Table of Contents

Status

Current state: Under DiscussionAdopted

Discussion thread: here

JIRA: here

...

A new configuration will be added: errors.dead.letter.deadletterqueuequeue.topic.name. When set, this configuration indicates the default exception handler implementation to build a Dead letter queue record during the error handling.

...

This proposal is to:

Add a new attribute "deadLetterQueueRecord" getter and setter to configure dead letter queue records in the DeserializationHandlerResponseDeserializationExceptionHandler, ProductionExceptionHandlerResponse and ProcessExceptionHandlerResponse (KIP-1033) enumsProductionExceptionHandler and ProcessExceptionHandler.
Add a new attribute public static final String DEFAULTERRORS_DEAD_ERRORSLETTER_DEADLETTERQUEUEQUEUE_TOPIC_NAME_CONFIG = "errors.deadletterqueuedead.letter.queue.topic.name".
Change the existing exception handler to produce a DeadLetterQueue record if the parameter errors.deadletterqueuedead.letter.queue.topic.name is set.
If the DeadLetterQueue record can not be sent to Apache Kafka, the exception would be sent to the Kafka Streams uncaughtExceptionHandler.

...

.

Default Dead letter queue record

Key	Key of the input message , null if triggered that triggered the sub-topology, null if triggered by punctuate
Value	If available, contains the value of the input message that triggered the sub-topology, null if triggered by punctuate
Headers	Existing context headers are automatically forwarded into the new DLQ record
Header: __streams.errors.exception	Name of the thrown exception
Header: __streams.errors.stacktrace	Stacktrace of the thrown exception
Header: __streams.errors.message	Thrown exception message
Header: __streams.errors.topic	Source input topic, null if triggered by punctuate
Header: __streams.errors.partition	Source input partition, null if triggered by punctuate
Header: __streams.errors.offset	Source input offset, null if triggered by punctuate

...

The DLQ topic name is set through the configuration DEFAULTERRORS_DEAD_ERRORSLETTER_DEADLETTERQUEUEQUEUE_TOPIC_NAME_CONFIG = " errors.deadletterqueuedead.letter.queue.topic.name". Users can override the default behavior by implementing custom exception handlers to implement a different DLQ topic strategy if required.

Public Interfaces

StreamsConfig.java

...

language	java

...

Changes:

Adding the errors.dead.letter.queue.topic.name

...

configuration. This configuration is only modifying the behavior of the out of the box exceptions handlers and would have no effect if a custom exception handlers is implemented, for example:
- if errors.dead.letter.queue.topic.name=null (default), then no records are sent to any dead letter queue
- if errors.dead.letter.queue.topic.name is set, exceptions happening during processing, production or deserialization will result in the raw source messages that trigger the topology to be send to the DLQ topic. The processing might or might not continue depending of the configuration of the processing.exception.handler, default.production.exception.handler and default.deserialization.exception.handler configurations

Code Block

language	java

public static final String ERRORS_DEAD_LETTER_QUEUE_TOPIC_NAME_CONFIG = "errors.dead.letter.queue.topic.name";

.define(ERRORS_DEAD_LETTER_QUEUE_TOPIC_NAME_CONFIG,
       Type.STRING,
       null, /* default */
       Importance.MEDIUM,
       ERRORS_DEAD_LETTER_QUEUE_TOPIC_NAME_DOC)

If the user implements a custom exception handler, it is up to the custom handler to build DLQ records to send, in this case, the errors.dead.letter.queue.topic.name configuration has no impact.

Code Block

language	java

    @Override
    public Response handleError(final ErrorHandlerContext context, final Record<?, ?> record, final Exception exception) {         
        List<ProducerRecord<byte[], byte[]>> records = Collections.singletonList(new ProducerRecord<>("app-dlq", "Hello".getBytes(StandardCharsets.UTF_8), "World".getBytes(StandardCharsets.UTF_8)));

        return ProcessingExceptionHandler.Response.resume(records);  
   }

ProductionExceptionHandler.java

Changes:

Adding a Response nested class,that contains a Result indicating whether to continue processing, fail, or retry and the list of records to be sent to the dead letter queue topic
Deprecating the handler() and handlerSerializationException() methods and adding two new methods: handlerError() and handleSerializationException(). The return type is the Response
Deprecating the ProductionExceptionHandlerResponse enum and create a new Result enum. The result enum contains the 3 fields RESUME, FAIL and RETRY and a deprecated method to convert the old enum to the new one
As the ErrorHandlerContext does not provide the sourceKey/Value in the handle method to limit the memory impact, the Dead Letter Queue record would only contains metadata. handleSerializationException is not impacted.

