CHANGELOG.md

v2.0.2: Feb 09 2012

• InstrumentationModule in metrics-guice now uses the default MetricsRegistry and HealthCheckRegistry.

v2.0.1: Feb 08 2012

• Fixed a concurrency bug in JmxReporter.

v2.0.0: Feb 07 2012

• Upgraded to Jackson 1.9.4.
• Upgraded to Jetty 7.6.0.
• Added escaping for garbage collector and memory pool names in GraphiteReporter.
• Fixed the inability to start and stop multiple reporter instances.
• Switched to using a backported version of ThreadLocalRandom for UniformSample and ExponentiallyDecayingSample to reduce lock contention on random number generation.
• Removed Ordered from TimedAnnotationBeanPostProcessor in metrics-spring.
• Upgraded to JDBI 2.31.1.
• Upgraded to Ehcache 2.5.1.
• Added #timerContext() to Scala Timer.

v2.0.0-RC0: Jan 19 2012

• Added FindBugs checks to the build process.
• Fixed the catching of Error instances thrown during health checks.
• Added enable static methods to CsvReporter and changed CsvReporter(File, MetricsRegistry) to CsvReporter(MetricsRegistry, File).
• Slimmed down InstrumentedEhcache.
• Hid the internals of GangliaReporter.
• Hid the internals of metrics-guice.
• Changed metrics-httpclient to consistently associate metrics with the org.apache class being extended.
• Hid the internals of metrics-httpclient.
• Rewrote InstrumentedAppender in metrics-log4j. It no longer forwards events to an appender. Instead, you can just attach it to your root logger to instrument logging.
• Rewrote InstrumentedAppender in metrics-logback. No major API changes.
• Fixed bugs with @ExceptionMetered-annotated resource methods in metrics-jersey.
• Fixed bugs generating Snapshot instances from concurrently modified collections.
• Fixed edge case in MetricsServlet's thread dumps where one thread could be missed.
• Added RatioGauge and PercentGauge.
• Changed InstrumentedQueuedThreadPool's percent-idle gauge to be a ratio.
• Decomposed MetricsServlet into a set of focused servlets: HealthCheckServlet, MetricsServlet, PingServlet, and ThreadDumpServlet. The top-level servlet which provides the HTML menu page is now AdminServlet.
• Added metrics-spring.

v2.0.0-BETA19: Jan 07 2012

• Added absolute memory usage to MetricsServlet.
• Extracted @Timed etc. to metrics-annotations.
• Added metrics-jersey, which provides a class allowing you to automatically instrument all @Timed, @Metered, and @ExceptionMetered-annotated resource methods.
• Moved all classes in metrics-scala from com.yammer.metrics to com.yammer.metrics.scala.
• Renamed CounterMetric to Counter.
• Renamed GaugeMetric to Gauge.
• Renamed HistogramMetric to Histogram.
• Renamed MeterMetric to Meter.
• Renamed TimerMetric to Timer.
• Added ToggleGauge, which returns 1 the first time it's called and 0 every time after that.
• Now licensed under Apache License 2.0.
• Converted VirtualMachineMetrics to a non-singleton class.
• Removed Utils.
• Removed deprecated constructors from Meter and Timer.
• Removed LoggerMemoryLeakFix.
• DeathRattleExceptionHandler now logs to SLF4J, not syserr.
• Added MetricsRegistry#groupedMetrics().
• Removed Metrics#allMetrics().
• Removed Metrics#remove(MetricName).
• Removed MetricsRegistry#threadPools() and #newMeterTickThreadPool() and added #newScheduledThreadPool.
• Added MetricsRegistry#shutdown().
• Renamed ThreadPools#shutdownThreadPools() to #shutdown().
• Replaced HealthCheck's abstract name method with a required constructor parameter.
• HealthCheck#check() is now protected.
• Moved DeadlockHealthCheck from com.yammer.metrics.core to com.yammer.metrics.utils.
• Added HealthCheckRegistry#unregister(HealthCheck).
• Fixed typo in VirtualMachineMetrics and MetricsServlet: commited to committed.
• Changed MetricsRegistry#createName to protected.
• All metric types are created exclusively through MetricsRegistry now.
• Metrics.newJmxGauge and MetricsRegistry.newJmxGauge are deprecated.
• Fixed heap metrics in VirtualMachineMetrics.
• Added Snapshot, which calculates quantiles.
• Renamed Percentiled to Sampling and dropped percentile and percentiles in favor of producing Snapshot instances. This affects both Histogram and Timer.
• Renamed Summarized to Summarizable.
• Changed order of CsvReporter's construction parameters.
• Renamed VirtualMachineMetrics.GarbageCollector to VirtualMachineMetrics.GarbageCollectorStats.
• Moved Guice/Servlet support from metrics-servlet to metrics-guice.
• Removed metrics-aop.
• Removed newJmxGauge from both Metrics and MetricsRegistry. Just use JmxGauge.
• Moved JmxGauge to com.yammer.metrics.util.
• Moved MetricPredicate to com.yammer.metrics.core.
• Moved NameThreadFactory into ThreadPools and made ThreadPools package-visible.
• Removed Timer#values(), Histogram#values(), and Sample#values(). Use getSnapshot() instead.
• Removed Timer#dump(File) and Histogram#dump(File), and Sample#dump(File). Use Snapshot#dump(File) instead.

