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
Robert Haas ab02d702ef Remove non-functional code for unloading loadable modules.
The code for unloading a library has been commented-out for over 12
years, ever since commit 602a9ef5a7, and we're
no closer to supporting it now than we were back then.

Nathan Bossart, reviewed by Michael Paquier and by me.

Discussion: http://postgr.es/m/Ynsc9bRL1caUSBSE@paquier.xyz
2022-05-11 15:30:30 -04:00
Michael Paquier 8bbf8461a3 Silence extra logging when using "postgres -C" on runtime-computed GUCs
Presently, the server may emit a variety of log messages when inspecting
a runtime-computed GUC, mostly in the shape of one LOG message with the
default configuration, related to the startup sequence launched as such
GUCs require a load of the control file and of external shared
libraries.

For example, the server will always emit a "database system is shut
down" LOG (unless the user has set log_min_messages higher than LOG),
which is an annoying behavior as "postgres -C" is expected to only emit
in its output the parameter value we are looking for.  The parameter
value is sent to stdout, while the logs are sent to stderr so we could
recommend to use a redirection, but there was not much love for this
workaround either.

To avoid such extra log messages, per discussion, this change sets
log_min_messages to FATAL internally when -C is used on a
runtime-computed GUC (even if set to PANIC in postgresql.conf).  At
FATAL, the user will still receive messages explaining why a GUC value
cannot be inspected, and will know if the command is attempted on a
server already running, something not supported yet for a
runtime-computed GUC.

Reported-by: Magnus Hagander, Bruce Momjian
Author: Nathan Bossart, Michael Paquier
Discussion: https://postgr.es/m/Yni6ZHkGotUU+RSf@paquier.xyz
2022-05-11 14:21:06 +09:00
Robert Haas 701d918a42 Fix misleading comments about background worker registration.
Since 6bc8ef0b7f, the maximum number
of backends can't change as background workers are registered, but
these comments still reflect the way things worked prior to that.

Also, per recent discussion, some modules call SetConfigOption()
from _PG_init(). It's not entirely clear to me whether we want to
regard that as a fully supported operation, but since we know it's
a thing that happens, it at least deserves a mention in the comments,
so add that.

Nathan Bossart, reviewed by Anton A. Melnikov

Discussion: http://postgr.es/m/20220419154658.GA2487941@nathanxps13
2022-05-06 09:24:06 -04:00
Alvaro Herrera 24d2b2680a
Remove extraneous blank lines before block-closing braces
These are useless and distracting.  We wouldn't have written the code
with them to begin with, so there's no reason to keep them.

Author: Justin Pryzby <pryzby@telsasoft.com>
Discussion: https://postgr.es/m/20220411020336.GB26620@telsasoft.com
Discussion: https://postgr.es/m/attachment/133167/0016-Extraneous-blank-lines.patch
2022-04-13 19:16:02 +02:00
Robert Haas 7fc0e7de9f Revert the addition of GetMaxBackends() and related stuff.
This reverts commits 0147fc7, 4567596, aa64f23, and 5ecd018.
There is no longer agreement that introducing this function
was the right way to address the problem. The consensus now
seems to favor trying to make a correct value for MaxBackends
available to mdules executing their _PG_init() functions.

Nathan Bossart

Discussion: http://postgr.es/m/20220323045229.i23skfscdbvrsuxa@jrouhaud
2022-04-12 14:45:23 -04:00
Jeff Davis 5c279a6d35 Custom WAL Resource Managers.
Allow extensions to specify a new custom resource manager (rmgr),
which allows specialized WAL. This is meant to be used by a Table
Access Method or Index Access Method.

Prior to this commit, only Generic WAL was available, which offers
support for recovery and physical replication but not logical
replication.

Reviewed-by: Julien Rouhaud, Bharath Rupireddy, Andres Freund
Discussion: https://postgr.es/m/ed1fb2e22d15d3563ae0eb610f7b61bb15999c0a.camel%40j-davis.com
2022-04-06 23:06:46 -07:00
Andres Freund fbfe6910ec pgstat: move pgstat.c to utils/activity.
Now that pgstat is not related to postmaster anymore, src/backend/postmaster
is not a well fitting directory.

