Horton

Re: refactoring basebackup.c (zstd workers)

Robert Haas <robertmhaas@gmail.com>

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From: Robert Haas <robertmhaas@gmail.com>
To: Justin Pryzby <pryzby@telsasoft.com>
Cc: Dipesh Pandit <dipesh.pandit@gmail.com>, Andres Freund <andres@anarazel.de>, Jeevan Ladhe <jeevanladhe.os@gmail.com>, Alvaro Herrera <alvherre@alvh.no-ip.org>, "Shinoda, Noriyoshi (PN Japan FSIP)" <noriyoshi.shinoda@hpe.com>, Abhijit Menon-Sen <ams@toroid.org>, Dmitry Dolgov <9erthalion6@gmail.com>, Jeevan Ladhe <jeevan.ladhe@enterprisedb.com>, Mark Dilger <mark.dilger@enterprisedb.com>, "pgsql-hackers@postgresql.org" <pgsql-hackers@postgresql.org>, tushar <tushar.ahuja@enterprisedb.com>
Date: 2022-03-21T01:38:44Z
Lists: pgsql-hackers

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →

  1. Document BaseBackupSync and BaseBackupWrite wait events.

  2. Support long distance matching for zstd compression

  3. Fix possible NULL-pointer-deference in backup_compression.c.

  4. Allow parallel zstd compression when taking a base backup.

  5. Make PostgreSQL::Test::Cluster::run_log() return a useful value.

  6. Fix a few goofs in new backup compression code.

  7. Replace BASE_BACKUP COMPRESSION_LEVEL option with COMPRESSION_DETAIL.

  8. Add 'basebackup_to_shell' contrib module.

  9. Allow extensions to add new backup targets.

  10. Change HAVE_LIBLZ4 and HAVE_LIBZSTD tests to USE_LZ4 and USE_ZSTD.

  11. pg_basebackup: Clean up some bogus file extension tests.

  12. pg_basebackup: Avoid unclean failure with server-compression and -D -.

  13. Fix LZ4 tests for remaining buffer space.

  14. Add support for zstd base backup compression.

  15. pg_basebackup: Allow client-side LZ4 (de)compression.

  16. Add suport for server-side LZ4 base backup compression.

  17. Add min() and max() aggregates for xid8.

  18. Remove superfluous variable.

  19. pg_basebackup: Cleaner handling when compression is multiply specified.

  20. Allow server-side compression to be used with -Fp.

  21. pg_basebackup: Fix a couple of recently-introduced bugs.

  22. Tidy up a few cosmetic issues related to pg_basebackup.

  23. Server-side gzip compression.

  24. Unbreak pg_basebackup/t/010_pg_basebackup.pl on msys

  25. Suppress variable-set-but-not-used warning from clang 13.

  26. Extend the options of pg_basebackup to control compression

  27. Support base backup targets.

  28. Modify pg_basebackup to use a new COPY subprotocol for base backups.

  29. Document that tar archives are now properly terminated.

  30. Fix thinko in bbsink_throttle_manifest_contents.

  31. Have the server properly terminate tar archives.

  32. Minimal fix for unterminated tar archive problem.

  33. Introduce 'bbstreamer' abstraction to modularize pg_basebackup.

  34. Introduce 'bbsink' abstraction to modularize base backup code.

  35. Refactor basebackup.c's _tarWriteDir() function.

  36. Flexible options for CREATE_REPLICATION_SLOT.

  37. Flexible options for BASE_BACKUP.

On Sun, Mar 20, 2022 at 3:40 PM Justin Pryzby <pryzby@telsasoft.com> wrote:
> The user-facing docs are already standardized using "compression method", with
> 2 exceptions, of which one is contrib/ and the other is what I'm suggesting to
> make consistent here.
>
> $ git grep 'compression algorithm' doc
> doc/src/sgml/pgcrypto.sgml:    Which compression algorithm to use.  Only available if
> doc/src/sgml/ref/pg_basebackup.sgml:        compression algorithm is selected, or if server-side compression

Well, if you just count the number of occurrences of each string in
the documentation, sure. But all of the ones that are talking about a
compression method seem to have to do with configurable TOAST
compression, and the fact that the documentation for that feature is
more extensive than for the pre-existing feature that refers to a
compression algorithm does not, at least in my view, turn it into a
project standard from which no deviation is permitted.

> > Did the latter. The former would need to be fixed in a bunch of places
> > and while I'm happy to accept an expert opinion on exactly what needs
> > to be done here, I don't want to try to do it and do it wrong. Better
> > to let someone with good knowledge of the subject matter patch it up
> > later than do a crummy job now.
>
> I believe it just needs _("foo")
> See git grep '= _('

Hmm. Maybe.

> I mentioned another issue off-list:
> pg_basebackup.c:2741:10: warning: suggest parentheses around assignment used as truth value [-Wparentheses]
>  2741 |   Assert(compressloc = COMPRESS_LOCATION_SERVER);
>       |          ^~~~~~~~~~~
> pg_basebackup.c:2741:3: note: in expansion of macro ‘Assert’
>  2741 |   Assert(compressloc = COMPRESS_LOCATION_SERVER);
>
> This crashes the server using your v2 patch:
>
> src/bin/pg_basebackup/pg_basebackup --wal-method fetch -Ft -D - -h /tmp --no-sync --no-manifest --compress=server-zstd:level, |wc -c

Well that's unfortunate. Will fix.

> I wonder whether the syntax should really use both ":" and ",".
> Maybe ":" isn't needed at all.

I don't think we should treat the compression method name in the same
way as a compression algorithm option.

> This patch also needs to update the other user-facing docs.

Which ones exactly?

> typo: contain a an

OK, will fix.

-- 
Robert Haas
EDB: http://www.enterprisedb.com