apache/seatunnel · warning · InterruptedException

Thread interrupted

Error message

Thread interrupted

What it means

MySqlUtils.skipReadAndSortSampleData samples a column's values during chunk planning and throws InterruptedException when it detects Thread.currentThread().isInterrupted() mid-scan. The library throws this to abort long sampling scans promptly when the task is being cancelled or the checkpoint/job is stopping, preserving interruption semantics.

Source

Thrown at seatunnel-connectors-v2/connector-cdc/connector-cdc-mysql/src/main/java/org/apache/seatunnel/connectors/seatunnel/cdc/mysql/utils/MySqlUtils.java:171

            stmt =
                    jdbc.connection()
                            .createStatement(
                                    ResultSet.TYPE_FORWARD_ONLY, ResultSet.CONCUR_READ_ONLY);

            stmt.setFetchSize(Integer.MIN_VALUE);
            rs = stmt.executeQuery(sampleQuery);

            int count = 0;
            while (rs.next()) {
                count++;
                if (count % 100000 == 0) {
                    log.info("Processing row index: {}", count);
                }
                if (count % inverseSamplingRate == 0) {
                    results.add(rs.getObject(1));
                }
                if (Thread.currentThread().isInterrupted()) {
                    throw new InterruptedException("Thread interrupted");
                }
            }
        } finally {
            if (rs != null) {
                try {
                    rs.close();
                } catch (SQLException e) {
                    log.error("Failed to close ResultSet", e);
                }
            }
            if (stmt != null) {
                try {
                    stmt.close();
                } catch (SQLException e) {
                    log.error("Failed to close Statement", e);
                }
            }
        }

View on GitHub (pinned to cf67b549a7)

Solutions

1. This is usually an intentional cancellation — confirm whether the job was cancelled and simply restart it if the cancel was unintended
2. For very large tables, tune chunk size / sampling rate so planning finishes faster and is less likely to be cancelled
3. Check checkpoint timeout settings; raise them if long sampling trips checkpoint timeouts that trigger cancellation
4. Ensure the thread interrupt isn't caused by a shutdown hook or watchdog; inspect worker logs at cancellation time

try {
    List<Object> samples = MySqlUtils.skipReadAndSortSampleData(jdbc, tableId, col, rate, rows);
} catch (InterruptedException e) {
    Thread.currentThread().interrupt(); // restore flag before returning/cancelling
}

When it happens

Trigger: Calling skipReadAndSortSampleData when the snapshot task thread is interrupted: job cancelled via REST/CLI, checkpoint timeout leading to task cancel, or engine shutdown during the sampling scan of a large table.

Common situations: User cancels a slow snapshot job; sampling a very large table takes so long that the engine cancels the task; worker shutdown/restart; manual kill of the job while sampling is in progress.

Related errors

• Interrupted while emitting initial DROP TABLE events
• Thread interrupted
• Thread interrupted
• Thread interrupted
• Thread interrupted

AI-assisted analysis of apache/seatunnel@cf67b549a7 (2026-09-10). Data as JSON: /api/errors/10db1d6a026f0e25. Report an issue: GitHub.