io.micrometer.core.instrument.Timer Maven / Gradle / Ivy
Show all versions of micrometer-core Show documentation
/**
* Copyright 2017 Pivotal Software, 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
*
* 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 io.micrometer.core.instrument;
import io.micrometer.core.annotation.Timed;
import io.micrometer.core.instrument.distribution.CountAtBucket;
import io.micrometer.core.instrument.distribution.DistributionStatisticConfig;
import io.micrometer.core.instrument.distribution.HistogramSupport;
import io.micrometer.core.instrument.distribution.ValueAtPercentile;
import io.micrometer.core.instrument.distribution.pause.PauseDetector;
import io.micrometer.core.lang.Nullable;
import java.time.Duration;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.concurrent.Callable;
import java.util.concurrent.TimeUnit;
import java.util.function.Supplier;
/**
* Timer intended to track of a large number of short running events. Example would be something like
* an HTTP request. Though "short running" is a bit subjective the assumption is that it should be
* under a minute.
*
* @author Jon Schneider
*/
public interface Timer extends Meter, HistogramSupport {
static Sample start(MeterRegistry registry) {
return new Sample(registry.config().clock());
}
static Sample start(Clock clock) {
return new Sample(clock);
}
static Builder builder(String name) {
return new Builder(name);
}
/**
* Create a timer builder from a {@link Timed} annotation.
*
* @param timed The annotation instance to base a new timer on.
* @param defaultName A default name to use in the event that the value attribute is empty.
* @return This builder.
*/
static Builder builder(Timed timed, String defaultName) {
if (timed.longTask() && timed.value().isEmpty()) {
// the user MUST name long task timers, we don't lump them in with regular
// timers with the same name
throw new IllegalArgumentException("Long tasks instrumented with @Timed require the value attribute to be non-empty");
}
return new Builder(timed.value().isEmpty() ? defaultName : timed.value())
.tags(timed.extraTags())
.description(timed.description().isEmpty() ? null : timed.description())
.publishPercentileHistogram(timed.histogram())
.publishPercentiles(timed.percentiles().length > 0 ? timed.percentiles() : null);
}
/**
* Updates the statistics kept by the counter with the specified amount.
*
* @param amount Duration of a single event being measured by this timer. If the amount is less than 0
* the value will be dropped.
* @param unit Time unit for the amount being recorded.
*/
void record(long amount, TimeUnit unit);
/**
* Updates the statistics kept by the counter with the specified amount.
*
* @param duration Duration of a single event being measured by this timer.
*/
default void record(Duration duration) {
record(duration.toNanos(), TimeUnit.NANOSECONDS);
}
/**
* Executes the Supplier `f` and records the time taken.
*
* @param f Function to execute and measure the execution time.
* @param The return type of the {@link Supplier}.
* @return The return value of `f`.
*/
T record(Supplier f);
/**
* Executes the callable `f` and records the time taken.
*
* @param f Function to execute and measure the execution time.
* @param The return type of the {@link Callable}.
* @return The return value of `f`.
* @throws Exception Any exception bubbling up from the callable.
*/
T recordCallable(Callable f) throws Exception;
/**
* Executes the runnable `f` and records the time taken.
*
* @param f Function to execute and measure the execution time.
*/
void record(Runnable f);
/**
* Wrap a {@link Runnable} so that it is timed when invoked.
*
* @param f The Runnable to time when it is invoked.
* @return The wrapped Runnable.
*/
default Runnable wrap(Runnable f) {
return () -> record(f);
}
/**
* Wrap a {@link Callable} so that it is timed when invoked.
*
* @param f The Callable to time when it is invoked.
* @param The return type of the callable.
* @return The wrapped callable.
*/
default Callable wrap(Callable f) {
return () -> recordCallable(f);
}
/**
* @return The number of times that stop has been called on this timer.
*/
long count();
/**
* @param unit The base unit of time to scale the total to.
* @return The total time of recorded events.
*/
double totalTime(TimeUnit unit);
/**
* @param unit The base unit of time to scale the mean to.
* @return The distribution average for all recorded events.
*/
default double mean(TimeUnit unit) {
return count() == 0 ? 0 : totalTime(unit) / count();
}
/**
* @param unit The base unit of time to scale the max to.
* @return The maximum time of a single event.
*/
double max(TimeUnit unit);
@Override
default Iterable measure() {
return Arrays.asList(
new Measurement(() -> (double) count(), Statistic.COUNT),
new Measurement(() -> totalTime(baseTimeUnit()), Statistic.TOTAL_TIME),
new Measurement(() -> max(baseTimeUnit()), Statistic.MAX)
);
}
/**
* Provides cumulative histogram counts.