Code Block

language	java

public interface ProductionExceptionHandler extends Configurable {
   ...   
     

    @Deprecated
    default ProductionExceptionHandlerResponse handle(final ErrorHandlerContext context,
                                                      final ProducerRecord<byte[], byte[]> record,
                                                      final Exception exception) {
        ...
    }

    /**
     * Inspect a record that we attempted to produce, and the exception that resulted
     * from attempting to produce it and determine to continue or stop processing.
     *
     * @param context
     *     The error handler context metadata.
     * @param record
     *     The record that failed to produce.
     * @param exception
     *     The exception that occurred during production.
     *
     * @return a {@link Response} object
     */
    default Response handleError(final ErrorHandlerContext context,
                                                    final ProducerRecord<byte[], byte[]> record,
                                                    final Exception exception) {                          
          return new Response(Result.from(handle(context, record, exception)), Collections.emptyList());
     }

    @Deprecated
    default ProductionExceptionHandlerResponse handleSerializationException(final ProducerRecord record,
                                                                            final Exception exception) {
        ...
    }

    /**
     * Handles serialization exception and determine if the process should continue. The default implementation is to
     * fail the process.
     *
     * @param context
     *     The error handler context metadata.
     * @param record
     *     The record that failed to serialize.
     * @param exception
     *     The exception that occurred during serialization.
     * @param origin
     *     The origin of the serialization exception.
     *
     * @return a {@link Response} object
     */     
    default Response handleSerializationError(final ErrorHandlerContext context,
                                                                 final ProducerRecord record,
                                                                 final Exception exception,
                                                                 final SerializationExceptionOrigin origin) {                  
        return new Response(Result.from(handleSerializationException(context, record, exception, origin)), Collections.emptyList());
    }          
    
    @Deprecated
    enum ProductionExceptionHandlerResponse {
      ...
    }

        /**
     * Enumeration that describes the response from the exception handler.
     */
    enum Result {
        /** Resume processing.
         *
         * <p> For this case, output records which could not be written successfully are lost.
         * Use this option only if you can tolerate data loss.
         */
        RESUME(0, "RESUME"),
        /** Fail processing.
         *
         * <p> Kafka Streams will raise an exception and the {@code StreamsThread} will fail.
         * No offsets (for {@link org.apache.kafka.streams.StreamsConfig#AT_LEAST_ONCE at-least-once}) or transactions
         * (for {@link org.apache.kafka.streams.StreamsConfig#EXACTLY_ONCE_V2 exactly-once}) will be committed.
         */
        FAIL(1, "FAIL"),
        /** Retry the failed operation.
         *
         * <p> Retrying might imply that a {@link TaskCorruptedException} exception is thrown, and that the retry
         * is started from the last committed offset.
         *
         * <p> <b>NOTE:</b> {@code RETRY} is only a valid return value for
         * {@link org.apache.kafka.common.errors.RetriableException retriable exceptions}.
         * If {@code RETRY} is returned for a non-retriable exception it will be interpreted as {@link #FAIL}.
         */
        RETRY(2, "RETRY");

        /**
         * An english description for the used option. This is for debugging only and may change.
         */
        public final String name;

        /**
         * The permanent and immutable id for the used option. This can't change ever.
         */
        public final int id;

        Result(final int id, final String name) {
            this.id = id;
            this.name = name;
        }

        /**
         * Converts the deprecated enum ProductionExceptionHandlerResponse into the new Result enum.
         *
         * @param value the old ProductionExceptionHandlerResponse enum value
         * @return a {@link ProductionExceptionHandler.Result} enum value
         * @throws IllegalArgumentException if the provided value does not map to a valid {@link ProductionExceptionHandler.Result}
         */
        private static ProductionExceptionHandler.Result from(final ProductionExceptionHandlerResponse value) {
            switch (value) {
                case FAIL:
                    return Result.FAIL;
                case CONTINUE:
                    return Result.RESUME;
                case RETRY:
                    return Result.RETRY;
                default:
                    throw new IllegalArgumentException("No Result enum found for old value: " + value);
            }
        }
    }

