org.apache.manifoldcf.crawler.interfaces
Class PerformanceStatistics

java.lang.Object
  org.apache.manifoldcf.crawler.interfaces.PerformanceStatistics

public class PerformanceStatistics
extends java.lang.Object

An instance of this class keeps a running average of how long it takes for every connection to process a document. This information is used to limit queuing per connection to something reasonable given the characteristics of the connection.

Nested Class Summary

protected static class	PerformanceStatistics.AveragingQueue This class keeps track of some depth of fetch history for an individual connection, and is used to calculate a weighted average fetches-per-minute rate.
protected static class	PerformanceStatistics.AveragingRecord This class contains the data for a single document set against the given connection

Field Summary

static java.lang.String	_rcsid
protected java.util.HashMap	connectionHash This hash is keyed by the connection name, and has elements of type AveragingQueue
protected static double	DEFAULT_FETCH_RATE This is the fetch rate that will be returned in the complete absence of any other information.
protected static long	DEFAULT_FETCH_TIME
protected static double[]	weights These are the weighting coefficients for the average.

Constructor Summary

PerformanceStatistics()
Constructor

Method Summary

double	calculateConnectionFetchRate(java.lang.String connectionName) Obtain current average document fetch rate (in documents per minute per connection)
void	noteDocumentsCompleted(java.lang.String connectionName, int documentSetSize, long elapsedTime) Note the successful completion of a set of documents using a single connection, and record the statistics for them.

Methods inherited from class java.lang.Object

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

Field Detail

_rcsid

public static final java.lang.String _rcsid

See Also:

Constant Field Values

DEFAULT_FETCH_RATE

protected static double DEFAULT_FETCH_RATE

This is the fetch rate that will be returned in the complete absence of any other information. This represents a 'wild guess' of a sort, used only at the very start of a job, and designed to not hopelessly overload the queue with stuff from one connection only.

DEFAULT_FETCH_TIME

protected static long DEFAULT_FETCH_TIME

weights

protected static double[] weights

These are the weighting coefficients for the average. They should all add up to 1.0

connectionHash

protected java.util.HashMap connectionHash

This hash is keyed by the connection name, and has elements of type AveragingQueue

Constructor Detail

PerformanceStatistics

public PerformanceStatistics()

Constructor

Method Detail

noteDocumentsCompleted

public void noteDocumentsCompleted(java.lang.String connectionName,
                                   int documentSetSize,
                                   long elapsedTime)

Note the successful completion of a set of documents using a single connection, and record the statistics for them.

calculateConnectionFetchRate

public double calculateConnectionFetchRate(java.lang.String connectionName)

Obtain current average document fetch rate (in documents per minute per connection)