NOAI

[MMeent]

We can't FlushOneBuffer when we're in redo-only mode on PageServer, so make execution of that function conditional on us not running in pageserver walredo mode.

Problem

https://neondb.slack.com/archives/C033RQ5SPDH/p1726847895245409

Summary of changes

We make sure to not call into FlushOneBuffer when we're in WALRedoPostgres mode.

See

• PG14: Fix: Don't flush a buffer in am_wal_redo_postgres mode postgres#510
• PG15: Fix: Don't flush a buffer in am_wal_redo_postgres mode postgres#511
• PG16: Fix: Don't flush a buffer in am_wal_redo_postgres mode postgres#513
• PG17: Fix: Don't flush a buffer in am_wal_redo_postgres mode postgres#512

Checklist before requesting a review

• I have performed a self-review of my code.
• If it is a core feature, I have added thorough tests.
• Do we need to implement analytics? if so did you add the relevant metrics to the dashboard?
• If this PR requires public announcement, mark it with /release-notes label and add several sentences in this section.

Checklist before merging

• Do not forget to reformat commit message to not include the above checklist

[skyzh]

works with my testing

[hlinnaka]

Can we add a test to the test suite, please?

[MMeent]

Can we add a test to the test suite, please?

I've updated the test that checks compatibility with unlogged tables, would that be sufficient?

[github-actions]

5029 tests run: 4865 passed, 0 failed, 164 skipped (full report)

---

Flaky tests (4)

Postgres 17

• test_pageserver_compaction_smoke: release-arm64

Postgres 16

• test_subscriber_synchronous_commit: release-arm64
• test_neon_cli_basics: release-arm64

Postgres 14

• test_lfc_resize: release-arm64

Code coverage* (full report)

• functions: 32.1% (7446 of 23213 functions)
• lines: 49.9% (59956 of 120174 lines)

* collected from Rust tests only

---

_{The comment gets automatically updated with the latest test results
7eb96e2 at 2024-09-23T21:26:16.583Z :recycle:}

[MMeent]

cc @hlinnaka

[arpad-m]

very strange @hlinnaka @bayandin link:

  HEAD is now at 4d5add9 compact_level0_phase1: remove final traces of value access mode config (#8935)
  M	vendor/postgres-v14
  M	vendor/postgres-v15
  M	vendor/postgres-v16
  M	vendor/postgres-v17
  vendor/postgres-v16
  fatal: unable to read tree (1d7081a3b076ddf5086e0b118d4329820e6a7427)
  fatal: Unable to checkout '1d7081a3b076ddf5086e0b118d4329820e6a7427' in submodule path 'vendor/postgres-v16'
  Error: __Line:133__Error: Could not checkout submodule hash referenced by main. It may not be pushed to remote or deeper than workflow shallow clone