dynamicstream: remove batch configuration from the stream level, and support it at the area level

[3AceShowHand]

What problem does this PR solve?

Issue Number: close #xxx

What is changed and how it works?

Check List

Tests

• Unit test
• Integration test
• Manual test (add detailed scripts or steps below)
• No code

Questions

Will it cause performance regression or break compatibility?

Do you need to update user documentation, design documentation or monitoring documentation?

Release note

Please refer to [Release Notes Language Style Guide](https://pingcap.github.io/tidb-dev-guide/contribute-to-tidb/release-notes-style-guide.html) to write a quality release note.

If you don't think this PR needs a release note then fill it with `None`.

[gemini-code-assist]

Summary of Changes

Hello @3AceShowHand, 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 refactors the batching configuration within the dynamicstream utility. It shifts the responsibility of defining batching parameters from the individual stream level to the AreaSettings level. This change introduces a more modular and policy-driven approach to batching, allowing for greater flexibility and potentially more granular control over how events are batched.

Highlights

• Configuration Refactoring: Removed BatchCount and BatchBytes fields from the Option struct, signifying the removal of stream-level batch configuration.
• New Batching Policies: Introduced new interfaces and structs (sizePolicy, countPolicy, bytesPolicy) to define flexible batching policies.
• Area-Level Batching: Relocated batching configuration by adding a batcher field to the AreaSettings struct, enabling batching to be configured at the area level.

🧠 New Feature in Public Preview: You can now enable Memory to help Gemini Code Assist learn from your team's feedback. This makes future code reviews more consistent and personalized to your project's style. Click here to enable Memory in your admin console.

Using Gemini Code Assist

The full guide for Gemini Code Assist can be found on our documentation page, here are some quick tips.

Invoking Gemini

You can request assistance from Gemini at any point by creating a comment using either /gemini <command> or @gemini-code-assist <command>. Below is a summary of the supported commands on the current page.

Feature	Command	Description
Code Review	/gemini review	Performs a code review for the current pull request in its current state.
Pull Request Summary	/gemini summary	Provides a summary of the current pull request in its current state.
Comment	@gemini-code-assist	Responds in comments when explicitly tagged, both in pull request comments and review comments.
Help	/gemini help	Displays a list of available commands.

Customization

To customize Gemini Code Assist for GitHub experience, repository maintainers can create a configuration file and/or provide a custom code review style guide (such as PEP-8 for Python) by creating and adding files to a .gemini/ folder in the base of the repository. Detailed instructions can be found here.

Limitations & Feedback

Gemini Code Assist may make mistakes. Please leave feedback on any instances where its feedback is incorrect or counter productive. You can react with 👍 and 👎 on @gemini-code-assist comments. If you're interested in giving your feedback about your experience with Gemini Code Assist for Github and other Google products, sign up here.

You can also get AI-powered code generation, chat, as well as code reviews directly in the IDE at no cost with the Gemini Code Assist IDE Extension.

Footnotes

1. Review the Privacy Notices, Generative AI Prohibited Use Policy, Terms of Service, and learn how to configure Gemini Code Assist in GitHub here. Gemini can make mistakes, so double check it and use code with caution. ↩

[gemini-code-assist]

Code Review

This pull request refactors batching configuration by removing it from the stream-level Option and introducing it at the area-level via AreaSettings. This is achieved by adding a batcher field to AreaSettings and defining new sizePolicy, countPolicy, and bytesPolicy types to handle different batching strategies. My review has identified a critical issue regarding the initialization of the new batcher field, which could lead to a nil pointer dereference. I've also pointed out a minor inconsistency in receiver naming for better code maintainability. Please address these points to ensure the stability and clarity of the new implementation.

[gemini-code-assist]

The new batcher field is not initialized in NewAreaSettingsWithMaxPendingSize or (s *AreaSettings) fix(). This will result in batcher.policy being nil, leading to a nil pointer dereference when the policy is accessed. Please ensure batcher is initialized with a default policy to prevent panics. For example, you could default to a count-based policy to maintain previous behavior.

[gemini-code-assist]

For consistency with (b bytesPolicy) String() and Go conventions, the receiver for bytesPolicy methods should have a consistent name. It's c here but b for the String() method. Please use b for all bytesPolicy methods, including in the method body.

Suggested change

	func (c bytesPolicy) currentSize() int {
	return c.current
	}
	func (b bytesPolicy) currentSize() int {
	return b.current
	}

[3AceShowHand]

/test all

[3AceShowHand]

originally, it's set to 1024, so set it here .

[ti-chi-bot]

[APPROVALNOTIFIER] This PR is NOT APPROVED

This pull-request has been approved by:
Once this PR has been reviewed and has the lgtm label, please assign flowbehappy for approval. For more information see the Code Review Process.
Please ensure that each of them provides their approval before proceeding.

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

Details

Needs approval from an approver in each of these files:

• OWNERS
• pkg/config/OWNERS

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

[3AceShowHand]

/test all

[ti-chi-bot]

[FORMAT CHECKER NOTIFICATION]

Notice: To remove the do-not-merge/needs-linked-issue label, please provide the linked issue number on one line in the PR body, for example: Issue Number: close #123 or Issue Number: ref #456.

_{📖 For more info, you can check the "Contribute Code" section in the development guide.}

[ti-chi-bot]

@3AceShowHand: 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-light-next-gen	c60f623	link	false	/test pull-cdc-mysql-integration-light-next-gen
pull-cdc-kafka-integration-heavy	c60f623	link	true	/test pull-cdc-kafka-integration-heavy
pull-unit-test	d9b544c	link	true	/test pull-unit-test
pull-unit-test-next-gen	d9b544c	link	false	/test pull-unit-test-next-gen
pull-check	ae12398	link	true	/test pull-check

Full PR test history. Your PR dashboard.

Details

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes-sigs/prow repository. I understand the commands that are listed here.