postgres

Michael Paquier a1b8b3b2e3 Fix unconditional WAL receiver shutdown during stream-archive transition Commit `b4f584f9d2` (affecting v15~, later backpatched down to 13 as of `3635a0a35a`) introduced an unconditional WAL receiver shutdown when switching from streaming to archive WAL sources. This causes problems during a timeline switch, when a WAL receiver enters WALRCV_WAITING state but remains alive, waiting for instructions. The unconditional shutdown can break some monitoring scenarios as the WAL receiver gets repeatedly terminated and re-spawned, causing pg_stat_wal_receiver.status to show a "streaming" instead of "waiting" status, masking the fact that the WAL receiver is waiting for a new TLI and a new LSN to be able to continue streaming. This commit changes the WAL receiver behavior so as the shutdown becomes conditional, with InstallXLogFileSegmentActive being always reset to prevent the regression fixed by b4f584f9d2a1: only terminate the WAL receiver when it is actively streaming (WALRCV_STREAMING, WALRCV_STARTING, or WALRCV_RESTARTING). When in WALRCV_WAITING state, just reset InstallXLogFileSegmentActive flag to allow archive restoration without killing the process. WALRCV_STOPPED and WALRCV_STOPPING are not reachable states in this code path. For the latter, the startup process is the one in charge of setting WALRCV_STOPPING via ShutdownWalRcv(), waiting for the WAL receiver to reach a WALRCV_STOPPED state after switching walRcvState, so WaitForWALToBecomeAvailable() cannot be reached while a WAL receiver is in a WALRCV_STOPPING state. A regression test is added to check that a WAL receiver is not stopped on timeline jump, that fails when the fix of this commit is reverted. Reported-by: Ryan Bird <ryanzxg@gmail.com> Author: Xuneng Zhou <xunengzhou@gmail.com> Reviewed-by: Noah Misch <noah@leadboat.com> Reviewed-by: Michael Paquier <michael@paquier.xyz> Discussion: https://postgr.es/m/19093-c4fff49a608f82a0@postgresql.org Backpatch-through: 13		1 month ago
config	Don't put library-supplied -L/-I switches before user-supplied ones.	5 months ago
contrib	Fix privilege checks for pg_prewarm() on indexes.	2 months ago
doc	Doc: cover index CONCURRENTLY causing errors in INSERT ... ON CONFLICT.	1 month ago
src	Fix unconditional WAL receiver shutdown during stream-archive transition	1 month ago
.abi-compliance-history	Add .abi-compliance-history to back-branches.	2 months ago
.dir-locals.el	…
.editorconfig	…
.git-blame-ignore-revs	Add previous commit to .git-blame-ignore-revs.	2 months ago
.gitattributes	Exclude LLVM files from whitespace checks	1 year ago
.gitignore	Add portlock directory to .gitignore	3 years ago
COPYRIGHT	Align organization wording in copyright statement	7 months ago
GNUmakefile.in	Remove temporary portlock directory during make [dist]clean.	3 years ago
HISTORY	Canonicalize some URLs	6 years ago
Makefile	…
README	Canonicalize some URLs	6 years ago
README.git	Canonicalize some URLs	6 years ago
aclocal.m4	Probe $PROVE not $PERL while checking for modules needed by TAP tests.	4 years ago
configure	Stamp 14.19.	4 months ago
configure.ac	Stamp 14.19.	4 months ago

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/.