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author | Ivan Topolnjak <ivantopo@gmail.com> | 2014-07-03 14:36:42 -0300 |
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committer | Ivan Topolnjak <ivantopo@gmail.com> | 2014-07-03 14:36:18 -0300 |
commit | a3353d3e3fcb1dfab3e8f401187e236e99df2202 (patch) | |
tree | 4e9e246201cf169f1496bc72928ea2d35d03fcd0 /kamon-core/src/main/scala/kamon/metric/instrument/Gauge.scala | |
parent | 6d7970c6dd5b96b512c846181771bb11a43bc82a (diff) | |
download | Kamon-a3353d3e3fcb1dfab3e8f401187e236e99df2202.tar.gz Kamon-a3353d3e3fcb1dfab3e8f401187e236e99df2202.tar.bz2 Kamon-a3353d3e3fcb1dfab3e8f401187e236e99df2202.zip |
! all: refactor the core metric recording instruments and accomodate UserMetrics
This PR is including several changes to the kamon-core, most notably:
- Formalize the interface for Histograms, Counters and MinMaxCounters. Making sure
that the interfaces are as clean as possible.
- Move away from the all Vector[Measurement] based Histogram snapshot to a new approach
in which we use a single long to store both the index in the counts array and the
frequency on that bucket. The leftmost 2 bytes of each long are used for storing the
counts array index and the remaining 6 bytes are used for the actual count, and
everything is put into a simple long array. This way only the buckets that actually
have values will be included in the snapshot with the smallest possible memory
footprint.
- Introduce Gauges.
- Reorganize the instrumentation for Akka and Scala and rewrite most of the tests
of this components to avoid going through the subscription protocol to test.
- Introduce trace tests and fixes on various tests.
- Necessary changes on new relic, datadog and statsd modules to compile with the new
codebase.
Pending:
- Finish the upgrade of the new relic to the current model.
- Introduce proper limit checks for histograms to ensure that we never pass the 2/6 bytes
limits.
- More testing, more testing, more testing.
- Create the KamonStandalone module.
Diffstat (limited to 'kamon-core/src/main/scala/kamon/metric/instrument/Gauge.scala')
-rw-r--r-- | kamon-core/src/main/scala/kamon/metric/instrument/Gauge.scala | 78 |
1 files changed, 78 insertions, 0 deletions
diff --git a/kamon-core/src/main/scala/kamon/metric/instrument/Gauge.scala b/kamon-core/src/main/scala/kamon/metric/instrument/Gauge.scala new file mode 100644 index 00000000..1efff2bc --- /dev/null +++ b/kamon-core/src/main/scala/kamon/metric/instrument/Gauge.scala @@ -0,0 +1,78 @@ +package kamon.metric.instrument + +import java.util.concurrent.TimeUnit +import java.util.concurrent.atomic.AtomicReference + +import akka.actor.{ Cancellable, ActorSystem } +import com.typesafe.config.Config +import kamon.metric.{ CollectionContext, Scale, MetricRecorder } + +import scala.concurrent.duration.FiniteDuration + +trait Gauge extends MetricRecorder { + type SnapshotType = Histogram.Snapshot + + def record(value: Long) + def record(value: Long, count: Long) +} + +object Gauge { + + trait CurrentValueCollector { + def currentValue: Long + } + + def apply(precision: Histogram.Precision, highestTrackableValue: Long, scale: Scale, refreshInterval: FiniteDuration, + system: ActorSystem)(currentValueCollector: CurrentValueCollector): Gauge = { + + val underlyingHistogram = Histogram(highestTrackableValue, precision, scale) + val gauge = new HistogramBackedGauge(underlyingHistogram, currentValueCollector) + + val refreshValuesSchedule = system.scheduler.schedule(refreshInterval, refreshInterval) { + gauge.refreshValue() + }(system.dispatcher) // TODO: Move this to Kamon dispatchers + + gauge.refreshValuesSchedule.set(refreshValuesSchedule) + gauge + } + + def fromDefaultConfig(system: ActorSystem)(currentValueCollectorFunction: () ⇒ Long): Gauge = + fromDefaultConfig(system, functionZeroAsCurrentValueCollector(currentValueCollectorFunction)) + + def fromDefaultConfig(system: ActorSystem, currentValueCollector: CurrentValueCollector): Gauge = { + val config = system.settings.config.getConfig("kamon.metrics.precision.default-gauge-precision") + fromConfig(config, system)(currentValueCollector) + } + + def fromConfig(config: Config, system: ActorSystem)(currentValueCollector: CurrentValueCollector): Gauge = { + import scala.concurrent.duration._ + + val highest = config.getLong("highest-trackable-value") + val significantDigits = config.getInt("significant-value-digits") + val refreshInterval = config.getDuration("refresh-interval", TimeUnit.MILLISECONDS) + + Gauge(Histogram.Precision(significantDigits), highest, Scale.Unit, refreshInterval.millis, system)(currentValueCollector) + } + + implicit def functionZeroAsCurrentValueCollector(f: () ⇒ Long): CurrentValueCollector = new CurrentValueCollector { + def currentValue: Long = f.apply() + } +} + +class HistogramBackedGauge(underlyingHistogram: Histogram, currentValueCollector: Gauge.CurrentValueCollector) extends Gauge { + val refreshValuesSchedule = new AtomicReference[Cancellable]() + + def record(value: Long): Unit = underlyingHistogram.record(value) + + def record(value: Long, count: Long): Unit = underlyingHistogram.record(value, count) + + def collect(context: CollectionContext): Histogram.Snapshot = underlyingHistogram.collect(context) + + def cleanup: Unit = { + if (refreshValuesSchedule.get() != null) + refreshValuesSchedule.get().cancel() + } + + def refreshValue(): Unit = underlyingHistogram.record(currentValueCollector.currentValue) +} + |