    /**
     * Represents the result of handling a production exception.
     * <p>
     * The {@code Response} class encapsulates a {@link ProductionExceptionHandlerResponse},
     * indicating whether processing should continue or fail, along with an optional list of
     * {@link ProducerRecord} instances to be sent to a dead letter queue.
     * </p>
     */
    class Response {

        private Result result;

        private List<ProducerRecord<byte[], byte[]>> deadLetterQueueRecords;

        /**
         * Constructs a new {@code Response} object.
         *
         * @param result the result indicating whether processing should continue or fail;
         *                                  must not be {@code null}.
         * @param deadLetterQueueRecords    the list of records to be sent to the dead letter queue; may be {@code null}.
         */
        private Response(final Result result,
                         final List<ProducerRecord<byte[], byte[]>> deadLetterQueueRecords) {
            this.result = result;
            this.deadLetterQueueRecords = deadLetterQueueRecords;
        }

        /**
         * Creates a {@code Response} indicating that processing should fail.
         *
         * @param deadLetterQueueRecords the list of records to be sent to the dead letter queue; may be {@code null}.
         * @return a {@code Response} with a {@link ProductionExceptionHandler.Result#FAIL} status.
         */
        public static Response fail(final List<ProducerRecord<byte[], byte[]>> deadLetterQueueRecords) {
            return new Response(Result.FAIL, deadLetterQueueRecords);
        }

        /**
         * Creates a {@code Response} indicating that processing should fail.
         *
         * @return a {@code Response} with a {@link ProductionExceptionHandler.Result#FAIL} status.
         */
        public static Response fail() {
            return fail(Collections.emptyList());
        }

        /**
         * Creates a {@code Response} indicating that processing should continue.
         *
         * @param deadLetterQueueRecords the list of records to be sent to the dead letter queue; may be {@code null}.
         * @return a {@code Response} with a {@link ProductionExceptionHandler.Result#RESUME} status.
         */
        public static Response resume(final List<ProducerRecord<byte[], byte[]>> deadLetterQueueRecords) {
            return new Response(Result.RESUME, deadLetterQueueRecords);
        }

        /**
         * Creates a {@code Response} indicating that processing should continue.
         *
         * @return a {@code Response} with a {@link ProductionExceptionHandler.Result#RESUME} status.
         */
        public static Response resume() {
            return resume(Collections.emptyList());
        }

        /**
         * Creates a {@code Response} indicating that processing should retry.
         *
         * @return a {@code Response} with a {@link ProductionExceptionHandler.Result#RETRY} status.
         */
        public static Response retry() {
            return new Response(Result.RETRY, Collections.emptyList());
        }

        /**
         * Retrieves the production exception handler result.
         *
         * @return the {@link Result} indicating whether processing should continue, fail or retry.
         */
        public Result result() {
            return result;
        }

        /**
         * Retrieves an unmodifiable list of records to be sent to the dead letter queue.
         * <p>
         * If the list is {@code null}, an empty list is returned.
         * </p>
         *
         * @return an unmodifiable list of {@link ProducerRecord} instances
         *         for the dead letter queue, or an empty list if no records are available.
         */
        public List<ProducerRecord<byte[], byte[]>> deadLetterQueueRecords() {
            if (deadLetterQueueRecords == null) {
                return Collections.emptyList();
            }
            return Collections.unmodifiableList(deadLetterQueueRecords);
        }
    }
}

DeserializationExceptionHandler.java

Changes:

Adding a Response nested class,that contains a Result indicating whether to continue processing or fail, and the list of records to be sent to the dead letter queue topic
Deprecating the handler() method and adding a new method: handlerError(). The return type is the Response
Deprecating the DeserializationHandlerResponse enum and create a new Result enum. The result enum contains the 2 fields RESUME and Fail and a deprecated method to convert the old enum to the new one

Code Block

language	java

public interface DeserializationExceptionHandler extends Configurable {

   ...      
  
