Horton

Re: backup manifests and contemporaneous buildfarm failures

Robert Haas <robertmhaas@gmail.com>

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From: Robert Haas <robertmhaas@gmail.com>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Fabien COELHO <coelho@cri.ensmp.fr>, Alvaro Herrera <alvherre@2ndquadrant.com>, David Steele <david@pgmasters.net>, Andres Freund <andres@anarazel.de>, Noah Misch <noah@leadboat.com>, Stephen Frost <sfrost@snowman.net>, Amit Kapila <amit.kapila16@gmail.com>, Suraj Kharage <suraj.kharage@enterprisedb.com>, tushar <tushar.ahuja@enterprisedb.com>, Rajkumar Raghuwanshi <rajkumar.raghuwanshi@enterprisedb.com>, Rushabh Lathia <rushabh.lathia@gmail.com>, Tels <nospam-pg-abuse@bloodgate.com>, Andrew Dunstan <andrew.dunstan@2ndquadrant.com>, PostgreSQL Hackers <pgsql-hackers@postgresql.org>, Jeevan Chalke <jeevan.chalke@enterprisedb.com>, vignesh C <vignesh21@gmail.com>, Thomas Munro <thomas.munro@gmail.com>
Date: 2020-04-04T17:05:22Z
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. Try to avoid compiler warnings in optimized builds.

  2. Fix option related issues in pg_verifybackup.

  3. Add index term for backup manifest in documentation.

  4. Code review for backup manifest.

  5. Document the backup manifest file format.

  6. Fix typo in pg_validatebackup documentation.

  7. Exclude backup_manifest file that existed in database, from BASE_BACKUP.

  8. Msys2 tweaks for pg_validatebackup corruption test

  9. Fix resource management bug with replication=database.

  10. Be more careful about time_t vs. pg_time_t in basebackup.c.

  11. pg_validatebackup: Fix 'make clean' to remove tmp_check.

  12. pg_validatebackup: Also use perl2host in TAP tests.

  13. Generate backup manifests for base backups, and validate them.

  14. Add checksum helper functions.

  15. pg_waldump: Add a --quiet option.

  16. Catversion bump for b9b408c48724

  17. pg_basebackup: Refactor code for reading COPY and tar data.

  18. Use a ResourceOwner to track buffer pins in all cases.

  19. Use ARMv8 CRC instructions where available.

  20. Logical replication support for initial data copy

  21. Use Intel SSE 4.2 CRC instructions where available.

  22. Switch to CRC-32C in WAL and other places.

  23. Remove support for 64-bit CRC.

  24. Change CRCs in WAL records from 64bit to 32bit for performance reasons.

On Sat, Apr 4, 2020 at 10:57 AM Tom Lane <tgl@sss.pgh.pa.us> wrote:
> It's not so surprising that we could get a different result that way
> from a CLOBBER_CACHE_ALWAYS animal like hyrax, since CCA-forced
> cache reloads would cause extra stack expenditure at a lot of places.
> And it could vary depending on totally random details, like the number
> of local variables in seemingly unrelated code.

Oh, yeah. That's unfortunate.

> What is odd is that
> (AFAIR) we've never seen this before.  Maybe somebody recently added
> an error cursor callback in a place that didn't have it before, and
> is involved in SQL-function processing?  None of the commits leading
> up to the earlier failure look promising for that, though.

The relevant range of commits (e8b1774fc2 to a7b9d24e4e) includes an
ereport change (bda6dedbea) and a couple of "simple expression"
changes (8f59f6b9c0, fbc7a71608) but I don't know exactly why they
would have caused this. It seems at least possible, though, that
changing the return type of functions involved in error reporting
would slightly change the amount of stack space used; and the others
are related to SQL-function processing. Other than experimenting on
that machine, I'm not sure how we could really determine the relevant
factors here.

-- 
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company