package io.dropwizard.metrics;
import org.junit.Test;
import io.dropwizard.metrics.EWMA;
import java.util.concurrent.TimeUnit;
import static org.assertj.core.api.Assertions.assertThat;
import static org.assertj.core.api.Assertions.offset;
public class EWMATest {
@Test
public void aOneMinuteEWMAWithAValueOfThree() throws Exception {
final EWMA ewma = EWMA.oneMinuteEWMA();
ewma.update(3);
ewma.tick();
assertThat(ewma.getRate(TimeUnit.SECONDS)).isEqualTo(0.6, offset(0.000001));
elapseMinute(ewma);
assertThat(ewma.getRate(TimeUnit.SECONDS)).isEqualTo(0.22072766, offset(0.000001));
elapseMinute(ewma);
assertThat(ewma.getRate(TimeUnit.SECONDS)).isEqualTo(0.08120117, offset(0.000001));
elapseMinute(ewma);
assertThat(ewma.getRate(TimeUnit.SECONDS)).isEqualTo(0.02987224, offset(0.000001));
elapseMinute(ewma);
assertThat(ewma.getRate(TimeUnit.SECONDS)).isEqualTo(0.01098938, offset(0.000001));
elapseMinute(ewma);
assertThat(ewma.getRate(TimeUnit.SECONDS)).isEqualTo(0.00404277, offset(0.000001));
elapseMinute(ewma);
assertThat(ewma.getRate(TimeUnit.SECONDS)).isEqualTo(0.00148725, offset(0.000001));
elapseMinute(ewma);
assertThat(ewma.getRate(TimeUnit.SECONDS)).isEqualTo(0.00054713, offset(0.000001));
elapseMinute(ewma);
assertThat(ewma.getRate(TimeUnit.SECONDS)).isEqualTo(0.00020128, offset(0.000001));
elapseMinute(ewma);
assertThat(ewma.getRate(TimeUnit.SECONDS)).isEqualTo(0.00007405, offset(0.000001));
elapseMinute(ewma);
assertThat(ewma.getRate(TimeUnit.SECONDS)).isEqualTo(0.00002724, offset(0.000001));
elapseMinute(ewma);
assertThat(ewma.getRate(TimeUnit.SECONDS)).isEqualTo(0.00001002, offset(0.000001));
elapseMinute(ewma);
assertThat(ewma.getRate(TimeUnit.SECONDS)).isEqualTo(0.00000369, offset(0.000001));
elapseMinute(ewma);
assertThat(ewma.getRate(TimeUnit.SECONDS)).isEqualTo(0.00000136, offset(0.000001));
elapseMinute(ewma);
assertThat(ewma.getRate(TimeUnit.SECONDS)).isEqualTo(0.00000050, offset(0.000001));
elapseMinute(ewma);
assertThat(ewma.getRate(TimeUnit.SECONDS)).isEqualTo(0.00000018, offset(0.000001));
}
@Test
public void aFiveMinuteEWMAWithAValueOfThree() throws Exception {
final EWMA ewma = EWMA.fiveMinuteEWMA();
ewma.update(3);
ewma.tick();
assertThat(ewma.getRate(TimeUnit.SECONDS)).isEqualTo(0.6, offset(0.000001));
elapseMinute(ewma);
assertThat(ewma.getRate(TimeUnit.SECONDS)).isEqualTo(0.49123845, offset(0.000001));
elapseMinute(ewma);
assertThat(ewma.getRate(TimeUnit.SECONDS)).isEqualTo(0.40219203, offset(0.000001));
elapseMinute(ewma);
assertThat(ewma.getRate(TimeUnit.SECONDS)).isEqualTo(0.32928698, offset(0.000001));
elapseMinute(ewma);
assertThat(ewma.getRate(TimeUnit.SECONDS)).isEqualTo(0.26959738, offset(0.000001));
elapseMinute(ewma);
assertThat(ewma.getRate(TimeUnit.SECONDS)).isEqualTo(0.22072766, offset(0.000001));
elapseMinute(ewma);
assertThat(ewma.getRate(TimeUnit.SECONDS)).isEqualTo(0.18071653, offset(0.000001));