    @Deprecated
    default DeserializationHandlerResponse handle(final ErrorHandlerContext context,
                                                  final ConsumerRecord<byte[], byte[]> record,
                                                  final Exception exception) {
        ...
    }

    /**
     * Inspects a record and the exception received during deserialization.
     *
     * @param context
     *     Error handler context.
     * @param record
     *     Record that failed deserialization.
     * @param exception
     *     The actual exception.
     *
     * @return a {@link Response} object
     */
    default Response handleError(final ErrorHandlerContext context, final ConsumerRecord<byte[], byte[]> record, final Exception exception) {           
        return new Response(Result.from(handle(context, record, exception)), Collections.emptyList());
    }     

    @Deprecated
    enum DeserializationHandlerResponse {
        ...
    }

    /**
     * Enumeration that describes the response from the exception handler.
     */
    enum Result {
        /** Continue processing. */
        RESUME(0, "RESUME"),
        /** Fail processing. */
        FAIL(1, "FAIL");

        /**
         * An english description for the used option. This is for debugging only and may change.
         */
        public final String name;

        /**
         * The permanent and immutable id for the used option. This can't change ever.
         */
        public final int id;

        Result(final int id, final String name) {
            this.id = id;
            this.name = name;
        }

        /**
         * Converts the deprecated enum DeserializationHandlerResponse into the new Result enum.
         *
         * @param value the old DeserializationHandlerResponse enum value
         * @return a {@link Result} enum value
         * @throws IllegalArgumentException if the provided value does not map to a valid {@link Result}
         */
        private static DeserializationExceptionHandler.Result from(final DeserializationHandlerResponse value) {
            switch (value) {
                case FAIL:
                    return Result.FAIL;
                case CONTINUE:
                    return Result.RESUME;
                default:
                    throw new IllegalArgumentException("No Result enum found for old value: " + value);
            }
        }
    }

    /**
     * Represents the result of handling a deserialization exception.
     * <p>
     * The {@code Response} class encapsulates a {@link ProcessingExceptionHandler.Result},
     * indicating whether processing should continue or fail, along with an optional list of
     * {@link ProducerRecord} instances to be sent to a dead letter queue.
     * </p>
     */
    class Response {

        private Result result;

        private List<ProducerRecord<byte[], byte[]>> deadLetterQueueRecords;

        /**
         * Constructs a new {@code DeserializationExceptionResponse} object.
         *
         * @param result the result indicating whether processing should continue or fail;
         *                                  must not be {@code null}.
         * @param deadLetterQueueRecords    the list of records to be sent to the dead letter queue; may be {@code null}.
         */
        private Response(final Result result,
                         final List<ProducerRecord<byte[], byte[]>> deadLetterQueueRecords) {
            this.result = result;
            this.deadLetterQueueRecords = deadLetterQueueRecords;
        }

        /**
         * Creates a {@code Response} indicating that processing should fail.
         *
         * @param deadLetterQueueRecords the list of records to be sent to the dead letter queue; may be {@code null}.
         * @return a {@code Response} with a {@link DeserializationExceptionHandler.Result#FAIL} status.
         */
        public static Response fail(final List<ProducerRecord<byte[], byte[]>> deadLetterQueueRecords) {
            return new Response(Result.FAIL, deadLetterQueueRecords);
        }

        /**
         * Creates a {@code Response} indicating that processing should fail.
         *
         * @return a {@code Response} with a {@link DeserializationExceptionHandler.Result#FAIL} status.
         */
        public static Response fail() {
            return fail(Collections.emptyList());
        }

        /**
         * Creates a {@code Response} indicating that processing should continue.
         *
         * @param deadLetterQueueRecords the list of records to be sent to the dead letter queue; may be {@code null}.
         * @return a {@code Response} with a {@link DeserializationExceptionHandler.Result#RESUME} status.
         */
        public static Response resume(final List<ProducerRecord<byte[], byte[]>> deadLetterQueueRecords) {
            return new Response(Result.RESUME, deadLetterQueueRecords);
        }

        /**
         * Creates a {@code Response} indicating that processing should continue.
         *
         * @return a {@code Response} with a {@link DeserializationHandlerResponse#CONTINUE} status.
         */
        public static Response resume() {
            return resume(Collections.emptyList());
        }

        /**
         * Retrieves the deserialization handler result.
         *
         * @return the {@link Result} indicating whether processing should continue or fail.
         */
        public Result result() {
            return result;
        }

        /**
         * Retrieves an unmodifiable list of records to be sent to the dead letter queue.
         * <p>
         * If the list is {@code null}, an empty list is returned.
         * </p>
         *
         * @return an unmodifiable list of {@link ProducerRecord} instances
         *         for the dead letter queue, or an empty list if no records are available.
         */
        public List<ProducerRecord<byte[], byte[]>> deadLetterQueueRecords() {
            if (deadLetterQueueRecords == null) {
                return Collections.emptyList();
            }
            return Collections.unmodifiableList(deadLetterQueueRecords);
        }
    }
}

