chore: update data_substrate — fix BackFill dirty_data_key_count_ underflow

[githubzilla]

Summary

Update data_substrate submodule to include the fix for an intermittent assertion failure during cluster scale-out.

• data_substrate PR: fix: reorder BackFill operations to prevent dirty_data_key_count_ underflow tx_service#465

Problem

test_add_node_with_double_write intermittently crashes with:

eloqkv: cc_shard.cpp:428: void txservice::CcShard::AdjustDataKeyStats(...):
Assertion `dirty_delta >= 0 || dirty_data_key_count_ >= static_cast<size_t>(-dirty_delta)' failed.

dirty_data_key_count_ is being decremented below zero — more entries are "un-dirtied" than were ever counted as dirty.

Root Cause

BackFill() in TemplateCcMap called operations in the wrong order:

1. SetCkptTs(commit_ts) — sets the flush bit (marks entry as persistent)
2. OnFlushed() — accounting sees the entry as persistent, no dirty-count increment
3. SetCommitTsPayloadStatus(commit_ts, status) — overwrites the field entirely, clearing the flush bit

The entry ends up dirty with no matching dirty-count increment. When checkpoint later flushes and decrements the counter, it underflows.

Fix (in data_substrate)

1. template_cc_map.h — BackFill(): Reorder so SetCommitTsPayloadStatus() runs before SetCkptTs(), preserving the flush bit. Add OnCommittedUpdate() to reconcile stats.
2. template_cc_map.h — RemoteReadOutsideCc(): Add OnCommittedUpdate() for consistency.
3. cc_req_misc.cpp — UpdateCceCkptTsCc::Execute(): Relax 4 assertions that checked !IsPersistent() — BackFill can now legitimately mark entries persistent before the checkpoint callback fires.

Testing

Ran test_add_node_with_double_write 6 consecutive times after the fix — all passed with zero assertion failures:

Run	Result	Time
1	OK	589s
2	OK	560s
3	OK	583s
4	OK	665s
5	OK	621s
6	OK	603s

Summary by CodeRabbit

• Chores
  • Updated an internal dependency reference to a newer commit; no user-facing functionality changed.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro

Run ID: 87dd4a8b-eb59-4863-aad9-be3c15173679

📥 Commits

Reviewing files that changed from the base of the PR and between ec5f92a and da92602.

📒 Files selected for processing (1)

• data_substrate

🚧 Files skipped from review as they are similar to previous changes (1)

• data_substrate

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Walkthrough

This PR updates the data_substrate git submodule pointer from 1a4729b71e08b72f0461bd3fbe107fd728592516 to 60c8665f33beca1e87d5c9d5290b4d80588b075c. No functional code changes were made.

Changes

Cohort / File(s)	Summary
Submodule Update ./.gitmodules, path/to/submodules/data_substrate	Bumped data_substrate submodule commit pointer to 60c8665f33be... (metadata-only change).

Estimated code review effort

🎯 1 (Trivial) | ⏱️ ~1 minute

Possibly related PRs

• subm #456: Also updates the data_substrate submodule pointer to a different commit — closely related metadata change.
• update subm #379: Submodule pointer-only update for data_substrate, no code changes.
• chore:update submodule data_substrate #435: Previous PR that updated data_substrate submodule to an intermediate commit.

Suggested reviewers

• thweetkomputer
• liunyl
• MrGuin

Poem

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🚥 Pre-merge checks | ✅ 3

✅ Passed checks (3 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title accurately summarizes the main change: updating the data_substrate submodule to fix a BackFill dirty_data_key_count_ underflow issue. It is concise, specific, and directly related to the primary purpose of the PR.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.

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