io.debezium.transforms

Class UnwrapFromEnvelope<R extends org.apache.kafka.connect.connector.ConnectRecord<R>>

java.lang.Object

io.debezium.transforms.UnwrapFromEnvelope<R>

Type Parameters:

R - the subtype of ConnectRecord on which this transformation will operate

All Implemented Interfaces:

Closeable, AutoCloseable, org.apache.kafka.common.Configurable, org.apache.kafka.connect.transforms.Transformation<R>

public class UnwrapFromEnvelope<R extends org.apache.kafka.connect.connector.ConnectRecord<R>>
extends Object
implements org.apache.kafka.connect.transforms.Transformation<R>

Debezium generates CDC (Envelope) records that are struct of values containing values before and after change. Sink connectors usually are not able to work with a complex structure so a user use this SMT to extract after value and send it down unwrapped in Envelope.

The functionality is similar to ExtractField SMT but has a special semantics for handling delete events; when delete event is emitted by database then Debezium emits two messages: a delete message and a tombstone message that serves as a signal to Kafka compaction process.

The SMT by default drops the tombstone message created by Debezium and converts the delete message into a tombstone message that can be dropped, too, if required.

Author:

Jiri Pechanec

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	UnwrapFromEnvelope.DeleteHandling

Field Summary

Fields

Modifier and Type	Field and Description
private org.apache.kafka.connect.transforms.ExtractField<R>	afterDelegate
private org.apache.kafka.connect.transforms.ExtractField<R>	beforeDelegate
private static String	DELETED_FIELD
private static Field	DROP_DELETES
private static Field	DROP_TOMBSTONES
private boolean	dropDeletes
private boolean	dropTombstones
private static String	ENVELOPE_SCHEMA_NAME_SUFFIX
private static Field	HANDLE_DELETES
private UnwrapFromEnvelope.DeleteHandling	handleDeletes
private org.slf4j.Logger	logger
private org.apache.kafka.connect.transforms.InsertField<R>	removedDelegate
private org.apache.kafka.connect.transforms.InsertField<R>	updatedDelegate

Constructor Summary

Constructors

Constructor and Description
UnwrapFromEnvelope()

Method Summary

Modifier and Type	Method and Description
R	apply(R record)
void	close()
org.apache.kafka.common.config.ConfigDef	config()
void	configure(Map<String,?> configs)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

ENVELOPE_SCHEMA_NAME_SUFFIX

private static final String ENVELOPE_SCHEMA_NAME_SUFFIX

See Also:

Constant Field Values

DELETED_FIELD

private static final String DELETED_FIELD

See Also:

Constant Field Values

logger

private final org.slf4j.Logger logger

DROP_TOMBSTONES

private static final Field DROP_TOMBSTONES

DROP_DELETES

private static final Field DROP_DELETES

HANDLE_DELETES

private static final Field HANDLE_DELETES

dropTombstones

private boolean dropTombstones

dropDeletes

private boolean dropDeletes

handleDeletes

private UnwrapFromEnvelope.DeleteHandling handleDeletes

afterDelegate

private final org.apache.kafka.connect.transforms.ExtractField<R extends org.apache.kafka.connect.connector.ConnectRecord<R>> afterDelegate

beforeDelegate

private final org.apache.kafka.connect.transforms.ExtractField<R extends org.apache.kafka.connect.connector.ConnectRecord<R>> beforeDelegate

removedDelegate

private final org.apache.kafka.connect.transforms.InsertField<R extends org.apache.kafka.connect.connector.ConnectRecord<R>> removedDelegate

updatedDelegate

private final org.apache.kafka.connect.transforms.InsertField<R extends org.apache.kafka.connect.connector.ConnectRecord<R>> updatedDelegate

Constructor Detail

UnwrapFromEnvelope

public UnwrapFromEnvelope()

Method Detail

configure

public void configure(Map<String,?> configs)

Specified by:

configure in interface org.apache.kafka.common.Configurable

apply

public R apply(R record)

Specified by:

apply in interface org.apache.kafka.connect.transforms.Transformation<R extends org.apache.kafka.connect.connector.ConnectRecord<R>>

config

public org.apache.kafka.common.config.ConfigDef config()

Specified by:

config in interface org.apache.kafka.connect.transforms.Transformation<R extends org.apache.kafka.connect.connector.ConnectRecord<R>>

close

public void close()

Specified by:

close in interface Closeable

Specified by:

close in interface AutoCloseable

Specified by:

close in interface org.apache.kafka.connect.transforms.Transformation<R extends org.apache.kafka.connect.connector.ConnectRecord<R>>