Package org.apache.hadoop.hbase.namequeues

Class LogEventHandler

java.lang.Object

org.apache.hadoop.hbase.namequeues.LogEventHandler

All Implemented Interfaces:

com.lmax.disruptor.EventHandler<RingBufferEnvelope>

@Private
class LogEventHandler
extends Object
implements com.lmax.disruptor.EventHandler<RingBufferEnvelope>

Event Handler run by disruptor ringbuffer consumer. Although this is generic implementation for namedQueue, it can have individual queue specific logic.

Field Summary

Fields

Modifier and Type	Field	Description
private static final org.slf4j.Logger	LOG
private static final String	NAMED_QUEUE_PROVIDER_CLASSES
private final Map<NamedQueuePayload.NamedQueueEvent,NamedQueueService>	namedQueueServices

Constructor Summary

Constructors

Constructor	Description
LogEventHandler(org.apache.hadoop.conf.Configuration conf)

Method Summary

Modifier and Type	Method	Description
(package private) boolean	clearNamedQueue(NamedQueuePayload.NamedQueueEvent namedQueueEvent)	Cleans up queues maintained by services.
(package private) NamedQueueGetResponse	getNamedQueueRecords(NamedQueueGetRequest request)	Retrieve in memory queue records from ringbuffer
void	onEvent(RingBufferEnvelope event, long sequence, boolean endOfBatch)	Called when a publisher has published an event to the RingBuffer.
(package private) void	persistAll(NamedQueuePayload.NamedQueueEvent namedQueueEvent, Connection connection)	Add all in memory queue records to system table.

Methods inherited from class java.lang.Object

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

Field Details

LOG

private static final org.slf4j.Logger LOG

namedQueueServices

private final Map<NamedQueuePayload.NamedQueueEvent,NamedQueueService> namedQueueServices

NAMED_QUEUE_PROVIDER_CLASSES

private static final String NAMED_QUEUE_PROVIDER_CLASSES

See Also:

• Constant Field Values

Constructor Details

LogEventHandler

LogEventHandler(org.apache.hadoop.conf.Configuration conf)

Method Details

onEvent

public void onEvent(RingBufferEnvelope event,
 long sequence,
 boolean endOfBatch)

Called when a publisher has published an event to the RingBuffer. This is generic consumer of disruptor ringbuffer and for each new namedQueue that we add, we should also provide specific consumer logic here.

Specified by:

onEvent in interface com.lmax.disruptor.EventHandler<RingBufferEnvelope>

Parameters:

event - published to the RingBuffer

sequence - of the event being processed

endOfBatch - flag to indicate if this is the last event in a batch from the RingBuffer

clearNamedQueue

boolean clearNamedQueue(NamedQueuePayload.NamedQueueEvent namedQueueEvent)

Cleans up queues maintained by services.

Parameters:

namedQueueEvent - type of queue to clear

Returns:

true if queue is cleaned up, false otherwise

persistAll

void persistAll(NamedQueuePayload.NamedQueueEvent namedQueueEvent,
 Connection connection)

Add all in memory queue records to system table. The implementors can use system table or direct HDFS file or ZK as persistence system.

getNamedQueueRecords

NamedQueueGetResponse getNamedQueueRecords(NamedQueueGetRequest request)

Retrieve in memory queue records from ringbuffer

Parameters:

request - namedQueue request with event type

Returns:

queue records from ringbuffer after filter (if applied)