maintainer: add redo scheduler

[wk989898]

What problem does this PR solve?

Issue Number: ref #1061

What is changed and how it works?

• Refactored MaintainerController for Dual Management: The MaintainerController has been refactored to manage two distinct sets of operator.Controller, span.Controller, and Barrier instances. Helper functions (getOperatorController, getSpanController, getBarrier) are introduced to provide access to the appropriate instance based on the isRedo flag, streamlining the management of parallel data flows.
• Comprehensive Integration Testing for Redo Scheduler: Several new integration tests have been added (e.g., consistent_ddl_for_split_tables, consistent_ddl_for_split_tables_with_failover). These tests specifically target the new redo scheduler and its consistency properties, particularly in complex scenarios involving split tables and failover, ensuring robustness and reliability.

Check List

Tests

• Unit test
• Integration test

Questions

Will it cause performance regression or break compatibility?

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

Release note

 `None`.

[ti-chi-bot]

Skipping CI for Draft Pull Request.
If you want CI signal for your change, please convert it to an actual PR.
You can still manually trigger a test run with /test all

[gemini-code-assist]

Summary of Changes

Hello @wk989898, 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 dedicated redo scheduler and associated consistency mechanisms within the maintainer component. The core change involves establishing a parallel processing path for redo-related operations, distinct from the main data flow. This is achieved by propagating an isRedo flag throughout various components, allowing for separate management of redo-specific spans, operators, and barriers. The aim is to enhance the system's ability to handle redo logs with their own scheduling and consistency requirements, improving overall data integrity and fault tolerance.

Highlights

• Redo-specific Scheduling and Consistency: Introduced a parallel scheduling and consistency mechanism specifically for redo logs. This includes new redoDDLSpan and redoTsMap in Maintainer, and redoOperatorController, redoSpanController, and redoBarrier in MaintainerController.
• isRedo Flag for Differentiated Processing: A new isRedo boolean flag has been added and propagated across critical components like Barrier, BarrierEvent, TableSpanStatus, SpanReplication, and various scheduler/operator functions. This flag enables the system to differentiate and process normal operations separately from redo-related ones.
• Enhanced Operator Interface: The Operator interface in pkg/scheduler/operator has been extended with IsRepeat() and SetRepeat() methods. All concrete operator implementations now include these methods, allowing for better tracking of operator execution status and preventing redundant processing.
• Refactored MaintainerController for Dual Management: The MaintainerController has been refactored to manage two distinct sets of operator.Controller, span.Controller, and Barrier instances. Helper functions (getOperatorController, getSpanController, getBarrier) are introduced to provide access to the appropriate instance based on the isRedo flag, streamlining the management of parallel data flows.
• Comprehensive Integration Testing for Redo Scheduler: Several new integration tests have been added (e.g., consistent_ddl_for_split_tables, consistent_ddl_for_split_tables_with_failover). These tests specifically target the new redo scheduler and its consistency properties, particularly in complex scenarios involving split tables and failover, ensuring robustness and reliability.

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[gemini-code-assist]

Code Review

This pull request introduces a redo scheduler to the maintainer, enabling eventual consistency for replication. The implementation adds a parallel processing pipeline for redo logs, including dedicated span controllers, operator controllers, and barriers, which are distinguished by an isRedo flag. This is a significant but well-structured change that reuses existing components effectively. The addition of extensive integration tests covering various DDL, failover, and table movement scenarios is commendable. I've found one potential issue regarding an uninitialized field that could impact performance, which I've detailed in a specific comment.

[wk989898]

/test pull-cdc-mysql-integration-heavy

[wk989898]

/test all

[wk989898]

/retest-required

[wk989898]

/retest

[ti-chi-bot]

[APPROVALNOTIFIER] This PR is NOT APPROVED

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[wk989898]

/retest-required

[ti-chi-bot]

@wk989898: 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-error-log-review	11cdbfa	link	true	/test pull-error-log-review
pull-cdc-mysql-integration-light	11cdbfa	link	true	/test pull-cdc-mysql-integration-light
pull-cdc-mysql-integration-heavy	11cdbfa	link	true	/test pull-cdc-mysql-integration-heavy

Full PR test history. Your PR dashboard.

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