Horton

Re: should frontend tools use syncfs() ?

Nathan Bossart <nathandbossart@gmail.com>

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From: Nathan Bossart <nathandbossart@gmail.com>
To: Justin Pryzby <pryzby@telsasoft.com>
Cc: Michael Paquier <michael@paquier.xyz>, Thomas Munro <thomas.munro@gmail.com>, David Steele <david@pgmasters.net>, Fujii Masao <masao.fujii@oss.nttdata.com>, Bruce Momjian <bruce@momjian.us>, Tom Lane <tgl@sss.pgh.pa.us>, Michael Brown <michael.brown@discourse.org>, pgsql-hackers@postgresql.org
Date: 2023-08-08T20:06:06Z
Lists: pgsql-hackers 
I ran a couple of tests for pg_upgrade with 100k tables (created using the
script here [0]) in order to demonstrate the potential benefits of this
patch.

pg_upgrade --sync-method fsync
    real    5m50.072s
    user    0m10.606s
    sys     0m40.298s

pg_upgrade --sync-method syncfs
    real    3m44.096s
    user    0m8.906s
    sys     0m26.398s

pg_upgrade --no-sync
    real    3m27.697s
    user    0m9.056s
    sys     0m26.605s

[0] https://postgr.es/m/3612876.1689443232%40sss.pgh.pa.us

-- 
Nathan Bossart
Amazon Web Services: https://aws.amazon.com

Commits

  1. Adjust documentation for syncfs().

  2. Improve the naming in wal_sync_method code.

  3. Allow using syncfs() in frontend utilities.

  4. Add support for syncfs() in frontend support functions.

  5. Make enum for sync methods available to frontend code.

  6. Move PG_TEMP_FILE* macros to file_utils.h.

  7. Change client-side fsync_fname() to report errors fatally