io.micrometer.core.instrument.dropwizard.DropwizardRate Maven / Gradle / Ivy
/*
* Copyright 2017 VMware, Inc.
*
* 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
*
* https://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 io.micrometer.core.instrument.dropwizard;
import com.codahale.metrics.EWMA;
import io.micrometer.core.instrument.Clock;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicLong;
/**
* For use in Dropwizard implementations of
* {@link io.micrometer.core.instrument.FunctionTimer} and
* {@link io.micrometer.core.instrument.FunctionCounter}.
*/
class DropwizardRate {
private static final long TICK_INTERVAL = TimeUnit.SECONDS.toNanos(5);
private final AtomicLong lastTime;
private final EWMA m1Rate = EWMA.oneMinuteEWMA();
private final EWMA m5Rate = EWMA.fiveMinuteEWMA();
private final EWMA m15Rate = EWMA.fifteenMinuteEWMA();
private final Clock clock;
DropwizardRate(Clock clock) {
this.clock = clock;
this.lastTime = new AtomicLong(clock.monotonicTime());
}
/**
* @param increment Spread the increment out over the interval
*/
private synchronized void tickIfNecessary(long increment) {
final long oldTime = lastTime.get();
final long currentTime = clock.monotonicTime();
final long age = currentTime - oldTime;
if (age > TICK_INTERVAL) {
final long newIntervalStartTick = currentTime - age % TICK_INTERVAL;
if (lastTime.compareAndSet(oldTime, newIntervalStartTick)) {
final long requiredTicks = age / TICK_INTERVAL;
// divide the increment equally over the interval to arrive at a
// reasonable approximation
// of rate behavior in many cases (but not all)
final long updateAtEachInterval = increment / requiredTicks;
for (long i = 0; i < requiredTicks; i++) {
m1Rate.update(updateAtEachInterval);
m5Rate.update(updateAtEachInterval);
m15Rate.update(updateAtEachInterval);
m1Rate.tick();
m5Rate.tick();
m15Rate.tick();
}
final long updateRemainder = increment % requiredTicks;
m1Rate.update(updateRemainder);
m5Rate.update(updateRemainder);
m15Rate.update(updateRemainder);
}
}
else {
m1Rate.update(increment);
m5Rate.update(increment);
m15Rate.update(increment);
}
}
/**
* Mimicks what happens inside of {@link com.codahale.metrics.Meter#mark(long)}, but
* ticks AFTER the increment.
*/
public void increment(long n) {
tickIfNecessary(n);
}
public double getOneMinuteRate() {
tickIfNecessary(0);
return m1Rate.getRate(TimeUnit.SECONDS);
}
public double getFifteenMinuteRate() {
tickIfNecessary(0);
return m15Rate.getRate(TimeUnit.SECONDS);
}
public double getFiveMinuteRate() {
tickIfNecessary(0);
return m5Rate.getRate(TimeUnit.SECONDS);
}
}