*:improve memory control

[asddongmen]

What problem does this PR solve?

Issue Number: close #4172

What is changed and how it works?

Check List

Tests

• Unit test
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Questions

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[ti-chi-bot]

Skipping CI for Draft Pull Request.
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[gemini-code-assist]

Summary of Changes

Hello @asddongmen, I'm Gemini Code Assist¹! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!

This pull request introduces a significant enhancement to the system's memory control by upgrading the congestion control messaging to include detailed memory usage and maximum memory limits. A new dynamic scan interval adjustment mechanism has been implemented, allowing changefeeds to adapt their scanning rate based on real-time memory consumption. This adaptive approach is designed to improve system stability and performance by proactively managing memory pressure.

Highlights

• Versioned Congestion Control: Introduced CongestionControlVersion2 to include Used and Max memory information for changefeeds in congestion control messages, allowing for more granular memory management.
• Dynamic Scan Interval Adjustment: Implemented a mechanism to dynamically adjust the scan interval for changefeeds based on their observed memory usage, aiming to prevent memory overruns and improve stability.
• Memory Usage Tracking: Added a new memoryUsageWindow component to sample and average memory usage ratios over time, which informs the dynamic scan interval adjustments.
• Enhanced Event Collector: The EventCollector now gathers and reports detailed memory usage metrics (Used and Max) from memory quotas, sending them via the new CongestionControlVersion2 messages.
• Event Broker Integration: The EventBroker was updated to process the new versioned congestion control messages, extract memory usage data, and apply the dynamic scan interval adjustments to changefeeds.

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[gemini-code-assist]

Code Review

This pull request enhances memory control by introducing a version 2 for congestion control messages, which now include used and max memory details. This new information is leveraged to dynamically adjust the event scanning interval, making memory management more adaptive. The implementation is solid and includes relevant tests for the new functionality. My feedback primarily focuses on opportunities to refactor duplicated code in the serialization logic to improve long-term maintainability.

[gemini-code-assist]

The logic for updating changefeedUsedMemory and changefeedMaxMemory is duplicated. To improve maintainability and reduce redundancy, consider extracting this logic into a helper function.

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[asddongmen]

/test all

[ti-chi-bot]

@asddongmen: The following tests failed, say /retest to rerun all failed tests or /retest-required to rerun all mandatory failed tests:

Test name	Commit	Details	Required	Rerun command
pull-cdc-mysql-integration-heavy	ee4f5ff	link	true	/test pull-cdc-mysql-integration-heavy
pull-cdc-storage-integration-heavy	ee4f5ff	link	true	/test pull-cdc-storage-integration-heavy

Full PR test history. Your PR dashboard.

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