Author: Andres Freund <andres@anarazel.de>
Discussion: https://postgr.es/m/20220303021600.hs34ghqcw6zcokdh@alap3.anarazel.de
2022-04-06 21:29:46 -07:00
Andres Freund 6f0cf87872 pgstat: remove stats_temp_directory.
With stats now being stored in shared memory, the GUC isn't needed
anymore. However, the pg_stat_tmp directory and PG_STAT_TMP_DIR define are
kept, as pg_stat_statements (and some out-of-core extensions) store data in
it.

Docs will be updated in a subsequent commit, together with the other pending
docs updates due to shared memory stats.

Author: Andres Freund <andres@anarazel.de>
Author: Kyotaro Horiguchi <horikyota.ntt@gmail.com>
Reviewed-By: Kyotaro Horiguchi <horikyota.ntt@gmail.com>
Discussion: https://postgr.es/m/20220330233550.eiwsbearu6xhuqwe@alap3.anarazel.de
Discussion: https://postgr.es/m/20220303021600.hs34ghqcw6zcokdh@alap3.anarazel.de
2022-04-06 21:29:46 -07:00
Andres Freund 5891c7a8ed pgstat: store statistics in shared memory.
Previously the statistics collector received statistics updates via UDP and
shared statistics data by writing them out to temporary files regularly. These
files can reach tens of megabytes and are written out up to twice a
second. This has repeatedly prevented us from adding additional useful
statistics.

Now statistics are stored in shared memory. Statistics for variable-numbered
objects are stored in a dshash hashtable (backed by dynamic shared
memory). Fixed-numbered stats are stored in plain shared memory.

The header for pgstat.c contains an overview of the architecture.

The stats collector is not needed anymore, remove it.

By utilizing the transactional statistics drop infrastructure introduced in a
prior commit statistics entries cannot "leak" anymore. Previously leaked
statistics were dropped by pgstat_vacuum_stat(), called from [auto-]vacuum. On
systems with many small relations pgstat_vacuum_stat() could be quite
expensive.

Now that replicas drop statistics entries for dropped objects, it is not
necessary anymore to reset stats when starting from a cleanly shut down
replica.

Subsequent commits will perform some further code cleanup, adapt docs and add
tests.

Bumps PGSTAT_FILE_FORMAT_ID.

Author: Kyotaro Horiguchi <horikyota.ntt@gmail.com>
Author: Andres Freund <andres@anarazel.de>
Author: Melanie Plageman <melanieplageman@gmail.com>
Reviewed-By: Andres Freund <andres@anarazel.de>
Reviewed-By: Thomas Munro <thomas.munro@gmail.com>
Reviewed-By: Justin Pryzby <pryzby@telsasoft.com>
Reviewed-By: "David G. Johnston" <david.g.johnston@gmail.com>
Reviewed-By: Tomas Vondra <tomas.vondra@2ndquadrant.com> (in a much earlier version)
Reviewed-By: Arthur Zakirov <a.zakirov@postgrespro.ru> (in a much earlier version)
Reviewed-By: Antonin Houska <ah@cybertec.at> (in a much earlier version)
Discussion: https://postgr.es/m/20220303021600.hs34ghqcw6zcokdh@alap3.anarazel.de
Discussion: https://postgr.es/m/20220308205351.2xcn6k4x5yivcxyd@alap3.anarazel.de
Discussion: https://postgr.es/m/20210319235115.y3wz7hpnnrshdyv6@alap3.anarazel.de
2022-04-06 21:29:46 -07:00
Andres Freund be902e2651 pgstat: normalize function naming.
Most of pgstat uses pgstat_<verb>_<subject>() or just <verb>_<subject>(). But
not all (some introduced fairly recently by me). Rename ones that aren't
intentionally following a different scheme (e.g. AtEOXact_*).
2022-04-06 21:29:46 -07:00
Andres Freund e41aed674f pgstat: revise replication slot API in preparation for shared memory stats.
Previously the pgstat <-> replication slots API was done with on the basis of
names. However, the upcoming move to storing stats in shared memory makes it
more convenient to use a integer as key.