v2.0.0-BETA18: Dec 16 2011

• Added DeathRattleExceptionHandler.
• Fixed NPE in VirtualMachineMetrics.
• Added decorators for connectors and thread pools in metrics-jetty.
• Added TimerMetric#time() and TimerContext.
• Added a shorter factory method for millisecond/second timers.
• Switched tests to JUnit.
• Improved logging in GangliaReporter.
• Improved random number generation for UniformSample.
• Added metrics-httpclient for instrumenting Apache HttpClient 4.1.
• Massively overhauled the reporting code.
• Added support for instrumented, non-public methods in metrics-guice.
• Added @ExceptionMetered to metrics-guice.
• Added group prefixes to GangliaReporter.
• Added CvsReporter, which outputs metric values to .csv files.
• Improved metric name sanitization in GangliaReporter.
• Added Metrics.shutdown() and improved metrics lifecycle behavior.
• Added metrics-web.
• Upgraded to ehcache 2.5.0.
• Many, many refactorings.
• metrics-servlet now responds with 501 Not Implememented when no health checks have been registered.
• Many internal refactorings for testability.
• Added histogram counts to metrics-servlet.
• Fixed a race condition in ExponentiallyDecayingSample.
• Added timezone and locale support to ConsoleReporter.
• Added metrics-aop for Guiceless support of method annotations.
• Added metrics-jdbi which adds instrumentation to JDBI.
• Fixed NPE for metrics which belong to classes in the default package.
• Now deploying artifacts to Maven Central.

v2.0.0-BETA17: Oct 07 2011

• Added an option message to successful health check results.
• Fixed locale issues in GraphiteReporter.
• Added GangliaReporter.
• Added per-HTTP method timers to InstrumentedHandler in metrics-jetty.
• Fixed a thread pool leak for meters.
• Added #dump(File) to HistogramMetric and TimerMetric.
• Upgraded to Jackson 1.9.x.
• Upgraded to slf4j 1.6.2.
• Upgraded to logback 0.9.30.
• Upgraded to ehcache 2.4.5.
• Surfaced Metrics.removeMetric().

v2.0.0-BETA16: Aug 23 2011

• Fixed a bug in GC monitoring.

v2.0.0-BETA15: Aug 15 2011

• Fixed dependency scopes for metrics-jetty.
• Added time and VM version to vm output of MetricsServlet.
• Dropped com.sun.mangement-based GC instrumentation in favor of a java.lang.management-based one. getLastGcInfo has a nasty native memory leak in it, plus it often returned incorrect data.
• Upgraded to Jackson 1.8.5.
• Upgraded to Jetty 7.4.5.
• Added sanitization for metric names in GraphiteReporter.
• Extracted out a Clock interface for timers for non-wall-clock timing.
• Extracted out most of the remaining statics into MetricsRegistry and HealthCheckRegistry.
• Added an init parameter to MetricsServlet for disabling the jvm section.
• Added a Guice module for MetricsServlet.
• Added dynamic metric names.
• Upgraded to ehcache 2.4.5.
• Upgraded to logback 0.9.29.
• Allowed for the removal of metrics.
• Added the ability to filter metrics exposed by a reporter to those which match a given predicate.

v2.0.0-BETA14: Jul 05 2011

• Moved to Maven for a build system and extracted the Scala façade to a metrics-scala module which is now the only cross-built module. All other modules dropped the Scala version suffix in their artifactIds.
• Fixed non-heap metric name in GraphiteReporter.
• Fixed stability error in GraphiteReporter when dealing with unavailable servers.
• Fixed error with anonymous, instrumented classes.
• Fixed error in MetricsServlet when a gauge throws an exception.
• Fixed error with bogus GC run times.
• Link to the pretty JSON output from the MetricsServlet menu page.
• Fixed potential race condition in histograms' variance calculations.
• Fixed memory pool reporting for the G1 collector.

v2.0.0-BETA13: May 13 2011

• Fixed a bug in the initial startup phase of the JmxReporter.
• Added metrics-ehcache, for the instrumentation of Ehcache instances.
• Fixed a typo in metrics-jetty's InstrumentedHandler.
• Added name prefixes to GraphiteReporter.
• Added JVM metrics reporting to GraphiteReporter.
• Actually fixed MetricsServlet's links when the servlet has a non-root context path.
• Now cross-building for Scala 2.9.0.
• Added pretty query parameter for MetricsServlet to format the JSON object for human consumption.
• Added no-cache headers to the MetricsServlet responses.