*
* @param valueNanos The histogram bucket to retrieve a count for.
* @return The count of all events less than or equal to the bucket. If valueNanos does not
* match a preconfigured bucket boundary, returns NaN.
* @deprecated Use {@link #takeSnapshot()} to retrieve bucket counts.
*/
@Deprecated
default double histogramCountAtValue(long valueNanos) {
for (CountAtBucket countAtBucket : takeSnapshot().histogramCounts()) {
if ((long) countAtBucket.bucket(TimeUnit.NANOSECONDS) == valueNanos) {
return countAtBucket.count();
}
}
return Double.NaN;
}
/**
* @param percentile A percentile in the domain [0, 1]. For example, 0.5 represents the 50th percentile of the
* distribution.
* @param unit The base unit of time to scale the percentile value to.
* @return The latency at a specific percentile. This value is non-aggregable across dimensions. Returns NaN if
* percentile is not a preconfigured percentile that Micrometer is tracking.
* @deprecated Use {@link #takeSnapshot()} to retrieve bucket counts.
*/
@Deprecated
default double percentile(double percentile, TimeUnit unit) {
for (ValueAtPercentile valueAtPercentile : takeSnapshot().percentileValues()) {
if (valueAtPercentile.percentile() == percentile) {
return valueAtPercentile.value(unit);
}
}
return Double.NaN;
}
/**
* @return The base time unit of the timer to which all published metrics will be scaled
*/
TimeUnit baseTimeUnit();
/**
* Maintains state on the clock's start position for a latency sample. Complete the timing
* by calling {@link Sample#stop(Timer)}. Note how the {@link Timer} isn't provided until the
* sample is stopped, allowing you to determine the timer's tags at the last minute.
*/
class Sample {
private final long startTime;
private final Clock clock;
Sample(Clock clock) {
this.clock = clock;
this.startTime = clock.monotonicTime();
}
/**
* Records the duration of the operation
*
* @param timer The timer to record the sample to.
* @return The total duration of the sample in nanoseconds
*/
public long stop(Timer timer) {
long durationNs = clock.monotonicTime() - startTime;
timer.record(durationNs, TimeUnit.NANOSECONDS);
return durationNs;
}
}
/**
* Fluent builder for timers.
*/
class Builder {
private final String name;
private final List tags = new ArrayList<>();
private final DistributionStatisticConfig.Builder distributionConfigBuilder;
@Nullable
private String description;
@Nullable
private PauseDetector pauseDetector;
private Builder(String name) {
this.name = name;
this.distributionConfigBuilder = new DistributionStatisticConfig.Builder();
minimumExpectedValue(Duration.ofMillis(1));
maximumExpectedValue(Duration.ofSeconds(30));
}
/**
* @param tags Must be an even number of arguments representing key/value pairs of tags.
* @return This builder.
*/
public Builder tags(String... tags) {
return tags(Tags.of(tags));
}
/**
* @param tags Tags to add to the eventual meter.
* @return The timer builder with added tags.
*/
public Builder tags(Iterable tags) {
tags.forEach(this.tags::add);
return this;
}
/**
* @param key The tag key.
* @param value The tag value.
* @return This builder.
*/
public Builder tag(String key, String value) {
tags.add(Tag.of(key, value));
return this;
}
/**
* Produces an additional time series for each requested percentile. This percentile
* is computed locally, and so can't be aggregated with percentiles computed across other
* dimensions (e.g. in a different instance). Use {@link #publishPercentileHistogram()}
* to publish a histogram that can be used to generate aggregable percentile approximations.
*
* @param percentiles Percentiles to compute and publish. The 95th percentile should be expressed as {@code 0.95}.
* @return This builder.
*/
public Builder publishPercentiles(@Nullable double... percentiles) {
this.distributionConfigBuilder.percentiles(percentiles);
return this;
}
/**
* Determines the number of digits of precision to maintain on the dynamic range histogram used to compute
* percentile approximations. The higher the degrees of precision, the more accurate the approximation is at the
* cost of more memory.
*
* @param digitsOfPrecision The digits of precision to maintain for percentile approximations.
* @return This builder.
*/
public Builder percentilePrecision(int digitsOfPrecision) {
this.distributionConfigBuilder.percentilePrecision(digitsOfPrecision);
return this;
}
/**
* Adds histogram buckets used to generate aggregable percentile approximations in monitoring
* systems that have query facilities to do so (e.g. Prometheus' {@code histogram_quantile},
* Atlas' {@code :percentiles}).
*
* @return This builder.
