org.apache.hadoop.hbase.rsgroup

Class RSGroupBasedLoadBalancer

java.lang.Object

org.apache.hadoop.hbase.rsgroup.RSGroupBasedLoadBalancer

All Implemented Interfaces:

org.apache.hadoop.conf.Configurable, ConfigurationObserver, LoadBalancer, RSGroupableBalancer, Stoppable

@InterfaceAudience.Private
public class RSGroupBasedLoadBalancer
extends Object
implements RSGroupableBalancer

GroupBasedLoadBalancer, used when Region Server Grouping is configured (HBase-6721) It does region balance based on a table's group membership. Most assignment methods contain two exclusive code paths: Online - when the group table is online and Offline - when it is unavailable. During Offline, assignments are assigned based on cached information in zookeeper. If unavailable (ie bootstrap) then regions are assigned randomly. Once the GROUP table has been assigned, the balancer switches to Online and will then start providing appropriate assignments for user tables.

Field Summary

Fields

Modifier and Type	Field and Description
static String	FALLBACK_GROUP_ENABLE_KEY Set this key to true to allow region fallback.

Fields inherited from interface org.apache.hadoop.hbase.rsgroup.RSGroupableBalancer

HBASE_RSGROUP_LOADBALANCER_CLASS

Fields inherited from interface org.apache.hadoop.hbase.master.LoadBalancer

BOGUS_SERVER_NAME, SYSTEM_TABLES_ON_MASTER, TABLES_ON_MASTER

Constructor Summary

Constructors

Constructor and Description
RSGroupBasedLoadBalancer() Used by reflection in LoadBalancerFactory.

Method Summary

Modifier and Type	Method and Description
List<RegionPlan>	balanceCluster(Map<TableName,Map<ServerName,List<RegionInfo>>> loadOfAllTable) Override to balance by RSGroup not invoke balanceTable(TableName, Map)
List<RegionPlan>	balanceTable(TableName tableName, Map<ServerName,List<RegionInfo>> loadOfOneTable) can achieve table balanced rather than overall balanced
org.apache.hadoop.conf.Configuration	getConf()
void	initialize()
boolean	isFallbackEnabled()
boolean	isOnline()
boolean	isStopped()
void	onConfigurationChange(org.apache.hadoop.conf.Configuration conf)
void	postMasterStartupInitialize()
ServerName	randomAssignment(RegionInfo region, List<ServerName> servers)
void	regionOffline(RegionInfo regionInfo)
void	regionOnline(RegionInfo regionInfo, ServerName sn)
Map<ServerName,List<RegionInfo>>	retainAssignment(Map<RegionInfo,ServerName> regions, List<ServerName> servers)
Map<ServerName,List<RegionInfo>>	roundRobinAssignment(List<RegionInfo> regions, List<ServerName> servers)
void	setClusterMetrics(ClusterMetrics sm)
void	setConf(org.apache.hadoop.conf.Configuration conf)
void	setMasterServices(MasterServices masterServices)
void	setRsGroupInfoManager(RSGroupInfoManager rsGroupInfoManager)
void	stop(String why)
void	updateBalancerStatus(boolean status)

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.hadoop.hbase.master.LoadBalancer

isMasterCanHostUserRegions, isSystemTablesOnlyOnMaster, isTablesOnMaster

Field Detail

FALLBACK_GROUP_ENABLE_KEY

public static final String FALLBACK_GROUP_ENABLE_KEY

Set this key to true to allow region fallback. Fallback to the default rsgroup first, then fallback to any group if no online servers in default rsgroup. Please keep balancer switch on at the same time, which is relied on to correct misplaced regions

See Also:

Constant Field Values

Constructor Detail

RSGroupBasedLoadBalancer

@InterfaceAudience.Private
public RSGroupBasedLoadBalancer()

Used by reflection in LoadBalancerFactory.

Method Detail

getConf

public org.apache.hadoop.conf.Configuration getConf()

Specified by:

getConf in interface org.apache.hadoop.conf.Configurable

setConf

public void setConf(org.apache.hadoop.conf.Configuration conf)

Specified by:

setConf in interface org.apache.hadoop.conf.Configurable

setClusterMetrics

public void setClusterMetrics(ClusterMetrics sm)

Specified by:

setClusterMetrics in interface LoadBalancer

setMasterServices

public void setMasterServices(MasterServices masterServices)

Specified by:

setMasterServices in interface LoadBalancer

balanceCluster

public List<RegionPlan> balanceCluster(Map<TableName,Map<ServerName,List<RegionInfo>>> loadOfAllTable)
                                throws IOException

Override to balance by RSGroup not invoke balanceTable(TableName, Map)

Specified by:

balanceCluster in interface LoadBalancer

Throws:

IOException

roundRobinAssignment

@NonNull
public Map<ServerName,List<RegionInfo>> roundRobinAssignment(List<RegionInfo> regions,
                                                                      List<ServerName> servers)
                                                               throws HBaseIOException

Specified by:

roundRobinAssignment in interface LoadBalancer

Throws:

HBaseIOException

retainAssignment

@NonNull
public Map<ServerName,List<RegionInfo>> retainAssignment(Map<RegionInfo,ServerName> regions,
                                                                  List<ServerName> servers)
                                                           throws HBaseIOException

Specified by:

retainAssignment in interface LoadBalancer

Throws:

HBaseIOException

randomAssignment

public ServerName randomAssignment(RegionInfo region,
                                   List<ServerName> servers)
                            throws HBaseIOException

Specified by:

randomAssignment in interface LoadBalancer

Throws:

HBaseIOException

initialize

public void initialize()
                throws HBaseIOException

Specified by:

initialize in interface LoadBalancer

Throws:

HBaseIOException

isOnline

public boolean isOnline()

isFallbackEnabled

public boolean isFallbackEnabled()

regionOnline

public void regionOnline(RegionInfo regionInfo,
                         ServerName sn)

Specified by:

regionOnline in interface LoadBalancer

regionOffline

public void regionOffline(RegionInfo regionInfo)

Specified by:

regionOffline in interface LoadBalancer

onConfigurationChange

public void onConfigurationChange(org.apache.hadoop.conf.Configuration conf)

Specified by:

onConfigurationChange in interface ConfigurationObserver

Specified by:

onConfigurationChange in interface LoadBalancer

stop

public void stop(String why)

Specified by:

stop in interface Stoppable

isStopped

public boolean isStopped()

Specified by:

isStopped in interface Stoppable

setRsGroupInfoManager

public void setRsGroupInfoManager(RSGroupInfoManager rsGroupInfoManager)

postMasterStartupInitialize

public void postMasterStartupInitialize()

Specified by:

postMasterStartupInitialize in interface LoadBalancer

updateBalancerStatus

public void updateBalancerStatus(boolean status)

Specified by:

updateBalancerStatus in interface LoadBalancer

balanceTable

public List<RegionPlan> balanceTable(TableName tableName,
                                     Map<ServerName,List<RegionInfo>> loadOfOneTable)

can achieve table balanced rather than overall balanced

Specified by:

balanceTable in interface LoadBalancer