org.apache.hadoop.mapred
Class ClusterStatus

java.lang.Object
  extended by org.apache.hadoop.mapred.ClusterStatus
All Implemented Interfaces:
Writable

@InterfaceAudience.Public
@InterfaceStability.Stable
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.
  6. Details regarding black listed trackers.

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 task trackers in the cluster.
 Collection<String> getBlacklistedTrackerNames()
          Get the names of task trackers in the cluster.
 int getBlacklistedTrackers()
          Get the number of blacklisted task trackers in the cluster.
 Collection<org.apache.hadoop.mapred.ClusterStatus.BlackListInfo> getBlackListedTrackersInfo()
          Gets the list of blacklisted trackers along with reasons for blacklisting.
 Collection<String> getGraylistedTrackerNames()
          Deprecated. 
 int getGraylistedTrackers()
          Deprecated. 
 org.apache.hadoop.mapred.JobTracker.State getJobTrackerState()
          Deprecated. 
 org.apache.hadoop.mapreduce.Cluster.JobTrackerStatus getJobTrackerStatus()
          Get the JobTracker's status.
 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()
          Deprecated. 
 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 task trackers in the cluster.
 long getTTExpiryInterval()
          Get the tasktracker expiry interval for the cluster
 long getUsedMemory()
          Deprecated. 
 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 task trackers in the cluster.

Returns:
the number of task trackers in the cluster.

getActiveTrackerNames

public Collection<String> getActiveTrackerNames()
Get the names of task trackers in the cluster.

Returns:
the active task trackers in the cluster.

getBlacklistedTrackerNames

public Collection<String> getBlacklistedTrackerNames()
Get the names of task trackers in the cluster.

Returns:
the blacklisted task trackers in the cluster.

getGraylistedTrackerNames

@Deprecated
public Collection<String> getGraylistedTrackerNames()
Deprecated. 

Get the names of graylisted task trackers in the cluster. The gray list of trackers is no longer available on M/R 2.x. The function is kept to be compatible with M/R 1.x applications.

Returns:
an empty graylisted task trackers in the cluster.

getGraylistedTrackers

@Deprecated
public int getGraylistedTrackers()
Deprecated. 

Get the number of graylisted task trackers in the cluster. The gray list of trackers is no longer available on M/R 2.x. The function is kept to be compatible with M/R 1.x applications.

Returns:
0 graylisted 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.

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.

getJobTrackerStatus

public org.apache.hadoop.mapreduce.Cluster.JobTrackerStatus getJobTrackerStatus()
Get the JobTracker's status.

Returns:
Cluster.JobTrackerStatus of the JobTracker

getMaxMemory

@Deprecated
public long getMaxMemory()
Deprecated. 

Returns UNINITIALIZED_MEMORY_VALUE (-1)


getUsedMemory

@Deprecated
public long getUsedMemory()
Deprecated. 

Returns UNINITIALIZED_MEMORY_VALUE (-1)


getBlackListedTrackersInfo

public Collection<org.apache.hadoop.mapred.ClusterStatus.BlackListInfo> getBlackListedTrackersInfo()
Gets the list of blacklisted trackers along with reasons for blacklisting.

Returns:
the collection of ClusterStatus.BlackListInfo objects.

getJobTrackerState

@Deprecated
public org.apache.hadoop.mapred.JobTracker.State getJobTrackerState()
Deprecated. 

Get the current state of the JobTracker, as JobTracker.State JobTracker.State should no longer be used on M/R 2.x. The function is kept to be compatible with M/R 1.x applications.

Returns:
the invalid state of 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


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