@yibin87 This PR has conflicts, I have hold it.
Please resolve them or ask others to resolve them, then comment /unhold to remove the hold label.

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This is an automated cherry-pick of #63796

What problem does this PR solve?

Issue Number: close #62920

Problem Summary: Add client network in/out stats in topsql. And record topN network usage sqls adding to current topN cpu usage sqls. Note one sql will be added at most once.

What changed and how does it work?

1. Add two new session variable "InPacketBytes", "OutPacketBytes" to record the network traffic from/to clients.
2. When query finishes, record the network traffic info to topsql stmtstats
3. Pick topN query with highest network traffic.

Check List

Sysbench Performance Test

The performance impact of this PR is not noticable. Turn off topsql

Turn on topsql

Tests

• Unit test
• Integration test
• Manual test (add detailed scripts or steps below)
  Run tpch benchmark, print topsql report data on tidb side, and check the network in/out data using sql digest manually to ensure network data make sense.
• No need to test

  • I checked and no code files have been changed.

Side effects

• Performance regression: Consumes more CPU
• Performance regression: Consumes more Memory
• Breaking backward compatibility

Documentation

• Affects user behaviors
• Contains syntax changes
• Contains variable changes
• Contains experimental features
• Changes MySQL compatibility

Release note

Please refer to Release Notes Language Style Guide to write a quality release note.

Collects client network data for topsql to pick topN sql with highest network traffic.

Merge the other cp into this one: #65688

/test build

/test unit-test

@yibin87: The specified target(s) for /test were not found.
The following commands are available to trigger required jobs:

/test fast_test_tiprow_for_release

@yibin87: The specified target(s) for /test were not found.
The following commands are available to trigger required jobs:

/test fast_test_tiprow_for_release

Codecov Report

❌ Patch coverage is 87.50000% with 15 lines in your changes missing coverage. Please review.
⚠️ Please upload report for BASE (release-8.5@06bcd2d). Learn more about missing BASE report.

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/test unit-test

@yibin87: The specified target(s) for /test were not found.
The following commands are available to trigger required jobs:

/test fast_test_tiprow_for_release

/unhold

/cc @zimulala

[APPROVALNOTIFIER] This PR is NOT APPROVED

This pull-request has been approved by: yibin87, zimulala
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[LGTM Timeline notifier]

Timeline:

• 2026-02-03 02:12:28.295348598 +0000 UTC m=+146619.396747317: ☑️ agreed by yibin87.
• 2026-02-03 08:38:44.39193593 +0000 UTC m=+169795.493334660: ☑️ agreed by zimulala.

/hold