Package org.apache.hadoop.hbase

Provides HBase, the Hadoop simple database.

See:
          Description

Interface Summary
HConstants HConstants holds a bunch of HBase-related constants
HInternalScannerInterface Internally, we need to be able to determine if the scanner is doing wildcard column matches (when only a column family is specified or if a column regex is specified) or if multiple members of the same column family were specified.
HMasterInterface Clients interact with the HMasterInterface to gain access to meta-level HBase functionality, like finding an HRegionServer and creating/destroying tables.
HMasterRegionInterface HRegionServers interact with the HMasterRegionInterface to report on local goings-on and to obtain data-handling instructions from the HMaster.
HRegionInterface Clients interact with HRegionServers using a handle to the HRegionInterface.
HScannerInterface HScannerInterface iterates through a set of rows.
LeaseListener LeaseListener is an interface meant to be implemented by users of the Leases class.
RegionUnavailableListener Used as a callback mechanism so that an HRegion can notify the HRegionServer of the different stages making an HRegion unavailable.
 

Class Summary
BloomFilterDescriptor Supplied as a parameter to HColumnDescriptor to specify what kind of bloom filter to use for a column, and its configuration parameters
HAbstractScanner Abstract base class that implements the HScannerInterface.
HBaseConfiguration  
HClient HClient manages a connection to a single HRegionServer.
HClient.RegionLocation  
HColumnDescriptor A HColumnDescriptor contains information about a column family such as the number of versions, compression settings, etc.
HGlobals Global values used for finding and scanning the root and meta tables.
HLocking HLocking is a set of lock primitives that does not rely on a particular thread holding the monitor for an object.
HLog HLog stores all the edits to the HStore.
HLogEdit A log value.
HLogKey A Key for an entry in the change log.
HMaster HMaster is the "master server" for a HBase.
HMemcache The HMemcache holds in-memory modifications to the HRegion.
HMemcache.Snapshot represents the state of the memcache at a specified point in time
HMsg HMsg is for communicating instructions between the HMaster and the HRegionServers.
HRegion HRegion stores data for a certain region of a table.
HRegionInfo HRegion information.
HRegionServer HRegionServer makes a set of HRegions available to clients.
HServerAddress HServerAddress is a "label" for a HBase server that combines the host name and port number.
HServerInfo HRSInfo contains metainfo about an HRegionServer, including details about the source machine and load statistics.
HStoreFile Each HStore maintains a bunch of different data files.
HStoreKey A Key for a stored row
HTableDescriptor HTableDescriptor contains the name of an HTable, and its column families.
Leases Leases There are several server classes in HBase that need to track external clients that occasionally send heartbeats.
RemoteExceptionHandler An immutable class which contains a static method for handling org.apache.hadoop.ipc.RemoteException exceptions.
Shell An hbase shell.
 

Enum Summary
HColumnDescriptor.CompressionType The type of compression.
 

Exception Summary
InvalidColumnNameException  
LockException  
MasterNotRunningException  
NoServerForRegionException  
NotServingRegionException  
RegionNotFoundException  
RegionServerRunningException Thrown if the region server log directory exists (which indicates another region server is running at the same address)
TableExistsException  
TableNotDisabledException  
UnknownScannerException  
WrongRegionException  
 

Package org.apache.hadoop.hbase Description

Provides HBase, the Hadoop simple database.

Requirements

Getting Started

First, you need a working instance of Hadoop. Download a recent release from Hadoop downloads. Unpack the release and connect to its top-level directory. Let this be ${HADOOP_HOME}. Edit the file ${HADOOP_HOME}/conf/hadoop-env.sh to define at least JAVA_HOME. Also, add site-particular customizations to the file ${HADOOP_HOME}/conf/hadoop-site.xml. Try the following command:

bin/hadoop

Next, change to the hbase root. Let this be ${HBASE_HOME} It is usually located at ${HADOOP_HOME}/src/contrib/hbase. Configure hbase. Edit ${HBASE_HOME}/conf/hbase-env.sh and ${HBASE_HOME}/conf/hbase-site.xml to make site particular settings. List the hosts running regionservers in ${HBASE_HOME}/conf/regionservers.

Here is how to start and then stop hbase:

${HBASE_HOME}/bin/start-hbase.sh
${HBASE_HOME}/bin/stop-hbase.sh
Logs can be found in ${HADOOP_LOG_DIR}.

To obtain a shell against a running hbase instance, run:

${HBASE_HOME}/bin/hbase shell
Once the shell is up, type help; to see list of supported commands.

Related Documentation



Copyright © 2006 The Apache Software Foundation