v2.0.0-BETA12: May 09 2011

• Upgraded to Jackson 1.7.6.
• Added a new instrumented Log4J appender.
• Added a new instrumented Logback appender. Thanks to Bruce Mitchener (@waywardmonkeys) for the patch.
• Added a new reporter for the Graphite aggregation system. Thanks to Mahesh Tiyyagura (@tmahesh) for the patch.
• Added scoped metric names.
• Added Scala 2.9.0.RC{2,3,4} as build targets.
• Added meters to Jetty handler for the percent of responses which have 4xx or 5xx status codes.
• Changed the Servlet API to be a provided dependency. Thanks to Mårten Gustafson (@chids) for the patch.
• Separated project into modules:
  • metrics-core: A dependency-less project with all the core metrics.
  • metrics-graphite: A reporter for the Graphite aggregation system.
  • metrics-guice: Guice AOP support.
  • metrics-jetty: An instrumented Jetty handler.
  • metrics-log4j: An instrumented Log4J appender.
  • metrics-logback: An instrumented Logback appender.
  • metrics-servlet: The Metrics servlet with context listener.

v2.0.0-BETA11: Apr 27 2011

• Added thread state and deadlock detection metrics.
• Fix VirtualMachineMetrics' initialization.
• Context path fixes for the servlet.
• Added the @Gauge annotation.
• Big reworking of the exponentially-weighted moving average code for meters. Thanks to JD Maturen (@sku) and John Ewart (@johnewart) for pointing this out.
• Upgraded to Guice 3.0.
• Upgraded to Jackson 1.7.5.
• Upgraded to Jetty 7.4.0.
• Big rewrite of the servlet's thread dump code.
• Fixed race condition in ExponentiallyDecayingSample. Thanks to Martin Traverso (@martint) for the patch.
• Lots of spelling fixes in Javadocs. Thanks to Bruce Mitchener (@waywardmonkeys) for the patch.
• Added Scala 2.9.0.RC1 as a build target. Thanks to Bruce Mitchener (@waywardmonkeys) for the patch.
• Patched a hilarious memory leak in java.util.logging.

v2.0.0-BETA10: Mar 25 2011

• Added Guice AOP annotations.
• Added HealthCheck#name().
• Added Metrics.newJmxGauge().
• Moved health checks into HealthChecks.
• Upgraded to Jackson 1.7.3 and Jetty 7.3.1.

v2.0.0-BETA10: Mar 25 2011

• Added Guice AOP annotations: @Timed and @Metered.
• Added HealthCheck#name().
• Added Metrics.newJmxGauge().
• Moved health checks into HealthChecks.
• Upgraded to Jackson 1.7.3 and Jetty 7.3.1.

v2.0.0-BETA9: Mar 14 2011

• Fixed JmxReporter lag.
• Added default arguments to timers and meters.
• Added default landing page to the servlet.
• Improved the performance of ExponentiallyDecayingSample.
• Fixed an integer overflow bug in UniformSample.
• Added linear scaling to ExponentiallyDecayingSample.

v2.0.0-BETA8: Mar 01 2011

• Added histograms.
• Added biased sampling for timers.
• Added dumping of timer/histogram samples via the servlet.
• Added dependency on jackon-mapper.
• Added classname filtering for the servlet.
• Added URI configuration for the servlet.

v2.0.0-BETA7: Jan 12 2011

• Added JettyHandler.
• Made the Servlet dependency optional.

v2.0.0-BETA6: Jan 12 2011

• Fix JmxReporter initialization.

v2.0.0-BETA5: Jan 11 2011

• Dropped Counter#++ and Counter#--.
• Added Timer#update.
• Upgraded to Jackson 1.7.0.
• Made JMX reporting implicit.
• Added health checks.

v2.0.0-BETA3: Dec 23 2010

• Fixed thread names and some docs.

v2.0.0-BETA2: Dec 22 2010

• Fixed a memory leak in MeterMetric.

v2.0.0-BETA1: Dec 22 2010

• Total rewrite in Java.

v1.0.7: Sep 21 2010

• Added median to Timer.
• Added p95 to Timer (95th percentile).
• Added p98 to Timer (98th percentile).
• Added p99 to Timer (99th percentile).

v1.0.6: Jul 15 2010

• Now compiled exclusively for 2.8.0 final.

v1.0.5: Jun 01 2010

• Documentation fix.
• Added TimedToggle, which may or may not be useful at all.
• Now cross-building for RC2 and RC3.

v1.0.4: Apr 27 2010

• Blank Timers (i.e., those which have recorded no timings yet) no longer explode when asked for metrics for that which does not yet exist.
• Nested classes, companion objects, and singletons don't have trailing $s messing up JMX's good looks.

v1.0.3: Apr 16 2010

• Fixed some issues with the implicit.ly plumbing.
• Tweaked the sample size for Timer, giving it 99.9% confidence level with a %5 margin of error (for a normally distributed variable, which it almost certainly isn't.)
• Sample#iterator returns only the recorded data, not a bunch of zeros.
• Moved units of Timer, Meter, and LoadMeter to their own attributes, which allows for easy export of Metrics data via JMX to things like Ganglia or whatever.

v1.0.2: Mar 08 2010

• Timer now uses Welford's algorithm for calculating running variance, which means no more hilariously wrong standard deviations (e.g., NaN).
• Timer now supports +=(Long) for pre-recorded, nanosecond-precision timings.

v1.0.1: Mar 05 2010

• changed Sample to use an AtomicReferenceArray

v1.0.0: Feb 27 2010

• Initial release