If you want to enable the primitive run-time tracing in JRun it is very simple, open up the /bin/jvm.config file and modify the java.args entry to include the tracing.

Example to trace all: java.args=-Dtrace.all -Xms32m -Xmx128m

Example to trace servlet container and clustering:
java.args=-Dtrace.servlet -Dtrace.clusterjrpp -Xms32m -Xmx128m

All of the tracing options can be found below, each entry is after public static final boolean {option}

/**
 * Primitive run-time tracing class
 *
 * Code as follows:
 * if (Trace.foo)
 *     Trace.trace("trace msg"...);
 *
 * Enable as follows:
 * java -Dtrace.foo -Dtrace.foo2 -Dtrace.foo3 or -Dtrace.all
 *
 * Special flags:
 * -Dtrace.all                   -- enables all tracing
 * -Dtrace.timeStamp             -- timeStamp all output lines
 * -Dtrace.caller                -- print the Class:method caller
 * -Dtrace.stackLines=10         -- print 10 stack lines
 * -Dtrace.stackPrefix=java.lang -- print the stack up to java.lang
 *
 * Add new xxx members as desired.
 */

public class Trace {
    public static final boolean all = (System.getProperty("trace.all") != null);
    // Use Trace.debug for temporary stuff. For a more permanent trace add a new line below
    public static final boolean debug = all || (System.getProperty("trace.debug") != null);
    public static final boolean deploy = all || (System.getProperty("trace.deploy") != null);
    public static final boolean ejb = all || (System.getProperty("trace.ejb") != null);
    public static final boolean persistence = all || (System.getProperty("trace.persistence") != null);
    public static final boolean invoke = all || (System.getProperty("trace.invoke") != null);
    public static final boolean security = all || (System.getProperty("trace.security") != null);
    public static final boolean jndi = all || (System.getProperty("trace.jndi") != null);
    public static final boolean servlet = all || (System.getProperty("trace.servlet") != null);
    public static final boolean websecurity = all || (System.getProperty("trace.websecurity") != null);
    public static final boolean classloader = all || (System.getProperty("trace.classloader") != null);
    public static final boolean jdbc = all || (System.getProperty("trace.jdbc") != null);
    public static final boolean mdb = all || (System.getProperty("trace.mdb") != null);
    public static final boolean mdbinvoke = all || mdb || (System.getProperty("trace.mdbinvoke") != null);
    public static final boolean mdbdeploy = all || mdb || (System.getProperty("trace.mdbdeploy") != null);
    public static final boolean jms = all ||  (System.getProperty("trace.jms") != null);
    public static final boolean jmscore = all || jms || (System.getProperty("trace.jmscore") != null);
    public static final boolean jmsj2ee = all || jms || (System.getProperty("trace.jmsj2ee") != null);
    public static final boolean jmswrapper = all || jmsj2ee || (System.getProperty("trace.jmswrapper") != null);
    public static final boolean jmsadapter = all || jmsj2ee || (System.getProperty("trace.jmsadapter") != null);
    public static final boolean jmssecurity = all || jmsj2ee || (System.getProperty("trace.jmssecurity") != null);
    public static final boolean jmsxa = all || jmsj2ee || jmswrapper || (System.getProperty("trace.jmsxa") != null);
    public static final boolean cluster = all ||debug || (System.getProperty("trace.cluster") != null);
    public static final boolean iiop = all | (System.getProperty("trace.iiop") != null);
    public static final boolean ci = all | (System.getProperty("trace.ci") != null);
    public static final boolean xml = all | (System.getProperty("trace.xml") != null);
    public static final boolean appclient = all | (System.getProperty("trace.appclient") != null);
    public static final boolean clustertrn = all | (System.getProperty("trace.clustertrn") != null);
    public static final boolean jca = all | (System.getProperty("trace.jca") != null);
    public static final boolean jmsgc = jmscore | (System.getProperty("trace.jmsgc") != null);
    public static final boolean jmscc = jmscore |  (System.getProperty("trace.jmscc") != null);
    public static final boolean clusterjrpp = all || (System.getProperty("trace.clusterjrpp") != null);
    public static final boolean usrtrn = all | (System.getProperty("trace.usrtrn") != null);
    public static final boolean trn = all | (System.getProperty("trace.trn") != null);

}