Sources Overview

Sources are the databases from which EZ-CDC captures changes. EZ-CDC connects to your source database's change stream and captures every INSERT, UPDATE, and DELETE operation in real-time.

Supported Sources

Source	CDC Method	Status	Documentation
PostgreSQL	Logical Replication (pgoutput)	✅ Stable	Setup Guide
MySQL	Binary Log (binlog)	🔜 Coming Soon	-
Oracle	LogMiner	🔜 Planned	-
SQL Server	Change Tracking	🔜 Planned	-

How Sources Work

Change Data Capture (CDC)

CDC captures changes by reading the database's transaction log:

Simple CDC Flow: PostgreSQL to StarRocks via EZ-CDC

Event Types

EZ-CDC captures these event types:

Event	Description	Data Included
INSERT	New row added	All column values
UPDATE	Row modified	New values + primary key
DELETE	Row removed	Primary key
BEGIN	Transaction start	Transaction ID
COMMIT	Transaction end	Transaction ID, LSN

Normalized Format

All sources emit events in a normalized CdcRecord format:

enum CdcRecord {
    Insert {
        schema: String,
        table: String,
        values: HashMap<String, Value>,
    },
    Update {
        schema: String,
        table: String,
        values: HashMap<String, Value>,
        key: HashMap<String, Value>,
    },
    Delete {
        schema: String,
        table: String,
        key: HashMap<String, Value>,
    },
    // ...
}

This allows any source to work with any sink.

Source Configuration

Common Settings

All sources share these configuration options:

Setting	Description	Default
Connection URL	Database connection string	Required
Tables	Tables to replicate	Required
SSL Mode	TLS connection settings	prefer

Source-Specific Settings

Each source has additional settings:

• PostgreSQL: Replication slot, publication name
• MySQL: Server ID, binlog position
• Oracle: LogMiner settings

Adding a Source

Via Portal

1. Go to Datasources → New Datasource
2. Select source type (e.g., PostgreSQL)
3. Enter connection details
4. Test connection
5. Save

Best Practices

1. Use Dedicated CDC User

Create a user specifically for CDC with minimal permissions:

-- PostgreSQL example
CREATE USER cdc_user WITH REPLICATION LOGIN PASSWORD 'secret';
GRANT SELECT ON ALL TABLES IN SCHEMA public TO cdc_user;

2. Enable SSL/TLS

Always use encrypted connections:

{
  "ssl_mode": "require"
}

3. Monitor Replication Lag

Set up alerts for replication lag to detect issues early.

4. Plan for Schema Changes

• Test schema changes in staging first
• Use compatible changes when possible (add columns, not remove)
• Monitor jobs after schema changes

Next Steps

• PostgreSQL Setup - Configure PostgreSQL source