Re: backup manifests

Robert Haas <robertmhaas@gmail.com>

From: Robert Haas <robertmhaas@gmail.com>
To: David Steele <david@pgmasters.net>
Cc: "pgsql-hackers@postgresql.org" <pgsql-hackers@postgresql.org>
Date: 2019-09-20T14:59:55Z
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 Fri, Sep 20, 2019 at 9:46 AM Robert Haas <robertmhaas@gmail.com> wrote:
> - appendStringInfo et. al. I don't think it would be that hard to move
> this to src/common, but I'm also not sure it really solves the
> problem, because StringInfo has a 1GB limit, and there's no rule at
> all that a backup manifest has got to be less than 1GB.

Hmm.  That's actually going to be a problem on the server side, no
matter what we do on the client side.  We have to send the manifest
after we send everything else, so that we know what we sent. But if we
sent a lot of files, the manifest might be really huge. I had been
thinking that we would generate the manifest on the server and send it
to the client after everything else, but maybe this is an argument for
generating the manifest on the client side and writing it
incrementally. That would require the client to peek at the contents
of every tar file it receives all the time, which it currently doesn't
need to do, but it does peek inside them a little bit, so maybe it's
OK.

Another alternative would be to have the server spill the manifest in
progress to a temp file and then stream it from there to the client.

Thoughts?

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