apache/seatunnel · error · RuntimeException

Failed to serialize EdgeIngressPacket to JSON

Error message

Failed to serialize EdgeIngressPacket to JSON

What it means

PacketPayloadSerializer.serialize builds an EdgeIngressPacket and writes it with Jackson's ObjectMapper. A JsonProcessingException (theoretically unchecked data, broken generators, invalid state) is wrapped in a RuntimeException with the message "Failed to serialize EdgeIngressPacket to JSON" and the original exception as cause. Other failures (e.g. encryption/IV generation) are wrapped with a different WAL-payload message.

Source

Thrown at seatunnel-edge-agent/seatunnel-edge-agent-transport/src/main/java/org/apache/seatunnel/edge/agent/transport/serialize/PacketPayloadSerializer.java:82

                ivBase64 = Base64.getEncoder().encodeToString(iv);
            } else {
                body = compressed;
            }

            String payloadBase64 = Base64.getEncoder().encodeToString(body);

            EdgeIngressPacket packet =
                    EdgeIngressPacket.builder()
                            .version(1)
                            .payload(payloadBase64)
                            .compression(compressionType.getValue())
                            .encryption(encryptionType.getValue())
                            .iv(ivBase64)
                            .build();

            return objectMapper.writeValueAsString(packet);
        } catch (JsonProcessingException e) {
            throw new RuntimeException("Failed to serialize EdgeIngressPacket to JSON", e);
        } catch (Exception e) {
            throw new RuntimeException("Failed to serialize WAL payload to packet wire format", e);
        }
    }
}

View on GitHub (pinned to cf67b549a7)

Solutions

1. Inspect the cause (JsonProcessingException) in the stack trace — it names the exact field/type Jackson failed on; fix that payload object (add getters or @JsonIgnore).
2. Align Jackson versions across the classpath (check the fat jar for duplicate jackson-databind artifacts).
3. Ensure the EdgeIngressPacket and payload classes are on the same build/version as the serializer.
4. If you added a custom field type, register a serializer module or make the field a JSON-friendly type (String/byte[] with Base64).

Example fix

// before
public class CustomPayload {
    private CustomObject obj; // not JSON-serializable
}

// after
public class CustomPayload {
    private String objJson; // pre-serialized JSON string
}

// Ensure the packet is Jackson-friendly before serializing
Objects.requireNonNull(payload, "payload");
try {
    new ObjectMapper().writeValueAsString(packet);
} catch (JsonProcessingException probe) {
    throw new IllegalStateException("Packet not JSON-serializable: " + probe.getOriginalMessage(), probe);
}

boolean isJsonFriendly(Object o) {
    return o == null || o instanceof String || o instanceof Number
        || o instanceof Boolean || o instanceof byte[] || o instanceof java.util.Map
        || o instanceof java.util.Collection;
}

try {
    String json = serializer.serialize(payload, key, iv);
} catch (RuntimeException e) {
    if (e.getCause() instanceof JsonProcessingException jpe) {
        LOG.error("Serialization failed: " + jpe.getOriginalMessage(), e);
    }
    throw e;
}

When it happens

Trigger: Calling serialize on a payload whose resulting EdgeIngressPacket cannot be serialized by Jackson — e.g. a value object without a serializable representation, an ObjectMapper misconfigured for the packet type, or an incompatible Jackson version on the classpath.

Common situations: Classpath conflicts where an older jackson-databind lacks features the packet annotations need; custom payload types added to the packet without Jackson-compatible getters; running with shaded-vs-unshaded Jackson mixtures in the fat jar.

Understand the failure class

Background: "JSON serialization failed", "not JSON serializable", "Failed to serialize": why JSON marshaling errors happen and how to fix them — this error's family across 46 libraries.

Related errors

• JSON_OPERATION_FAILED
• Failed to serialize WAL payload to packet wire format
• Object to json exception!
• Object json deserialization exception.
• Failed to convert row to JSON

AI-assisted analysis of apache/seatunnel@cf67b549a7 (2026-09-10). Data as JSON: /api/errors/c825a0942ab7dd2d. Report an issue: GitHub.