Fix remote scanslice request

[yangsw26]

Send remote scan slice request to correct core.

Summary by CodeRabbit

• Bug Fixes

  • Improved null-pointer handling during range initialization to prevent crashes.
  • Enhanced error handling for initialization failures with proper logging and graceful abort mechanisms.

• Quality Improvements

  • Added fault-injection capabilities for testing range-split scenarios.
  • Optimized task distribution logic for improved load balancing across system cores.

[coderabbitai]

Walkthrough

The changes add null-safety checks for range initialization, implement conditional CCM initialization with retry logic during split-range operations, introduce a fault-injection hook to skip auto-split-range data sync tasks, and modify scan-slice task dispatch to compute destination cores dynamically based on range ID instead of pinning to core 0.

Changes

Cohort / File(s)	Summary
Range CCMap Null Handling tx_service/include/cc/range_cc_map.h	Guard against TypedStoreRange() returning nullptr by storing pointer and conditionally calling PostCkptSize(); add CCM initialization with retry logic on split-range operations, handling null returns and initialization failures with error logging and request abortion.
Fault Injection for Split Range Data Sync tx_service/src/cc/local_cc_shards.cpp	Add fault-injection hook at CreateSplitRangeDataSyncTask entry point for term_skip_auto_split_range fault name, enabling early return to prevent metadata lock acquisition, DataSyncStatus creation, and task enqueuing.
Scan-Slice Core Dispatch Logic tx_service/src/remote/cc_stream_receiver.cpp	Replace static core 0 pinning with dynamic destination-core computation using (range_id & 0x3FF) % local_shards_.Count() formula for scan-slice task enqueue operations.

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~20 minutes

Possibly related PRs

• Update datasyncscan execution #324: Modifies scan-slice datasync dispatch and pinning behavior alongside split-range operations, related through core dispatching strategies.
• Change bucket num to 1024 and dss support multi-shards #199: Implements matching shard-to-core mapping formula using (shard_code & 0x3FF) pattern consistent with the main PR's range-id dispatch computation.

Suggested reviewers

• liunyl
• githubzilla

Poem

🐰 A rabbit checks each pointer's fate,
Null-guards the ranges, keeps them straight!
When faults inject, we hop, skip, flee—
And scatter tasks to cores with glee! 🌰

🚥 Pre-merge checks | ❌ 3

❌ Failed checks (2 warnings, 1 inconclusive)

Check name	Status	Explanation	Resolution
Description check	⚠️ Warning	The pull request description is minimal and lacks required sections from the template such as tests, documentation, issue references, and test suite confirmation.	Expand the description to include test coverage, documentation references, issue links, and confirmation of passing the specified test suites per the template.
Docstring Coverage	⚠️ Warning	Docstring coverage is 0.00% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.
Title check	❓ Inconclusive	The title 'Fix remote scanslice request' is partially related to the changeset but lacks specificity; it describes the problem area rather than the specific solution implemented (routing to correct core).	Consider a more specific title like 'Route remote scan slice requests to correct core based on range ID' to better communicate the actual implementation change.

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✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch fix_remotescanslice

📝 Coding Plan

• Generate coding plan for human review comments

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[coderabbitai]

Actionable comments posted: 1

🧹 Nitpick comments (1)

tx_service/src/cc/local_cc_shards.cpp (1)

2955-2955: Use non-debug logging for this injected skip path.

At Line 2955, DLOG(INFO) may be invisible in non-debug builds. Prefer a regular LOG(WARNING) (with table/range/term context) so fault-triggered behavior is diagnosable during staging/chaos runs.

🤖 Prompt for AI Agents

Verify each finding against the current code and only fix it if needed.

In `@tx_service/src/cc/local_cc_shards.cpp` at line 2955, Replace the debug-only
DLOG(INFO) call that emits "FaultInject term_skip_auto_split_range" with a
non-debug LOG(WARNING) and include contextual identifiers (e.g., table id, range
id, term number) so the injected skip is visible in staging/chaos runs; locate
the DLOG(INFO) call in local_cc_shards.cpp that emits "FaultInject
term_skip_auto_split_range" and change it to LOG(WARNING) with a descriptive
message containing the table/range/term variables available in that scope.

🤖 Prompt for all review comments with AI agents

Verify each finding against the current code and only fix it if needed.

Inline comments:
In `@tx_service/src/cc/local_cc_shards.cpp`:
- Around line 2954-2957: The fault-injection branch in
CODE_FAULT_INJECTOR("term_skip_auto_split_range") returns early and prevents
scheduling the split data-sync task, which can permanently stall an auto-split
because need_split is latched by
TemplateCcMap::UpdateRangeSize(uint32_t,int32_t,bool) and only cleared via
ResetRangeStatus(partition_id). Modify the fault path so it does not permanently
suppress retries: instead of returning immediately, either (a) re-arm/clear the
latch by calling ResetRangeStatus(partition_id) or (b) enqueue a
deferred/rescheduled split task (same code path used for normal retries) before
returning; ensure the change references term_skip_auto_split_range and preserves
the original scheduling semantics used by the split data-sync task so future
retries still occur after the fault is disabled.

---

Nitpick comments:
In `@tx_service/src/cc/local_cc_shards.cpp`:
- Line 2955: Replace the debug-only DLOG(INFO) call that emits "FaultInject
term_skip_auto_split_range" with a non-debug LOG(WARNING) and include contextual
identifiers (e.g., table id, range id, term number) so the injected skip is
visible in staging/chaos runs; locate the DLOG(INFO) call in local_cc_shards.cpp
that emits "FaultInject term_skip_auto_split_range" and change it to
LOG(WARNING) with a descriptive message containing the table/range/term
variables available in that scope.

🪄 Autofix (Beta)

Fix all unresolved CodeRabbit comments on this PR:

• Push a commit to this branch (recommended)
• Create a new PR with the fixes

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ℹ️ Review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro

Run ID: 94ebff56-1b9c-4840-84fd-edf82f2bed69

📥 Commits

Reviewing files that changed from the base of the PR and between 1a4729b and aed57c6.

📒 Files selected for processing (3)

• tx_service/include/cc/range_cc_map.h
• tx_service/src/cc/local_cc_shards.cpp
• tx_service/src/remote/cc_stream_receiver.cpp