LogRoller (Apache HBase 1.2.12 API)

java.lang.Object
- org.apache.hadoop.hbase.util.HasThread
- - org.apache.hadoop.hbase.regionserver.LogRoller

All Implemented Interfaces:

Runnable
```
@InterfaceAudience.Private
public class LogRoller
extends HasThread
```
Runs periodically to determine if the WAL should be rolled. NOTE: This class extends Thread rather than Chore because the sleep time can be interrupted when there is something to do, rather than the Chore sleep time which is invariant. TODO: change to a pool of threads

Field Summary

Fields
Modifier and Type	Field and Description
`private long`	`checkLowReplicationInterval`
`private long`	`lastrolltime`
`private static org.apache.commons.logging.Log`	`LOG`
`private ReentrantLock`	`rollLock`
`private AtomicBoolean`	`rollLog`
`private long`	`rollperiod`
`private Server`	`server`
`protected RegionServerServices`	`services`
`private int`	`threadWakeFrequency`
`private ConcurrentHashMap<WAL,Boolean>`	`walNeedsRoll`

Constructor Summary

Constructors
Constructor and Description

LogRoller(Server server, RegionServerServices services)

Constructors
Constructor and Description
`LogRoller(Server server, RegionServerServices services)`

Method Summary

Methods
Modifier and Type	Method and Description
`void`	`addWAL(WAL wal)`
`(package private) void`	`checkLowReplication(long now)` we need to check low replication in period, see HBASE-18132
`void`	`interrupt()`
`void`	`requestRollAll()`
`void`	`run()`
`private void`	`scheduleFlush(byte[] encodedRegionName)`
`boolean`	`walRollFinished()` For testing only

Methods inherited from class org.apache.hadoop.hbase.util.HasThread
getName, getThread, isAlive, isInterrupted, join, join, join, setDaemon, setName, setPriority, setUncaughtExceptionHandler, start

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

Field Detail

LOG

private static final org.apache.commons.logging.Log LOG

rollLock
```
private final ReentrantLock rollLock
```

rollLog
```
private final AtomicBoolean rollLog
```

walNeedsRoll

private final ConcurrentHashMap<WAL,Boolean> walNeedsRoll

server
```
private final Server server
```

services

protected final RegionServerServices services

lastrolltime
```
private volatile long lastrolltime
```

rollperiod
```
private final long rollperiod
```

threadWakeFrequency
```
private final int threadWakeFrequency
```

checkLowReplicationInterval

private long checkLowReplicationInterval

Constructor Detail

LogRoller

public LogRoller(Server server,
         RegionServerServices services)

Parameters:: server -

Method Detail
- addWAL
```
public void addWAL(WAL wal)
```
- requestRollAll
```
public void requestRollAll()
```
- interrupt
```
public void interrupt()
```
  Overrides:
  
  interrupt in class HasThread
- checkLowReplication
```
void checkLowReplication(long now)
```
  we need to check low replication in period, see HBASE-18132
- run
```
public void run()
```
  Specified by:
  
  run in interface Runnable
  
  Specified by:
  
  run in class HasThread
- scheduleFlush
```
private void scheduleFlush(byte[] encodedRegionName)
```
  Parameters:
  encodedRegionName - Encoded name of region to flush.
- walRollFinished
```
public boolean walRollFinished()
```
  For testing only
  
  Returns:
  true if all WAL roll finished

Class LogRoller

Field Summary

Constructor Summary

Method Summary

Methods inherited from class org.apache.hadoop.hbase.util.HasThread

Methods inherited from class java.lang.Object

Field Detail

LOG

rollLock

rollLog

walNeedsRoll

server

services

lastrolltime

rollperiod

threadWakeFrequency

checkLowReplicationInterval

Constructor Detail

LogRoller

Method Detail

addWAL

requestRollAll

interrupt

checkLowReplication

run

scheduleFlush

walRollFinished