org.apache.hadoop.hbase

Interface ClusterMetrics

All Known Implementing Classes:

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.

 {
   @code
   // 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:

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

Method Summary

Modifier and Type	Method and Description
default double	getAverageLoad() Returns the average cluster load
List<ServerName>	getBackupMasterNames() Returns the names of backup masters
Boolean	getBalancerOn()
String	getClusterId()
List<ServerName>	getDeadServerNames() Returns the names of region servers on the dead list
String	getHBaseVersion() Returns the HBase version string as reported by the HMaster
default long	getLastMajorCompactionTimestamp(byte[] regionName)
default long	getLastMajorCompactionTimestamp(TableName table)
Map<ServerName,ServerMetrics>	getLiveServerMetrics() Returns the names of region servers on the live list
List<String>	getMasterCoprocessorNames()
int	getMasterInfoPort()
ServerName	getMasterName() Returns detailed information about the current master ServerName.
List<ServerTask>	getMasterTasks() Provide the list of master tasks
default int	getRegionCount() Returns the number of regions deployed on the cluster
default long	getRequestCount() Returns the number of requests since last report
List<ServerName>	getServersName()
Map<TableName,org.apache.hadoop.hbase.client.RegionStatesCount>	getTableRegionStatesCount() Provide region states count for given table.
List<ServerName>	getUnknownServerNames() Returns the names of region servers on the unknown list

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

getUnknownServerNames

List<ServerName> getUnknownServerNames()

Returns the names of region servers on the unknown 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

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()

getServersName

List<ServerName> getServersName()

getAverageLoad

default double getAverageLoad()

Returns the average cluster load

getTableRegionStatesCount

Map<TableName,org.apache.hadoop.hbase.client.RegionStatesCount> getTableRegionStatesCount()

Provide region states count for given table. e.g howmany regions of give table are opened/closed/rit etc

Returns:

map of table to region states count

getMasterTasks

@Nullable
List<ServerTask> getMasterTasks()

Provide the list of master tasks