Sunday Jan 18, 2009

New VisualVM 1.1 Release


There is a New VisualVM 1.1 Release (Screencast). The Release Notes describe the new features but also notice the expanded Plugin API, the integration with Eclipse and IntelliJ, the support for IBM's JVM (via JMX), these new CLI commands, and its use of NB 6.5 RCP.

VisualVM has been part of Sun's JDK since JDK 6 Update 7; together with the above changes, this makes it a good platform for writing performance analysis tools (e.g. see news).

Thanks to Danny for the tip; also see other entries at TheAquarium tagged as See VisualVM

Wednesday Jun 06, 2007

Debugging Your GlassFish App Via Eclipse

Eclipse Logo

Back in early 2006, Filippo Diotalevi put together a screencast showing how to use Eclipse to debug an application which has been deployed to a GlassFish container. It was a nice piece of work, and we featured it here just a few days after its publication.

Unfortunately, Filippo has reported that a cracker later broke into his Wordpress instance and deleted all of his content (including the screencast). But even sad stories can have happy endings. Filippo has a new tutorial which covers the original content.

And the best part? As the tutorial demonstrates, it's still very easy to attach a debugger to GlassFish.

Wednesday Apr 25, 2007

Debugging a Clustered GlassFish


Say you want to debug a clustered deployment. So you open your laptop, start your appserver cluster with debugging enabled, then start one instance first, then the second instance, and ... wham! you have a port collision because both instances try to open the same jdwp port! But this has changed...

Byron reports that starting in b45 (downloads) this has been fixed: you can start the instances and delay the debugging port binding. The syntax is not (yet?) pretty, but it is very useable. Check out Byron's blog for the details!

BTW, I see that the last posted build is GFv2b 43; I'll check the status on b45 and will update this blog.

Tuesday Apr 24, 2007

Improved Debugging in GlassFish -- Thread Dumps and Logging

Liebherr T282 Dump Truck

We are racing towards GlassFish v2 with the usual fine-tunings on performance and bug fixes, but also with usability improvements, as shown by these writeups by Byron:

•  The new model for getting Thread Dumps: it is automatic, works in native and non-native modes and with all 3 kinds of servers -- Domain Administration Servers, Node Agents and Server Instances.

•  How to use -verbose to easily get Logging Reporting in GlassFish.

Wednesday Oct 11, 2006

GlassFish Issue 539: Problems with Locked JARs

Diagram of a Normal GF Deployment

If you are using GlassFish on Windows and are deploying via archives (like EAR, a WAR, an EJB JAR, or an app client JAR) you may have encountered a variation of GlassFish Issue 539 where a problem during deployment leads to a locked JAR that requires a server restart. The good news is that Tim and Hong have checked in changes to address this problem: when possible the problem no longer occurs and, when it does, there is a nice error message that leads to a prompt resolution.

Expect the fix in the next promotion of GlassFish V2. Check Tim's Blog for a detailed description of the problem and the solution.

Thursday Jan 26, 2006

FindBugs - Find the little critters

The log for finding the first computer bug: a Moth

FindBugs is a most excellent program that finds bugs in Java programs by looking for bug patterns. Aditya used it in GlassFish and writes about Finding Bugs made easy.

Once you remove the bugs you will want to be sure they don't creep back in (as with lint) and the best arrangement is to use FindBugs in your IDE. There already was a Plugin for Eclipse and Roumen just reports that Sven Reimers has released a PlugIn for NetBeans. Seems like a real winner - check it out!