NamedQueueRecorder (Apache HBase 1.7.2 API)

java.lang.Object
- org.apache.hadoop.hbase.namequeues.NamedQueueRecorder

All Implemented Interfaces:

Closeable, AutoCloseable
```
@InterfaceAudience.Private
@InterfaceStability.Evolving
public final class NamedQueueRecorder
extends Object
implements Closeable
```
NamedQueue recorder that maintains various named queues. The service uses LMAX Disruptor to save queue records which are then consumed by a queue and based on the ring buffer size, the available records are then fetched from the queue in thread-safe manner.

Method Summary

Methods
Modifier and Type	Method and Description
`void`	`addRecord(NamedQueuePayload namedQueuePayload)` Add various NamedQueue records to ringbuffer.
`boolean`	`clearNamedQueue(NamedQueuePayload.NamedQueueEvent namedQueueEvent)` clears queue records from ringbuffer
`void`	`close()`
`static NamedQueueRecorder`	`getInstance(org.apache.hadoop.conf.Configuration conf)`
`NamedQueueGetResponse`	`getNamedQueueRecords(NamedQueueGetRequest request)` Retrieve in memory queue records from ringbuffer
`void`	`persistAll(NamedQueuePayload.NamedQueueEvent namedQueueEvent)` 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

- Method Detail
  - getInstance
```
public static NamedQueueRecorder getInstance(org.apache.hadoop.conf.Configuration conf)
```
  - getNamedQueueRecords
```
public 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)
  - clearNamedQueue
```
public boolean clearNamedQueue(NamedQueuePayload.NamedQueueEvent namedQueueEvent)
```
    clears queue records from ringbuffer
    
    Parameters:
    namedQueueEvent - type of queue to clear
    
    Returns:
    true if slow log payloads are cleaned up or hbase.regionserver.slowlog.buffer.enabled is not set to true, false if failed to clean up slow logs
  - addRecord
```
public void addRecord(NamedQueuePayload namedQueuePayload)
```
    Add various NamedQueue records to ringbuffer. Based on the type of the event (e.g slowLog), consumer of disruptor ringbuffer will have specific logic. This method is producer of disruptor ringbuffer which is initialized in NamedQueueRecorder constructor.
    
    Parameters:
    namedQueuePayload - namedQueue payload sent by client of ring buffer service
  - persistAll
```
public void persistAll(NamedQueuePayload.NamedQueueEvent namedQueueEvent)
```
    Add all in memory queue records to system table. The implementors can use system table or direct HDFS file or ZK as persistence system.
  - close
```
public void close()
           throws IOException
```
    Specified by:
    
    close in interface Closeable
    
    Specified by:
    
    close in interface AutoCloseable
    
    Throws:
    
    IOException

Class NamedQueueRecorder

Method Summary

Methods inherited from class java.lang.Object

Method Detail

getInstance

getNamedQueueRecords

clearNamedQueue

addRecord

persistAll

close