com.ververica.cdc.debezium.internal

Class DebeziumChangeFetcher<T>

java.lang.Object

com.ververica.cdc.debezium.internal.DebeziumChangeFetcher<T>

Type Parameters:

T - The type of elements produced by the handler.

@Internal
public class DebeziumChangeFetcher<T>
extends Object

A Handler that convert change messages from DebeziumEngine to data in Flink. Considering Debezium in different mode has different strategies to hold the lock, e.g. snapshot, the handler also needs different strategy. In snapshot phase, the handler needs to hold the lock until the snapshot finishes. But in non-snapshot phase, the handler only needs to hold the lock when emitting the records.

Constructor Summary

Constructors

Constructor and Description
DebeziumChangeFetcher(org.apache.flink.streaming.api.functions.source.SourceFunction.SourceContext<T> sourceContext, DebeziumDeserializationSchema<T> deserialization, boolean isInDbSnapshotPhase, String heartbeatTopicPrefix, Handover handover)

Method Summary

Modifier and Type	Method and Description
void	close()
long	getEmitDelay() The metric indicates delay from data generation to leaving the source operator.
long	getFetchDelay() The metric indicates delay from data generation to entry into the system.
long	getIdleTime()
void	runFetchLoop() Process change messages from the Handover and collect the processed messages by Collector.
byte[]	snapshotCurrentState() Take a snapshot of the Debezium handler state.

Methods inherited from class java.lang.Object

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

Constructor Detail

DebeziumChangeFetcher

public DebeziumChangeFetcher(org.apache.flink.streaming.api.functions.source.SourceFunction.SourceContext<T> sourceContext,
                             DebeziumDeserializationSchema<T> deserialization,
                             boolean isInDbSnapshotPhase,
                             String heartbeatTopicPrefix,
                             Handover handover)

Method Detail

snapshotCurrentState

public byte[] snapshotCurrentState()
                            throws Exception

Take a snapshot of the Debezium handler state.

Important: This method must be called under the checkpoint lock.

Throws:

Exception

runFetchLoop

public void runFetchLoop()
                  throws Exception

Process change messages from the Handover and collect the processed messages by Collector.

Throws:

Exception

close

public void close()

getFetchDelay

public long getFetchDelay()

The metric indicates delay from data generation to entry into the system.

Note: the metric is available during the binlog phase. Use 0 to indicate the metric is unavailable.

getEmitDelay

public long getEmitDelay()

The metric indicates delay from data generation to leaving the source operator.

Note: the metric is available during the binlog phase. Use 0 to indicate the metric is unavailable.

getIdleTime

public long getIdleTime()