## org.apache.hadoop.mapreduce
Class ClusterMetrics

    java.lang.Object
      org.apache.hadoop.mapreduce.ClusterMetrics

All Implemented Interfaces:
  Writable

    public class ClusterMetrics

extends Object
implements Writable

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

`ClusterMetrics` provides clients with information such as:

1. Size of the cluster.
2. Number of blacklisted and decommissioned trackers.
3. Slot capacity of the cluster.
4. The number of currently occupied/reserved map & reduce slots.
5. The number of currently running map & reduce tasks.
6. The number of job submissions.

Constructor Summary
`ClusterMetrics()`
`ClusterMetrics(int runningMaps, int runningReduces, int occupiedMapSlots, int occupiedReduceSlots, int reservedMapSlots, int reservedReduceSlots, int mapSlots, int reduceSlots, int totalJobSubmissions, int numTrackers, int numBlacklistedTrackers, int numGraylistedTrackers, int numDecommissionedNodes)`

Method Summary
`int` `getBlackListedTaskTrackerCount()` Get the number of blacklisted trackers in the cluster.
`int` `getDecommissionedTaskTrackerCount()` Get the number of decommissioned trackers in the cluster.
`int` `getGrayListedTaskTrackerCount()` Get the number of graylisted trackers in the cluster.
`int` `getMapSlotCapacity()` Get the total number of map slots in the cluster.
`int` `getOccupiedMapSlots()` Get number of occupied map slots in the cluster.
`int` `getOccupiedReduceSlots()` Get the number of occupied reduce slots in the cluster.
`int` `getReduceSlotCapacity()` Get the total number of reduce slots in the cluster.
`int` `getReservedMapSlots()` Get number of reserved map slots in the cluster.
`int` `getReservedReduceSlots()` Get the number of reserved reduce slots in the cluster.
`int` `getRunningMaps()` Get the number of running map tasks in the cluster.
`int` `getRunningReduces()` Get the number of running reduce tasks in the cluster.
`int` `getTaskTrackerCount()` Get the number of active trackers in the cluster.
`int` `getTotalJobSubmissions()` Get the total number of job submissions in the cluster.
`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`

Constructor Detail

### ClusterMetrics

    public ClusterMetrics()

### ClusterMetrics

    public ClusterMetrics(int runningMaps,
                          int runningReduces,
                          int occupiedMapSlots,
                          int occupiedReduceSlots,
                          int reservedMapSlots,
                          int reservedReduceSlots,
                          int mapSlots,
                          int reduceSlots,
                          int totalJobSubmissions,
                          int numTrackers,
                          int numBlacklistedTrackers,
                          int numGraylistedTrackers,
                          int numDecommissionedNodes)

Method Detail

### getRunningMaps

    public int getRunningMaps()

  Get the number of running map tasks in the cluster.

  Returns:
    running maps

### getRunningReduces

    public int getRunningReduces()

  Get the number of running reduce tasks in the cluster.

  Returns:
    running reduces

### getOccupiedMapSlots

    public int getOccupiedMapSlots()

  Get number of occupied map slots in the cluster.

  Returns:
    occupied map slot count

### getOccupiedReduceSlots

    public int getOccupiedReduceSlots()

  Get the number of occupied reduce slots in the cluster.

  Returns:
    occupied reduce slot count

### getReservedMapSlots

    public int getReservedMapSlots()

  Get number of reserved map slots in the cluster.

  Returns:
    reserved map slot count

### getReservedReduceSlots

    public int getReservedReduceSlots()

  Get the number of reserved reduce slots in the cluster.

  Returns:
    reserved reduce slot count

### getMapSlotCapacity

    public int getMapSlotCapacity()

  Get the total number of map slots in the cluster.

  Returns:
    map slot capacity

### getReduceSlotCapacity

    public int getReduceSlotCapacity()

  Get the total number of reduce slots in the cluster.

  Returns:
    reduce slot capacity

### getTotalJobSubmissions

    public int getTotalJobSubmissions()

  Get the total number of job submissions in the cluster.

  Returns:
    total number of job submissions

### getTaskTrackerCount

    public int getTaskTrackerCount()

  Get the number of active trackers in the cluster.

  Returns:
    active tracker count.

### getBlackListedTaskTrackerCount

    public int getBlackListedTaskTrackerCount()

  Get the number of blacklisted trackers in the cluster.

  Returns:
    blacklisted tracker count

### getGrayListedTaskTrackerCount

    public int getGrayListedTaskTrackerCount()

  Get the number of graylisted trackers in the cluster.

  Returns:
    graylisted tracker count

### getDecommissionedTaskTrackerCount

    public int getDecommissionedTaskTrackerCount()

  Get the number of decommissioned trackers in the cluster.

  Returns:
    decommissioned tracker count

### 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`

### 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`

Copyright © 2009 The Apache Software Foundation