MODCLUSTER000045: AverageSystemLoadMetric is not supported on this system and will be disabled

[valsaraj007]

Hi,

I am seeing the following warning in JBoss log when I start Apache with mod_cluster in Windows. I am using WildFly-8.2.0.Final:

WARN  [org.jboss.modcluster] (UndertowEventHandlerAdapter - 1) MODCLUSTER000045: AverageSystemLoadMetric is not supported on this system and will be disabled.

WildFly conf:

<subsystem xmlns="urn:jboss:domain:modcluster:1.2">

            <mod-cluster-config advertise-socket="modcluster" connector="ajp">

                <dynamic-load-provider>

                    <load-metric type="cpu"/>

                </dynamic-load-provider>

            </mod-cluster-config>

        </subsystem>

Apache conf:

<IfModule manager_module>

  Listen 127.0.0.1:6666

  ManagerBalancerName mycluster

  <VirtualHost 127.0.0.1:6666>

    <Location />

     Order deny,allow

     Deny from all

     Allow from 127.0.0.

    </Location>

    KeepAliveTimeout 300

    MaxKeepAliveRequests 0

    #ServerAdvertise on http://127.0.0.1:6666

    AdvertiseFrequency 5

    #AdvertiseSecurityKey secret

    #AdvertiseGroup 224.0.1.105:23364

    EnableMCPMReceive

    <Location /mod_cluster_manager>

       SetHandler mod_cluster-manager

       Order deny,allow

       Deny from all

       Allow from 127.0.0

    </Location>

  </VirtualHost>

</IfModule>

Thanks!

[pferraro]

The "cpu" load metric uses the value returned by:

http://docs.oracle.com/javase/7/docs/api/java/lang/management/OperatingSystemMXBean.html#getSystemLoadAverage()

If the value returned is negative number, then your jvm/platform doesn't support this.

[valsaraj007]

Thanks Paul. I am using Windows 7. What can I use if "cpu" load metric is not supported?

[pferraro]

The supported load-metrics are defined here: wildfly/jboss-as-mod-cluster_2_0.xsd at master · wildfly/wildfly · GitHub

[valsaraj007]

We will need to implement a load balanced cluster where users are able to connect to the node with the least load.

Which one is best suited for this?

[pferraro]

There is no definitive answer to that question.  The best load metric(s) for use with a given system depends on the nature of the deployed applications and the limiting factors of your environment.  There's a detailed (albeit somewhat outdated, i.e. the example configuration is from AS5) description of the load metrics here, including how they can be combined to best represent the load of your nodes:

Chapter 10. Server-Side Load Metrics