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Michael Paquier bc0581f8fb Fix recovery of 2PC transaction during crash recovery
A crash in the middle of a checkpoint with some two-phase state data
already flushed to disk by this checkpoint could cause a follow-up crash
recovery to recover twice the same transaction, once from what has been
found in pg_twophase/ at the beginning of recovery and a second time
when replaying its corresponding record.

This would lead to FATAL failures in the startup process during
recovery, where the same transaction would have a state recovered twice
instead of once:
LOG:  recovering prepared transaction 731 from shared memory
LOG:  recovering prepared transaction 731 from shared memory
FATAL:  lock ExclusiveLock on object 731/0/0 is already held

This issue is fixed by skipping the addition of any 2PC state coming
from a record whose equivalent 2PC state file has already been loaded in
TwoPhaseState at the beginning of recovery by restoreTwoPhaseData(),
which is OK as long as the system has not reached a consistent state.

The timing to get a messed up recovery processing is very racy, and
would very unlikely happen.  The thread that has reported the issue has
demonstrated the bug using injection points to force a PANIC in the
middle of a checkpoint.

Issue introduced in 728bd99, so backpatch all the way down.

Reported-by: "suyu.cmj" <mengjuan.cmj@alibaba-inc.com>
Author: "suyu.cmj" <mengjuan.cmj@alibaba-inc.com>
Author: Michael Paquier
Discussion: https://postgr.es/m/109e6994-b971-48cb-84f6-829646f18b4c.mengjuan.cmj@alibaba-inc.com
Backpatch-through: 11
2023-07-18 13:44:35 +09:00
config Use --strip-unneeded when stripping static libraries with GNU strip. 2023-04-20 18:12:32 -04:00
contrib Remove unnecessary pfree() in g_intbig_compress(). 2023-07-13 13:08:40 -04:00
doc Handle DROP DATABASE getting interrupted 2023-07-13 13:03:37 -07:00
src Fix recovery of 2PC transaction during crash recovery 2023-07-18 13:44:35 +09:00
.dir-locals.el Make Emacs perl-mode indent more like perltidy. 2019-01-13 11:32:36 -08:00
.git-blame-ignore-revs Backpatch addition of .git-blame-ignore-revs 2022-08-05 19:36:24 +02:00
.gitattributes Remove contrib/tsearch2. 2017-02-13 11:06:11 -05:00
.gitignore Add portlock directory to .gitignore 2022-11-26 07:47:27 -05:00
COPYRIGHT Update copyright for 2023 2023-01-02 15:00:36 -05:00
GNUmakefile.in Remove temporary portlock directory during make [dist]clean. 2022-11-26 10:31:08 -05:00
HISTORY Change documentation references to PG website to use https: not http: 2017-05-20 21:50:47 -04:00
Makefile Don't unset MAKEFLAGS in non-GNU Makefile. 2019-06-25 09:40:20 +12:00
README Change documentation references to PG website to use https: not http: 2017-05-20 21:50:47 -04:00
README.git Change documentation references to PG website to use https: not http: 2017-05-20 21:50:47 -04:00
aclocal.m4 Probe $PROVE not $PERL while checking for modules needed by TAP tests. 2021-11-22 12:54:52 -05:00
configure Define OPENSSL_API_COMPAT 2023-06-24 20:29:42 +09:00
configure.in Define OPENSSL_API_COMPAT 2023-06-24 20:29:42 +09:00

README

PostgreSQL Database Management System
=====================================

This directory contains the source code distribution of the PostgreSQL
database management system.

PostgreSQL is an advanced object-relational database management system
that supports an extended subset of the SQL standard, including
transactions, foreign keys, subqueries, triggers, user-defined types
and functions.  This distribution also contains C language bindings.

PostgreSQL has many language interfaces, many of which are listed here:

	https://www.postgresql.org/download

See the file INSTALL for instructions on how to build and install
PostgreSQL.  That file also lists supported operating systems and
hardware platforms and contains information regarding any other
software packages that are required to build or run the PostgreSQL
system.  Copyright and license information can be found in the
file COPYRIGHT.  A comprehensive documentation set is included in this
distribution; it can be read as described in the installation
instructions.

The latest version of this software may be obtained at
https://www.postgresql.org/download/.  For more information look at our
web site located at https://www.postgresql.org/.