The Common ReusAble SHell (CRaSH) is an interactive shell (with history support and autocompletion) that attaches to a running JVM and can execute several commands for retrieving JVM statistics or changing JVM internals on the fly. It can be used for remote monitoring and administration of existing Java applications and it is fully extensible via custom Groovy scripts.
OpenCore, a lightweight Java application performance monitor by JINSPIRED, released version 6.0 this month. InfoQ reviews what lightweight monitoring is and some of the terms and concepts involved
JMX has been around for quite some time and now it's gone Groovy. Find out what one developer is doing to provide an easy to use Groovy Builder for exposing your beans.
A port of the popular code coverage tool rcov is now available for JRuby. Ola Bini started a Hibernate-based library for persisting Ruby objects named Ribs. And finally, JRuby trunk contains a new MBean for analysing parse times.
Orbitz Worldwide, a leading global online travel company, has open sourced two monitoring tools Extremely Reusable Monitoring API (ERMA) and Graphite, a persistence and visualization component. ERMA is a home grown Java API and library that has been used in several web applications at Orbitz to capture monitoring statistics in the applications at run-time.
Monitoring JVMs just became easier with jmx4r, a library that allows to easily access JMX MBeans with JRuby. If used from jirb, the interactive Ruby shell, this even allows to automate bulk changes or queries.
Matt Morton asked the question "Can Java be as Agile as the Dynamics (Ruby, Python, Groovy)?" and went to Anil Hemrajani's book to find out. He found a readable, useful book, and helps idenfity the right audience for this book.