*/
public Builder publishPercentileHistogram() {
return publishPercentileHistogram(true);
}
/**
* Adds histogram buckets used to generate aggregable percentile approximations in monitoring
* systems that have query facilities to do so (e.g. Prometheus' {@code histogram_quantile},
* Atlas' {@code :percentiles}).
*
* @param enabled Determines whether percentile histograms should be published.
* @return This builder.
*/
public Builder publishPercentileHistogram(@Nullable Boolean enabled) {
this.distributionConfigBuilder.percentilesHistogram(enabled);
return this;
}
/**
* Publish at a minimum a histogram containing your defined SLA boundaries. When used in conjunction with
* {@link Builder#publishPercentileHistogram()}, the boundaries defined here are included alongside
* other buckets used to generate aggregable percentile approximations.
*
* @param sla Publish SLA boundaries in the set of histogram buckets shipped to the monitoring system.
* @return This builder.
*/
public Builder sla(@Nullable Duration... sla) {
if (sla != null) {
long[] slaNano = new long[sla.length];
for (int i = 0; i < slaNano.length; i++) {
slaNano[i] = sla[i].toNanos();
}
this.distributionConfigBuilder.sla(slaNano);
}
return this;
}
/**
* Sets the minimum value that this timer is expected to observe. Sets a lower bound
* on histogram buckets that are shipped to monitoring systems that support aggregable percentile approximations.
*
* @param min The minimum value that this timer is expected to observe.
* @return This builder.
*/
public Builder minimumExpectedValue(@Nullable Duration min) {
if (min != null)
this.distributionConfigBuilder.minimumExpectedValue(min.toNanos());
return this;
}
/**
* Sets the maximum value that this timer is expected to observe. Sets an upper bound
* on histogram buckets that are shipped to monitoring systems that support aggregable percentile approximations.
*
* @param max The maximum value that this timer is expected to observe.
* @return This builder.
*/
public Builder maximumExpectedValue(@Nullable Duration max) {
if (max != null)
this.distributionConfigBuilder.maximumExpectedValue(max.toNanos());
return this;
}
/**
* Statistics emanating from a timer like max, percentiles, and histogram counts decay over time to
* give greater weight to recent samples (exception: histogram counts are cumulative for those systems that expect cumulative
* histogram buckets). Samples are accumulated to such statistics in ring buffers which rotate after
* this expiry, with a buffer length of {@link #distributionStatisticBufferLength(Integer)}.
*
* @param expiry The amount of time samples are accumulated to a histogram before it is reset and rotated.
* @return This builder.
*/
public Builder distributionStatisticExpiry(@Nullable Duration expiry) {
this.distributionConfigBuilder.expiry(expiry);
return this;
}
/**
* Statistics emanating from a timer like max, percentiles, and histogram counts decay over time to
* give greater weight to recent samples (exception: histogram counts are cumulative for those systems that expect cumulative
* histogram buckets). Samples are accumulated to such statistics in ring buffers which rotate after
* {@link #distributionStatisticExpiry(Duration)}, with this buffer length.
*
* @param bufferLength The number of histograms to keep in the ring buffer.
* @return This builder.
*/
public Builder distributionStatisticBufferLength(@Nullable Integer bufferLength) {
this.distributionConfigBuilder.bufferLength(bufferLength);
return this;
}
/**
* Sets the pause detector implementation to use for this timer. Can also be configured on a registry-level with
* {@link MeterRegistry.Config#pauseDetector(PauseDetector)}.
*
* @param pauseDetector The pause detector implementation to use.
* @return This builder.
* @see io.micrometer.core.instrument.distribution.pause.NoPauseDetector
* @see io.micrometer.core.instrument.distribution.pause.ClockDriftPauseDetector
*/
public Builder pauseDetector(@Nullable PauseDetector pauseDetector) {
this.pauseDetector = pauseDetector;
return this;
}
/**
* @param description Description text of the eventual timer.
* @return This builder.
*/
public Builder description(@Nullable String description) {
this.description = description;
return this;
}
/**
* Add the timer to a single registry, or return an existing timer in that registry. The returned
* timer will be unique for each registry, but each registry is guaranteed to only create one timer
* for the same combination of name and tags.
*
* @param registry A registry to add the timer to, if it doesn't already exist.
* @return A new or existing timer.
*/
public Timer register(MeterRegistry registry) {
// the base unit for a timer will be determined by the monitoring system implementation
return registry.timer(new Meter.Id(name, tags, null, description, Type.TIMER), distributionConfigBuilder.build(),
pauseDetector == null ? registry.config().pauseDetector() : pauseDetector);
}
}
}