elapseMinute(ewma);
assertThat(ewma.getRate(TimeUnit.SECONDS)).isEqualTo(0.14795818, offset(0.000001));
elapseMinute(ewma);
assertThat(ewma.getRate(TimeUnit.SECONDS)).isEqualTo(0.12113791, offset(0.000001));
elapseMinute(ewma);
assertThat(ewma.getRate(TimeUnit.SECONDS)).isEqualTo(0.09917933, offset(0.000001));
elapseMinute(ewma);
assertThat(ewma.getRate(TimeUnit.SECONDS)).isEqualTo(0.08120117, offset(0.000001));
elapseMinute(ewma);
assertThat(ewma.getRate(TimeUnit.SECONDS)).isEqualTo(0.06648190, offset(0.000001));
elapseMinute(ewma);
assertThat(ewma.getRate(TimeUnit.SECONDS)).isEqualTo(0.05443077, offset(0.000001));
elapseMinute(ewma);
assertThat(ewma.getRate(TimeUnit.SECONDS)).isEqualTo(0.04456415, offset(0.000001));
elapseMinute(ewma);
assertThat(ewma.getRate(TimeUnit.SECONDS)).isEqualTo(0.03648604, offset(0.000001));
elapseMinute(ewma);
assertThat(ewma.getRate(TimeUnit.SECONDS)).isEqualTo(0.02987224, offset(0.000001));
}
@Test
public void aFifteenMinuteEWMAWithAValueOfThree() throws Exception {
final EWMA ewma = EWMA.fifteenMinuteEWMA();
ewma.update(3);
ewma.tick();
assertThat(ewma.getRate(TimeUnit.SECONDS)).isEqualTo(0.6, offset(0.000001));
elapseMinute(ewma);
assertThat(ewma.getRate(TimeUnit.SECONDS)).isEqualTo(0.56130419, offset(0.000001));
elapseMinute(ewma);
assertThat(ewma.getRate(TimeUnit.SECONDS)).isEqualTo(0.52510399, offset(0.000001));
elapseMinute(ewma);
assertThat(ewma.getRate(TimeUnit.SECONDS)).isEqualTo(0.49123845, offset(0.000001));
elapseMinute(ewma);
assertThat(ewma.getRate(TimeUnit.SECONDS)).isEqualTo(0.45955700, offset(0.000001));
elapseMinute(ewma);
assertThat(ewma.getRate(TimeUnit.SECONDS)).isEqualTo(0.42991879, offset(0.000001));
elapseMinute(ewma);
assertThat(ewma.getRate(TimeUnit.SECONDS)).isEqualTo(0.40219203, offset(0.000001));
elapseMinute(ewma);
assertThat(ewma.getRate(TimeUnit.SECONDS)).isEqualTo(0.37625345, offset(0.000001));
elapseMinute(ewma);
assertThat(ewma.getRate(TimeUnit.SECONDS)).isEqualTo(0.35198773, offset(0.000001));
elapseMinute(ewma);
assertThat(ewma.getRate(TimeUnit.SECONDS)).isEqualTo(0.32928698, offset(0.000001));
elapseMinute(ewma);
assertThat(ewma.getRate(TimeUnit.SECONDS)).isEqualTo(0.30805027, offset(0.000001));
elapseMinute(ewma);
assertThat(ewma.getRate(TimeUnit.SECONDS)).isEqualTo(0.28818318, offset(0.000001));
elapseMinute(ewma);
assertThat(ewma.getRate(TimeUnit.SECONDS)).isEqualTo(0.26959738, offset(0.000001));
elapseMinute(ewma);
assertThat(ewma.getRate(TimeUnit.SECONDS)).isEqualTo(0.25221023, offset(0.000001));
elapseMinute(ewma);
assertThat(ewma.getRate(TimeUnit.SECONDS)).isEqualTo(0.23594443, offset(0.000001));
elapseMinute(ewma);
assertThat(ewma.getRate(TimeUnit.SECONDS)).isEqualTo(0.22072766, offset(0.000001));
}
private void elapseMinute(EWMA ewma) {
for (int i = 1; i <= 12; i++) {
ewma.tick();
}
}
}