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sink: Add schema/table routing support for mysql and redo sinks#3704

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a-cong wants to merge 45 commits intopingcap:masterfrom
a-cong:sink-routing
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sink: Add schema/table routing support for mysql and redo sinks#3704
a-cong wants to merge 45 commits intopingcap:masterfrom
a-cong:sink-routing

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@a-cong a-cong commented Dec 18, 2025

What problem does this PR solve?

Issue Number: close #3700

What is changed and how it works?

Porting changes from pingcap/tiflow#12435 to new ticdc architecture.

The dispatchers config is the same as in tiflow -

[[sink.dispatchers]]
matcher = ["uds_000.*"]
schema = "tidb_failover_test"
table = "{table}"

[[sink.dispatchers]]
matcher = ["oyster_production.*"]
schema = "oyster_production"
table = "{table}"

We also add the TargetSchema and TargetTable fields to the TableName struct. Since there is now a shared TableInfo object that can be accessed by multiple changefeeds and a new concept of Dispatcher objects, we clone the TableInfo in each dispatcher with the routing information for that table in handleHandshakeEvent (which is executed when the dispatcher starts), and then store that cloned/routed TableInfo for the dispatcher. Subsequent DMLs then look up the stored info. Subsequent DDLs also explicitly update routing in handleSingleDataEvents.

Another difference between ticdc and tiflow is that DDLs are now handled per-sink instead of in one single entry point. Because of this, we need to apply routing in both the mysql and redo sinks separately - the shared rewriting functionality is in pkg/sink/util/ddl_routing.go.

We also copied FetchDDLTables and RenameDDLTable (and the corresponding tests) from https://github.com/pingcap/tiflow/blob/master/dm/pkg/parser/common.go so we could use them to rewrite DDLs.

Check List

Tests

  • Unit tests
  • Integration tests
  • Manual test - deployed to internal dev cluster and bootstrapped a migration shadow with schema mapping, verified changefeed routes DDLs/DMLs correctly

Questions

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

Yes - will do so in separate PR

Release note

Added support for schema and table routing for mysql-compatible sinks by extending the `dispatchers` config

Summary by CodeRabbit

  • New Features

    • Schema/table routing added to dispatch rules with {schema}/{table} placeholders; routing applied to DML and DDL and exposed via sink routers
    • DDL rewrite support so routed DDLs target configured destinations
    • Redo logs now preserve and restore routing targets during replay
    • Routing expression validation with clear error types
  • Testing

    • Extensive unit and integration tests covering routing, DDL rewrite, SQL generation, and redo replay scenarios

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ti-chi-bot bot commented Dec 18, 2025

Adding the "do-not-merge/release-note-label-needed" label because no release-note block was detected, please follow our release note process to remove it.

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@ti-chi-bot ti-chi-bot bot added do-not-merge/release-note-label-needed Indicates that a PR should not merge because it's missing one of the release note labels. contribution This PR is from a community contributor. first-time-contributor Indicates that the PR was contributed by an external member and is a first-time contributor. needs-ok-to-test Indicates a PR created by contributors and need ORG member send '/ok-to-test' to start testing. labels Dec 18, 2025
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ti-chi-bot bot commented Dec 18, 2025

Hi @a-cong. Thanks for your PR.

I'm waiting for a pingcap member to verify that this patch is reasonable to test. If it is, they should reply with /ok-to-test on its own line. Until that is done, I will not automatically test new commits in this PR, but the usual testing commands by org members will still work. Regular contributors should join the org to skip this step.

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pingcap-cla-assistant bot commented Dec 18, 2025

CLA assistant check
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@ti-chi-bot ti-chi-bot bot added the size/XXL Denotes a PR that changes 1000+ lines, ignoring generated files. label Dec 18, 2025
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Summary of Changes

Hello @a-cong, 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 significantly enhances the data replication capabilities by introducing schema and table routing for MySQL-compatible and Redo sinks. It allows users to dynamically remap database and table names from the source to the target, providing greater flexibility for data integration and consolidation. The changes involve updating configuration structures, implementing DDL query rewriting logic, and ensuring concurrency safety through event cloning, ultimately enabling seamless replication to custom target schemas and tables.

