Assuming that the OutOfMemory exception was caused by an application with increased memory requirements, you should probably take a look at the -Xmx parameter for the JVM to increase the amount of available heap memory. The default maximum heap size can be a little conservative.
As you're running JBoss 2.4.4, edit the batch file/shell script that you use to start JBoss (run.bat, run.sh, run_with_tomcat.bat etc), and on the line where it executes the JVM, add the parameter:
e.g. from the Windows batch file:
java -Xmx256m %JAXP% -classpath "%JBOSS_CLASSPATH%" org.jboss.Main %1 %2 %3 %4 %5 %6 %7 %8 %9
In this example -Xmx256m allocates a maximum heap size of 256 megs.
In JBoss 3.0, you can specify this option within the JAVA_OPTS environment variable.
in my case that setting is already Xmx 1024M ,then also the problem arise