Re: backup manifests

Rushabh Lathia <rushabh.lathia@gmail.com>

From: Rushabh Lathia <rushabh.lathia@gmail.com>
To: Andrew Dunstan <andrew.dunstan@2ndquadrant.com>
Cc: Robert Haas <robertmhaas@gmail.com>, PostgreSQL Hackers <pgsql-hackers@postgresql.org>, Jeevan Chalke <jeevan.chalke@enterprisedb.com>, vignesh C <vignesh21@gmail.com>, David Steele <david@pgmasters.net>
Date: 2019-11-20T05:28:18Z
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 Tue, Nov 19, 2019 at 7:19 PM Andrew Dunstan <
andrew.dunstan@2ndquadrant.com> wrote:

>
> On 11/19/19 5:00 AM, Rushabh Lathia wrote:
> >
> >
> > My colleague Suraj did testing and noticed the performance impact
> > with the checksums.   On further testing, he found that specifically with
> > sha its more of performance impact.
> >
> >
>
> I admit I haven't been following along closely, but why do we need a
> cryptographic checksum here instead of, say, a CRC? Do we think that
> somehow the checksum might be forged? Use of cryptographic hashes as
> general purpose checksums has become far too common IMNSHO.
>

Yeah, maybe.  I was thinking to give the user an option to choose checksums
algorithms (SHA256. CRC, MD5, etc),  so that they are open to choose what
suites for their environment.

If we decide to do that than we need  to store the checksums algorithm
information in the manifest file.

Thoughts?



>
> cheers
>
>
> andrew
>
>
> --
> Andrew Dunstan                https://www.2ndQuadrant.com
> PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
>
>

-- 
Rushabh Lathia