24-4: Fix follower assertions on attach snapshot races

[snaury]

Changelog entry

Fixed a rare assertion (process crash) when followers attached to leaders with an inconsistent snapshot. Fixes #15042.

Changelog category

• Bugfix

Description for reviewers

Followers produced crashes in production periodically complaining about log reordering, with an error message indicating as if they tried to apply a duplicate redo log entry (which shouldn't have been possible). Turns out snapshots created within read-only transactions that used QueueScan (e.g. ReadTable and ScanQuery) persisted an incorrect Serial field (a monotonically increasing change number) that was equal to the next transaction. When follower attached at just the right time, it could bootstrap from such a snapshot, and discover the next commit has the same Serial, indicating a duplicate or reordered change.

Thankfully this didn't affect leaders, since they apply pre-snapshot and post-snapshot redo log entries together, and only use snapshot serial as a hint of previously compacted changes. So even though snapshot technically had an inconsistent value it was self-healing and couldn't produce any externally visible inconsistencies.

[github-actions]

⚪ 2025-02-26 14:23:21 UTC Pre-commit check for b9dbf12 has started.
⚪ 2025-02-26 14:26:07 UTC Build linux-x86_64-relwithdebinfo is running...
🟢 2025-02-26 15:06:43 UTC Build successful.
⚪ 2025-02-26 15:06:59 UTC Tests are running...
🔴 2025-02-26 16:36:55 UTC Some tests failed, follow the links below.

Test history | Test log

TESTS	PASSED	ERRORS	FAILED	SKIPPED	MUTED?
15019	13659	0	23	1301	36

🟢 2025-02-26 16:37:52 UTC ydbd size 8.3 GiB changed* by +792 Bytes, which is < 100.0 KiB vs stable-24-4: OK

ydbd size dash	stable-24-4: bd3c9d7	merge: b9dbf12	diff	diff %
ydbd size	8 896 418 032 Bytes	8 896 418 824 Bytes	+792 Bytes	+0.000%
ydbd stripped size	484 973 160 Bytes	484 973 224 Bytes	+64 Bytes	+0.000%

^{*please be aware that the difference is based on comparing your commit and the last completed build from the post-commit, check comparation}

[github-actions]

⚪ 2025-02-26 14:23:43 UTC Pre-commit check for b9dbf12 has started.
⚪ 2025-02-26 14:26:24 UTC Build linux-x86_64-release-asan is running...
🟢 2025-02-26 14:51:03 UTC Build successful.
⚪ 2025-02-26 14:51:21 UTC Tests are running...
🔴 2025-02-26 17:07:16 UTC Some tests failed, follow the links below.

Test history | Test log

TESTS	PASSED	ERRORS	FAILED	SKIPPED	MUTED?
10586	10476	0	36	26	48

🟢 2025-02-26 17:08:33 UTC ydbd size 5.6 GiB changed* by +512 Bytes, which is < 100.0 KiB vs stable-24-4: OK

ydbd size dash	stable-24-4: bd3c9d7	merge: b9dbf12	diff	diff %
ydbd size	6 026 457 120 Bytes	6 026 457 632 Bytes	+512 Bytes	+0.000%
ydbd stripped size	1 508 253 056 Bytes	1 508 253 120 Bytes	+64 Bytes	+0.000%

^{*please be aware that the difference is based on comparing your commit and the last completed build from the post-commit, check comparation}