/**
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* 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 "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.apache.cassandra.stress;
import com.yammer.metrics.stats.Snapshot;
import java.io.PrintStream;
import org.apache.commons.lang3.time.DurationFormatUtils;
/**
* Gathers and aggregates statistics for an operation
*/
public class StressStatistics
{
private Session client;
private PrintStream output;
private long durationInSeconds;
/** The sum of the interval_op_rate values collected by tallyAverages */
private int tallyOpRateSum;
/** The number of interval_op_rate values collected by tallyAverages */
private int tallyOpRateCount;
/** The sum of the interval_key_rate values collected by tallyAverages */
private int tallyKeyRateSum;
/** The number of interval_key_rate values collected by tallyAverages */
private int tallyKeyRateCount;
/** The sum of the latency values collected by tallyAverages */
private double tallyLatencySum;
/** The number of latency values collected by tallyAverages */
private int tallyLatencyCount;
/** The sum of the 95%tile latency values collected by tallyAverages */
private double tally95thLatencySum;
/** The number of 95%tile latency values collected by tallyAverages */
private int tally95thLatencyCount;
/** The sum of the 99.9%tile latency values collected by tallyAverages */
private double tally999thLatencySum;
/** The number of 99.9%tile latency values collected by tallyAverages */
private int tally999thLatencyCount;
public StressStatistics(Session client, PrintStream out)
{
this.client = client;
this.output = out;
tallyOpRateSum = 0;
tallyOpRateCount = 0;
}
/**
* Collect statistics per-interval
*/
public void addIntervalStats(int totalOperations, int intervalOpRate,
int intervalKeyRate, Snapshot latency,
long currentTimeInSeconds)
{
this.tallyAverages(totalOperations, intervalKeyRate, intervalKeyRate,
latency, currentTimeInSeconds);
}
/**
* Collect interval_op_rate and interval_key_rate averages
*/
private void tallyAverages(int totalOperations, int intervalOpRate,
int intervalKeyRate, Snapshot latency,
long currentTimeInSeconds)
{
//Skip the first and last 10% of values.
//The middle values of the operation are the ones worthwhile
//to collect and average:
if (totalOperations > (0.10 * client.getNumKeys()) &&
totalOperations < (0.90 * client.getNumKeys())) {
tallyOpRateSum += intervalOpRate;
tallyOpRateCount += 1;
tallyKeyRateSum += intervalKeyRate;
tallyKeyRateCount += 1;
tallyLatencySum += latency.getMedian();
tallyLatencyCount += 1;
tally95thLatencySum += latency.get95thPercentile();
tally95thLatencyCount += 1;
tally999thLatencySum += latency.get999thPercentile();
tally999thLatencyCount += 1;
}
durationInSeconds = currentTimeInSeconds;
}
public void printStats()
{
output.println("\n");
if (tallyOpRateCount > 0) {
output.println("Averages from the middle 80% of values:");
output.println(String.format("interval_op_rate : %d",
(tallyOpRateSum / tallyOpRateCount)));
output.println(String.format("interval_key_rate : %d",
(tallyKeyRateSum / tallyKeyRateCount)));
output.println(String.format("latency median : %.1f",
(tallyLatencySum / tallyLatencyCount)));
output.println(String.format("latency 95th percentile : %.1f",
(tally95thLatencySum / tally95thLatencyCount)));
output.println(String.format("latency 99.9th percentile : %.1f",
(tally999thLatencySum / tally999thLatencyCount)));
}
output.println("Total operation time : " + DurationFormatUtils.formatDuration(
durationInSeconds*1000, "HH:mm:ss", true));
}
}