Change the replication slot functions to take the slot rather than the slot
name, and expose ReplicationSlotIndex() to compute the index of an replication
slot. Special handling will be required for restarts, as the index is not
stable across restarts. For now pgstat internally still uses names.

Rename pgstat_report_replslot_{create,drop}() to
pgstat_{create,drop}_replslot() to match the functions for other kinds of
stats.

Reviewed-By: Kyotaro Horiguchi <horikyota.ntt@gmail.com>
Discussion: https://postgr.es/m/20220404041516.cctrvpadhuriawlq@alap3.anarazel.de
2022-04-06 18:38:24 -07:00
Andres Freund 8b1dccd37c pgstat: scaffolding for transactional stats creation / drop.
One problematic part of the current statistics collector design is that there
is no reliable way of getting rid of statistics entries. Because of that
pgstat_vacuum_stat() (called by [auto-]vacuum) matches all stats for the
current database with the catalog contents and tries to drop now-superfluous
entries. That's quite expensive. What's worse, it doesn't work on physical
replicas, despite physical replicas collection statistics entries.

This commit introduces infrastructure to create / drop statistics entries
transactionally, together with the underlying catalog objects (functions,
relations, subscriptions). pgstat_xact.c maintains a list of stats entries
created / dropped transactionally in the current transaction. To ensure the
removal of statistics entries is durable dropped statistics entries are
included in commit / abort (and prepare) records, which also ensures that
stats entries are dropped on standbys.

Statistics entries created separately from creating the underlying catalog
object (e.g. when stats were previously lost due to an immediate restart)
are *not* WAL logged. However that can only happen outside of the transaction
creating the catalog object, so it does not lead to "leaked" statistics
entries.

For this to work, functions creating / dropping functions / relations /
subscriptions need to call into pgstat. For subscriptions this was already
done when dropping subscriptions, via pgstat_report_subscription_drop() (now
renamed to pgstat_drop_subscription()).

This commit does not actually drop stats yet, it just provides the
infrastructure. It is however a largely independent piece of infrastructure,
so committing it separately makes sense.

Bumps XLOG_PAGE_MAGIC.

Author: Andres Freund <andres@anarazel.de>
Reviewed-By: Thomas Munro <thomas.munro@gmail.com>
Reviewed-By: Kyotaro Horiguchi <horikyota.ntt@gmail.com>
Discussion: https://postgr.es/m/20220303021600.hs34ghqcw6zcokdh@alap3.anarazel.de
2022-04-06 18:27:52 -07:00
Andres Freund 8fb580a35c pgstat: prepare APIs used by pgstatfuncs for shared memory stats.
With the introduction of PgStat_Kind PgStat_Single_Reset_Type,
PgStat_Shared_Reset_Target don't make sense anymore. Replace them with
PgStat_Kind.

Instead of having dedicated reset functions for different kinds of stats, use
two generic helper routines (one to reset all stats of a kind, one to reset
one stats entry).

A number of reset functions were named pgstat_reset_*_counter(), despite
affecting multiple counters. The generic helper routines get rid of
pgstat_reset_single_counter(), pgstat_reset_subscription_counter().

Rename pgstat_reset_slru_counter(), pgstat_reset_replslot_counter() to
pgstat_reset_slru(), pgstat_reset_replslot() respectively, and have them only
deal with a single SLRU/slot. Resetting all SLRUs/slots goes through the
generic pgstat_reset_of_kind().

Previously pg_stat_reset_replication_slot() used SearchNamedReplicationSlot()
to check if a slot exists. API wise it seems better to move that to
pgstat_replslot.c.

This is done separately from the - quite large - shared memory statistics
patch to make review easier.