Highlights

  • Schema and Table Routing for MySQL and Redo Sinks: Introduces comprehensive support for schema and table routing, allowing users to define rules to map source database and table names to different target names in MySQL-compatible and Redo sinks. This enables flexible data migration and consolidation scenarios.
  • DDL Query Rewriting: Implements a mechanism to parse and rewrite DDL (Data Definition Language) queries based on configured routing rules. This ensures that DDL statements like CREATE TABLE, ALTER TABLE, and RENAME TABLE are executed against the correct target schema and table names in the downstream.
  • Event Cloning for Concurrency Safety: Adds cloning logic for BatchDMLEvent and DDLEvent objects before applying routing. This prevents race conditions and unintended mutations when the same event is processed by multiple dispatchers (e.g., the main event dispatcher and the redo log dispatcher), ensuring each can apply routing independently.
  • Enhanced TableName and TableInfo: Extends the TableName struct with TargetSchema and TargetTable fields to store routed names. The TableInfo struct now includes a CloneWithRouting method to create a routed copy, and DML SQL generation functions (buildInsert, buildDelete, buildUpdate) are updated to use these target names.
  • Integration with Redo Log Replay: Ensures that DDL routing is applied before writing events to the redo log. This means that when redo logs are replayed (e.g., during disaster recovery), the DDLs will correctly target the routed schema and table names, maintaining data consistency.

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Code Review

This pull request introduces a significant new feature: schema and table routing for MySQL and redo log sinks. The changes are extensive, touching upon the API, configuration, dispatchers, and sinks to support this functionality. The design thoughtfully addresses potential concurrency issues by cloning event objects to prevent race conditions, especially when events are shared between the main sink and the redo log sink. A comprehensive set of unit and integration tests has been added to validate the new routing logic. Overall, this is a well-structured implementation of a complex feature. I've identified one critical issue in BatchDMLEvent.CloneForRouting that could lead to data corruption or mis-routing due to improper cloning of nested event objects. Please address this to ensure the correctness of the feature.

Comment thread pkg/common/event/dml_event.go Outdated
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/ok-to-test

@ti-chi-bot ti-chi-bot bot added ok-to-test Indicates a PR is ready to be tested. and removed needs-ok-to-test Indicates a PR created by contributors and need ORG member send '/ok-to-test' to start testing. labels Dec 26, 2025
@a-cong a-cong force-pushed the sink-routing branch 2 times, most recently from d9fa289 to beac037 Compare January 2, 2026 23:14
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a-cong commented Jan 3, 2026

/test all

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@3AceShowHand
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/test all

@a-cong
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a-cong commented Jan 5, 2026

/test all

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a-cong commented Jan 6, 2026

/test all

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a-cong commented Jan 6, 2026

/test all

// for the new table. In this case, we should NOT update the stored tableInfo.
dispatcherTableID := d.target.GetTableSpan().TableID
ddlTableID := ddl.TableInfo.TableName.TableID
if ddlTableID != dispatcherTableID {
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Based on the calculation, ddlTableID appears to represent the logical ID of the DDL table; however, dispatcherID may correspond to the physical ID of a partitioned table, which would explain the mismatch. I am not certain whether this aligns with the intended design.

@hongyunyan
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Based on the current review, the changes related to the router span a significant number of distinct components—such as the event collector, dispatcher, and sink. Could we consider consolidating all unified router behaviors within a single module to prevent the logic from becoming scattered across various locations?

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/test all

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/test all

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/test all

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/test all

fi

echo "SUCCESS: Changefeed resumes normally after redo apply!"
echo " - All $final_target_count rows correctly in target_db.t1"
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/test all

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ti-chi-bot bot commented Apr 1, 2026

@a-cong: 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-kafka-integration-heavy 4c57fc9 link true /test pull-cdc-kafka-integration-heavy
pull-error-log-review 37664ca link true /test pull-error-log-review

Full PR test history. Your PR dashboard.

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Schema/table routing support for ticdc

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