Implementation:Risingwavelabs Risingwave JniDbzSourceHandler RunJniDbzSourceThread

Knowledge Sources	RisingWave Debezium Documentation
Domains	CDC, JNI, Data_Replication
Last Updated	2026-02-09 07:00 GMT

Overview

Concrete tool for running Debezium CDC source threads via JNI provided by the RisingWave Java connector node.

Description

JniDbzSourceHandler.runJniDbzSourceThread() is the JNI entry point for starting a CDC capture thread. Called from the Rust engine via JNI, it deserializes the protobuf request, creates a DbzConnectorConfig, launches a DbzCdcEngineRunner, and streams change events back to Rust through a CdcSourceChannel.

Usage

This method is called by the Rust engine when a user creates a CDC source table (e.g., CREATE TABLE ... WITH (connector='mysql-cdc')). It runs in a dedicated thread managed by the JNI runtime.

Code Reference

Source Location

• Repository: risingwave
• File: java/connector-node/risingwave-connector-service/src/main/java/com/risingwave/connector/source/core/JniDbzSourceHandler.java
• Lines: L61-101

Signature

public class JniDbzSourceHandler {
    public static void runJniDbzSourceThread(
        byte[] getEventStreamRequestBytes,
        long channelPtr
    ) {
        // Deserializes GetEventStreamRequest protobuf
        // Creates DbzConnectorConfig
        // Launches DbzCdcEngineRunner
        // Streams events via CdcSourceChannel(channelPtr)
    }
}

Import

import com.risingwave.connector.source.core.JniDbzSourceHandler;

I/O Contract

Inputs

Name	Type	Required	Description
getEventStreamRequestBytes	byte[]	Yes	Serialized protobuf GetEventStreamRequest containing sourceId, sourceType, and CDC properties
channelPtr	long	Yes	JNI pointer to CdcSourceChannel for sending events to Rust

Outputs

Name	Type	Description
CDC events	CdcSourceChannel stream	Change events (insert/update/delete) streamed to Rust via JNI
Handler registration	Side effect	Handler registered in JniDbzSourceRegistry for lifecycle management

Usage Examples

Create MySQL CDC Source

-- This SQL triggers JniDbzSourceHandler on the Java side
CREATE TABLE mysql_orders (
    order_id INT PRIMARY KEY,
    customer_name VARCHAR,
    total_amount DECIMAL
) WITH (
    connector = 'mysql-cdc',
    hostname = 'mysql',
    port = '3306',
    username = 'root',
    password = '123456',
    database.name = 'mydb',
    table.name = 'orders',
    server.id = '1'
);

Create PostgreSQL CDC Source

CREATE TABLE pg_users (
    user_id INT PRIMARY KEY,
    username VARCHAR,
    email VARCHAR
) WITH (
    connector = 'postgres-cdc',
    hostname = 'postgres',
    port = '5432',
    username = 'postgres',
    password = '123456',
    database.name = 'mydb',
    table.name = 'users',
    slot.name = 'rw_slot_users'
);

Related Pages

Implements Principle

• Principle:Risingwavelabs_Risingwave_CDC_Change_Data_Capture

Requires Environment

• Environment:Risingwavelabs_Risingwave_Java_Connector_Environment