org.apache.hadoop.hbase

Interface ClusterMetrics

All Known Implementing Classes:

ClusterMetricsBuilder.ClusterMetricsImpl, ClusterStatus

@InterfaceAudience.Public
public interface ClusterMetrics

Metrics information on the HBase cluster.

ClusterMetrics provides clients with information such as:

• The count and names of region servers in the cluster.
• The count and names of dead region servers in the cluster.
• The name of the active master for the cluster.
• The name(s) of the backup master(s) for the cluster, if they exist.
• The average cluster load.
• The number of regions deployed on the cluster.
• The number of requests since last report.
• Detailed region server loading and resource usage information, per server and per region.
• Regions in transition at master
• The unique cluster ID

ClusterMetrics.Option provides a way to get desired ClusterStatus information. The following codes will get all the cluster information.

 
 // Original version still works
 Admin admin = connection.getAdmin();
 ClusterMetrics metrics = admin.getClusterStatus();
 // or below, a new version which has the same effects
 ClusterMetrics metrics = admin.getClusterStatus(EnumSet.allOf(Option.class));
 
 

If information about live servers is the only wanted. then codes in the following way:

 
 Admin admin = connection.getAdmin();
 ClusterMetrics metrics = admin.getClusterStatus(EnumSet.of(Option.LIVE_SERVERS));
 
 

Nested Class Summary

Nested Classes

Modifier and Type	Interface and Description
static class	ClusterMetrics.Option Kinds of ClusterMetrics

Method Summary

Modifier and Type	Method and Description
default double	getAverageLoad()
List<ServerName>	getBackupMasterNames()
Boolean	getBalancerOn()
String	getClusterId()
List<ServerName>	getDeadServerNames()
String	getHBaseVersion()
default long	getLastMajorCompactionTimestamp(byte[] regionName)
default long	getLastMajorCompactionTimestamp(TableName table)
Map<ServerName,ServerMetrics>	getLiveServerMetrics()
List<String>	getMasterCoprocessorNames()
int	getMasterInfoPort()
ServerName	getMasterName() Returns detailed information about the current master ServerName.
default int	getRegionCount()
List<RegionState>	getRegionStatesInTransition()
default long	getRequestCount()

Method Detail

getHBaseVersion

@Nullable
String getHBaseVersion()

Returns:

the HBase version string as reported by the HMaster

getDeadServerNames

List<ServerName> getDeadServerNames()

Returns:

the names of region servers on the dead list

getLiveServerMetrics

Map<ServerName,ServerMetrics> getLiveServerMetrics()

Returns:

the names of region servers on the live list

getRegionCount

default int getRegionCount()

Returns:

the number of regions deployed on the cluster

getRequestCount

default long getRequestCount()

Returns:

the number of requests since last report

getMasterName

@Nullable
ServerName getMasterName()

Returns detailed information about the current master ServerName.

Returns:

current master information if it exists

getBackupMasterNames

List<ServerName> getBackupMasterNames()

Returns:

the names of backup masters

getRegionStatesInTransition

@InterfaceAudience.Private
List<RegionState> getRegionStatesInTransition()

getClusterId

@Nullable
String getClusterId()

getMasterCoprocessorNames

List<String> getMasterCoprocessorNames()

getLastMajorCompactionTimestamp

default long getLastMajorCompactionTimestamp(TableName table)

getLastMajorCompactionTimestamp

default long getLastMajorCompactionTimestamp(byte[] regionName)

getBalancerOn

@Nullable
Boolean getBalancerOn()

getMasterInfoPort

int getMasterInfoPort()

getAverageLoad

default double getAverageLoad()

Returns:

the average cluster load