Reviewed-By: Kyotaro Horiguchi <horikyota.ntt@gmail.com>
Discussion: https://postgr.es/m/20220404041516.cctrvpadhuriawlq@alap3.anarazel.de
2022-04-06 17:56:19 -07:00
Andres Freund cc96373cf3 pgstat: rename some pgstat_send_* functions to pgstat_report_*.
Only the pgstat_send_* functions that are called from outside pgstat*.c are
renamed (the rest will go away). This is done separately from the - quite
large - shared memory statistics patch to make review easier.

Author: Andres Freund <andres@anarazel.de>
Reviewed-By: Kyotaro Horiguchi <horikyota.ntt@gmail.com>
Discussion: https://postgr.es/m/20220404041516.cctrvpadhuriawlq@alap3.anarazel.de
2022-04-06 14:08:57 -07:00
Andres Freund bdbd3d9064 pgstat: stats collector references in comments.
Soon the stats collector will be no more, with statistics instead getting
stored in shared memory. There are a lot of references to the stats collector
in comments. This commit replaces most of these references with "cumulative
statistics system", with the remaining ones getting replaced as part of
subsequent commits.

This is done separately from the - quite large - shared memory statistics
patch to make review easier.

Author: Andres Freund <andres@anarazel.de>
Reviewed-By: Justin Pryzby <pryzby@telsasoft.com>
Reviewed-By: Thomas Munro <thomas.munro@gmail.com>
Reviewed-By: Kyotaro Horiguchi <horikyota.ntt@gmail.com>
Discussion: https://postgr.es/m/20220303021600.hs34ghqcw6zcokdh@alap3.anarazel.de
Discussion: https://postgr.es/m/20220308205351.2xcn6k4x5yivcxyd@alap3.anarazel.de
2022-04-06 13:56:06 -07:00
Andres Freund ab62a642d5 pgstat: move transactional code into pgstat_xact.c.
The transactional integration code is largely independent from the rest of
pgstat.c. Subsequent commits will add more related code.

Author: Andres Freund <andres@anarazel.de>
Reviewed-By: Thomas Munro <thomas.munro@gmail.com>
Discussion: https://postgr.es/m/20220404041516.cctrvpadhuriawlq@alap3.anarazel.de
2022-04-06 13:23:47 -07:00
Stephen Frost 39969e2a1e Remove exclusive backup mode
Exclusive-mode backups have been deprecated since 9.6 (when
non-exclusive backups were introduced) due to the issues
they can cause should the system crash while one is running and
generally because non-exclusive provides a much better interface.
Further, exclusive backup mode wasn't really being tested (nor was most
of the related code- like being able to log in just to stop an exclusive
backup and the bits of the state machine related to that) and having to
possibly deal with an exclusive backup and the backup_label file
existing during pg_basebackup, pg_rewind, etc, added other complexities
that we are better off without.

This patch removes the exclusive backup mode, the various special cases
for dealing with it, and greatly simplifies the online backup code and
documentation.

Authors: David Steele, Nathan Bossart
Reviewed-by: Chapman Flack
Discussion: https://postgr.es/m/ac7339ca-3718-3c93-929f-99e725d1172c@pgmasters.net
https://postgr.es/m/CAHg+QDfiM+WU61tF6=nPZocMZvHDzCK47Kneyb0ZRULYzV5sKQ@mail.gmail.com
2022-04-06 14:41:03 -04:00
Andres Freund edadf8098f pgstat: consistent function comment formatting.
There was a wild mishmash of function comment formatting in pgstat, making it
hard to know what to use for any new function and hard to extend existing
comments (particularly due to randomly different forms of indentation).

Author: Andres Freund <andres@anarazel.de>
Reviewed-By: Thomas Munro <thomas.munro@gmail.com>
Discussion: https://postgr.es/m/20220329191727.mzzwbl7udhpq7pmf@alap3.anarazel.de
Discussion: https://postgr.es/m/20220308205351.2xcn6k4x5yivcxyd@alap3.anarazel.de
2022-04-04 13:53:34 -07:00
Andres Freund ce8c978295 pgstat: fix function name in comment.
Introduced in 3fa17d3771.
2022-03-22 08:15:40 -07:00
Andres Freund 315ae75e9b pgstat: reorder pgstat.[ch] contents.
Now that 13619598f1 has split pgstat up into multiple files it isn't quite as
hard to come up with a sensible order for pgstat.[ch]. Inconsistent naming
makes it still not quite right looking, but that's work for another commit.

