Using Java Flight RecorderFor Developers

HASUNUMA KenjiGlassFish Communitykhasunuma@java.net

• Java Flight Recorder is so useful tool for running softwares based on Java certainly.

• But Java Flight Recorder is also powerful tool for development softwares based on Java efficiently.

Java Flight Recorder?

Project “HotRockit”

• Integration of two JVM; HotSpot VM and JRockit VM

• “HotRockit” is HotSpot VM with JRockit tools

“HotRockit” is ...

From HotSpot VM:

• JIT Compiler

• Heap management (Improvement itself)

• Garbage Collectors

From JRockit VM:

• Deterministic GC

• Some powerful toolsjrcmd, JRockit Flight Recorder, JRockit Mission Control

HotSpot v23(JDK7u4~u25)

• Developer preview of “HotRockit”

• jcmd (ex. jrcmd)

• JRockit compatible JMX Agent

• Preparing for Flight Recorder

HotSpot v24(JDK7u40~)

• Public preview of “HotRockit”

• Java Flight Recorder

• Java Mission Control

• Some tools (e.g. Memory leak detector) is not implemented

HotSpot v25(JDK8 GA)

• Complete “HotRockit” (maybe...)

• Almost all tools readiness

• PermGen removed (exactly!)

• Deterministic GC (maybe...)

[FYI] JDK Updatesuntil JDK7 Update 25,

• odd number - security updates

• even number - feature updates

since JDK7 Update 40,

• +20 - feature updates (e.g. JDK7u40)

• +5 - security updates (e.g. JDK7u45)

• other - unplanned updates

Java Flight Recorder(ex. JRockit Flight Recorder)

Java Flight Recorder is ...

• JDK7 Update 40 or later

• Small impact for running Java VM

• Using same as JRockit Flight Recorder

• Integrated with Java Mission Control

• Free for trial or development

Usage:

• Set following options:

-XX:+UnlockCommercialFeatures

-XX:+FlightRecorder

• control from jcmd (JFR.*) or Java Mission Control

Using Java Flight RecorderFor Developers

HASUNUMA KenjiGlassFish Communitykhasunuma@java.net

http://www.coppermine.jp/docs/programming/