TableDescriptor

TableDescriptor contains the details about an HBase table such as the descriptors of all the column families, is the table a catalog table, if the table is read only, the maximum size of the memstore, when the region split should occur, coprocessors associated with it etc…

HStore

A Store holds a column family in a Region.
Its a memstore and a set of zero or more StoreFiles, which stretch backwards over time.

HRegion

Regions store data for a certain region of a table.
It stores all columns for each row.
A given table consists of one or more Regions.

WAL

A Write Ahead Log (WAL) provides service for reading, writing waledits.
This interface provides APIs for WAL users to use the WAL.

AbstractFSWAL

FSHLog

AsyncFSWAL

LoadBalancer

Makes decisions about the placement and movement of Regions across RegionServers.

BaseLoadBalancer

EventHandler