MetricsWAL (Apache HBase 1.7.1 API)

java.lang.Object
- org.apache.hadoop.hbase.regionserver.wal.WALActionsListener.Base
- - org.apache.hadoop.hbase.regionserver.wal.MetricsWAL

All Implemented Interfaces:

WALActionsListener
```
@InterfaceAudience.Private
public class MetricsWAL
extends WALActionsListener.Base
```
Class used to push numbers about the WAL into the metrics subsystem. This will take a single function call and turn it into multiple manipulations of the hadoop metrics system.

Nested Class Summary
- Nested classes/interfaces inherited from interface org.apache.hadoop.hbase.regionserver.wal.WALActionsListener
  WALActionsListener.Base, WALActionsListener.RollRequestReason

Constructor Summary

Constructors
Constructor and Description

MetricsWAL()

Constructors
Constructor and Description
`MetricsWAL()`

Method Summary

Methods
Modifier and Type	Method and Description
`void`	`logRollRequested(WALActionsListener.RollRequestReason reason)` A request was made that the WAL be rolled.
`void`	`postAppend(long size, long time, WALKey logkey, WALEdit logEdit)` For notification post append to the writer.
`void`	`postLogRoll(org.apache.hadoop.fs.Path oldPath, org.apache.hadoop.fs.Path newPath)` The WAL has been rolled.
`void`	`postSync(long timeInNanos, int handlerSyncs)` For notification post writer sync.

Methods inherited from class org.apache.hadoop.hbase.regionserver.wal.WALActionsListener.Base
logCloseRequested, postLogArchive, preLogArchive, preLogRoll, visitLogEntryBeforeWrite, visitLogEntryBeforeWrite

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - MetricsWAL
```
public MetricsWAL()
```
- Method Detail
  - postSync
```
public void postSync(long timeInNanos,
            int handlerSyncs)
```
    Description copied from interface: WALActionsListener
    
    For notification post writer sync. Used by metrics system at least.
    
    Specified by:
    
    postSync in interface WALActionsListener
    
    Overrides:
    
    postSync in class WALActionsListener.Base
    
    Parameters:
    timeInNanos - How long the filesystem sync took in nanoseconds.
    handlerSyncs - How many sync handler calls were released by this call to filesystem sync.
  - postAppend
```
public void postAppend(long size,
              long time,
              WALKey logkey,
              WALEdit logEdit)
                throws IOException
```
    Description copied from interface: WALActionsListener
    
    For notification post append to the writer. Used by metrics system at least. TODO: Combine this with above.
    
    Specified by:
    
    postAppend in interface WALActionsListener
    
    Overrides:
    
    postAppend in class WALActionsListener.Base
    
    Parameters:
    size - approx length of cells in this append.
    time - elapsed time in milliseconds.
    logkey - A WAL key
    logEdit - A WAL edit containing list of cells.
    
    Throws:
    
    IOException - if any network or I/O occurred
  - logRollRequested
```
public void logRollRequested(WALActionsListener.RollRequestReason reason)
```
    Description copied from interface: WALActionsListener
    
    A request was made that the WAL be rolled.
    
    Specified by:
    
    logRollRequested in interface WALActionsListener
    
    Overrides:
    
    logRollRequested in class WALActionsListener.Base
  - postLogRoll
```
public void postLogRoll(org.apache.hadoop.fs.Path oldPath,
               org.apache.hadoop.fs.Path newPath)
```
    Description copied from interface: WALActionsListener
    
    The WAL has been rolled. The oldPath can be null if this is the first log file from the regionserver.
    
    Specified by:
    
    postLogRoll in interface WALActionsListener
    
    Overrides:
    
    postLogRoll in class WALActionsListener.Base
    
    Parameters:
    oldPath - the path to the old wal
    newPath - the path to the new wal

Class MetricsWAL

Nested Class Summary

Nested classes/interfaces inherited from interface org.apache.hadoop.hbase.regionserver.wal.WALActionsListener

Constructor Summary

Method Summary

Methods inherited from class org.apache.hadoop.hbase.regionserver.wal.WALActionsListener.Base

Methods inherited from class java.lang.Object

Constructor Detail

MetricsWAL

Method Detail

postSync

postAppend

logRollRequested

postLogRoll