MovingPercentileStrategy.java

/**
 * Copyright 2014 SAP AG
 *
 * Licensed 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 "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.spotter.ext.detection.appHiccups.strategies;

import java.util.ArrayList;
import java.util.List;

import org.lpe.common.util.NumericPairList;
import org.spotter.core.detection.DetectionResultManager;
import org.spotter.ext.detection.appHiccups.IHiccupAnalysisStrategy;
import org.spotter.ext.detection.appHiccups.utils.Hiccup;
import org.spotter.ext.detection.appHiccups.utils.HiccupDetectionConfig;
import org.spotter.ext.detection.utils.Utils;
import org.spotter.shared.result.model.SpotterResult;

/**
 * Applies Moving Average Analysis in order to identify hiccups.
 * 
 * @author Alexander Wert
 * 
 */
public class MovingPercentileStrategy implements IHiccupAnalysisStrategy {
	@Override
	public List<Hiccup> findHiccups(final NumericPairList<Long, Double> responsetimeSeries,
			final HiccupDetectionConfig hiccupConfig, double perfReqThreshold, double perfReqConfidence,
			DetectionResultManager resultManager, SpotterResult result) {
		List<Hiccup> hiccups = new ArrayList<Hiccup>();
		Hiccup currentHiccup = null;
		double maxRT = Double.MIN_VALUE;
		double mvaResponseTime = 0.0;
		double responseTime = 0.0;
		long timestamp = 0L;
		for (int i = 0; i < responsetimeSeries.size(); i++) {
			timestamp = responsetimeSeries.get(i).getKey();
			responseTime = responsetimeSeries.get(i).getValue();
			mvaResponseTime = Utils.calculateWindowPercentile(responsetimeSeries, perfReqConfidence, i,
					hiccupConfig.getMvaWindowSize());

			if (mvaResponseTime > perfReqThreshold) {
				maxRT = Math.max(maxRT, responseTime);
				if (currentHiccup == null) {
					// new hiccup begin detected
					currentHiccup = new Hiccup();
					currentHiccup.setStartTimestamp(timestamp);
					hiccups.add(currentHiccup);
				}
				currentHiccup.setEndTimestamp(timestamp);
			} else {
				if (currentHiccup != null) {
					currentHiccup.setMaxHiccupResponseTime(maxRT);
					currentHiccup = null;
				}
				maxRT = Double.MIN_VALUE;
			}
		}

		if (currentHiccup != null) {
			currentHiccup.setMaxHiccupResponseTime(maxRT);
		}

		return hiccups;
	}

}