Capturing JVM- and application-level metrics. So you know what's going on.

This is the Scala API for Dropwizard's Metrics library.

Initially this project started out as a line for line copy of the Metrics-scala module, released for multiple scala versions. Metrics dropped the scala module in version 3.0.0 and this project continued separately with the help of @scullxbones.

• Usage
• Manual
• Manual (version 2.x)
• Features
• Available versions
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• License

Metrics-scala provides an easy way to create metrics and health checks in Scala. Metrics-core requires an application wide MetricRegistry. Create an Instrumented trait that refers to that registry and extends the InstrumentedBuilder trait.

object YourApplication {
  /** The application wide metrics registry. */
  val metricRegistry = new com.codahale.metrics.MetricRegistry()
}
trait Instrumented extends nl.grons.metrics.scala.InstrumentedBuilder {
  val metricRegistry = YourApplication.metricRegistry
}

Now you can create metrics by using the metrics metrics builder.

class Example(db: Database) extends Instrumented {
  private[this] val loading = metrics.timer("loading")

  def loadStuff(): Seq[Row] = loading.time {
    db.fetchRows()
  }
}

For more detailed information see the manual. For more information on Metrics-core 3.x, please see the documentation.

See the change log for API changes compared to the 2.x versions.

• Easy creation of all metrics types.
• Easy creation of Health Checks.
• Almost invisible syntax for using timers (see example above).
• Scala specific methods on metrics (e.g. += on counters).
• Derives proper metrics names for Scala objects and closures.
• Actor support.
• Future support.
• Hdrhistogram support.

This table shows the most relevant versions of metrics-scala. For the full list, including the Scala 2.9 versions, see all available versions.

If you need another version mix please open an issue, or sent an email to the metrics mailing list.

Note: If Akka or hdrhistogram has a newer minor-version, you can use that instead of the version metrics-scala was build against.

(*) Hdrhistogram is an optional dependency.

SBT:

libraryDependencies += "nl.grons" %% "metrics-scala" % "3.5.1_a2.3"

Maven:

<properties>
    <scala.version>2.11.0</scala.version>
    <scala.dep.version>2.11</scala.dep.version>
</properties>
<dependency>
    <groupId>nl.grons</groupId>
    <artifactId>metrics-scala_${scala.dep.version}</artifactId>
    <version>3.5.1_a2.3</version>
</dependency>

To use hdrhistogram additional dependencies are needed. See the hdrhistogram manual page.

If you find a bug, please open an issue, better yet: send a pull request. For questions, please sent an email to the metrics mailing list.

Copyright (c) 2010-2012 Coda Hale, Yammer.com (before 3.0.0)

Copyright (c) 2013-2015 Erik van Oosten (3.0.0 and later)

Published under Apache Software License 2.0, see LICENSE