Horton

Re: backup manifests

Andres Freund <andres@anarazel.de>

View thread
From: Andres Freund <andres@anarazel.de>
To: Robert Haas <robertmhaas@gmail.com>
Cc: David Steele <david@pgmasters.net>, 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>
Date: 2020-04-02T18:23:46Z
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.

Hi,

On 2020-04-02 14:16:27 -0400, Robert Haas wrote:
> On Thu, Apr 2, 2020 at 1:23 PM Andres Freund <andres@anarazel.de> wrote:
> > I suspect its possible to control the timing by preventing the
> > checkpoint at the end of recovery from completing within a relevant
> > timeframe. I think configuring a large checkpoint_timeout and using a
> > non-fast base backup ought to do the trick. The state can be advanced by
> > separately triggering an immediate checkpoint? Or by changing the
> > checkpoint_timeout?
> 
> That might make the window fairly wide on normal systems, but I'm not
> sure about Raspberry Pi BF members or things running
> CLOBBER_CACHE_ALWAYS/RECURSIVELY. I guess I could try it.

You can set checkpoint_timeout to be a day. If that's not enough, well,
then I think we have other problems.


> > FWIW, the only check I'd really like to see in this release is the
> > crosscheck with the files length and the actually read data (to be able
> > to disagnose FS issues).
> 
> Not sure I understand this comment. Isn't that a subset of what the
> patch already does? Are you asking for something to be changed?

Yes, I am asking for something to be changed: I'd like the code that
read()s the file when computing the checksum to add up how many bytes
were read, and compare that to the size in the manifest. And if there's
a difference report an error about that, instead of a checksum failure.

I've repeatedly seen filesystem issues lead to to earlier EOFs when
read()ing than what stat() returns. It'll be pretty annoying to have to
debug a general "checksum failure", rather than just knowing that
reading stopped after 100MB of 1GB.

Greetings,

Andres Freund