Debug an application in WildFly with Eclipse

You can debug a deployed applications running in WildFly with the Eclipse Debugging feature.

First you need to start WildFly in debug mode with the following command: --debug --server-config=standalone.xml

Now WildFly starts in the debug mode and listens to the port 8787.

To enable debugging in your Eclipse IDE you now can add a new Debug Configuration:


This will connect Eclipse to the WildFly Debug port.

Connection refused!

It may happen that – even if you have started glassfish in debug mode and configured all well – you got the following eclipse error message:

Failed to connect to remote VM. Connection refused.


In this case – it maybe can help if you add a project to the debug configuration. In the screen example above I have let the field ‘Project’ empty. It may help in some cases that you select a project there

GlassFish performance analyzing with VisualVM

This is a short overview how to do a performance analyze in GlassFish using VisualVM. When GlassFish is running and you start VisualVM it will typically connect to GlassFish. You see a local node of your GlassFish instance.


If GlassFish Server is not found than you need to verfy your profiler settings n GlassFish Web Console.

Now you can test the performance of your application deployed on GlassFish. Continue reading “GlassFish performance analyzing with VisualVM”

WildFly – HotDeployment

Today I extended the functionality of the manik-hot-deploy Plugin for Eclipse. The goal of this plugin is to provide an easy way for autodeployment and also hotdeployment (incremental deployment) in maven based Java Enterprise Projects.

With this Eclipse plugin you can add a configuration to your maven based JEE project to enable an autodeploy mechanism. Each time you build your maven jee project the artefacts will be automatically deployed on your application server.

Until version 1.3 only GlassFish was supported. But now I am also supporting the new WildFly Application server from Red Hat. This was a little bit tricky because in different to GlassFish WildFly did not extract (unzip) an artifact during the deployment process. But for hotdeployment you need access to the extracted web module folders. With a trick in the maven ear plugin you can create EAR artifacts with unpacked web modules. Simply add the following configuration to your ear pom.xml:



With a new option in the manik-hot-deploy plugin you can now enable the feature to autodeploy extracted versions of ear and web modules and activate the WildFly autodeployment mechanism.

Read more about mani-hot-deploy on GitHub.


WildFly – Performance tuning

If you run the RedHat Application Server WildFly in standalone configuraiton you can customize the Java VM options to do some performance tuning.

The VM Options

In different to GlassFish the VM Options can not be set from the WildFly Web Console. But you can change or add VM Options by changing the standalone.conf file in the /bin directory. (Note that this is not the same as the standalone.xml configuration inside the /stanalone/ folder!)

Typical values to use for a 3G RAM machine  are:


or for a machine with 4G RAM.


The JAVA_OPTS section in your standalone.conf file then should look like this:

# Specify options to pass to the Java VM.
if [ "x$JAVA_OPTS" = "x" ]; then
JAVA_OPTS="-Xms1024m -Xmx1024m -XX:MaxPermSize=256m -XX:NewRatio=2 -XX:PermSize=64m"
 JAVA_OPTS="$JAVA_OPTS -Djboss.modules.system.pkgs=$JBOSS_MODULES_SYSTEM_PKGS -Djava.awt.headless=true"
 echo "JAVA_OPTS already set in environment; overriding default settings with values: $JAVA_OPTS"

You can verify your new settings directly in the beginning of the output when starting your WildFly


 JBoss Bootstrap Environment
 JBOSS_HOME: /opt/wildfly-8.0.0.Final
 JAVA: java
 JAVA_OPTS: -server -XX:+UseCompressedOops -Xms1024m -Xmx1024m -XX:MaxPermSize=256m -Djboss.modules.system.pkgs=org.jboss.byteman -Djava.awt.headless=true


Database Pool

Also the Database Pool Configuration in WildFly is different to the settings in GlassFish. GlassFish comes with some useful default values. In WildFly you should add the following Pool Settings:

  • Min Pool Size = 5
  • Max Pools Size = 25
  • Share Prepared Statements = true
  • Statement Cache Size: 32


Session EJB Pooling

For some reason the pooling of stateless EJBs is disabled per default in WildFly. If you have  expensive initialization in your stateless session EJBs it is very useful to add pooling for that kind of beans. This can increase the performance of your application dramatically.

Edit the standalone.xml file in the WildFly /standalone/configuration/ directory and change the section “session-bean” like in the following example:

  <subsystem xmlns="urn:jboss:domain:ejb3:2.0">
                    <bean-instance-pool-ref pool-name="slsb-strict-max-pool"/>
                <stateful default-access-timeout="5000" cache-ref="simple" passivation-disabled-cache-ref="simple"/>
                <singleton default-access-timeout="5000"/>
                    <strict-max-pool name="slsb-strict-max-pool" max-pool-size="32" instance-acquisition-timeout="5" instance-acquisition-timeout-unit="MINUTES"/>
                    <strict-max-pool name="mdb-strict-max-pool" max-pool-size="20" instance-acquisition-timeout="5" instance-acquisition-timeout-unit="MINUTES"/>

See also:

Gnome3 – system did not shutdown correctly

With the latest release of Gnome Shell (3.8) you possible can run in a situation where your system did not shutdown correctly if you select shutdown from the system menu or try to shutdown with the hardware power-off switch. In this case just check if you have the new package ‘systemd-shim’ installed. This will possible solve a missing dependency in gnome.



