Horton

Re: trying again to get incremental backup

Alexander Law <exclusion@gmail.com>

View thread View on postgr.es
From: Alexander Lakhin <exclusion@gmail.com>
To: Robert Haas <robertmhaas@gmail.com>
Cc: Jakub Wartak <jakub.wartak@enterprisedb.com>, Alvaro Herrera <alvherre@alvh.no-ip.org>, Andres Freund <andres@anarazel.de>, Peter Eisentraut <peter@eisentraut.org>, Dilip Kumar <dilipbalaut@gmail.com>, "pgsql-hackers@postgresql.org" <pgsql-hackers@postgresql.org>
Date: 2023-12-21T15:00:00Z
Lists: pgsql-hackers

Attachments

21.12.2023 15:07, Robert Haas wrote:
> On Wed, Dec 20, 2023 at 11:00 PM Alexander Lakhin <exclusion@gmail.com> wrote:
>> I've found several typos/inconsistencies introduced with 174c48050 and
>> dc2123400. Maybe you would want to fix them, while on it?:
> That's an impressively long list of mistakes in something I thought
> I'd been careful about. Sigh.
>
> I don't suppose you could provide these corrections in the form of a
> patch? I don't really want to run these sed commands across the entire
> tree and then try to figure out what's what...

Please look at the attached patch; it corrects all 29 items ("recods"
fixed in two places), but maybe you find some substitutions wrong...

I've also observed that those commits introduced new warnings:
$ CC=gcc-12 CPPFLAGS="-Wtype-limits" ./configure -q && make -s -j8
reconstruct.c: In function ‘read_bytes’:
reconstruct.c:511:24: warning: comparison of unsigned expression in ‘< 0’ is always false [-Wtype-limits]
   511 |                 if (rb < 0)
       |                        ^
reconstruct.c: In function ‘write_reconstructed_file’:
reconstruct.c:650:40: warning: comparison of unsigned expression in ‘< 0’ is always false [-Wtype-limits]
   650 |                                 if (rb < 0)
       |                                        ^
reconstruct.c:662:32: warning: comparison of unsigned expression in ‘< 0’ is always false [-Wtype-limits]
   662 |                         if (wb < 0)

There are also two deadcode.DeadStores complaints from clang. First one is
about:
         /*
          * Align the wait time to prevent drift. This doesn't really matter,
          * but we'd like the warnings about how long we've been waiting to say
          * 10 seconds, 20 seconds, 30 seconds, 40 seconds ... without ever
          * drifting to something that is not a multiple of ten.
          */
         timeout_in_ms -=
             TimestampDifferenceMilliseconds(current_time, initial_time) %
             timeout_in_ms;
It looks like this timeout is really not used.

And the minor one (similar to many existing, maybe doesn't deserve fixing):
walsummarizer.c:808:5: warning: Value stored to 'summary_end_lsn' is never read [deadcode.DeadStores]
                                         summary_end_lsn = private_data->read_upto;
                                         ^ ~~~~~~~~~~~~~~~~~~~~~~~

>> Also, a comment above MaybeRemoveOldWalSummaries() basically repeats a
>> comment above redo_pointer_at_last_summary_removal declaration, but
>> perhaps it should say about removing summaries instead?
> Wow, yeah. Thanks, will fix.

Thank you for paying attention to it!

Best regards,
Alexander

Commits

  1. Minor fixes to pg_combinebackup and its documentation.

  2. Fix defects in PrepareForIncrementalBackup.

  3. Add WALSummarizerLock to wait_event_names.txt

  4. Initialize variable to placate compiler.

  5. Replace nonsense comment with a relevant one.

  6. Fix numerous typos in incremental backup commits.

  7. Add support for incremental backup.

  8. Add a new WAL summarizer process.

  9. Move src/bin/pg_verifybackup/parse_manifest.c into src/common.

  10. Fix brown paper bag bug in 5c47c6546c413d5eb51c1626070a807026e6139d.

  11. Rename pg_verifybackup's JsonManifestParseContext callback functions.

  12. Rename JsonManifestParseContext callbacks.

  13. Change how a base backup decides which files have checksums.

  14. Change struct tablespaceinfo's oid member from 'char *' to 'Oid'

  15. Refactor parse_filename_for_nontemp_relation to parse more.

  16. During online checkpoints, insert XLOG_CHECKPOINT_REDO at redo point.

  17. In basebackup.c, refactor to create read_file_data_into_buffer.

  18. In basebackup.c, refactor to create verify_page_checksum.

  19. Report syncscan position at end of scan.

  20. Exclude additional directories in pg_basebackup

  21. Add new JSON processing functions and parser API.