org.apache.hadoop.mapred
Class ClusterStatus

java.lang.Object
  org.apache.hadoop.mapred.ClusterStatus

All Implemented Interfaces:

Writable

public class ClusterStatus
extends Object
implements Writable

Status information on the current state of the Map-Reduce cluster.

ClusterStatus provides clients with information such as:

1. Size of the cluster.
2. Name of the trackers.
3. Task capacity of the cluster.
4. The number of currently running map & reduce tasks.
5. State of the JobTracker.

Clients can query for the latest ClusterStatus, via JobClient.getClusterStatus().

See Also:

JobClient

Field Summary

static long

UNINITIALIZED_MEMORY_VALUE

Method Summary

Collection<String>	getActiveTrackerNames() Get the names of active task trackers in the cluster.
Collection<String>	getBlacklistedTrackerNames() Get the names of blacklisted task trackers in the cluster.
int	getBlacklistedTrackers() Get the number of blacklisted task trackers in the cluster.
Collection<String>	getGraylistedTrackerNames() Get the names of graylisted task trackers in the cluster.
int	getGraylistedTrackers() Get the number of graylisted task trackers in the cluster.
JobTracker.State	getJobTrackerState() Get the current state of the JobTracker, as JobTracker.State
int	getMapTasks() Get the number of currently running map tasks in the cluster.
int	getMaxMapTasks() Get the maximum capacity for running map tasks in the cluster.
long	getMaxMemory() Get the maximum configured heap memory that can be used by the JobTracker
int	getMaxReduceTasks() Get the maximum capacity for running reduce tasks in the cluster.
int	getNumExcludedNodes() Get the number of excluded hosts in the cluster.
int	getReduceTasks() Get the number of currently running reduce tasks in the cluster.
int	getTaskTrackers() Get the number of active task trackers in the cluster.
long	getTTExpiryInterval() Get the tasktracker expiry interval for the cluster
long	getUsedMemory() Get the total heap memory used by the JobTracker
void	readFields(DataInput in) Deserialize the fields of this object from in.
void	write(DataOutput out) Serialize the fields of this object to out.

Methods inherited from class java.lang.Object

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

Field Detail

UNINITIALIZED_MEMORY_VALUE

public static final long UNINITIALIZED_MEMORY_VALUE

See Also:

Constant Field Values

Method Detail

getTaskTrackers

public int getTaskTrackers()

Get the number of active task trackers in the cluster. Includes graylisted but not blacklisted trackers.

Returns:

the number of active task trackers in the cluster.

getActiveTrackerNames

public Collection<String> getActiveTrackerNames()

Get the names of active task trackers in the cluster. Includes graylisted but not blacklisted trackers.

Returns:

the active task trackers in the cluster.

getBlacklistedTrackerNames

public Collection<String> getBlacklistedTrackerNames()

Get the names of blacklisted task trackers in the cluster.

Returns:

the blacklisted task trackers in the cluster.

getBlacklistedTrackers

public int getBlacklistedTrackers()

Get the number of blacklisted task trackers in the cluster.

Returns:

the number of blacklisted task trackers in the cluster.

getGraylistedTrackerNames

public Collection<String> getGraylistedTrackerNames()

Get the names of graylisted task trackers in the cluster.

Returns:

the graylisted task trackers in the cluster.

getGraylistedTrackers

public int getGraylistedTrackers()

Get the number of graylisted task trackers in the cluster.

Returns:

the number of graylisted task trackers in the cluster.

getNumExcludedNodes

public int getNumExcludedNodes()

Get the number of excluded hosts in the cluster.

Returns:

the number of excluded hosts in the cluster.

getTTExpiryInterval

public long getTTExpiryInterval()

Get the tasktracker expiry interval for the cluster

Returns:

the expiry interval in msec

getMapTasks

public int getMapTasks()

Get the number of currently running map tasks in the cluster.

Returns:

the number of currently running map tasks in the cluster.

getReduceTasks

public int getReduceTasks()

Get the number of currently running reduce tasks in the cluster.

Returns:

the number of currently running reduce tasks in the cluster.

getMaxMapTasks

public int getMaxMapTasks()

Get the maximum capacity for running map tasks in the cluster.

Returns:

the maximum capacity for running map tasks in the cluster.

getMaxReduceTasks

public int getMaxReduceTasks()

Get the maximum capacity for running reduce tasks in the cluster.

Returns:

the maximum capacity for running reduce tasks in the cluster.

getJobTrackerState

public JobTracker.State getJobTrackerState()

Get the current state of the JobTracker, as JobTracker.State

Returns:

the current state of the JobTracker.

getUsedMemory

public long getUsedMemory()

Get the total heap memory used by the JobTracker

Returns:

the size of heap memory used by the JobTracker

getMaxMemory

public long getMaxMemory()

Get the maximum configured heap memory that can be used by the JobTracker

Returns:

the configured size of max heap memory that can be used by the JobTracker

write

public void write(DataOutput out)
           throws IOException

Description copied from interface: Writable

Serialize the fields of this object to out.

Specified by:

write in interface Writable

Parameters:

out - DataOuput to serialize this object into.

Throws:

IOException

readFields

public void readFields(DataInput in)
                throws IOException

Description copied from interface: Writable

Deserialize the fields of this object from in.

For efficiency, implementations should attempt to re-use storage in the existing object where possible.

Specified by:

readFields in interface Writable

Parameters:

in - DataInput to deseriablize this object from.

Throws:

IOException