JVM Sounds

This is a very simple JVM library that plays JVM events as audio sounds.

• Memory allocation rate as a sine tone
• Minor GC is a wood percussion
• Major GC is a noise hit
• Hiccups (underlying JVM timejumps) are played as sample hiccups.

Please see Logging vs Memory and the tweet.

Examples

There are MP3 recordings available that show how the JVM sounds using an example program:

• Light Load with 10000 wastage
• Medium Load with 20000 wastage
• Heavy Load with 30000 wastage

There's also an example of a JVM running under Virtualbox while under a Gatling load test, which makes it prone to hiccups:

• Gatling with Hiccups

Resolver

The libraries are in Bintray under tersesystems/maven. Installation instructions are similar to terse-logback installation:

repositories {
    maven {
        url  "https://dl.bintray.com/tersesystems/maven" 
    }
}

or SBT:

resolvers += Resolver.bintrayRepo("tersesystems", "maven")

Library

The library has dependencies on jSyn and on jvm-alloc-rate-meter and jvm-hiccup-meter. It is plain Java, no Scala library required.

libraryDependencies += "com.tersesystems.jvmsounds" % "jvmsounds" % "0.0.1"

Java Agent

You can run this as a java agent. I like using sbt-javaagent.

javaAgents += "com.tersesystems.jvmsounds" % "jvmsounds" % "0.0.1"

Options

• -n napTimeMs
• -at allocThresholdMs - default is 300 MB/second, below that it is silent
• -av allocVolume 0.0 - 1.0 - volume of the allocation tone, default 0.1
• -mv minorGCVolume 0.0 - 1.0 - volume of the minor GC event, default 0.6
• -Mv mixedGCVolume 0.0 - 1.0 - volume of the mixed GC event, default 0.6
• -ht hiccupThresholdMs - default is 50 ms, below that no hiccup
• -hv hiccupVolume 0.0 - 1.0 - volume of the hiccup, default 1.0