Question about load metrics in jboss 6

[gvtc09405]

Hi,

my environment :

jboss 6.1.0final

mod_cluster 1.1.0

and i was tried to test load metrics and had a question:

When i configured JBOSS_HOME/ server/all/deploy/mod_cluster.sar/META-INF/mod_cluster-jboss-beans.xml

the default load metrics are:

<set elementClass="org.jboss.modcluster.load.metric.LoadMetric">

        <inject bean="BusyConnectorsLoadMetric"/>

        <inject bean="HeapMemoryUsageLoadMetric"/>

      </set>

if i tried to modify it to:

<set elementClass="org.jboss.modcluster.load.metric.LoadMetric">

      </set>

it still works

but how it works? use which load metrics to  calculate load factor?

THX!