internal/client: close stream on first recv error

[windtalker]

Issue Number: close #2018

Problem Summary:

Stream RPC leases can be retained indefinitely in tikvrpc.CheckStreamTimeoutLoop if a stream is registered into connArray.streamTimeout and the setup path returns after the first Recv reports a non-EOF error without closing the stream. Recv resets the lease deadline to 0 before returning, and the timeout loop treats deadline == 0 as active/idle, so the stale lease can remain tracked indefinitely.

What is changed:

• Close CopStream when the first Recv returns a non-EOF error.
• Close BatchCopStream when the first Recv returns a non-EOF error.
• Close MPPStream when the first Recv returns a non-EOF error.
• Add TestStreamFirstRecvErrorClosesLease to cover all three stream setup paths and verify the stream context is canceled.

Tests:

• go test ./internal/client -run '^TestStreamFirstRecvErrorClosesLease$'

Summary by CodeRabbit

• Bug Fixes
  • Improved reliability when streaming requests encounter an error immediately.
  • Streaming connections are now properly closed in these failure cases, preventing resource leaks and helping ensure requests terminate cleanly.
  • Added coverage to verify that failed streams are canceled and return the expected error.

[ti-chi-bot]

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[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro

Run ID: 9bb83760-8a9c-489c-9cbb-4f388578541b

📥 Commits

Reviewing files that changed from the base of the PR and between a5548a3 and 2a79cc3.

📒 Files selected for processing (2)

• internal/client/client.go
• internal/client/client_test.go

🚧 Files skipped from review as they are similar to previous changes (2)

• internal/client/client.go
• internal/client/client_test.go

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📝 Walkthrough

Walkthrough

First-receive non-EOF errors now close coprocessor, batch coprocessor, and MPP streams. Tests simulate these failures and verify that the associated stream contexts are canceled.

Changes

Stream lease cleanup

Layer / File(s)	Summary
Close streams on first-receive errors internal/client/client.go	The coprocessor, batch coprocessor, and MPP response handlers close registered streams before returning non-EOF first-receive errors.
Verify lease cancellation internal/client/client_test.go	Test wrappers inject first-receive failures, and subtests verify nil responses, propagated errors, and canceled stream contexts.

Estimated code review effort: 2 (Simple) | ~10 minutes

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title clearly matches the main change: closing streams on first non-EOF recv errors.
Linked Issues check	✅ Passed	The PR implements the linked issue's primary fix for CopStream, BatchCopStream, and MPPStream first-Recv error cleanup and adds coverage.
Out of Scope Changes check	✅ Passed	The changes stay focused on stream-close handling and the corresponding test, with no obvious unrelated additions.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests

---

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[ti-chi-bot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: ekexium, zyguan

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Details

Needs approval from an approver in each of these files:

• internal/client/OWNERS [ekexium,zyguan]

Approvers can indicate their approval by writing /approve in a comment
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[ti-chi-bot]

[LGTM Timeline notifier]

Timeline:

• 2026-07-17 08:19:25.733982205 +0000 UTC m=+960951.770077261: ☑️ agreed by zyguan.
• 2026-07-23 07:49:44.295767051 +0000 UTC m=+1477570.331862097: ☑️ agreed by ekexium.