apache/seatunnel · error

A deserialization failure event arrived

Error message

A deserialization failure event arrived

What it means

The binlog client delivered an EventDeserializer.DeserializationException event to the connector. The message is logged at WARN, DEBUG, or ERROR depending on event.deserialization.failure.handling.mode; in FAIL mode the error handler's producer throwable is set (connector stops), in WARN mode streaming continues, otherwise it is logged at DEBUG.

Solutions

1. Inspect the wrapped exception and use mysqlbinlog --start-position/--stop-position --verbose on the reported file/position to examine the event
2. Upgrade the Debezium-based connector version to match or exceed the source MySQL version
3. If the binlog is corrupt, restart streaming from a clean earlier offset/GTID or re-snapshot
4. Decide the desired policy: set event.deserialization.failure.handling.mode=fail to stop on bad events, or warn to skip them (risk of data loss)

Example fix

// before
"event.deserialization.failure.handling.mode": "warn"
// after (stop instead of silently skipping unreadable events)
"event.deserialization.failure.handling.mode": "fail"

// Before streaming:
// SELECT @@version; -- connector Debezium must support this MySQL version
// mysqlbinlog --verify-binlog-checksum <file>; -- binlog integrity

try {
    handleEvent(deserialized);
} catch (DeserializationException ex) {
    switch (failureMode) {
        case FAIL: errorHandler.setProducerThrowable(wrap(ex)); break;
        case WARN: logAndSkip(ex); break;
        default:   logDebugAndSkip(ex); break;
    }
}

When it happens

Trigger: execute()'s event loop receives a deserialization exception from the binlog client; handling mode is FAIL (stops via errorHandler.setProducerThrowable), WARN (continues), or default/other (debug log) — all paths log 'A deserialization failure event arrived'.

Common situations: Truncated binlogs after a server crash; binlog events written by a newer MySQL version than the connector supports; corrupted binlog transfer over network; reading GTID ranges spanning incompatible servers.

Understand the failure class

Background: "failed to unmarshal" / json.Unmarshal errors: why parsing a response into a Go struct fails and how to fix it — this error's family across 23 libraries.

Related errors

• Error while deserializing binlog event at offset
• Cannot read the binlog filename and position via
• Cannot read the binlog filename and position via
• Cannot read the binlog filename and position via
• Encountered change event

AI-assisted analysis of apache/seatunnel@cf67b549a7 (2026-09-10). Data as JSON: /api/errors/ddbebf21683a8a59. Report an issue: GitHub.

Appendix: source

Thrown at seatunnel-connectors-v2/connector-cdc/connector-cdc-mysql/src/main/java/io/debezium/connector/mysql/MySqlStreamingChangeEventSource.java:1571

            try {
                // Stop BinaryLogClient background threads
                client.disconnect();
            } catch (final Exception e) {
                LOGGER.debug("Exception while closing client", e);
            }
            errorHandler.setProducerThrowable(wrap(ex));
        }

        @Override
        public void onEventDeserializationFailure(BinaryLogClient client, Exception ex) {
            if (eventDeserializationFailureHandlingMode
                    == EventProcessingFailureHandlingMode.FAIL) {
                LOGGER.debug("A deserialization failure event arrived", ex);
                logStreamingSourceState();
                errorHandler.setProducerThrowable(wrap(ex));
            } else if (eventDeserializationFailureHandlingMode
                    == EventProcessingFailureHandlingMode.WARN) {
                LOGGER.warn("A deserialization failure event arrived", ex);
                logStreamingSourceState(Level.WARN);
            } else {
                LOGGER.debug("A deserialization failure event arrived", ex);
                logStreamingSourceState(Level.DEBUG);
            }
        }
    }

    @FunctionalInterface
    private interface TableIdProvider<E extends EventData> {
        TableId getTableId(E data);
    }

    @FunctionalInterface
    private interface RowsProvider<E extends EventData, U> {
        List<U> getRows(E data);
    }
}

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