Debian freezes randomly

Since about one year I own a ultrabook ‘Wortmann Terra Mobile 1450 II’ which I run on Linux.  The system contains a Intel Core i7-351U chip set and 8GB RAM. But this system shows a very strange problem on Linux (and as I guess maybe also on other operating systems): randomly the system freezes.

When the system freezes no mouse , no keyboard, no REISUB was possible. The screen is corrupted and did not update. The only key board functionality which is still possible is Fn+F9 (switch display on/off). So the only possibility was to to switch off the system hard.

The freeze occurs when the system runs on battery as also when it is plugged. It looked as if the errors occurs more frequently at high memory usage.

The memory…

A memory check (with memtest86+) indicates no problem. Therefore, I thought it had to do something with the kernel. See also the discussion here. But updating every week a new kernel version and playing around with several kernel boot options the problem still occurs.

Back to the idea that the problem comes from the RAM I installed the tool ‘memtester’. With this tool you can test memory when linux is running. For Example I started a test to check 7GB RAM with the following command:

memtester 7G 1

And now I was able to force the freeze. During such a test each time my system freezes. Also when I booted in kernel recovery mode the same situation – system freezes! So this indicated to me that the problem is with the memory.

The solution

If the memory seems to be ok in general (memtest86+ indicates no errors) but the system freezes in situations with heavy  memory usage (memtester) then it may have something to do with overclocking the memory?

In my BIOS settings () I found the following setting:

-> System Agent (SA) Configuration
-> Memory Configuration
-> Memory Frequency Limiter

This was defined as ‘AUTO’. What ever this means I changed the value to lowest available setting of ‘1067’ (other values where 1600, 1867, … up to 2667). With this setting I can not see any substantial impairment of the speed. But from now on my system runs without any more freezes!

So if you are also faced with the problem of random freezes, first try to control the overclocking of your memory. I hope this will help you too.

After all the last question is: Is my hardware to fast for linux or is linux to fast for my hardware 😉


Maven Incremental hot deploy – a plugin for the Eclipse IDE

There are different ways how to deploy Java EE application into an application server like Glassfish or JBoss. You can deploy your application using a command line tool or a web interface provided by your sever. Or you can use the autodeploy feature which means that you simply copy your application into a specific folder of your server (e.g. ../domains/mydomain/autodeploy/ for Glassfish)

The Eclipse IDE provides a plugin called “Web Tools Plattform” (WTP) which supports the hot deployment functionality for some application and web servers. But if you are using the Maven build tool the Ecipse WTP feature did not integrate smoothly with the maven project structure. So is most cases the hot deployment feature will get lost and the development and deployment will become time intensive and frustrating. This is the moment where manik-hot-deploy comes into play. manik-hot-deploy is an Eclipse plugin which supports hotdeployment functionality for your maven java enterprise project. It is easy to configure and speed-up the development of web and enterprise applications.

Autodeployment vs. Hotdeployment (Incremental Deployment)

Most application servers like GlassFish? or JBoss are supporting two different modes of automatic deployment. The autodeployment and the hotdeplyoment (also called incremental deployment).


Autodeployment means that you simply copy a web- (.war) or enterprise application (.ear) into a specific directory of our application server. For Glassfish this is the folder:


When you copy an application into that directory Glassfish will automatically detect the new artefact and starts a deployment process. If the application was already deployed before a redeployment will be started.


In different to autodeplyoment the hotdeplyoment (or incremental deployment) will not deploy the whole application but parts of your application which are updated or changed during development. This is a powerful feature which can save you a lot of time during development. Incremental deployment means, that in the moment when you are changing a web resource (like a .xhtml, .jsf or .css files) this change is immediately transferred into your deployed and running application. So there is no need to build and redeploy the application.

The Manik Hot Deploy Plugin for Eclipse

See how to install and use the Mani-Hot-Deploy Plugin for Eclipse to find an easy way to autodeploy your JEE projects form Eclipse into your application server.

Virtual Box not working

If VirtualBox is not working properly one reason can be the CPU configuration controlled by the BIOS. Try to activate the setting

Intel Virtualization Technology = Enabled


Migrate from GlassFish to WildFly

In this blog I just want to post some of my thoughts about migrating from GlassFish to WildFly. The main issue here for me is to deploy an existing EAR currently running on GlassFish 3. This EAR contains EJBs, Web, and REST modules and includes TimerServices, Security Issues and custom servlets. So it’s not the easy hello-world example.

I am working on Linux Debian 7 and using Open JDK 1.7.0_55. The examples show the configuration for the Imixs Office Workflow Suite. Continue reading “Migrate from GlassFish to WildFly”