org.apache.pulsar.broker.loadbalance.impl

Class DeviationShedder

java.lang.Object

org.apache.pulsar.broker.loadbalance.impl.DeviationShedder

All Implemented Interfaces:

LoadSheddingStrategy

public abstract class DeviationShedder
extends Object
implements LoadSheddingStrategy

An abstract class which makes a LoadSheddingStrategy which makes decisions based on standard deviation easier to implement. Assuming there exists some real number metric which may estimate the load on a server, this load shedding strategy calculates the standard deviation with respect to that metric and sheds load on brokers whose standard deviation is above some threshold.

Field Summary

Fields

Modifier and Type	Field and Description
protected TreeSet<org.apache.commons.lang3.tuple.Pair<Double,String>>	bundleTreeSetCache
protected TreeSet<org.apache.commons.lang3.tuple.Pair<Double,String>>	metricTreeSetCache

Constructor Summary

Constructors

Constructor and Description
DeviationShedder() Initialize this DeviationShedder.

Method Summary

Modifier and Type	Method and Description
protected abstract double	brokerValue(BrokerData brokerData, ServiceConfiguration conf)
protected abstract double	bundleValue(String bundle, BrokerData brokerData, ServiceConfiguration conf)
com.google.common.collect.Multimap<String,String>	findBundlesForUnloading(LoadData loadData, ServiceConfiguration conf) Recommend that all of the returned bundles be unloaded based on observing excessive standard deviations according to some metric.
protected abstract double	getDeviationThreshold(ServiceConfiguration conf)

Methods inherited from class java.lang.Object

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

Field Detail

metricTreeSetCache

protected TreeSet<org.apache.commons.lang3.tuple.Pair<Double,String>> metricTreeSetCache

bundleTreeSetCache

protected TreeSet<org.apache.commons.lang3.tuple.Pair<Double,String>> bundleTreeSetCache

Constructor Detail

DeviationShedder

public DeviationShedder()

Initialize this DeviationShedder.

Method Detail

bundleValue

protected abstract double bundleValue(String bundle,
                                      BrokerData brokerData,
                                      ServiceConfiguration conf)

brokerValue

protected abstract double brokerValue(BrokerData brokerData,
                                      ServiceConfiguration conf)

getDeviationThreshold

protected abstract double getDeviationThreshold(ServiceConfiguration conf)

findBundlesForUnloading

public com.google.common.collect.Multimap<String,String> findBundlesForUnloading(LoadData loadData,
                                                                                 ServiceConfiguration conf)

Recommend that all of the returned bundles be unloaded based on observing excessive standard deviations according to some metric.

Specified by:

findBundlesForUnloading in interface LoadSheddingStrategy

Parameters:

loadData - The load data to used to make the unloading decision.

conf - The service configuration.

Returns:

A map from all selected bundles to the brokers on which they reside.