ProcessingExceptionHandler.java

Changes:

Adding a Response nested class,that contains a Result indicating whether to continue processing or fail, and the list of records to be sent to the dead letter queue topic
Deprecating the handler() method and adding a new method: handlerError(). The return type is the Response
Deprecating the ProcessingHandlerResponse enum and create a new Result enum. The result enum contains the 2 fields RESUME and Fail and a deprecated method to convert the old enum to the new one

Code Block

language	java

public interface ProcessingExceptionHandler extends Configurable {

   ...   
    
    @Deprecated
    default ProcessingHandlerResponse handle(final ErrorHandlerContext context, final Record<?, ?> record, final Exception exception){
       ...
    };

    /**
     * Inspects a record and the exception received during processing.
     *
     * @param context
     *     Processing context metadata.
     * @param record
     *     Record where the exception occurred.
     * @param exception
     *     The actual exception.
     *
     * @return a {@link Response} object
     */
    default Response handleError(final ErrorHandlerContext context, final Record<?, ?> record, final Exception exception) {                          
        return new Response(ProcessingExceptionHandler.Result.from(handle(context, record, exception)), Collections.emptyList());
    }   

    @Deprecated
    enum ProcessingHandlerResponse {
       ...
    } 

    /**
     * Enumeration that describes the response from the exception handler.
     */
    enum Result {
        /** Resume processing. */
        RESUME(1, "RESUME"),
        /** Fail processing. */
        FAIL(2, "FAIL");

        /**
         * An english description for the used option. This is for debugging only and may change.
         */
        public final String name;

        /**
         * The permanent and immutable id for the used option. This can't change ever.
         */
        public final int id;

        Result(final int id, final String name) {
            this.id = id;
            this.name = name;
        }

        /**
         * Converts the deprecated enum ProcessingHandlerResponse into the new Result enum.
         *
         * @param value the old DeserializationHandlerResponse enum value
         * @return a {@link ProcessingExceptionHandler.Result} enum value
         * @throws IllegalArgumentException if the provided value does not map to a valid {@link ProcessingExceptionHandler.Result}
         */
        private static ProcessingExceptionHandler.Result from(final ProcessingHandlerResponse value) {
            switch (value) {
                case FAIL:
                    return Result.FAIL;
                case CONTINUE:
                    return Result.RESUME;
                default:
                    throw new IllegalArgumentException("No Result enum found for old value: " + value);
            }
        }
    }
          /**
     * Represents the result of handling a processing exception.
     * <p>
     * The {@code Response} class encapsulates a {@link Result},
     * indicating whether processing should continue or fail, along with an optional list of
     * {@link org.apache.kafka.clients.producer.ProducerRecord} instances to be sent to a dead letter queue.
     * </p>
     */
    class Response {

        private Result result;

        private List<ProducerRecord<byte[], byte[]>> deadLetterQueueRecords;

        /**
         * Constructs a new {@code ProcessingExceptionResponse} object.
         *
         * @param result the result indicating whether processing should continue or fail;
         *                                  must not be {@code null}.
         * @param deadLetterQueueRecords    the list of records to be sent to the dead letter queue; may be {@code null}.
         */
        private Response(final Result result,
                         final List<ProducerRecord<byte[], byte[]>> deadLetterQueueRecords) {
            this.result = result;
            this.deadLetterQueueRecords = deadLetterQueueRecords;
        }

        /**
         * Creates a {@code Response} indicating that processing should fail.
         *
         * @param deadLetterQueueRecords the list of records to be sent to the dead letter queue; may be {@code null}.
         * @return a {@code Response} with a {@link ProcessingExceptionHandler.Result#FAIL} status.
         */
        public static Response fail(final List<ProducerRecord<byte[], byte[]>> deadLetterQueueRecords) {
            return new Response(Result.FAIL, deadLetterQueueRecords);
        }

        /**
         * Creates a {@code Response} indicating that processing should fail.
         *
         * @return a {@code Response} with a {@link ProcessingExceptionHandler.Result#FAIL} status.
         */
        public static Response fail() {
            return fail(Collections.emptyList());
        }

