package azkaban.metrics;
import com.codahale.metrics.Gauge;
import com.codahale.metrics.Meter;
import com.codahale.metrics.MetricRegistry;
import com.codahale.metrics.Timer;
import java.util.function.Supplier;
/**
* Creating an utility class to facilitate metrics class like {@link azkaban.metrics.CommonMetrics}
* to share common operations easily.
*/
public final class MetricsUtility {
private MetricsUtility() {
//Utility class's constructor should not be called
}
/**
* A {@link Meter} measures the rate of events over time (e.g., “requests per second”).
* Here we track 1-minute moving averages.
*/
public static Meter addMeter(String name, MetricRegistry registry) {
Meter curr = registry.meter(name);
registry.register(name + "-gauge", (Gauge<Double>) curr::getFifteenMinuteRate);
return curr;
}
/**
* A {@link Gauge} is an instantaneous reading of a particular value.
* This method leverages Supplier, a Functional Interface, to get Generics metrics values.
* With this support, no matter what our interesting metrics is a Double or a Long, we could pass it
* to Metrics Parser.
*
* E.g., in {@link CommonMetrics#setupAllMetrics()}, we construct a supplier lambda by having
* a AtomicLong object and its get method, in order to collect dbConnection metric.
*/
public static <T> void addGauge(String name, MetricRegistry registry, Supplier<T> gaugeFunc) {
registry.register(name, (Gauge<T>) gaugeFunc::get);
}
}