enable active-active check

[Leavrth]

What problem does this PR solve?

Issue Number: close #xxx

What is changed and how it works?

Check List

Tests

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[gemini-code-assist]

Summary of Changes

Hello @Leavrth, 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 new configuration flag to fine-tune the behavior of active-active replication by allowing a bypass of certain conflict detection checks. This provides operators with more granular control over how DML events are processed in an active-active setup, potentially optimizing performance or handling specific replication scenarios.

Highlights

• New Configuration Option: Introduced a new boolean configuration field, EnableActiveActiveCheck, across the API, internal configuration, and replica configuration structures. This new field provides a toggle for specific active-active replication checks.
• Conditional Active-Active Check Bypass: Modified the EvaluateRowPolicy function in pkg/common/event/active_active.go to conditionally bypass active-active row policy evaluation. When EnableActiveActiveCheck is true, the function will immediately return RowPolicyKeep, effectively disabling certain conflict filtering for the row.
• Propagation of New Field: The EnableActiveActiveCheck field has been propagated through the downstreamadapter/dispatcher components, including SharedInfo struct, constructor functions, and calls to FilterDMLEvent, ensuring the new configuration is accessible and utilized where needed.
• Test Updates: Updated various test files within the downstreamadapter/dispatcher and pkg/common/event directories to accommodate the new enableActiveActiveCheck parameter in function calls and test setups.

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[gemini-code-assist]

Code Review

This pull request introduces a new configuration option, enable_active_active_check, to control event filtering in active-active replication scenarios. The changes are propagated through the configuration and dispatcher layers to the core event filtering logic.

My review focuses on two main points:

1. Missing Validation: The new configuration lacks validation, which could lead to misconfiguration and potential issues. I've pointed out where similar validation for enable_active_active exists and suggested adding checks for the new flag.
2. Code Clarity: The implementation of the new logic in the event filtering function could be clearer. I've suggested a refactoring to improve readability and maintainability.

Overall, the changes are in the right direction, but addressing the validation point is crucial before merging.

[gemini-code-assist]

The new configuration EnableActiveActiveCheck seems to be missing validation in ValidateAndAdjust. Given its name and its effect in EvaluateRowPolicy, it appears to be related to active-active replication.

The existing EnableActiveActive flag has several important validations, such as ensuring BDRMode is enabled, checking for a compatible sink (MySQL/TiDB), and ensuring it's not used with redo log consistency.

To prevent potential data inconsistency or runtime errors from misconfiguration, similar validations should be added for EnableActiveActiveCheck. For example:

• Should BDRMode be required?
• Is it only compatible with MySQL/TiDB sinks?
• Is it incompatible with redo log?

Please add the necessary validation logic for EnableActiveActiveCheck in the ValidateAndAdjust function.

[gemini-code-assist]

The logic here is a bit confusing. This check for enableActiveActiveCheck is only executed if enableActiveActive is false due to the preceding if statement. If the intention is for either flag to have the same effect of keeping the row, it would be clearer to combine them into a single condition: if enableActiveActive || enableActiveActiveCheck. While this would require changing code outside this diff, it's worth considering for better maintainability.