        /**
         * Creates a {@code Response} indicating that processing should continue.
         *
         * @param deadLetterQueueRecords the list of records to be sent to the dead letter queue; may be {@code null}.
         * @return a {@code Response} with a {@link ProcessingExceptionHandler.Result#RESUME} status.
         */
        public static Response resume(final List<ProducerRecord<byte[], byte[]>> deadLetterQueueRecords) {
            return new Response(Result.RESUME, deadLetterQueueRecords);
        }

        /**
         * Creates a {@code Response} indicating that processing should continue.
         *
         * @return a {@code Response} with a {@link ProcessingExceptionHandler.Result#RESUME} status.
         */
        public static Response resume() {
            return resume(Collections.emptyList());
        }

        /**
         * Retrieves the processing handler result.
         *
         * @return the {@link Result} indicating whether processing should continue or fail.
         */
        public Result result() {
            return result;
        }

        /**
         * Retrieves an unmodifiable list of records to be sent to the dead letter queue.
         * <p>
         * If the list is {@code null}, an empty list is returned.
         * </p>
         *
         * @return an unmodifiable list of {@link ProducerRecord} instances
         *         for the dead letter queue, or an empty list if no records are available.
         */
        public List<ProducerRecord<byte[], byte[]>> deadLetterQueueRecords() {
            if (deadLetterQueueRecords == null) {
                return Collections.emptyList();
            }
            return Collections.unmodifiableList(deadLetterQueueRecords);
        }
    }
 }

RecordContext.java

Changes:

Adding the public byte[] sourceRawKey and byte[] sourceRawValue in the RecordContext pointing to the source record data

Code Block

language	java
title	ErrorHandlerContext.java

/**
 * RecordContext interface
 */
public interface RecordContext {
    . . .          
    /**
     * Return the non-deserialized byte[] of the input message key if the context has been triggered by a message.
     *
     * <p> If this method is invoked within a {@link Punctuator#punctuate(long)
     * punctuation callback}, or while processing a record that was forwarded by a punctuation
     * callback, it will return {@code null}.
     *
     * <p> If this method is invoked in a sub-topology due to a repartition, the returned key would be one sent
     * to the repartition topic.
     *
     * @return the raw byte of the key of the source message
     */
    byte[] sourceRawKey();


    /**
     * Return the non-deserialized byte[] of the input message value if the context has been triggered by a message.
     *
     * <p> If this method is invoked within a {@link Punctuator#punctuate(long)
     * punctuation callback}, or while processing a record that was forwarded by a punctuation
     * callback, it will return {@code null}.
     *
     * <p> If this method is invoked in a sub-topology due to a repartition, the returned key would be one sent
     * to the repartition topic.
     *
     * @return the raw byte of the value of the source message
     */
    byte[] sourceRawValue();
       . . .
}

ErrorHandlerContext.java

Changes:

Adding the public byte[] sourceRawKey and byte[] sourceRawValue in the ErrorHandlerContext pointing to the source record data

Code Block

language	java
title	ErrorHandlerContext.java

/**
 * ErrorHandlerContext interface
 */
public interface ErrorHandlerContext {
    . . .
     
    /**
    * Return the non-deserialized byte[] of the input message key if the context has been triggered by a message.
     *
     * <p> If this method is invoked within a {@link Punctuator#punctuate(long)
     * punctuation callback}, or while processing a record that was forwarded by a punctuation
     * callback, it will return {@code null}.
     *
     * <p> If this method is invoked in a sub-topology due to a repartition, the returned key would be one sent
     * to the repartition topic.
     *
     * <p> Always returns null if this method is invoked within a
     * {@link ProductionExceptionHandler.handle(ErrorHandlerContext, ProducerRecord, Exception)}
     *
     * @return the raw byte of the key of the source message
     */
     byte[] sourceRawKey();
 
     /**
     * Return the non-deserialized byte[] of the input message value if the context has been triggered by a message.
     *
     * <p> If this method is invoked within a {@link Punctuator#punctuate(long)
     * punctuation callback}, or while processing a record that was forwarded by a punctuation
     * callback, it will return {@code null}.
     *
     * <p> If this method is invoked in a sub-topology due to a repartition, the returned value would be one sent
     * to the repartition topic.
     *
     * <p> Always returns null if this method is invoked within a
     * {@link ProductionExceptionHandler.handle(ErrorHandlerContext, ProducerRecord, Exception)}
     *
     * @return the raw byte of the value of the source message
     */
     byte[] sourceRawValue();
 
    . . .
}

Compatibility, Deprecation, and Migration Plan

All

ProductionExceptionHandler.java

Changes:

Adding the public ProducerRecord<byte[], byte[]> deadLetterQueueRecord; attribute in the ProductionExceptionHandlerResponse
As the ErrorHandlerContext does not provide the sourceKey/Value in the handle method to limit the memory impact, the Dead Letter Queue record would only contains metadata. handleSerializationException is not impacted.

