In order to make your issue reports as actionable as possible, please provide the following information, depending on the issue type.

Bug report

For bug reports, provide this information, please:

What Debezium connector do you use and what version?

MySQL / BigQuery

What is the connector configuration?

<Your answer>

What is the captured database version and mode of deployment?

(E.g. on-premises, with a specific cloud provider, etc.)

on-prem MySQL 8.4

What behavior do you expect?

For large string values deserialised by the json extractor not to cause failures

What behavior do you see?

2025-08-28 01:04:02,673 ERROR [io.deb.ser.ConnectorLifecycle] (pool-8-thread-1) Connector completed: success = 'false', message = 'java.lang.RuntimeException: com.fasterxml.jackson.core.exc.StreamConstraintsException: String value length (20054016) exceeds the maximum allowed (20000000, from `StreamReadConstraints.getMaxStringLength()`)', error = 'java.lang.RuntimeException: com.fasterxml.jackson.core.exc.StreamConstraintsException: String value length (20054016) exceeds the maximum allowed (20000000, from `StreamReadConstraints.getMaxStringLength()`)': java.lang.RuntimeException: com.fasterxml.jackson.core.exc.StreamConstraintsException: String value length (20054016) exceeds the maximum allowed (20000000, from `StreamReadConstraints.getMaxStringLength()`)
at io.debezium.serde.json.JsonSerde$JsonDeserializer.deserialize(JsonSerde.java:99)
at io.debezium.server.bigquery.BatchBigqueryChangeConsumer.eventAsRecordConverter(BatchBigqueryChangeConsumer.java:186)
at io.debezium.server.bigquery.BaseChangeConsumer.lambda$handleBatch$0(BaseChangeConsumer.java:104)
at java.base/java.util.stream.ReferencePipeline$3$1.accept(Unknown Source)
at java.base/java.util.ArrayList$ArrayListSpliterator.forEachRemaining(Unknown Source)
at java.base/java.util.stream.AbstractPipeline.copyInto(Unknown Source)
at java.base/java.util.stream.AbstractPipeline.wrapAndCopyInto(Unknown Source)
at java.base/java.util.stream.ReduceOps$ReduceOp.evaluateSequential(Unknown Source)
at java.base/java.util.stream.AbstractPipeline.evaluate(Unknown Source)
at java.base/java.util.stream.ReferencePipeline.collect(Unknown Source)
at io.debezium.server.bigquery.BaseChangeConsumer.handleBatch(BaseChangeConsumer.java:109)
at io.debezium.embedded.async.ParallelSmtAndConvertBatchProcessor.processRecords(ParallelSmtAndConvertBatchProcessor.java:56)
at io.debezium.embedded.async.AsyncEmbeddedEngine$PollRecords.doCall(AsyncEmbeddedEngine.java:1203)
at io.debezium.embedded.async.AsyncEmbeddedEngine$PollRecords.doCall(AsyncEmbeddedEngine.java:1183)
at io.debezium.embedded.async.RetryingCallable.call(RetryingCallable.java:47)
at java.base/java.util.concurrent.FutureTask.run(Unknown Source)
at java.base/java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source)
at java.base/java.util.concurrent.FutureTask.run(Unknown Source)
at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at java.base/java.lang.Thread.run(Unknown Source)
Caused by: com.fasterxml.jackson.core.exc.StreamConstraintsException: String value length (20054016) exceeds the maximum allowed (20000000, from `StreamReadConstraints.getMaxStringLength()`)
at com.fasterxml.jackson.core.StreamReadConstraints._constructException(StreamReadConstraints.java:549)
at com.fasterxml.jackson.core.StreamReadConstraints.validateStringLength(StreamReadConstraints.java:484)
at com.fasterxml.jackson.core.util.ReadConstrainedTextBuffer.validateStringLength(ReadConstrainedTextBuffer.java:27)
at com.fasterxml.jackson.core.util.TextBuffer.finishCurrentSegment(TextBuffer.java:946)
at com.fasterxml.jackson.core.json.UTF8StreamJsonParser._finishString2(UTF8StreamJsonParser.java:2544)
at com.fasterxml.jackson.core.json.UTF8StreamJsonParser._finishAndReturnString(UTF8StreamJsonParser.java:2520)
at com.fasterxml.jackson.core.json.UTF8StreamJsonParser.getText(UTF8StreamJsonParser.java:294)
at com.fasterxml.jackson.databind.deser.std.BaseNodeDeserializer._deserializeContainerNoRecursion(JsonNodeDeserializer.java:572)
at com.fasterxml.jackson.databind.deser.std.JsonNodeDeserializer.deserialize(JsonNodeDeserializer.java:100)
at com.fasterxml.jackson.databind.deser.std.JsonNodeDeserializer.deserialize(JsonNodeDeserializer.java:25)
at com.fasterxml.jackson.databind.deser.DefaultDeserializationContext.readRootValue(DefaultDeserializationContext.java:342)
at com.fasterxml.jackson.databind.ObjectMapper._readTreeAndClose(ObjectMapper.java:4947)
at com.fasterxml.jackson.databind.ObjectMapper.readTree(ObjectMapper.java:3294)
at io.debezium.serde.json.JsonSerde$JsonDeserializer.deserialize(JsonSerde.java:94)
... 20 more

Do you see the same behaviour using the latest released Debezium version?

(Ideally, also verify with latest Alpha/Beta/CR version)

I have not tested

Do you have the connector logs, ideally from start till finish?

(You might be asked later to provide DEBUG/TRACE level log)

No

How to reproduce the issue using our tutorial deployment?

Difficult to say as I'm unsure which table/field is causing this issue atm

Feature request or enhancement

For feature requests or enhancements, provide this information, please:

Which use case/requirement will be addressed by the proposed feature?

<Your answer>

Implementation ideas (optional)

I will attempt a PR