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* Licensed to the Apache Software Foundation (ASF) under one
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* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
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package org.apache.brooklyn.entity.group.zoneaware;
import org.apache.brooklyn.api.location.Location;
import org.apache.brooklyn.util.time.Duration;
import com.google.common.base.Ticker;
public class ProportionalZoneFailureDetector extends AbstractZoneFailureDetector {
// TODO Would be nice to weight it disproportionately for more recent attempts; but this will do for now.
protected final int minDatapoints;
protected final long timeToConsider;
protected final double maxProportionFailures;
/**
* @param minDatapoints min number of attempts within the time period, to consider this measure reliable
* @param timeToConsider time for recent attempts (discard any attempts older than this)
* @param maxProportionFailures proportion (between 0 and 1) where numFailures/dataPoints >= this number means failure
*/
public ProportionalZoneFailureDetector(int minDatapoints, Duration timeToConsider, double maxProportionFailures) {
this(minDatapoints, timeToConsider, maxProportionFailures, Ticker.systemTicker());
}
public ProportionalZoneFailureDetector(int minDatapoints, Duration timeToConsider, double maxProportionFailures, Ticker ticker) {
super(ticker);
this.minDatapoints = minDatapoints;
this.timeToConsider = timeToConsider.toMilliseconds();
this.maxProportionFailures = maxProportionFailures;
}
@Override
protected boolean doHasFailed(Location loc, ZoneHistory zoneHistory) {
synchronized (zoneHistory) {
zoneHistory.trimOlderThan(currentTimeMillis() - timeToConsider);
int numDatapoints = zoneHistory.successes.size() + zoneHistory.failures.size();
double proportionFailure = ((double)zoneHistory.failures.size()) / ((double)numDatapoints);
return numDatapoints >= minDatapoints && proportionFailure >= maxProportionFailures;
}
}
}