Java performance tool makes shock reappearance
After two-year absence, JRockit Mission Control returns in Java 7u40 with support for HotSpot and more goodies.
JRockit’s JVM profiling functionality has returned – and has picked up some new tricks in its two-year absence.
Mission Control has had a considerable upgrade, now bundled for free with the regular desktop release (starting with Java SE 7 update 40) and providing support for both JRockit and HotSpot JVMs.
A key feature is Flight Recorder, which (as the name suggests) logs live data from production application for future analysis. The performance overhead incurred is “less than 2%”, claims Marcus Hirt, who joined Oracle when Appeal was acquired.
A new JVM Browser show sub-nodes for server side services available and can be viewed as a flat list or a tree, while performance-sapping code can be identified quickly using the new method profiling and improved allocation profiling tools.
The team say they are working on introducing additional functionality using experimental plugins such as JOverflow, a heap dump analysis tool, and DTrace, a more detailed recording tool. Not yet implemented, however, is JRockit Mission Control’s on-line heap analyser Memleak – though JOverflow now encompasses much of its functionality.
An Eclipse 3.8/4.2 plugin is also now available for Mission Control, although with a couple of caveats: the 4.2 performance issues apparently make it very slow, and 4.3 support is still in the works.
This week’s Java update also introduces a ‘Deployment Rule Set’ for restricting Java Web Start usage, which sysadmins who still need to support Java on their users’ desktops may find useful, as well as support for high-DPI ‘retina’ screens on OS X.
Photo by Ian Rutherford.