RegionReplicaFlushHandler (Apache HBase 1.2.12 API)

java.lang.Object
- org.apache.hadoop.hbase.executor.EventHandler
- - org.apache.hadoop.hbase.regionserver.handler.RegionReplicaFlushHandler

All Implemented Interfaces:

Comparable<Runnable>, Runnable
```
@InterfaceAudience.Private
public class RegionReplicaFlushHandler
extends EventHandler
```
HBASE-11580: With the async wal approach (HBASE-11568), the edits are not persisted to wal in secondary region replicas. This means that a secondary region replica can serve some edits from it's memstore that that is still not flushed from primary. We do not want to allow secondary region's seqId to go back in time, when this secondary region is opened elsewhere after a crash or region move. We will trigger a flush cache in the primary region replica and wait for observing a complete flush cycle before marking the region readsEnabled. This handler does the flushing of the primary region replica and ensures that regular region opening is not blocked while the secondary replica is blocked on flush.

Nested Class Summary
- Nested classes/interfaces inherited from class org.apache.hadoop.hbase.executor.EventHandler
  EventHandler.EventHandlerListener

Field Summary

Fields
Modifier and Type	Field and Description
`private ClusterConnection`	`connection`
`private static org.apache.commons.logging.Log`	`LOG`
`private int`	`operationTimeout`
`private HRegion`	`region`
`private RpcControllerFactory`	`rpcControllerFactory`
`private RpcRetryingCallerFactory`	`rpcRetryingCallerFactory`

Fields inherited from class org.apache.hadoop.hbase.executor.EventHandler
eventType, seqids, server, waitingTimeForEvents

Constructor Summary

Constructors
Constructor and Description
`RegionReplicaFlushHandler(Server server, ClusterConnection connection, RpcRetryingCallerFactory rpcRetryingCallerFactory, RpcControllerFactory rpcControllerFactory, int operationTimeout, HRegion region)`

Method Summary

Methods
Modifier and Type	Method and Description
`private int`	`getRetriesCount(org.apache.hadoop.conf.Configuration conf)`
`protected void`	`handleException(Throwable t)` Event exception handler, may be overridden
`void`	`process()` This method is the main processing loop to be implemented by the various subclasses.
`(package private) void`	`triggerFlushInPrimaryRegion(HRegion region)`

Methods inherited from class org.apache.hadoop.hbase.executor.EventHandler
compareTo, getEventType, getInformativeName, getListener, getPriority, getSeqid, prepare, run, setListener, toString

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

Field Detail

LOG

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

connection

private final ClusterConnection connection

rpcRetryingCallerFactory

private final RpcRetryingCallerFactory rpcRetryingCallerFactory

rpcControllerFactory

private final RpcControllerFactory rpcControllerFactory

operationTimeout
```
private final int operationTimeout
```

region
```
private final HRegion region
```

Constructor Detail

RegionReplicaFlushHandler

public RegionReplicaFlushHandler(Server server,
                         ClusterConnection connection,
                         RpcRetryingCallerFactory rpcRetryingCallerFactory,
                         RpcControllerFactory rpcControllerFactory,
                         int operationTimeout,
                         HRegion region)

Method Detail
- process
```
public void process()
             throws IOException
```
  Description copied from class: EventHandler
  
  This method is the main processing loop to be implemented by the various subclasses.
  
  Specified by:
  
  process in class EventHandler
  
  Throws:
  
  IOException
- handleException
```
protected void handleException(Throwable t)
```
  Description copied from class: EventHandler
  
  Event exception handler, may be overridden
  
  Overrides:
  
  handleException in class EventHandler
  
  Parameters:
  t - Throwable object
- getRetriesCount
```
private int getRetriesCount(org.apache.hadoop.conf.Configuration conf)
```
- triggerFlushInPrimaryRegion
```
void triggerFlushInPrimaryRegion(HRegion region)
                           throws IOException,
                                  RuntimeException
```
  Throws:
  
  IOException
  
  RuntimeException

Class RegionReplicaFlushHandler

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.hadoop.hbase.executor.EventHandler

Field Summary

Fields inherited from class org.apache.hadoop.hbase.executor.EventHandler

Constructor Summary

Method Summary

Methods inherited from class org.apache.hadoop.hbase.executor.EventHandler

Methods inherited from class java.lang.Object

Field Detail

LOG

connection

rpcRetryingCallerFactory

rpcControllerFactory

operationTimeout

region

Constructor Detail

RegionReplicaFlushHandler

Method Detail

process

handleException

getRetriesCount

triggerFlushInPrimaryRegion