What causes "Read the redoLog offset error" in apache/seatunnel?

Verify connection parameters (hostname, port, service name, username, password) in the Oracle CDC source config

apache/seatunnel · error · RuntimeException

Read the redoLog offset error

Error message

Read the redoLog offset error

What it means

RedoLogOffsetFactory.latest() opens a JDBC connection to the Oracle database and reads the current SCN (redo log offset) via OracleConnectionUtils.currentRedoLogOffset. Any exception during connection setup or the SCN query is rethrown as a plain RuntimeException wrapping the original cause. It signals that the connector could not determine the starting position for redo log (CDC) reading.

Solutions

Verify connection parameters (hostname, port, service name, username, password) in the Oracle CDC source config
Test connectivity with a plain SQL client using the same credentials: SELECT CURRENT_SCN FROM V$DATABASE
Grant the log-mining privileges required by Debezium/LogMiner to the CDC user
Check the wrapped cause (e.getCause()) in the stack trace for the root JDBC error

Example fix

// before
Offset offset = offsetFactory.latest(); // opaque RuntimeException
// after
try {
    Offset offset = offsetFactory.latest();
} catch (RuntimeException e) {
    LOG.error("Failed to read redo log offset; cause: " + e.getCause(), e);
    throw e;
}

Defensive patterns

Strategy: try-catch

Validate before calling

// Verify connectivity before starting CDC
try (Connection c = DriverManager.getConnection(jdbcUrl, user, pass);
     Statement s = c.createStatement();
     ResultSet rs = s.executeQuery("SELECT CURRENT_SCN FROM V$DATABASE")) {
    if (!rs.next()) throw new IllegalStateException("No SCN returned");
}

Try / catch

try {
    Offset offset = factory.latest();
} catch (RuntimeException e) {
    // inspect e.getCause() for the JDBC/ORA root error
    LOG.error("redo log offset read failed: {}", e.getCause() != null ? e.getCause().getMessage() : e.getMessage());
    throw e;
}

Prevention

Validate JDBC credentials and URL with a SQL client before submitting the job
Grant all required LogMiner/V$ privileges to the CDC user up front
Ensure network/firewall allows the Oracle listener port
Include database host/port/user context in your logging for diagnosis

When it happens

Trigger: Calling RedoLogOffsetFactory.latest() when the Oracle host/port is unreachable, credentials are wrong, the user lacks privileges on V$DATABASE, or the underlying SELECT CURRENT_SCN query throws a SQLException.

Common situations: Misconfigured hostname/port in source config; wrong username/password; Oracle user missing log-mining privileges (LOGMINING, SELECT ANY TRANSACTION); database in a restricted/unmounted state; network/firewall blocking the listener.

Understand the failure class

Background: "query failed", "%w: SQL error" — wrapped database query errors in Go libraries explained — this error's family across 3 libraries.

Related errors

AI-assisted analysis of apache/seatunnel@cf67b549a7 (2026-09-10). Data as JSON: /api/errors/ec7ee76354a9952a. Report an issue: GitHub.

Appendix: source

Thrown at seatunnel-connectors-v2/connector-cdc/connector-cdc-oracle/src/main/java/org/apache/seatunnel/connectors/seatunnel/cdc/oracle/source/offset/RedoLogOffsetFactory.java:60

        this.dialect = dialect;
    }

    @Override
    public Offset earliest() {
        return RedoLogOffset.INITIAL_OFFSET;
    }

    @Override
    public Offset neverStop() {
        return RedoLogOffset.NO_STOPPING_OFFSET;
    }

    @Override
    public Offset latest() {
        try (JdbcConnection jdbcConnection = dialect.openJdbcConnection(sourceConfig)) {
            return OracleConnectionUtils.currentRedoLogOffset(jdbcConnection);
        } catch (Exception e) {
            throw new RuntimeException("Read the redoLog offset error", e);
        }
    }

    @Override
    public Offset specific(Map<String, String> offset) {
        return new RedoLogOffset(offset);
    }

    @Override
    public Offset specific(String filename, Long position) {
        throw new UnsupportedOperationException(
                "not supported create new Offset by filename and position.");
    }

    @Override
    public Offset timestamp(long timestamp) {
        try (JdbcConnection jdbcConnection = dialect.openJdbcConnection(sourceConfig)) {
            return OracleConnectionUtils.timestampToScn(

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