org.apache.hadoop.hbase.mob.mapreduce

Class MemStoreWrapper

java.lang.Object

org.apache.hadoop.hbase.mob.mapreduce.MemStoreWrapper

@InterfaceAudience.Private
public class MemStoreWrapper
extends Object

The wrapper of a DefaultMemStore. This wrapper is used in the sweep reducer to buffer and sort the cells written from the invalid and small mob files. It's flushed when it's full, the mob data are written to the mob files, and their file names are written back to store files of HBase. This memStore is used to sort the cells in mob files. In a reducer of sweep tool, the mob files are grouped by the same prefix (start key and date), in each group, the reducer iterates the files and read the cells to a new and bigger mob file. The cells in the same mob file are ordered, but cells across mob files are not. So we need this MemStoreWrapper to sort those cells come from different mob files before flushing them to the disk, when the memStore is big enough it's flushed as a new mob file.

Constructor Summary

Constructors

Constructor and Description
MemStoreWrapper(org.apache.hadoop.mapreduce.Reducer.Context context, org.apache.hadoop.fs.FileSystem fs, HTable table, HColumnDescriptor hcd, MemStore memstore, CacheConfig cacheConfig)

Method Summary

Methods

Modifier and Type	Method and Description
void	addToMemstore(KeyValue kv) Adds a KeyValue into the memstore.
void	flushMemStore() Flushes the memstore anyway.
void	setPartitionId(SweepReducer.SweepPartitionId partitionId)

Methods inherited from class java.lang.Object

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

Constructor Detail

MemStoreWrapper

public MemStoreWrapper(org.apache.hadoop.mapreduce.Reducer.Context context,
               org.apache.hadoop.fs.FileSystem fs,
               HTable table,
               HColumnDescriptor hcd,
               MemStore memstore,
               CacheConfig cacheConfig)
                throws IOException

Throws:

IOException

Method Detail

setPartitionId

public void setPartitionId(SweepReducer.SweepPartitionId partitionId)

flushMemStore

public void flushMemStore()
                   throws IOException

Flushes the memstore anyway.

Throws:

IOException

addToMemstore

public void addToMemstore(KeyValue kv)
                   throws IOException

Adds a KeyValue into the memstore.

Parameters:

kv - The KeyValue to be added.

Throws:

IOException