org.apache.flink.state.changelog

Interface StateChangeLogger<Value,Namespace>

Type Parameters:

Value - type of state (value)

Namespace - type of namespace

All Superinterfaces:

AutoCloseable, Closeable

All Known Subinterfaces:

KvStateChangeLogger<Value,Namespace>

@Internal
public interface StateChangeLogger<Value,Namespace>
extends Closeable

Logs changes to a state created by ChangelogKeyedStateBackend. The changes are intended to be stored durably, included into a checkpoint and replayed on recovery in case of failure.

Note that the order of updating the delegated state and logging it using this class usually doesn't matter. However in some cases an already updated state needs to be logged. Besides that, delegated state update is usually local and would fail faster. Therefore, consider updating the delegated state first and logging the change second.

If state update succeeds and changelog append fails immediately then the updated change is discarded as no checkpoints can proceed.

If changelog append fails asynchronously then subsequent checkpoints can only succeed after state materialization.

Method Summary

Modifier and Type	Method and Description
void	resetWritingMetaFlag() Enable logging meta data before next writes.
void	valueAdded(Value addedValue, Namespace ns) State added, such as append to list.addAll.
void	valueCleared(Namespace ns) State cleared.
void	valueElementAdded(ThrowingConsumer<DataOutputView,IOException> dataSerializer, Namespace ns) State element added, such as append of a single element to a list.
void	valueElementAddedOrUpdated(ThrowingConsumer<DataOutputView,IOException> dataSerializer, Namespace ns) State element added or updated, such as put into a map.
void	valueElementRemoved(ThrowingConsumer<DataOutputView,IOException> dataSerializer, Namespace ns) State element removed, such mapping removal from a map.
void	valueUpdated(Value newValue, Namespace ns) State updated, such as by ListState.update(java.util.List<T>).
void	valueUpdatedInternal(Value newValue, Namespace ns) State update internally (usually with a value that the user has no control over).

Methods inherited from interface java.io.Closeable

close

Method Detail

valueUpdated

void valueUpdated(Value newValue,
                  Namespace ns)
           throws IOException

State updated, such as by ListState.update(java.util.List<T>).

Throws:

IOException

valueUpdatedInternal

void valueUpdatedInternal(Value newValue,
                          Namespace ns)
                   throws IOException

State update internally (usually with a value that the user has no control over).

Throws:

IOException

valueAdded

void valueAdded(Value addedValue,
                Namespace ns)
         throws IOException

State added, such as append to list.addAll.

Throws:

IOException

valueCleared

void valueCleared(Namespace ns)
           throws IOException

State cleared.

Throws:

IOException

valueElementAdded

void valueElementAdded(ThrowingConsumer<DataOutputView,IOException> dataSerializer,
                       Namespace ns)
                throws IOException

State element added, such as append of a single element to a list.

Throws:

IOException

valueElementAddedOrUpdated

void valueElementAddedOrUpdated(ThrowingConsumer<DataOutputView,IOException> dataSerializer,
                                Namespace ns)
                         throws IOException

State element added or updated, such as put into a map.

Throws:

IOException

valueElementRemoved

void valueElementRemoved(ThrowingConsumer<DataOutputView,IOException> dataSerializer,
                         Namespace ns)
                  throws IOException

State element removed, such mapping removal from a map.

Throws:

IOException

resetWritingMetaFlag

void resetWritingMetaFlag()

Enable logging meta data before next writes.