Ralph's Open Source Blog

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:

standalone.sh --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

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:

-Xmx1024m 
-Xms1024m 
-Xss128k
-XX:MaxPermSize=256m
-XX:PermSize=64m
-XX:NewRatio=2

or for a machine with 4G RAM.

-Xmx2048m 
-Xms2048m 
-Xss128k
-XX:MaxPermSize=256m
-XX:PermSize=64m
-XX:NewRatio=2

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

...
# Specify options to pass to the Java VM.
#
if [ "x$JAVA_OPTS" = "x" ]; then
JAVA_OPTS="-Xms1024m -Xmx1024m -XX:MaxPermSize=256m -XX:NewRatio=2 -XX:PermSize=64m -Djava.net.preferIPv4Stack=true"
 JAVA_OPTS="$JAVA_OPTS -Djboss.modules.system.pkgs=$JBOSS_MODULES_SYSTEM_PKGS -Djava.awt.headless=true"
else
 echo "JAVA_OPTS already set in environment; overriding default settings with values: $JAVA_OPTS"
fi

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 -Djava.net.preferIPv4Stack=true -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">
            <session-bean>
                <stateless>
                    <bean-instance-pool-ref pool-name="slsb-strict-max-pool"/>
                </stateless>
                <stateful default-access-timeout="5000" cache-ref="simple" passivation-disabled-cache-ref="simple"/>
                <singleton default-access-timeout="5000"/>
            </session-bean>
            <pools>
                <bean-instance-pools>
                    <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"/>
                </bean-instance-pools>
            </pools>
....
.....

See also: https://community.jboss.org/message/881747