apache/seatunnel · warning

Failed to load JDBC driver com.mysql.cj.jdbc.Driver

Error message

Failed to load JDBC driver com.mysql.cj.jdbc.Driver 

What it means

MySqlIncrementalSourceFactory.restoreSource() attempts to force-load the MySQL Connector/J driver (com.mysql.cj.jdbc.Driver) via Class.forName so it is registered with DriverManager. When the class cannot be found (or another exception occurs during loading) it logs this warning with the exception, then continues — the driver must already be on the classpath or a later connection attempt will fail.

Source

Thrown at seatunnel-connectors-v2/connector-cdc/connector-cdc-mysql/src/main/java/org/apache/seatunnel/connectors/seatunnel/cdc/mysql/source/MySqlIncrementalSourceFactory.java:122

                        SourceOptions.STARTUP_TIMESTAMP)
                .build();
    }

    @Override
    public Class<? extends SeaTunnelSource> getSourceClass() {
        return MySqlIncrementalSource.class;
    }

    @Override
    public <T, SplitT extends SourceSplit, StateT extends Serializable>
            TableSource<T, SplitT, StateT> restoreSource(
                    TableSourceFactoryContext context, List<CatalogTable> restoreTables) {
        return () -> {
            // Load the JDBC driver in to DriverManager
            try {
                Class.forName("com.mysql.cj.jdbc.Driver");
            } catch (Exception e) {
                log.warn("Failed to load JDBC driver com.mysql.cj.jdbc.Driver ", e);
            }
            ReadonlyConfig config = context.getOptions();
            List<CatalogTable> catalogTables =
                    CatalogTableUtil.getCatalogTables(config, context.getClassLoader());
            boolean enableSchemaChange =
                    context.getOptions()
                            .getOptional(SourceOptions.SCHEMA_CHANGES_ENABLED)
                            .orElse(
                                    // TODO remove this after all users used the new schema change
                                    // option
                                    context.getOptions()
                                            .getOptional(SourceOptions.DEBEZIUM_PROPERTIES)
                                            .map(
                                                    e ->
                                                            e.getOrDefault(
                                                                    MySqlSourceConfigFactory
                                                                            .SCHEMA_CHANGE_KEY,
                                                                    SourceOptions

View on GitHub (pinned to cf67b549a7)

Solutions

1. Add mysql-connector-java (8.x, com.mysql.cj.jdbc.Driver) to the classpath: copy mysql-connector-j-8.x.jar into $SEATUNNEL_HOME/lib/ (or the plugin dir) on all nodes.
2. Declare the dependency (com.mysql:mysql-connector-j) in your job's build if submitting a fat jar.
3. Check for conflicting older mysql connectors (mysql-connector-java 5.x provides com.mysql.jdbc.Driver, not com.mysql.cj.jdbc.Driver).
4. Re-run with -e local or check logs for the chained exception to see if it is ClassNotFoundException vs LinkageError.

Example fix

// before (pom.xml)
<!-- no mysql driver -->
// after (pom.xml)
<dependency>
  <groupId>com.mysql</groupId>
  <artifactId>mysql-connector-j</artifactId>
  <version>8.0.33</version>
</dependency>

// Before submission, check driver presence:
Class.forName("com.mysql.cj.jdbc.Driver");
// or shell: unzip -l seatunnel/lib/mysql-connector-j-*.jar | grep com/mysql/cj/jdbc/Driver

try {
    Class.forName("com.mysql.cj.jdbc.Driver");
} catch (ClassNotFoundException e) {
    throw new IllegalStateException("MySQL JDBC driver missing from classpath", e);
}

When it happens

Trigger: restoreSource() calls Class.forName("com.mysql.cj.jdbc.Driver") and the call throws ClassNotFoundException/LinkageError because the mysql-connector-java/mysql-connector-j artifact is not on the classpath of the SeaTunnel job.

Common situations: MySQL JDBC driver jar not installed in $SEATUNNEL_HOME/connectors/connector-plugin or lib/; driver bundled only transitively and excluded by shading; running a custom job with the cdc-mysql connector jar but not the driver; version conflicts removing the cj driver (old com.mysql.jdbc.Driver only).

Related errors

• Failed to load JDBC driver com.mysql.cj.jdbc.Driver
• Failed to load JDBC driver {}
• Failed to load JDBC driver com.mysql.cj.jdbc.Driver
• Failed to load JDBC driver {}
• Could not load service provider for factories.

AI-assisted analysis of apache/seatunnel@cf67b549a7 (2026-09-10). Data as JSON: /api/errors/f16cf444cfa91116. Report an issue: GitHub.