Code Block

language	java

public interface ProductionExceptionHandler extends Configurable {
   ...


   enum ProductionExceptionHandlerResponse {
       . . . 

       public ProductionExceptionHandlerResponse withDeadLetterQueueRecords(Iterable<org.apache.kafka.clients.producer.ProducerRecord<byte[], byte[]>> deadLetterQueueRecords) {
           this.deadLetterQueueRecord = deadLetterQueueRecord;
           return this;
       }
   }
}

DeserializationExceptionHandler.java

Changes:

Adding the public ProducerRecord<byte[], byte[]> deadLetterQueueRecord; attribute in the ProductionExceptionHandlerResponse

Code Block

language	java

public interface DeserializationExceptionHandler extends Configurable {

   ...

   /**
    * Enumeration that describes the response from the exception handler.
    */
   enum DeserializationHandlerResponse {
        . . .

       public DeserializationHandlerResponse withDeadLetterQueueRecords(Iterable<org.apache.kafka.clients.producer.ProducerRecord<byte[], byte[]>> deadLetterQueueRecords) {
           this.deadLetterQueueRecord = deadLetterQueueRecord;
           return this;
       }
   }
}

ProcessingExceptionHandler

With KIP-1033, a similar behavior would be added to the potential new ProcessingExceptionHandler: adding a public ProducerRecord<byte[], byte[]> deadLetterQueueRecord; attribute in the ProcessingExceptionHandlerResponse.

The goal is to support, regardless of the timeline, DLQ in the ProcessingExceptionHandler if KIP-1033 is approved. The change will either be part of KIP-1034 or KIP-1033 if this KIP is implemented first.

Compatibility, Deprecation, and Migration Plan

To build a valid record for the DeadLetterQueue, the ProductionExceptionHandler.handle method needs to have access to the ProcessingContext. To ensure backward compatibility, the previous interface would be deprecated and the default implementation of the new interface would invoke the previous one.

All other changes are backward compatible and should not impact existing applications.

...

Tests to ensure the backward compatibility of the ProductionExceptionHandler class
Tests to ensure that default exception handlers are sending record to the DLQ topic if the DLQ topic name is set
Ensure that failure to send the DLQ record kills the StreamThread
Ensure that punctuator triggered exceptions are producing the expected payload

Rejected Alternatives

Sending multiple DLQ record for a single issue.
Managing DeadLetterQueue directly in the DSL by extending the KStreams interface.
Providing no default implementation to build the Dead letter queue record and delegating this task to the user.
Only providing exception and metadata information in the default DLQ implementation.
Adding a new interface, that could be overload overloaded by the user, to build the DLQ record.records.
Adding dead letter queue records to the enum: problematic because the collection would be shared by all stream threads, leading to unnecessary concurrency and potential transaction issues.

Space shortcuts

Child pages

Versions Compared

Old Version 16

New Version Current

Key

Status

Default Dead letter queue record

Public Interfaces

StreamsConfig.java

ProductionExceptionHandler.java

DeserializationExceptionHandler.java

ProcessingExceptionHandler.java

RecordContext.java

ErrorHandlerContext.java

Compatibility, Deprecation, and Migration Plan

ProductionExceptionHandler.java

DeserializationExceptionHandler.java

ProcessingExceptionHandler

Compatibility, Deprecation, and Migration Plan

Rejected Alternatives

Space shortcuts

Child pages

Page History

Versions Compared

Old Version 16

New Version Current

Key

Status

Default Dead letter queue record

Public Interfaces

StreamsConfig.java

ProductionExceptionHandler.java

DeserializationExceptionHandler.java

ProcessingExceptionHandler.java

RecordContext.java

ErrorHandlerContext.java

Compatibility, Deprecation, and Migration Plan

ProductionExceptionHandler.java

DeserializationExceptionHandler.java

ProcessingExceptionHandler

Compatibility, Deprecation, and Migration Plan

Rejected Alternatives