Horton

Re: Back-patch of: avoid multiple hard links to same WAL file after a crash

Noah Misch <noah@leadboat.com>

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From: Noah Misch <noah@leadboat.com>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Michael Paquier <michael@paquier.xyz>, Nathan Bossart <nathandbossart@gmail.com>, Andres Freund <andres@anarazel.de>, Robert Pang <robertpang@google.com>, Kyotaro Horiguchi <horikyota.ntt@gmail.com>, robertmhaas@gmail.com, pgsql-hackers@postgresql.org
Date: 2025-04-05T19:13:39Z
Lists: pgsql-hackers 
On Sat, Apr 05, 2025 at 11:07:13AM -0400, Tom Lane wrote:
> Michael Paquier <michael@paquier.xyz> writes:
> > On Wed, Apr 02, 2025 at 05:29:00PM -0700, Noah Misch wrote:
> >> Here it is.  Making it fail three times took looping 1383s, 5841s, and 2594s.
> >> Hence, it couldn't be expected to catch the regression before commit, but it
> >> would have made sufficient buildfarm and CI noise in the day after commit.
> 
> > Hmm.  Not much of a fan of the addition of a test that has less than
> > 1% of reproducibility for the problem, even if it's good to see that
> > this can be made portable to run down to v13.
> 
> Yeah, it's good to have a test but I doubt we should commit it.
> Too many buildfarm cycles will be expended for too little result.

Current extent of our archive recovery restartpoint test coverage:

$ grep -c 'restartpoint starting' $(grep -rl 'restored log file' **/log) | grep -v :0
src/bin/pg_combinebackup/tmp_check/log/002_compare_backups_pitr1.log:1
src/test/recovery/tmp_check/log/020_archive_status_standby2.log:1
src/test/recovery/tmp_check/log/002_archiving_standby.log:1
src/test/recovery/tmp_check/log/020_archive_status_standby.log:1
src/test/recovery/tmp_check/log/035_standby_logical_decoding_standby.log:2

Since the 2025-02 releases made non-toy-size archive recoveries fail easily,
that's not enough.  If the proposed 3-second test is the wrong thing, what
instead?

Commits

  1. Test restartpoints in archive recovery.

  2. Reset InstallXLogFileSegmentActive after walreceiver self-initiated exit.

  3. Skip WAL recycling and preallocation during archive recovery.

  4. Don't ERROR on PreallocXlogFiles() race condition.

  5. Revert "Add HINT for restartpoint race with KeepFileRestoredFromArchive()."

  6. Remove XLogFileInit() ability to unlink a pre-existing file.

  7. In XLogFileInit(), fix *use_existent postcondition to suit callers.

  8. Remove XLogFileInit() ability to skip ControlFileLock.

  9. Replace durable_rename_excl() by durable_rename(), take two

  10. Add HINT for restartpoint race with KeepFileRestoredFromArchive().

  11. Remove durable_rename_excl()

  12. Replace existing durable_rename_excl() calls with durable_rename()