com.bigdata.service

Class HostScore

java.lang.Object

com.bigdata.service.HostScore

All Implemented Interfaces:

Comparable<HostScore>

public class HostScore
extends Object
implements Comparable<HostScore>

Per-host metadata and a score for that host which gets updated periodically by LoadBalancerService.UpdateTask. HostScores are a resource utilization measure. They are higher for a host which is more highly utilized. There are several ways to look at the score, including the rawScore, the rank, and the normalized double-precision rank. The ranks move in the same direction as the rawScores - a higher rank indicates higher utilization. The least utilized host is always rank zero (0). The most utilized host is always in the last rank.

Version:

$Id$

Author:

Bryan Thompson

Field Summary

Fields

Modifier and Type	Field and Description
double	drank The normalized double precision rank in [0.0:1.0].
String	hostname
int	rank The rank in [0:#scored].
double	rawScore The raw score computed for that service.
double	score The normalized score computed for that service.

Constructor Summary

Constructors

Constructor and Description
HostScore(String hostname) Constructor variant used when you do not have performance counters for the host and could not compute its rawScore.
HostScore(String hostname, double rawScore) Constructor variant used when you have computed the rawStore.

Method Summary

Methods

Modifier and Type	Method and Description
int	compareTo(HostScore arg0) Places elements into order by ascending rawScore (aka increasing utilization).
static double	normalize(double rawScore, double totalRawScore) Normalizes a raw score in the context of totals for some host.
String	toString()

Methods inherited from class java.lang.Object

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

Field Detail

hostname

public final String hostname

rawScore

public final double rawScore

The raw score computed for that service.

score

public double score

The normalized score computed for that service.

rank

public int rank

The rank in [0:#scored]. This is an index into the Scores[].

drank

public double drank

The normalized double precision rank in [0.0:1.0].

Constructor Detail

HostScore

public HostScore(String hostname)

Constructor variant used when you do not have performance counters for the host and could not compute its rawScore.

Parameters:

hostname -

HostScore

public HostScore(String hostname,
         double rawScore)

Constructor variant used when you have computed the rawStore.

Parameters:

hostname -

rawScore -

Method Detail

toString

public String toString()

Overrides:

toString in class Object

compareTo

public int compareTo(HostScore arg0)

Places elements into order by ascending rawScore (aka increasing utilization). The hostname is used to break any ties.

Specified by:

compareTo in interface Comparable<HostScore>

normalize

public static double normalize(double rawScore,
               double totalRawScore)

Normalizes a raw score in the context of totals for some host.

Parameters:

rawScore - The raw score.

totalRawScore - The raw score computed from the totals.

Returns:

The normalized score.