*: revert gRPC stream operation duration metrics (#11048)

[ti-chi-bot]

This is an automated cherry-pick of #11048

What problem does this PR solve?

Issue Number: close #11040

grpcutil.NewMetricsStream registers histogram children labeled by peer IP with no lifecycle cleanup. Long-running PD/MCS processes accumulate unbounded label series (observed ~840k series from ~18k historical IPs), inflating memory and /metrics scrape cost until scrapes fail.

What is changed and how does it work?

Revert the gRPC stream operation duration metrics introduced in #10254 and the dependent Grafana stream-send panels from #10339. This removes `grpcutil.MetricsStream` and the peer-IP-labeled `grpc_stream_operation_duration_seconds` histograms from PD and MCS services, eliminating the unbounded cardinality leak until a safer replacement lands.

Check List

Tests

• No code

Related changes

• Need to cherry-pick to the release branch

Release note

Revert gRPC stream operation duration metrics to fix unbounded peer-IP label cardinality.

Summary by CodeRabbit

• Bug Fixes
  • Removed gRPC stream send-duration metrics from server endpoints and Grafana dashboards.
  • Simplified streaming operations by eliminating the associated instrumentation layer.
  • Removed the unsupported gRPC receive error and related utility behavior.
  • Existing request handling and service functionality remain unchanged.

[coderabbitai]

Important

Review skipped

Auto reviews are disabled on base/target branches other than the default branch.

Please check the settings in the CodeRabbit UI or the .coderabbit.yaml file in this repository. To trigger a single review, invoke the @coderabbitai review command.

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro Plus

Run ID: 262dcc00-0037-4a2a-81a8-7fb313beed76

You can disable this status message by setting the reviews.review_status to false in the CodeRabbit configuration file.

Use the checkbox below for a quick retry:

• 🔍 Trigger review

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests

---

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

• X
• Mastodon
• Reddit
• LinkedIn

_{Comment @coderabbitai help to get the list of available commands.}

[ti-chi-bot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: JmPotato, lhy1024

The full list of commands accepted by this bot can be found here.

The pull request process is described here

Details

Needs approval from an approver in each of these files:

• OWNERS [JmPotato,lhy1024]

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment

[ti-chi-bot]

[LGTM Timeline notifier]

Timeline:

• 2026-07-24 09:58:37.51829552 +0000 UTC m=+1571703.554390576: ☑️ agreed by JmPotato.
• 2026-07-24 10:13:48.198628681 +0000 UTC m=+1572614.234723727: ☑️ agreed by lhy1024.

[JmPotato]

/retest

[JmPotato]

/retest

[JmPotato]

/retest

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 79.16%. Comparing base (84a02ea) to head (026367b).
⚠️ Report is 1 commits behind head on release-nextgen-202603.

Additional details and impacted files

@@                    Coverage Diff                     @@
##           release-nextgen-202603   #11049      +/-   ##
==========================================================
- Coverage                   79.19%   79.16%   -0.04%     
==========================================================
  Files                         532      530       -2     
  Lines                       72818    72726      -92     
==========================================================
- Hits                        57668    57570      -98     
- Misses                      11114    11122       +8     
+ Partials                     4036     4034       -2     

Flag	Coverage Δ
unittests	79.16% <100.00%> (-0.04%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

[JmPotato]

/retest

[JmPotato]

/test pull-unit-test-next-gen-2