HdrMetricBuilder

import nl.grons.metrics4.scala._
import scala.concurrent.duration._
class UserRepository(db: Database) extends DefaultInstrumented {
 // Defines the gauge.
 metrics.cachedGauge("row-count", 5.minutes) {
   // Does a measurement at most once every 5 minutes.
   db.usersRowCount()
 }
}

import nl.grons.metrics4.scala._
class SessionStore(cache: Cache) extends DefaultInstrumented {
 // Defines the gauge.
 metrics.gauge("cache-evictions") {
   // Does a measurement.
   cache.getEvictionsCount()
 }
}

import nl.grons.metrics4.scala._
class ExternalCacheUpdater extends DefaultInstrumented {
 // Defines a push gauge
 private val cachedItemsCount = metrics.pushGauge[Int]("cached.items.count", 0)

 def updateExternalCache(): Unit = {
   val items = fetchItemsFromDatabase()
   pushItemsToExternalCache(items)
   // Pushes a new measurement to the gauge
   cachedItemsCount.push(items.size)
   // Alternative way to push a new measurement
   cachedItemsCount.value = items.size
 }
}

import nl.grons.metrics4.scala._
import scala.concurrent.duration._
class ExternalCacheUpdater extends DefaultInstrumented {
 // Defines a push gauge
 private val cachedItemsCount = metrics.pushGaugeWithTimeout[Int]("cached.items.count", 0, 10.minutes)

 def updateExternalCache(): Unit = {
   val items = fetchItemsFromDatabase()
   pushItemsToExternalCache(items)
   // Pushes a new measurement to the gauge
   cachedItemsCount.push(items.size)
   // Alternative way to push a new measurement
   cachedItemsCount.value = items.size
 }
}