Author: Andres Freund <andres@anarazel.de>
Discussion: https://postgr.es/m/20220303021600.hs34ghqcw6zcokdh@alap3.anarazel.de
2022-03-21 16:21:00 -07:00
Andres Freund 13619598f1 pgstat: split different types of stats into separate files.
pgstat.c is very long, and it's hard to find an order that makes sense and is
likely to be maintained over time. Splitting the different pieces into
separate files makes that a lot easier.

With a few exceptions, this commit just moves code around. Those exceptions
are:
- adding file headers for new files
- removing 'static' from functions
- adapting pgstat_assert_is_up() to work across TUs
- minor comment adjustments
git diff --color-moved=dimmed-zebra is very helpful separating code movement
from code changes.

The next commit in this series will reorder pgstat.[ch] contents to be a bit
more coherent.

Earlier revisions of this patch had "global" statistics (archiver, bgwriter,
checkpointer, replication slots, SLRU, WAL) in one file, because each seemed
small enough. However later commits will increase their size and their
aggregate size is not insubstantial. It also just seems easier to split each
type of statistic into its own file.

Author: Andres Freund <andres@anarazel.de>
Discussion: https://postgr.es/m/20220303021600.hs34ghqcw6zcokdh@alap3.anarazel.de
2022-03-21 12:02:25 -07:00
Andres Freund d4ba8b51c7 pgstat: separate "xact level" handling out of relation specific functions.
This is in preparation of a later commit moving relation stats handling into
its own file.

Author: Andres Freund <andres@anarazel.de>
Discussion: https://postgr.es/m/20220303021600.hs34ghqcw6zcokdh@alap3.anarazel.de
2022-03-20 19:12:09 -07:00
Andres Freund bff258a273 pgstat: rename pgstat_initstats() to pgstat_relation_init().
The old name was overly generic. An upcoming commit moves relation stats
handling into its own file, making pgstat_initstats() look even more out of
place.

Author: Andres Freund <andres@anarazel.de>
Discussion: https://postgr.es/m/20220303021600.hs34ghqcw6zcokdh@alap3.anarazel.de
2022-03-20 19:12:09 -07:00
Andres Freund 8363102009 pgstat: introduce pgstat_relation_should_count().
A later commit will make the check more complicated than the
current (rel)->pgstat_info != NULL. It also just seems nicer to have a central
copy of the logic, even while still simple.

Author: Andres Freund <andres@anarazel.de>
Discussion: https://postgr.es/m/20220303021600.hs34ghqcw6zcokdh@alap3.anarazel.de
2022-03-20 19:12:09 -07:00
Andres Freund 78f9506b38 pgstat: split out WAL handling from pgstat_{initialize,report_stat}.
A later commit will move the handling of the different kinds of stats into
separate files.  By splitting out WAL handling in this commit that later move
will just move code around without other changes.

Author: Andres Freund <andres@anarazel.de>
Discussion: https://postgr.es/m/20220303021600.hs34ghqcw6zcokdh@alap3.anarazel.de
2022-03-19 11:42:22 -07:00
Andres Freund 89c546c294 pgstat: split relation, database handling out of pgstat_report_stat().
pgstat_report_stat() handles several types of stats, yet relation stats have
so far been handled directly in pgstat_report_stat().

A later commit will move the handling of the different kinds of stats into
separate files.  By splitting out relation handling in this commit that later
move will just move code around without other changes.

Author: Andres Freund <andres@anarazel.de>
Discussion: https://postgr.es/m/20220303021600.hs34ghqcw6zcokdh@alap3.anarazel.de
2022-03-19 11:42:22 -07:00