Package org.apache.spark.sql.streaming

Class StreamingQueryListener

Object

org.apache.spark.sql.streaming.StreamingQueryListener

All Implemented Interfaces:

Serializable, scala.Serializable

public abstract class StreamingQueryListener
extends Object
implements scala.Serializable

Interface for listening to events related to StreamingQueries.

Since:

2.0.0

See Also:

• Serialized Form

Note:

The methods are not thread-safe as they may be called from different threads.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static interface	StreamingQueryListener.Event	Base type of StreamingQueryListener events
static class	StreamingQueryListener.QueryIdleEvent	Event representing that query is idle and waiting for new data to process.
static class	StreamingQueryListener.QueryProgressEvent	Event representing any progress updates in a query.
static class	StreamingQueryListener.QueryStartedEvent	Event representing the start of a query param: id A unique query id that persists across restarts.
static class	StreamingQueryListener.QueryTerminatedEvent	Event representing that termination of a query.

Constructor Summary

Constructors

Constructor	Description
StreamingQueryListener()

Method Summary

Modifier and Type	Method	Description
void	onQueryIdle(StreamingQueryListener.QueryIdleEvent event)	Called when the query is idle and waiting for new data to process.
abstract void	onQueryProgress(StreamingQueryListener.QueryProgressEvent event)	Called when there is some status update (ingestion rate updated, etc.)
abstract void	onQueryStarted(StreamingQueryListener.QueryStartedEvent event)	Called when a query is started.
abstract void	onQueryTerminated(StreamingQueryListener.QueryTerminatedEvent event)	Called when a query is stopped, with or without error.

Methods inherited from class java.lang.Object

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

Constructor Details

StreamingQueryListener

public StreamingQueryListener()

Method Details

onQueryStarted

public abstract void onQueryStarted(StreamingQueryListener.QueryStartedEvent event)

Called when a query is started.

Parameters:

event - (undocumented)

Since:

2.0.0

Note:

This is called synchronously with DataStreamWriter.start(), that is, onQueryStart will be called on all listeners before DataStreamWriter.start() returns the corresponding StreamingQuery. Please don't block this method as it will block your query.

onQueryProgress

public abstract void onQueryProgress(StreamingQueryListener.QueryProgressEvent event)

Called when there is some status update (ingestion rate updated, etc.)

Parameters:

event - (undocumented)

Since:

2.0.0

Note:

This method is asynchronous. The status in StreamingQuery will always be latest no matter when this method is called. Therefore, the status of StreamingQuery may be changed before/when you process the event. E.g., you may find StreamingQuery is terminated when you are processing QueryProgressEvent.

onQueryIdle

public void onQueryIdle(StreamingQueryListener.QueryIdleEvent event)

Called when the query is idle and waiting for new data to process.

Parameters:

event - (undocumented)

Since:

3.5.0

onQueryTerminated

public abstract void onQueryTerminated(StreamingQueryListener.QueryTerminatedEvent event)

Called when a query is stopped, with or without error.

Parameters:

event - (undocumented)

Since:

2.0.0