Re: backup manifests

Robert Haas <robertmhaas@gmail.com>

From: Robert Haas <robertmhaas@gmail.com>

To: Rushabh Lathia <rushabh.lathia@gmail.com>

Cc: Tels <nospam-pg-abuse@bloodgate.com>, David Steele <david@pgmasters.net>, Andrew Dunstan <andrew.dunstan@2ndquadrant.com>, PostgreSQL Hackers <pgsql-hackers@postgresql.org>, Jeevan Chalke <jeevan.chalke@enterprisedb.com>, vignesh C <vignesh21@gmail.com>

Date: 2019-12-04T18:47:07Z

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 →

Try to avoid compiler warnings in optimized builds.
- 05021a2c0cd2 13.0 landed
Fix option related issues in pg_verifybackup.
- 0a89e93bfaa6 13.0 landed
Add index term for backup manifest in documentation.
- 4db819ba4039 13.0 landed
Code review for backup manifest.
- a2ac73e7be7a 13.0 landed
Document the backup manifest file format.
- 149f2ae88ab0 13.0 landed
Fix typo in pg_validatebackup documentation.
- c4f82a779d26 13.0 landed
Exclude backup_manifest file that existed in database, from BASE_BACKUP.
- 1ec50a81ec0a 13.0 landed
Msys2 tweaks for pg_validatebackup corruption test
- c3e4cbaab936 13.0 landed
Fix resource management bug with replication=database.
- 3e0d80fd8d3d 13.0 cited
Be more careful about time_t vs. pg_time_t in basebackup.c.
- db1531cae009 13.0 cited
pg_validatebackup: Fix 'make clean' to remove tmp_check.
- 9f8f881caa0f 13.0 landed
pg_validatebackup: Also use perl2host in TAP tests.
- 460314db08e8 13.0 landed
Generate backup manifests for base backups, and validate them.
- 0d8c9c1210c4 13.0 landed
Add checksum helper functions.
- c12e43a2e0d4 13.0 landed
pg_waldump: Add a --quiet option.
- ac44367efbef 13.0 landed
Catversion bump for b9b408c48724
- afb5465e0cfc 13.0 cited
pg_basebackup: Refactor code for reading COPY and tar data.
- 431ba7bebf13 13.0 landed
Use a ResourceOwner to track buffer pins in all cases.
- 3cb646264e8c 12.0 cited
Use ARMv8 CRC instructions where available.
- f044d71e331d 11.0 cited
Logical replication support for initial data copy
- 7c4f52409a8c 10.0 cited
Use Intel SSE 4.2 CRC instructions where available.
- 3dc2d62d0486 9.5.0 cited
Switch to CRC-32C in WAL and other places.
- 5028f22f6eb0 9.5.0 cited
Remove support for 64-bit CRC.
- 404bc51cde9d 9.5.0 cited
Change CRCs in WAL records from 64bit to 32bit for performance reasons.
- 21fda22ec46d 8.1.0 cited

On Wed, Dec 4, 2019 at 1:01 PM Rushabh Lathia <rushabh.lathia@gmail.com> wrote:
> As per the  discussion on the thread, here is the patch which
>
> a) Make checksum for manifest file optional.
> b) Allow user to choose a particular algorithm.
>
> Currently with the WIP patch SHA256 and CRC checksum algorithm
> supported.  Patch also changed the manifest file format to append
> the used algorithm name before the checksum, this way it will be
> easy to validator to know which algorithm to used.
>
> Ex:
> ./db/bin/pg_basebackup -D bksha/ --manifest-with-checksums=SHA256
>
> $ cat bksha/backup_manifest  | more
> PostgreSQL-Backup-Manifest-Version 1
> File backup_label 226 2019-12-04 17:46:46 GMT SHA256:7cf53d1b9facca908678ab70d93a9e7460cd35cedf7891de948dcf858f8a281a
> File pg_xact/0000 8192 2019-12-04 17:46:46 GMT SHA256:8d2b6cb1dc1a6e8cee763b52d75e73571fddce06eb573861d44082c7d8c03c26
>
> ./db/bin/pg_basebackup -D bkcrc/ --manifest-with-checksums=CRC
> PostgreSQL-Backup-Manifest-Version 1
> File backup_label 226 2019-12-04 17:58:40 GMT CRC:343138313931333134
> File pg_xact/0000 8192 2019-12-04 17:46:46 GMT CRC:363538343433333133
>
> Pending TODOs:
> - Documentation update
> - Code cleanup
> - Testing.
>
> I will further continue to work on the patch and meanwhile feel free to provide
> thoughts/inputs.

+ initilize_manifest_checksum(&cCtx);

Spelling.

-

Spurious.

+ case MC_CRC:
+ INIT_CRC32C(cCtx->crc_ctx);

Suggest that we do CRC -> CRC32C throughout the patch. Someone might
conceivably want some other CRC variant, mostly likely 64-bit, in the
future.

+final_manifest_checksum(ChecksumCtx *cCtx, char *checksumbuf)

finalize

  printf(_("      --manifest-with-checksums\n"
- "                         do calculate checksums for manifest files\n"));
+ "                         calculate checksums for manifest files
using provided algorithm\n"));

Switch name is wrong. Suggest --manifest-checksums.
Help usually shows that an argument is expected, e.g.
--manifest-checksums=ALGORITHM or
--manifest-checksums=sha256|crc32c|none

This seems to apply over some earlier version of the patch.  A
consolidated patch, or the whole stack, would be better.

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