Package org.apache.hadoop.hbase.master.balancer

Interface ClusterInfoProvider

All Superinterfaces:

ConfigurationObserver

All Known Implementing Classes:

LoadBalancerPerformanceEvaluation.DummyClusterInfoProvider, MasterClusterInfoProvider

@Private
public interface ClusterInfoProvider
extends ConfigurationObserver

This is the cluster we want to balance. It provides methods to let us get the information we want.

Method Summary

Modifier and Type	Method	Description
HDFSBlocksDistribution	computeHDFSBlocksDistribution(org.apache.hadoop.conf.Configuration conf, TableDescriptor tableDescriptor, RegionInfo regionInfo)	Compute the block distribution for the given region.
List<RegionInfo>	getAssignedRegions()	Get all the regions of this cluster.
org.apache.hadoop.conf.Configuration	getConfiguration()	Get the configuration.
Connection	getConnection()	Returns a reference to the cluster's connection.
ServerMetrics	getLoad(ServerName serverName)	Returns server metrics of the given server if serverName is known else null
int	getNumberOfTables()	Returns the number of tables on this cluster.
List<ServerName>	getOnlineServersList()	Returns a copy of the internal list of online servers.
List<ServerName>	getOnlineServersListWithPredicator(List<ServerName> servers, Predicate<ServerMetrics> filter)	Returns a copy of the internal list of online servers matched by the given filter.
Map<ServerName,List<RegionInfo>>	getSnapShotOfAssignment(Collection<RegionInfo> regions)	Get a snapshot of the current assignment status.
TableDescriptor	getTableDescriptor(TableName tableName)	Get the table descriptor for the given table.
boolean	hasRegionReplica(Collection<RegionInfo> regions)	Check whether we have region replicas enabled for the tables of the given regions.
boolean	isOffPeakHour()	Test whether we are in off peak hour.
void	recordBalancerDecision(Supplier<BalancerDecision> decision)	Record the given balancer decision.
void	recordBalancerRejection(Supplier<BalancerRejection> rejection)	Record the given balancer rejection.
void	unassign(RegionInfo regionInfo)	Unassign the given region.

Methods inherited from interface org.apache.hadoop.hbase.conf.ConfigurationObserver

onConfigurationChange

Method Details

getConfiguration

org.apache.hadoop.conf.Configuration getConfiguration()

Get the configuration.

getConnection

Connection getConnection()

Returns a reference to the cluster's connection.

getAssignedRegions

List<RegionInfo> getAssignedRegions()

Get all the regions of this cluster.

Used to refresh region block locations on HDFS.

unassign

void unassign(RegionInfo regionInfo)
       throws IOException

Unassign the given region.

Throws:

IOException

getTableDescriptor

TableDescriptor getTableDescriptor(TableName tableName)
                            throws IOException

Get the table descriptor for the given table.

Throws:

IOException

getNumberOfTables

int getNumberOfTables()
               throws IOException

Returns the number of tables on this cluster.

Throws:

IOException

computeHDFSBlocksDistribution

HDFSBlocksDistribution computeHDFSBlocksDistribution(org.apache.hadoop.conf.Configuration conf,
 TableDescriptor tableDescriptor,
 RegionInfo regionInfo)
                                              throws IOException

Compute the block distribution for the given region.

Used to refresh region block locations on HDFS.

Throws:

IOException

hasRegionReplica

boolean hasRegionReplica(Collection<RegionInfo> regions)
                  throws IOException

Check whether we have region replicas enabled for the tables of the given regions.

Throws:

IOException

getOnlineServersList

List<ServerName> getOnlineServersList()

Returns a copy of the internal list of online servers.

getOnlineServersListWithPredicator

List<ServerName> getOnlineServersListWithPredicator(List<ServerName> servers,
 Predicate<ServerMetrics> filter)

Returns a copy of the internal list of online servers matched by the given filter.

getSnapShotOfAssignment

Map<ServerName,List<RegionInfo>> getSnapShotOfAssignment(Collection<RegionInfo> regions)

Get a snapshot of the current assignment status.

isOffPeakHour

boolean isOffPeakHour()

Test whether we are in off peak hour.

For peak and off peak hours we may have different cost for the same balancing operation.

recordBalancerDecision

void recordBalancerDecision(Supplier<BalancerDecision> decision)

Record the given balancer decision.

recordBalancerRejection

void recordBalancerRejection(Supplier<BalancerRejection> rejection)

Record the given balancer rejection.

getLoad

ServerMetrics getLoad(ServerName serverName)

Returns server metrics of the given server if serverName is known else null