org.apache.hadoop.hbase.favored

类 FavoredNodeLoadBalancer

java.lang.Object

org.apache.hadoop.hbase.master.balancer.BaseLoadBalancer

org.apache.hadoop.hbase.favored.FavoredNodeLoadBalancer

所有已实现的接口:

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

@InterfaceAudience.LimitedPrivate(value="Configuration")
public class FavoredNodeLoadBalancer
extends BaseLoadBalancer
implements FavoredNodesPromoter

An implementation of the LoadBalancer that assigns favored nodes for each region. There is a Primary RegionServer that hosts the region, and then there is Secondary and Tertiary RegionServers. Currently, the favored nodes information is used in creating HDFS files - the Primary RegionServer passes the primary, secondary, tertiary node addresses as hints to the DistributedFileSystem API for creating files on the filesystem. These nodes are treated as hints by the HDFS to place the blocks of the file. This alleviates the problem to do with reading from remote nodes (since we can make the Secondary RegionServer as the new Primary RegionServer) after a region is recovered. This should help provide consistent read latencies for the regions even when their primary region servers die.

嵌套类概要

从类继承的嵌套类/接口 org.apache.hadoop.hbase.master.balancer.BaseLoadBalancer

BaseLoadBalancer.Cluster

字段概要

从类继承的字段 org.apache.hadoop.hbase.master.balancer.BaseLoadBalancer

clusterStatus, config, maintenanceMode, masterServerName, metricsBalancer, MIN_SERVER_BALANCE, onlySystemTablesOnMaster, overallSlop, regionFinder, services, slop, useRegionFinder

从接口继承的字段 org.apache.hadoop.hbase.favored.FavoredNodesPromoter

FAVORED_ALWAYS_ASSIGN_REGIONS

从接口继承的字段 org.apache.hadoop.hbase.master.LoadBalancer

BOGUS_SERVER_NAME, SYSTEM_TABLES_ON_MASTER, TABLES_ON_MASTER

构造器概要

构造器

构造器和说明
FavoredNodeLoadBalancer()

方法概要

限定符和类型	方法和说明
List<RegionPlan>	balanceCluster(Map<ServerName,List<RegionInfo>> clusterState) Perform the major balance operation
List<RegionPlan>	balanceCluster(TableName tableName, Map<ServerName,List<RegionInfo>> clusterState) Perform the major balance operation
void	generateFavoredNodesForDaughter(List<ServerName> servers, RegionInfo parent, RegionInfo regionA, RegionInfo regionB)
void	generateFavoredNodesForMergedRegion(RegionInfo merged, RegionInfo regionA, RegionInfo regionB)
List<ServerName>	getFavoredNodes(RegionInfo regionInfo)
void	initialize() Initialize the load balancer.
ServerName	randomAssignment(RegionInfo regionInfo, List<ServerName> servers) Used to assign a single region to a random server.
Map<ServerName,List<RegionInfo>>	roundRobinAssignment(List<RegionInfo> regions, List<ServerName> servers) Generates a bulk assignment plan to be used on cluster startup using a simple round-robin assignment.
void	setConf(org.apache.hadoop.conf.Configuration conf)

从类继承的方法 org.apache.hadoop.hbase.master.balancer.BaseLoadBalancer

areSomeRegionReplicasColocated, assignMasterSystemRegions, balanceMasterRegions, createCluster, getConf, getRegionAssignmentsByServer, isStopped, needsBalance, onConfigurationChange, postMasterStartupInitialize, regionOffline, regionOnline, retainAssignment, setClusterLoad, setClusterMetrics, setMasterServices, setRackManager, setSlop, shouldBeOnMaster, stop, updateBalancerStatus

从类继承的方法 java.lang.Object

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

从接口继承的方法 org.apache.hadoop.hbase.master.LoadBalancer

isMasterCanHostUserRegions, isSystemTablesOnlyOnMaster, isTablesOnMaster

构造器详细资料

FavoredNodeLoadBalancer

public FavoredNodeLoadBalancer()

方法详细资料

setConf

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

指定者:

setConf 在接口中 org.apache.hadoop.conf.Configurable

覆盖:

setConf 在类中 BaseLoadBalancer

initialize

public void initialize()
                throws HBaseIOException

从接口复制的说明: LoadBalancer

Initialize the load balancer. Must be called after setters.

指定者:

initialize 在接口中 LoadBalancer

覆盖:

initialize 在类中 BaseLoadBalancer

抛出:

HBaseIOException

balanceCluster

public List<RegionPlan> balanceCluster(Map<ServerName,List<RegionInfo>> clusterState)

从接口复制的说明: LoadBalancer

Perform the major balance operation

指定者:

balanceCluster 在接口中 LoadBalancer

返回:

List of plans

roundRobinAssignment

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

从类复制的说明: BaseLoadBalancer

Generates a bulk assignment plan to be used on cluster startup using a simple round-robin assignment.

Takes a list of all the regions and all the servers in the cluster and returns a map of each server to the regions that it should be assigned.

Currently implemented as a round-robin assignment. Same invariant as load balancing, all servers holding floor(avg) or ceiling(avg). TODO: Use block locations from HDFS to place regions with their blocks

指定者:

roundRobinAssignment 在接口中 LoadBalancer

覆盖:

roundRobinAssignment 在类中 BaseLoadBalancer

参数:

regions - all regions

servers - all servers

返回:

map of server to the regions it should take, or null if no assignment is possible (ie. no regions or no servers)

抛出:

HBaseIOException

randomAssignment

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

从类复制的说明: BaseLoadBalancer

Used to assign a single region to a random server.

指定者:

randomAssignment 在接口中 LoadBalancer

覆盖:

randomAssignment 在类中 BaseLoadBalancer

参数:

regionInfo - Region for which this selection is being done.

返回:

Servername

抛出:

HBaseIOException

getFavoredNodes

public List<ServerName> getFavoredNodes(RegionInfo regionInfo)

generateFavoredNodesForDaughter

public void generateFavoredNodesForDaughter(List<ServerName> servers,
                                            RegionInfo parent,
                                            RegionInfo regionA,
                                            RegionInfo regionB)
                                     throws IOException

指定者:

generateFavoredNodesForDaughter 在接口中 FavoredNodesPromoter

抛出:

IOException

generateFavoredNodesForMergedRegion

public void generateFavoredNodesForMergedRegion(RegionInfo merged,
                                                RegionInfo regionA,
                                                RegionInfo regionB)
                                         throws IOException

指定者:

generateFavoredNodesForMergedRegion 在接口中 FavoredNodesPromoter

抛出:

IOException

balanceCluster

public List<RegionPlan> balanceCluster(TableName tableName,
                                       Map<ServerName,List<RegionInfo>> clusterState)
                                throws HBaseIOException

从接口复制的说明: LoadBalancer

Perform the major balance operation

指定者:

balanceCluster 在接口中 LoadBalancer

返回:

List of plans

抛出:

HBaseIOException