Package org.apache.druid.java.util.emitter.core

Class SwitchingEmitter

java.lang.Object

org.apache.druid.java.util.emitter.core.SwitchingEmitter

All Implemented Interfaces:

Closeable, Flushable, AutoCloseable, Emitter

public class SwitchingEmitter
extends Object
implements Emitter

An emitter than that offers the ability to direct an event to multiple emitters based on the event's feed.

Constructor Summary

Constructors

Constructor	Description
SwitchingEmitter(Map<String,List<Emitter>> feedToEmitters, Emitter[] defaultEmitter)	Constructor for the SwitchingEmitter

Method Summary

Modifier and Type	Method	Description
void	close()	Closes all emitters that the SwitchingEmitter uses
void	emit(Event event)	Emit an event.
void	flush()	Triggers this emitter to tell all emitters that this uses to flush.
void	start()	Start the emitter.

Methods inherited from class java.lang.Object

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

Constructor Detail

SwitchingEmitter

public SwitchingEmitter(Map<String,List<Emitter>> feedToEmitters,
                        Emitter[] defaultEmitter)

Constructor for the SwitchingEmitter

Parameters:

feedToEmitters - Map of feed to a list of emitters that correspond to each feed,

defaultEmitter - A list of emitters to use if there isn't a match of feed to an emitter

Method Detail

start

public void start()

Start the emitter. This will start all the emitters the SwitchingEmitter uses.

Specified by:

start in interface Emitter

emit

public void emit(Event event)

Emit an event. This method must not throw exceptions or block. The emitters that this uses must also not throw exceptions or block.

This emitter will direct events based on feed to a list of emitters specified. If there is no match the event will use a list of default emitters instead.

Emitters that this emitter uses that receive too many events and internal queues fill up, should drop events rather than blocking or consuming excessive memory.

If an emitter that this emitter uses receives input it considers to be invalid, or has an internal problem, it should deal with that by logging a warning rather than throwing an exception. Emitters that log warnings should consider throttling warnings to avoid excessive logs, since a busy Druid cluster can emit a high volume of events.

Specified by:

emit in interface Emitter

Parameters:

event - The event that will be emitted.

flush

public void flush()
           throws IOException

Triggers this emitter to tell all emitters that this uses to flush.

Specified by:

flush in interface Emitter

Specified by:

flush in interface Flushable

Throws:

IOException

close

public void close()
           throws IOException

Closes all emitters that the SwitchingEmitter uses

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Closeable

Specified by:

close in interface Emitter

Throws:

IOException